Unusual Intermolecular “Through-Space” J Couplings in P–Se Heterocycles Paula Sanz Camacho,1 Kasun S. Athukorala Arachchige,1 Alexandra M. Z. Slawin,1 Timothy F. G. Green,2 Jonathan R. Yates,2 Daniel M. Dawson,1 J. Derek Woollins1,* and Sharon E. Ashbrook1,* 1 School of Chemistry, EaStCHEM and Centre of Magnetic Resonance, University of St Andrews, Fife KY16 9ST UK 2 Department of Materials, University of Oxford, Oxford, OX1 3PH, UK Supporting Information S1. Experimental and theoretical methods S2. Single crystal diffraction structures S3. Full experimental 77Se NMR parameters S4. 13C and 31P solid-state NMR and variable-temperature 77Se NMR S5. DFT calculations and electronic coupling deformation density S6. References S1 S1. Experimental and theoretical methods Unless otherwise stated all experiments were carried out under an oxygen- and moisture-free nitrogen atmosphere using standard Schlenk techniques and glassware. Reagents were obtained from commercial sources and used as received. Dry solvents were collected from a MBraun solvent purification system. Elemental analyses were performed by Stephen Boyer at the London Metropolitan University. Infrared spectra were recorded for solids as KBr discs and oils on NaCl plates in the range 4000-300 cm–1 on a PerkinElmer System 2000 Fourier transform spectrometer. 1H and 13C solution-state NMR spectra were recorded on a Bruker Avance 400 MHz spectrometer with chemical shifts (reported in ppm) referenced to external (CH3)4Si or residual solvent peaks (CDCl3 δH = 7.26 ppm, δC = 77.2 ppm). 77Se and 31P solution-state NMR spectra were recorded on a Jeol GSX 270 MHz spectrometer with chemical shifts (reported in ppm) referenced to external (CH 3)2Se and 85% H3PO4, respectively. Assignments of 13C and 1H NMR spectra were made with the help of 1H-1H COSY and HSQC experiments. Coupling constants (J) are given in Hertz (Hz). Electron ionisation (EI+) mass spectra were carried out by the EPSRC National Mass Spectrometry Service, Swansea. The naphtho[1,8-cd]1,2-diselenole precursor was prepared using the following standard literature procedures.S1 Naphtho[1,8-cd]1,2-diselenole tertbutylphosphine (1) : To a solution of naphtho[1,8cd]1,2-diselenole (2.0 g, 12 mmol) in THF (80 mL) was added dropwise a 1 M solution of superhydride in THF (24 mL, 24 mmol). The mixture was stirred at room temperature for 15 min after which a solution of tertbutyldichlorophosphine (2.6 g, 16.4 mmol) in THF (15 mL) was added dropwise to the mixture. The resulting mixture was warmed to ∼66 °C and left overnight. After the solvent was removed in vacuo, the reaction mixture was extracted with hexane (250 mL), washed with distilled water (100 mL) and the organic layer dried with magnesium sulfate and concentrated under reduced pressure. The residue was passed through a shallow plug of dry silica and washed through with hexane to afford the purified target compound as a brown-purple solid. Recrystallization of the S2 target compound was obtained from hexane. (2.3 g, 48%); mp 85-88 °C; IR (KBr disk) : vmax cm-1 : 2933s, 2852w, 2363s, 1655w, 1540s, 1455s, 1350s, 1192s, 804vs, 752vs, 565s, 439w, 420s; 1H {31P} NMR (400 MHz; CDCl3) ) δ (ppm) = 7.8 (dd, 3JHH = 7.2 Hz, 4JHH = 1.3 Hz, 2H, Ar–H), 7.7 (dd, 3JHH = 8.3 Hz, 4JHH = 1.2 Hz, 2H, Ar–H), 7.3 (dd, 3JHH = 8.0 Hz, 3JHH = 7.3 Hz, 2H, Ar–H), 1.2 (s, 9H, 3 CH3); 13C {1H} NMR (100.6 MHz; CDCl3) δ (ppm): 134.9 (d, J = 3.2 Hz, 2 Cq, Ar–C), 131.4 (d, J = 4.5 Hz, 2 CH, Ar–C), 130.2 (s, 2 CH, Ar–C), 125.5 (s, 2 CH, Ar–C), 124.8 (d, J = 10.6 Hz, 2 Cq, Ar–C), 38.4 (d, J = 44.3 Hz, Cq) 27.7 (d, J = 18.3 Hz, 3 CH3); 31P {1H} NMR (109.4 MHz, CDCl3) δ (ppm)= 12.3 (t, 1J (31P,77Se) = 302 Hz); 77Se {1H} NMR (51.5 MHz, CDCl3) δ (ppm)= 210.2 (d, 1J (31P,77Se) = 302 Hz); MS (EI+): m/z (%) 373.9 (15) [M+], 285.9 (85) [C10H6Se2+], 236.9 (100) [C10H6SeP], 205.6 (23) [C10H6Se], 126.0 (30) [C10H6], elemental analysis calculated (%) for C14H15PSe2 (372.16) : C 45.18, H 4.06. Found C 45.29, H 4.15. Naphtho[1,8-cd]1,2-diselenole isopropylphosphine (2) : To a solution of naphtho[1,8cd]1,2-diselenole (2.0 g, 12.6 mmol) in THF (60 mL) was added dropwise a 1 M solution of superhydride in THF (25.3 mL, 25.3 mmol). The mixture was stirred at room temperature for 15 min, after which a solution of dicholoroisopropylphosphine (2.0 mL, 16.4 mmol) in THF (10 mL) was added dropwise to the mixture. The resulting mixture was warmed to ∼66 °C and left overnight. After the solvent was removed in vacuo, the reaction mixture was extracted with hexane (250 mL), washed with distilled water (100 mL) and the organic layer dried with magnesium sulfate and concentrated under reduced pressure. Column chromatography on silica gel (hexane) was performed to afford the purified target compound as a brown-light solid. Recrystallization of the target compound was obtained from hexane. (2.0 g, 45%); mp 83-91 °C; IR (KBr disk) : vmax cm-1 : 3422w, 2959w, 2854w, 1539w, 1487w, 1352w, 1191s, 1019w, 806vs, 750vs, 636w, 427s, 279w, 251s, 223s; 1H {31P} NMR (400 MHz, CDCl3) δ (ppm) = 7.6 (m, 4H, Ar–H) 7.2 (dd, 3JHH = 7.1 Hz, 3JHH = 7.2 Hz, 2H, Ar–H) 1.8 (m, 1H, CH) 1.0 (d, J = 7.0 Hz , 2 CH3, 6H); 13C {1H} NMR (100.6 MHz, CDCl3) δ (ppm) = 135.1 (d, J = 3 Hz, Cq, Ar–C) 133.0 (d, J = 4.0 Hz, 2 CH, Ar–C) 130.6 (s, 2 CH, Ar–C) 129.5 (d, J = 3.6 Hz, Cq, Ar–C) 125.5 (s, 2 CH, Ar–C) 123.3 (d, J = 8.7 Hz, S3 Cq, Ar–C) 30.2 (d, J = 35.3 Hz, CH) 19.3 (d, J = 21.9 Hz, 2 CH3); 31P {1H} NMR (109.3 MHz, CDCl3) δ (ppm) = –3.4 (s, 1J (31P, 77Se) = 276 Hz); 77Se {1H} NMR (51.52 MHz, CDCl3) δ (ppm) = 270.2 (s,1J (31P, 77Se) = 276 Hz); MS (EI+): m/z (%) 359.9 (12) [M+], 285.8 (100) [C10H6Se2+], 236.9 (82) [C10H6SeP], 205.9 (32) [C10H6Se], 126.0 (48) [C10H6]; elemental analysis calculated (%) for C13H13PSe2 (358.14) : C 43.60, H 3.66. Found C 43.68, H 3.74. Single crystal analysis The X-ray crystal structure for compound 1 was determined at –148(1) °C using a Rigaku MM007 high-brilliance RA generator (Mo Kα radiation, confocal optic) and Saturn CCD system. At least a full hemisphere of data was collected using ω scans. Intensities were corrected for Lorentz, polarization, and absorption. The X-ray crystal structure for compound 2 was determined at –180(1) °C using a Rigaku MM007 high-brilliance RA generator (Mo Kα radiation, confocal optic) and Mercury CCD system. At least a full hemisphere of data was collected using ω scans. Intensities were corrected for Lorentz, polarization, and absorption. Data for the complexes analyzed were collected and processed using CrystalClear (Rigaku). Structures were solved by direct methods and expanded using Fourier techniques. Non-hydrogen atoms were refined anisotropically. Hydrogen atoms were refined using the riding model. All calculations were performed using the CrystalStructure crystallographic software package except for refinement, which was performed using SHELXL-97. These X-ray data can be obtained free of charge via ww.ccdc.cam.ac.uk/conts/retrieving.html or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax (+44) 1223-336-033; email:deposit@ccdc.cam.ac.uk. CCDC numbers 1057057 and 1057058. Solid-state NMR measurements Solid-state NMR measurements were performed using Bruker Avance III spectrometers, operating at magnetic field strengths of 9.4, 14.1 and 20.0 T. Experiments S4 were carried out using conventional 4- or 2.5-mm MAS probes, with MAS rates between 5 and 12.5 kHz. Detailed parameters for each of the spectra obtained are given in Table S1.1. For 13C, transverse magnetization was obtained by cross-polarization (CP) from 1H using ramped contact pulse durations of 5-10 ms, and two-pulse phase modulation (TPPM) 1H decoupling during acquisition, in experiments carried out at 14.1 T. Chemical shifts are quoted in ppm relative to (CH3)4Si at 0 ppm, using the CH3 resonance of L-alanine at 20.5 ppm as a secondary reference. For 31P, MAS NMR spectra were acquired at 14.1 T, with parameters given in Table S1.1. Chemical shifts are shown referenced relative to 85% H3PO4 (aq) at 0 ppm, using BPO4 at –29.6 ppm as a secondary reference. For 77Se, CP MAS experiments (using ramped contact pulse durations of 5-8 ms and TPPM 1H decoupling) were carried out at 9.4, 14.1 and 20.0 T. Chemical shifts are referenced relative to (CH3)2Se at 0 ppm, using the isotropic resonance of solid H2SeO3 at 1288.1 ppm as a secondary reference. The position of the isotropic resonances within the spinning sideband patterns were unambiguously determined by recording a second spectrum at a different MAS rate. In some cases, spectra were also acquired with additional decoupling. Experimental 77Se 31P continuous wave (CW) NMR parameters were determined by lineshape analysis using Bruker Topspin software. For controlled-temperature experiments between 0 and 50 C, recorded at 9.4 and 14.1 T, the sample temperature was controlled using a Bruker BCU-II chiller and Bruker BVT/BVTB-3000 temperature controller and heater booster. The sample temperature (including frictional heating effects arising from sample spinning) was calibrated using the isotropic 87Rb shift of solid RbCl, as described by Skibsted and Jakobsen.S2 The chemical shift referencing for 87Rb was relative to 0.01 M RbCl in D2O (the standard chemical shift reference), rather than the 1 M RbCl in D2O reported by Skibsted and Jakobsen. However, owing to a 4.85 ppm shift difference between the two concentrations (corresponding to a temperature difference of ~134 K according to equation 1 of Ref. S1), using the more dilute solution as a reference gave shifts for solid RbCl corresponding to significantly more S5 realistic temperatures (i.e., within the operating range of the chiller), using equation 1 of Ref. S1. S6 Table S1.1 Experimental parameters (magnetic field strength, B0, MAS rate, CP contact pulse duration, decoupling, number of transients averaged and recycle interval) for solidstate NMR experiments for compounds 1 and 2. B0 / Rotor size MAS rate Contact T / mm / kHz time / ms Decoupling Number of Recycle transients interval / s 4096 3 8 30 1 Naphtho[1,8-cd]1,2-diselenole tertbutylphosphine 13C 14.1 4 12.5 10 31P 14.1 4 12.5 - 77Se 9.4 4 5 8 1H TPPM 1872 3 14.1 4 12.5 8 1H TPPM 23328 3 1H TPPM 26400 3 15168 3 1024 10 8 30 14.1 4 12.5 8 20.0 2.5 12.5 5 1H TPPM - 31P 1H CW TPPM 2 Naphtho[1,8-cd]1,2-diselenole isopropylphosphine 13C 14.1 4 12.5 5 31P 14.1 4 12.5 - 77Se 9.4 4 5 8 1H TPPM 5248 10 14.1 4 12.5 8 1H TPPM 336 10 1H TPPM 7880 10 17440 3 14.1 4 12.5 8 20.0 2.5 12.5 5 1H TPPM - 31P 1H S7 CW TPPM Computational detail The calculations of J-coupling were performed with the ultrasoft PAW J-coupling methodS3 implemented in CASTEP 8.0S4 using the PBES5 functional to describe electronic exchange-correlation, a planewave basis set described by a 50 Ry cut-off energy, a 2 2 2 k-point grid and a fine grid scale four times that of the standard grid scale. The default onthe-fly pseudopotential set was used, with both a Schrödinger (non-relativistic) and a ZORA (scalar-relativistic) atomic solver used to generate the isolated atomic solutions. S6 The latter calculations include the effects of special relativity at the scalar-relativistic ZORA level of theory. Prior to calculation of the J couplings the positions of the atoms were optimized to minimise forces on the atoms, keeping the unit cell fixed. Calculations were performed on the ARCHER UK National Supercomputing Service, supported by the UK Car-Parrinello consortium (UKCP). S8 S2. Single crystal diffraction structures Compound 1 Data collection A colorless platelet crystal of C14H15PSe2 having approximate dimensions of 0.12 0.06 0.03 mm was mounted in a loop. All measurements were made on a Rigaku Saturn70 diffractometer using graphite monochromated Mo-K radiation. The crystal-todetector distance was 40.00 mm. Cell constants and an orientation matrix for data collection corresponded to a primitive triclinic cell with dimensions: a = 7.3880(15) Å = 107.355(8)° b = 10.3745(19) Å = 107.255(8)° c = 10.8099(19) Å = 106.126(8)° V = 691.6(2) Å3 For Z = 2 and F.W. = 372.17, the calculated density is 1.787 g cm–3. Based on a statistical analysis of intensity distribution, and the successful solution and refinement of the structure, the space group was determined to be: P–1 (#2) The data were collected at a temperature of –148 ± 1 °C to a maximum 2 value of 50.7°. A total of 315 oscillation images were collected. A sweep of data was done using scans from –100.0 to 80.0° in 1.00° steps, at = 42.0° and = 0.0°. The exposure rate was 40.0 [s/°]. The detector swing angle was –10.00°. A second sweep was performed using scans from –35.0 to 70.0° in 1.00° steps, at = 42.0° and = 240.0°. The exposure rate was 40.0 [s/°]. The detector swing angle was –10.00°. Another sweep was performed using scans from –20.0 to 10.0° in 1.00° steps, at = 0.0° and = 120.0°. The exposure rate was 40.0 [s/°]. The detector swing angle was –10.00. The crystal-to-detector distance was 40.00 mm. Readout was performed in the 0.070 mm pixel mode. S9 Data reduction Of the 5346 reflections were collected, where 2422 were unique (Rint = 0.0356); equivalent reflections were merged. Data were collected and processed using CrystalClear (Rigaku).S7 The linear absorption coefficient, , for Mo-K radiation is 54.378 cm–1. An empirical absorption correction was applied which resulted in transmission factors ranging from 0.629 to 0.849. The data were corrected for Lorentz and polarization effects. Structure solution and refinement The structure was solved by direct methodsS8 and expanded using Fourier techniques. The non-hydrogen atoms were refined anisotropically. Hydrogen atoms were refined using the riding model. The final cycle of full-matrix least-squares refinementF1 on F2 was based on 2422 observed reflections and 154 variable parameters and converged (largest parameter shift was 0.00 times its esd) with unweighted and weighted agreement factors of: R1 = ||Fo| – |Fc|| / |Fo| = 0.0326 wR2 = [ ( w (Fo2 – Fc2)2)/ w(Fo2)2]1/2 = 0.0707 The goodness of fitF2 was 0.98. Unit weights were used. Plots of w (|Fo| – |Fc|)2 versus |Fo|, reflection order in data collection, sin / and various classes of indices showed no unusual trends. The maximum and minimum peaks on the final difference Fourier map corresponded to 0.51 and –0.66 e Å–3, respectively. Neutral atom scattering factors were taken from International Tables for Crystallography (IT), Vol. C, Table 6.1.1.4.S9 Anomalous dispersion effects were included in Fcalc;S10 the values for f' and f" were those of Creagh and McAuley.S11 The values for the mass attenuation coefficients are those of Creagh and Hubbell.S12 All calculations were performed using the CrystalStructureS13 crystallographic software package except for S10 refinement, which was performed using SHELXL2013.S8 Compound 1 ORTEP at 50% S11 Experimental details A. Crystal data Empirical Formula C14H15PSe2 Formula Weight 372.17 Crystal Color, Habit colorless, platelet Crystal Dimensions 0.12 0.06 0.03 mm Crystal System triclinic Lattice Type Primitive Lattice Parameters a = 7.3880(15) Å b = 10.3745(19) Å c = 10.8099(19) Å = 107.355(8)° = 107.255(8)° = 106.126(8)° V = 691.6(2) Å3 Space Group P–1 (#2) Z value 2 Dcalc 1.787 g cm–3 F000 364.00 (MoK) 54.378 cm–1 B. Intensity measurements Diffractometer Saturn70 Radiation MoK ( = 0.71075 Å) Voltage, Current 50 kV, 40 mA Temperature –148.0 °C Detector Aperture 70.0 70.0 mm Data Images 315 exposures S12 Oscillation Range ( = 42.0, = 0.0) –100.0 - 80.0° Exposure Rate 40.0 s/° Detector Swing Angle –10.00° Oscillation Range ( = 42.0, = 240.0) –35.0 - 70.0° Exposure Rate 40.0 s/° Detector Swing Angle –10.00° Oscillation Range ( = 0.0, = 120.0) –20.0 - 10.0° Exposure Rate 40.0 s/° Detector Swing Angle –10.00° Detector Position 40.00 mm Pixel Size 0.070 mm 2max 50.0° No. of Reflections Measured Total: 5346 Unique: 2422 (Rint = 0.0356) Corrections Lorentz-polarization Absorption (trans. factors: 0.629 - 0.849) C. Structure solution and refinement Structure Solution Direct Methods (SHELXS97) Refinement Full-matrix least-squares on F2 Function Minimized w (Fo2 – Fc2)2 Least Squares Weights w = 1/ [2(Fo2) + (0.0267 . P)2 + 0.6478 . P] where P = (Max(Fo2,0) + 2Fc2)/3 2max cutoff 50.0° Anomalous Dispersion All non-hydrogen atoms No. Observations (All reflections) 2422 No. Variables 154 Reflection/Parameter Ratio 15.73 S13 Residuals: R1 (I > 2.00 (I)) 0.0326 Residuals: R (All reflections) 0.0481 Residuals: wR2 (All reflections) 0.0707 Goodness of Fit Indicator 0.983 Max Shift/Error in Final Cycle 0.000 Maximum Peak in Final Diff. Map 0.51 e/Å–3 Minimum Peak in Final Diff. Map –0.66 e/Å–3 Table S2.1. Atomic coordinates and Biso/Beq atom x y z Beq Se1 Se2 P1 C1 C2 C3 0.42240(7) 0.86228(6) 0.73444(17) 0.3163(7) 0.1041(7) –0.0106(7) 0.87759(5) 0.95971(4) 0.87350(12) 0.7949(5) 0.7219(5) 0.6718(5) 0.31426(4) 0.26088(4) 0.39670(11) 0.1103(4) 0.0479(5) –0.0986(5) 2.047(11) 1.774(10) 1.65(2) 1.73(7) 2.37(8) 2.57(9) C4 C5 C6 C7 C8 C9 C10 C11 C12 0.0896(7) 0.3065(7) 0.4040(7) 0.6127(7) 0.7319(7) 0.6465(7) 0.4270(7) 0.6973(7) 0.5827(8) 0.6948(5) 0.7637(5) 0.7817(5) 0.8411(5) 0.8845(4) 0.8745(4) 0.8138(4) 0.6749(4) 0.6140(5) –0.1815(4) –0.1245(4) –0.2166(4) –0.1666(4) –0.0233(4) 0.0718(4) 0.0241(4) 0.3367(4) 0.4174(5) 2.23(8) 1.79(7) 2.05(8) 2.17(8) 1.80(7) 1.66(7) 1.58(7) 1.78(7) 2.70(9) C13 C14 0.5817(7) 0.9158(7) 0.5823(5) 0.6786(5) 0.1777(4) 0.3894(4) 2.03(8) 2.36(8) Beq = 8/3 2(U11(aa*)2 + U22(bb*)2 + U33(cc*)2 + 2 U12(aa*bb*)cos + 2 U13(aa*cc*)cos + 2 U23(bb*cc*)cos ) S14 Table S2.2. Atomic coordinates and Biso involving hydrogen atoms atom x y z Biso H2 H3 H4 H6 H7 H8 H12A 0.03338 –0.15704 0.01164 0.32190 0.67732 0.87828 0.66033 0.70504 0.62216 0.66386 0.75180 0.85299 0.92250 0.67559 0.10575 –0.13933 –0.28022 –0.31450 –0.22881 0.01005 0.51980 2.846 3.081 2.673 2.464 2.608 2.157 3.236 H12B H12C H13A H13B H13C H14A H14B H14C 0.44445 0.57014 0.44212 0.65591 0.57224 0.98866 0.90749 0.99116 0.61493 0.51270 0.58091 0.62477 0.48141 0.73879 0.57804 0.72140 0.38609 0.39792 0.14541 0.12825 0.15657 0.49229 0.36903 0.34071 3.236 3.236 2.437 2.437 2.437 2.831 2.831 2.831 S15 Table S2.3. Anisotropic displacement parameters atom U11 U22 U33 U12 U13 U23 Se1 Se2 P1 C1 C2 C3 C4 0.0235(3) 0.0174(3) 0.0196(6) 0.020(3) 0.019(3) 0.016(3) 0.028(3) 0.0352(3) 0.0236(3) 0.0228(6) 0.023(2) 0.036(3) 0.032(3) 0.027(3) 0.0242(2) 0.0237(2) 0.0198(5) 0.025(2) 0.038(3) 0.040(3) 0.026(2) 0.0160(2) 0.0055(2) 0.0089(5) 0.013(2) 0.014(2) 0.010(2) 0.017(2) 0.0136(2) 0.00734(18) 0.0081(5) 0.0090(19) 0.014(2) 0.004(2) 0.005(2) 0.01129(19) 0.01006(18) 0.0079(5) 0.0101(18) 0.014(2) 0.010(2) 0.0068(19) C5 C6 C7 C8 C9 C10 C11 C12 C13 0.022(3) 0.033(3) 0.039(3) 0.021(2) 0.025(3) 0.023(3) 0.026(3) 0.041(3) 0.029(3) 0.024(2) 0.026(3) 0.028(3) 0.021(2) 0.020(2) 0.016(2) 0.022(2) 0.033(3) 0.019(2) 0.025(2) 0.020(2) 0.026(2) 0.028(2) 0.024(2) 0.020(2) 0.019(2) 0.033(3) 0.025(2) 0.015(2) 0.017(2) 0.019(2) 0.008(2) 0.013(2) 0.010(2) 0.010(2) 0.013(2) 0.008(2) 0.0084(19) 0.009(2) 0.019(2) 0.0124(19) 0.0103(19) 0.0069(18) 0.0091(18) 0.019(2) 0.010(2) 0.0088(18) 0.0076(18) 0.015(2) 0.0113(19) 0.0113(18) 0.0056(17) 0.0083(18) 0.018(2) 0.0082(18) C14 0.032(3) 0.025(3) 0.029(2) 0.014(2) 0.007(2) 0.0097(19) The general temperature factor expression: exp(–2 (a* U11h + b* U22k + c* U33l + 2a*b*U12hk + 2a*c*U13hl + 2b*c*U23kl)) Table S2.4. Bond lengths (Å) atom atom distance atom atom distance Se1 Se2 P1 C1 C3 C5 C6 C8 C11 P1 P1 C11 C10 C4 C6 C7 C9 C12 2.2291(15) 2.2326(15) 1.878(5) 1.431(7) 1.352(8) 1.417(8) 1.352(7) 1.369(7) 1.532(8) Se1 Se2 C1 C2 C4 C5 C7 C9 C11 C1 C9 C2 C3 C5 C10 C8 C10 C13 1.919(4) 1.925(4) 1.377(6) 1.402(6) 1.405(6) 1.428(5) 1.390(6) 1.427(6) 1.514(5) C11 C14 1.529(7) S16 Table S2.5. Bond lengths involving hydrogens (Å) atom atom distance atom atom distance C2 C4 C7 C12 C12 C13 C14 H2 H4 H7 H12A H12C H13B H14A 0.950 0.950 0.950 0.980 0.980 0.980 0.980 C3 C6 C8 C12 C13 C13 C14 H3 H6 H8 H12B H13A H13C H14B 0.950 0.950 0.950 0.980 0.980 0.980 0.980 C14 H14C 0.980 Table S2.6. Bond angles (°) atom atom atom angle atom atom atom angle P1 Se1 Se2 Se1 P1 P1 C1 Se2 C11 107.40(16) 98.87(6) 106.74(17) P1 Se1 Se1 Se2 P1 C1 C9 C11 C2 108.58(15) 107.36(14) 111.6(4) Se1 C1 C3 C4 C5 C7 Se2 C1 C5 C1 C2 C4 C5 C6 C8 C9 C10 C10 C10 C3 C5 C10 C7 C9 C10 C5 C9 128.0(3) 121.8(5) 121.4(4) 120.4(5) 120.7(4) 122.6(4) 130.1(4) 117.0(4) 116.8(4) C2 C2 C4 C6 C6 Se2 C8 C1 P1 C1 C3 C5 C5 C7 C9 C9 C10 C11 C10 C4 C6 C10 C8 C8 C10 C9 C12 120.0(4) 119.3(4) 119.1(4) 120.5(4) 119.4(5) 109.8(3) 120.0(4) 126.2(4) 105.2(3) P1 C12 C13 C11 C11 C11 C13 C13 C14 115.4(4) 111.0(3) 110.4(4) P1 C12 C11 C11 C14 C14 105.1(3) 109.4(4) S17 Table S2.7. Bond angles involving hydrogens (°) atom atom atom angle atom atom atom angle C1 C2 C3 C5 C6 C7 C11 C2 C3 C4 C6 C7 C8 C12 H2 H3 H4 H6 H7 H8 H12A 119.1 120.4 119.3 119.7 120.3 118.7 109.5 C3 C4 C5 C7 C8 C9 C11 C2 C3 C4 C6 C7 C8 C12 H2 H3 H4 H6 H7 H8 H12B 119.1 120.4 119.3 119.7 120.3 118.7 109.5 C11 H12A C11 C11 H13A C11 C11 H14A C12 C12 C13 C13 C13 C14 C14 C14 H12C H12C H13A H13C H13C H14A H14C H14C 109.5 109.5 109.5 109.5 109.5 109.5 109.5 109.5 H12A H12B C11 H13A H13B C11 H14A H14B C12 C12 C13 C13 C13 C14 C14 C14 H12B H12C H13B H13B H13C H14B H14B H14C 109.5 109.5 109.5 109.5 109.5 109.5 109.5 109.5 S18 Table S2.8. Torsion angles (°) atom1 atom2 atom3 atom4 angle atom1 atom2 atom3 atom4 angle P1 C1 P1 C9 Se1 Se1 Se2 Se1 Se1 Se2 Se2 P1 P1 P1 C1 P1 C9 P1 C11 C11 C11 C2 Se2 C8 Se1 C12 C14 C13 148.1(3) 45.43(15) –160.1(2) –39.65(17) –67.3(2) 177.23(18) –49.8(3) P1 C1 P1 C9 Se1 Se2 Se2 Se1 Se1 Se2 Se2 P1 P1 P1 C1 P1 C9 P1 C11 C11 C11 C10 C11 C10 C11 C13 C12 C14 –38.6(4) –65.31(16) 22.9(4) 71.59(17) 55.4(3) –172.51(15) 72.0(2) Se1 Se1 C2 C1 C3 C4 C4 C6 C5 C1 C1 C1 C2 C4 C5 C5 C5 C6 C2 C10 C10 C3 C5 C6 C10 C10 C7 C3 C9 C9 C4 C6 C7 C9 C9 C8 170.3(3) 13.3(7) –173.9(4) 0.3(8) 178.4(4) –176.8(4) 176.4(4) –3.2(7) 0.1(7) Se1 C2 C10 C2 C3 C4 C6 C10 C6 C1 C1 C1 C3 C4 C5 C5 C5 C7 C10 C10 C2 C4 C5 C10 C10 C6 C8 C5 C5 C3 C5 C10 C1 C1 C7 C9 –168.4(3) 4.4(7) –3.6(8) 2.1(8) –1.2(7) –2.0(7) 178.4(4) 2.7(7) –2.4(7) C7 Se2 C8 C8 C9 C9 C9 C10 C10 Se2 C1 C1 –175.5(4) –4.2(7) 179.2(4) C7 Se2 C8 C8 C9 C9 C9 C10 C10 C10 C5 C5 1.8(7) 177.6(3) 1.0(6) Torsion angles > 160° and <120° are excluded Table S2.9. Intramolecular contacts less than 3.60 Å atom atom distance atom atom distance Se1 Se2 C1 C2 C5 C7 C10 C9 C1 C4 C5 C8 C10 C13 3.488(5) 3.529(4) 2.789(6) 2.770(8) 2.756(6) 2.833(8) 3.551(7) Se1 Se2 C1 C3 C6 C9 C12 C13 C13 C10 C9 C13 3.599(6) 3.567(4) 3.428(8) 2.833(6) 2.792(6) 3.510(7) S19 Table S2.10. Intramolecular contacts less than 3.60 Å involving hydrogen atom atom distance atom atom distance Se1 Se1 Se2 P1 P1 P1 C1 H2 H13A H13B H12A H13A H14A H3 2.727 3.143 3.040 2.779 3.036 2.778 3.280 Se1 Se2 Se2 P1 P1 P1 C1 H12B H8 H14C H12B H13B H14C H13A 3.080 2.666 3.140 2.877 3.020 2.868 2.715 C1 C2 C4 C5 C6 C8 C9 C10 C10 H13B H13A H6 H7 H8 H13B H13A H2 H6 3.438 3.298 2.602 3.268 3.216 3.549 3.435 3.287 3.324 C2 C4 C5 C6 C8 C9 C9 C10 C10 H4 H2 H3 H4 H6 H7 H13B H4 H8 3.236 3.227 3.263 2.592 3.228 3.270 2.848 3.311 3.275 C10 C12 C12 C12 C13 C13 C13 C14 C14 C14 H13A H13A H13C H14B H12A H12C H14B H12A H12C H13B 3.086 2.689 2.710 2.701 3.351 2.703 2.690 2.668 2.699 2.686 C10 C12 C12 C12 C13 C13 C13 C14 C14 C14 H13B H13B H14A H14C H12B H14A H14C H12B H13A H13C 3.163 3.354 2.665 3.347 2.703 3.342 2.690 3.346 3.345 2.686 H2 H3 H6 H12A H12A H12A H12B H12B H12C H3 H4 H7 H13A H14A H14C H13B H14A H13A 2.344 2.298 2.302 3.581 2.462 3.558 3.589 3.556 2.973 H2 H4 H7 H12A H12A H12B H12B H12B H12C H13A H6 H8 H13C H14B H13A H13C H14B H13B 3.561 2.402 2.326 3.597 2.970 2.513 3.005 3.598 3.600 H12C H13C 2.537 H12C H14A 2.962 S20 H12C H14B 2.533 H12C H14C 3.598 H13A H13B H13B H13C H14B H14A H14C H14B 3.583 3.577 2.507 2.507 H13A H13B H13C H13C H14C H14B H14A H14C 3.583 2.974 3.577 2.975 Table S2.11. Intermolecular contacts less than 3.60 Å atom atom distance atom atom distance Se2 P1 C3 C7 C8 C10 C13 P11 P11 C83 C12 C34 C72 C136 3.5135(12) 3.5857(15) 3.366(8) 3.500(7) 3.366(8) 3.583(7) 3.365(6) P1 C1 C5 C7 C9 C12 Se21 C72 C92 C102 C52 C125 3.5135(12) 3.500(7) 3.524(7) 3.583(7) 3.524(7) 3.535(8) Symmetry operators: (1) –X+2, –Y+2, –Z+1 (3) X–1, Y, Z (5) –X+1, –Y+1, –Z+1 (2) –X+1, –Y+2, –Z (4) X+1, Y, Z (6) –X+1, –Y+1, –Z S21 Table S2.12. Intermolecular contacts less than 3.60 Å involving hydrogens atom atom distance atom atom distance Se1 Se2 Se2 P1 C2 C3 C3 H71 H23 H74 H14A5 H82 H72 H12B6 3.390 3.444 3.591 3.591 3.052 3.591 3.473 Se1 Se2 Se2 C1 C2 C3 C3 H14C2 H61 H14A5 H71 H14C2 H82 H13A6 3.287 3.583 3.079 3.474 3.505 2.959 3.302 C4 C4 C5 C6 C6 C7 C7 C8 C8 H13C7 H14B7 H14B7 H13C7 H14B7 H84 H12C7 H23 H84 3.477 2.960 3.297 3.026 3.354 3.413 3.364 3.519 2.951 C4 C5 C6 C6 C7 C7 C7 C8 C8 H14A8 H13C7 H12C7 H14A8 H33 H12A9 H13C7 H33 H13C7 3.576 2.883 3.191 3.492 3.223 3.483 3.292 3.077 3.407 C9 C12 C12 C13 C13 C14 C14 H2 H2 H13C7 H36 H12A11 H36 H13B7 H23 H610 C82 H82 3.350 3.263 3.414 3.086 2.976 3.490 3.378 3.519 3.098 C10 C12 C12 C13 C13 C14 H2 H2 H2 H13C7 H410 H12C11 H13A7 H13C7 H410 Se22 C142 H13A6 3.105 3.596 3.012 3.323 3.241 3.488 3.444 3.490 3.501 H2 H3 H3 H3 H3 H3 H3 H4 H4 H4 H13B2 C72 C126 H72 H12B6 H13A6 H13C6 C148 H12B6 H14A8 2.786 3.223 3.263 3.237 2.738 2.500 2.883 3.488 3.369 2.765 H2 H3 H3 H3 H3 H3 H4 H4 H4 H4 H14C2 C82 C136 H82 H12C6 H13B2 C128 H12A8 H12C8 H14B8 2.611 3.077 3.086 2.946 3.053 3.553 3.596 2.903 3.518 3.411 S22 H4 H14B7 2.704 H6 Se21 3.583 H6 H6 H6 H7 H7 H7 H7 H8 H8 H8 C148 H13C7 H14B8 Se11 C11 H33 H12A9 C23 C74 H23 3.378 3.479 3.372 3.390 3.474 3.237 2.734 3.052 3.413 3.098 H6 H6 H6 H7 H7 H7 H7 H8 H8 H8 H12C7 H14A8 H14B7 Se24 C33 H84 H12C7 C33 C84 H33 3.024 2.653 3.148 3.591 3.591 3.108 3.332 2.959 2.951 2.946 H8 H12A H12A H12A H12A H12B H12B H12C H12C H74 C712 H410 H12A11 H12C11 H36 H12A11 C67 C1211 3.108 3.483 2.903 3.570 2.756 2.738 3.423 3.191 3.012 H8 H12A H12A H12A H12B H12B H12B H12C H12C H84 C1211 H712 H12B11 C36 H46 H12C11 C77 H36 2.168 3.414 2.734 3.423 3.473 3.369 3.022 3.364 3.053 H12C H12C H12C H13A H13A H13A H13A H13B H13B H410 H77 H12B11 C36 H26 H13A7 H13C7 H23 H13A7 3.518 3.332 3.022 3.302 3.501 3.560 3.096 2.786 2.817 H12C H12C H12C H13A H13A H13A H13B H13B H13B H67 H12A11 H12C11 C137 H36 H13B7 C137 H33 H13B7 3.024 2.756 2.751 3.323 2.500 2.817 2.976 3.553 2.883 H13B H13C H13C H13C H13C H13C H13C H14A H14A H14A H13C7 C57 C77 C97 C137 H67 H13B7 Se25 C410 H410 2.720 2.883 3.292 3.350 3.241 3.479 2.720 3.079 3.576 2.765 H13C H13C H13C H13C H13C H13C H13C H14A H14A H14A C47 C67 C87 C107 H36 H13A7 H13C7 P15 C610 H610 3.477 3.026 3.407 3.105 2.883 3.096 3.407 3.591 3.492 2.653 S23 H14B C47 2.960 H14B C57 3.297 H14B H14B H14B H14C C67 H47 H67 C23 3.354 2.704 3.148 3.505 H14B H14B H14C H14C H410 H610 Se13 H23 3.411 3.372 3.287 2.611 Symmetry operators: (1) –X+1, –Y+2, –Z (3) X+1, Y, Z (5) –X+2, –Y+2, –Z+1 (2) X–1, Y ,Z (4) –X+2, –Y+2, –Z (6) –X, –Y+1, –Z (7) –X+1, –Y+1, –Z (9) X, Y, Z–1 (11) –X+1, –Y+1, –Z+1 (8) X–1, Y, Z–1 (10) X+1, Y, Z+1 (12) X, Y, Z+1 S24 Compound 2 Data collection A purple block crystal of C13H13PSe2 having approximate dimensions of 0.18 0.15 0.05 mm was mounted in a loop. All measurements were made on a Rigaku Mercury70 diffractometer using filtered Mo-K radiation. The crystal-to-detector distance was 40.00 mm. Cell constants and an orientation matrix for data collection corresponded to a primitive triclinic cell with dimensions: a = 7.6709(17) Å = 106.421(8)° b = 9.404(2) Å = 104.690(7)° c = 10.484(2) Å = 106.308(8)° V = 649.1(3) Å3 For Z = 2 and F.W. = 358.14, the calculated density is 1.832 g cm–3. Based on a statistical analysis of intensity distribution, and the successful solution and refinement of the structure, the space group was determined to be: P–1 (#2) The data were collected at a temperature of –180 ± 1 °C to a maximum 2 value of 50.7°. A total of 278 oscillation images were collected. A sweep of data was done using scans from –100.0 to 80.0° in 1.00° steps, at = 0.0° and = 0.0°. The exposure rate was 6.0 [s/°]. The detector swing angle was –10.00°. A second sweep was performed using scans from –26.0 to 23.0° in 1.00° steps, at = –90.0° and = 0.0°. The exposure rate was 6.0 [s/°]. The detector swing angle was –10.00°. Another sweep was performed using scans from –26.0 to 23.0° in 1.00° steps, at = 90.0° and = 90.0°. The exposure rate was 6.0 [s/°]. The detector swing angle was –10.00. The crystal-to-detector distance was 40.00 mm. Readout was performed in the 0.136 mm pixel mode. Data reduction S25 Of the 4193 reflections were collected, where 2322 were unique (Rint = 0.0281); equivalent reflections were merged. Data were collected and processed using CrystalClear (Rigaku).S7 The linear absorption coefficient, , for Mo-K radiation is 57.896 cm–1. An empirical absorption correction was applied which resulted in transmission factors ranging from 0.429 to 0.749. The data were corrected for Lorentz and polarization effects. Structure solution and refinement The structure was solved by direct methods and expanded using Fourier techniques. The non-hydrogen atoms were refined anisotropically. Hydrogen atoms were refined using the riding model. The final cycle of full-matrix least-squares refinementF1 on F2 was based on 2221 observed reflections and 145 variable parameters and converged (largest parameter shift was 0.00 times its esd) with unweighted and weighted agreement factors of: R1 = ||Fo| – |Fc|| / |Fo| = 0.0294 wR2 = [ ( w (Fo2 – Fc2)2)/ w(Fo2)2]1/2 = 0.0467 The goodness of fitF2 was 0.95. Unit weights were used. Plots of w (|Fo| – |Fc|)2 versus |Fo|, reflection order in data collection, sin / and various classes of indices showed no unusual trends. The maximum and minimum peaks on the final difference Fourier map corresponded to 0.37 and –0.38 e Å–3, respectively. Neutral atom scattering factors were taken from International Tables for Crystallography (IT), Vol. C, Table 6.1.1.4.S9 Anomalous dispersion effects were included in Fcalc;S10 the values for f' and f" were those of Creagh and McAuley.S11 The values for the mass attenuation coefficients are those of Creagh and Hubbell.S12 All calculations were performed using the CrystalStructureS13 crystallographic software package except for refinement, which was performed using SHELXL2013.S14 S26 Compound 2 ORTEP at 50% S27 Experimental details A. Crystal data Empirical Formula C13H13PSe2 Formula Weight 358.14 Crystal Color, Habit purple, block Crystal Dimensions 0.18 0.15 0.05 mm Crystal System triclinic Lattice Type Primitive Lattice Parameters a = 7.6709(17) Å b = 9.404(2) Å c = 10.484(2) Å = 106.421(8)° = 104.690(7)° = 106.308(8)° V = 649.1(3) Å3 Space Group P–1 (#2) Z value 2 Dcalc 1.832 g cm–3 F000 348.00 (MoK) 57.896 cm–1 B. Intensity measurements Diffractometer Mercury70 Radiation MoK ( = 0.71075 Å) Voltage, Current 50 kV, 16 mA Temperature –180.0 °C Detector Aperture 70.0 70.0 mm Data Images 278 exposures S28 Oscillation Range ( = 0.0, = 0.0) 0.0 - 180.0° Exposure Rate 6.0 s/° Detector Swing Angle –10.00° Oscillation Range ( = –90.0, = 0.0) –26 - 23.0° Exposure Rate 6.0 s/° Detector Swing Angle –10.00° Oscillation Range ( = –90.0, = 90.0) –26 - 23.0° Exposure Rate 6.0 s/° Detector Swing Angle –10.00° Detector Position 40.00 mm Pixel Size 0.136 mm 2max 50.0° No. of Reflections Measured Total: 4082 Unique: 2221 (Rint = 0.0281) Corrections Lorentz-polarization Absorption (trans. factors: 0.429 - 0.749) C. Structure solution and refinement Structure Solution Direct Methods (SHELXS97) Refinement Full-matrix least-squares on F2 Function Minimized w (Fo2 – Fc2)2 Least Squares Weights w = 1/ [2(Fo2) + (0.0141 . P)2 + 0.000 . P] where P = (Max(Fo2,0) + 2Fc2)/3 2max cutoff 50.0° Anomalous Dispersion All non-hydrogen atoms No. Observations (All reflections) 2221 No. Variables 145 S29 Reflection/Parameter Ratio 15.32 Residuals: R1 (I > 2.00 (I)) 0.0294 Residuals: R (All reflections) 0.0430 Residuals: wR2 (All reflections) 0.0467 Goodness of Fit Indicator 0.949 Max Shift/Error in Final Cycle 0.000 Maximum Peak in Final Diff. Map 0.37 e/Å–3 Minimum Peak in Final Diff. Map –0.38 e/Å–3 Table S2.13. Atomic coordinates and Biso/Beq atom Se1 Se2 P1 C1 C2 x 0.33565(5) 0.00392(4) 0.31501(12) 0.2608(4) 0.3573(4) y 0.85913(4) 0.95468(4) 1.07371(10) 0.7008(4) 0.5974(4) z 0.53840(3) 0.66117(3) 0.68501(9) 0.6178(3) 0.5990(3) Beq 1.832(9) 1.861(9) 1.646(17) 1.18(6) 1.63(6) C3 C4 C5 C6 C7 C8 C9 C10 C11 0.3166(4) 0.1806(4) 0.0811(4) –0.0585(4) –0.1598(5) –0.1254(4) 0.0068(4) 0.1167(4) 0.4521(4) 0.4651(4) 0.4378(4) 0.5423(4) 0.5072(4) 0.6011(4) 0.7370(4) 0.7756(4) 0.6766(4) 1.0895(4) 0.6368(3) 0.6984(3) 0.7233(3) 0.7887(3) 0.8138(4) 0.7776(3) 0.7128(3) 0.6827(3) 0.8648(3) 1.66(6) 1.67(6) 1.41(6) 1.91(7) 2.22(7) 1.82(7) 1.41(6) 1.12(6) 1.51(6) C12 C13 0.4170(5) 0.6686(4) 1.2127(4) 1.1414(4) 0.9753(3) 0.8873(3) 2.70(8) 2.72(8) Beq = 8/3 2(U11(aa*)2 + U22(bb*)2 + U33(cc*)2 + 2 U12(aa*bb*)cos + 2 U13(aa*cc*)cos + 2 U23(bb*cc*)cos ) S30 Table S2.14. Atomic coordinates and Biso involving hydrogen atoms atom x y z Biso H2 H3 H4 H6 H7 H8 H11 0.45513 0.38290 0.15253 –0.08026 –0.25437 –0.19520 0.40494 0.61744 0.39428 0.34764 0.41665 0.57578 0.80399 0.98296 0.55875 0.61995 0.72483 0.81482 0.85593 0.79840 0.87281 1.957 1.993 2.007 2.289 2.666 2.187 1.814 H12A H12B H12C H13A H13B H13C 0.27756 0.48958 0.46129 0.68836 0.71397 0.74226 1.17747 1.22318 1.31656 1.06109 1.24498 1.15161 0.95934 1.07125 0.96629 0.81558 0.87788 0.98283 3.246 3.246 3.246 3.263 3.263 3.263 S31 Table S2.15. Anisotropic displacement parameters atom U11 U22 U33 U12 U13 U23 Se1 Se2 P1 C1 C2 C3 C4 0.0337(2) 0.02229(19) 0.0269(5) 0.0159(16) 0.0166(17) 0.0228(18) 0.0260(18) 0.0168(2) 0.0215(3) 0.0150(6) 0.009(2) 0.020(2) 0.018(2) 0.010(2) 0.0213(2) 0.0282(2) 0.0200(5) 0.0152(18) 0.0222(19) 0.025(2) 0.0191(19) 0.00743(17) 0.01175(17) 0.0074(4) 0.0003(15) 0.0050(17) 0.0128(17) 0.0033(17) 0.01487(18) 0.00519(17) 0.0075(4) 0.0034(15) 0.0089(16) 0.0086(17) 0.0002(17) 0.00803(17) 0.01127(18) 0.0073(4) 0.0044(15) 0.0036(17) 0.0079(17) 0.0037(16) C5 C6 C7 C8 0.0177(17) 0.0271(19) 0.0224(19) 0.0161(18) 0.011(2) 0.016(2) 0.032(3) 0.025(2) 0.0175(18) 0.026(2) 0.030(2) 0.023(2) –0.0000(16) 0.0030(17) 0.0049(18) 0.0078(17) 0.0022(16) 0.0101(18) 0.0159(18) 0.0073(17) 0.0037(16) 0.0085(17) 0.0116(19) 0.0023(18) C9 C10 C11 C12 C13 0.0162(17) 0.0123(16) 0.0201(17) 0.041(2) 0.027(2) 0.015(2) 0.011(2) 0.015(2) 0.029(3) 0.039(3) 0.0156(17) 0.0114(17) 0.0205(19) 0.023(2) 0.030(2) 0.0016(16) 0.0003(15) 0.0050(16) 0.012(2) 0.006(2) 0.0028(16) –0.0002(15) 0.0057(16) 0.005(2) 0.0078(19) 0.0031(16) 0.0006(15) 0.0068(16) 0.0031(19) 0.013(2) The general temperature factor expression: exp(–2 (a* U11h + b* U22k + c* U33l + 2a*b*U12hk + 2a*c*U13hl + 2b*c*U23kl)) Table S2.16. Bond lengths (Å) atom atom distance atom atom distance Se1 P1 2.2380(11) Se1 C1 1.924(4) Se2 P1 C1 C3 C5 C6 C8 C11 P1 C11 C10 C4 C6 C7 C9 C12 2.2471(11) 1.852(3) 1.437(5) 1.362(5) 1.424(5) 1.346(6) 1.380(5) 1.527(5) Se2 C1 C2 C4 C5 C7 C9 C11 C9 C2 C3 C5 C10 C8 C10 C13 1.913(4) 1.379(5) 1.388(6) 1.412(5) 1.422(5) 1.408(6) 1.444(5) 1.527(5) S32 Table S2.17. Bond lengths involving hydrogens (Å) atom atom distance atom atom distance C2 C4 C7 C11 C12 C13 C13 H2 H4 H7 H11 H12B H13A H13C 0.950 0.950 0.950 1.000 0.980 0.980 0.980 C3 C6 C8 C12 C12 C13 H3 H6 H8 H12A H12C H13B 0.950 0.950 0.950 0.980 0.980 0.980 Table S2.18. Bond angles (°) atom atom atom angle atom atom atom angle P1 Se1 Se2 Se1 Se1 P1 P1 C1 C1 Se2 C11 C10 102.69(10) 96.70(3) 102.51(11) 128.3(3) P1 Se1 Se1 C2 Se2 P1 C1 C1 C9 C11 C2 C10 102.86(10) 103.49(12) 111.5(3) 120.1(3) C1 C3 C4 C5 C7 Se2 C1 C5 P1 C2 C4 C5 C6 C8 C9 C10 C10 C11 C3 C5 C10 C7 C9 C10 C5 C9 C13 122.3(3) 120.6(4) 121.3(3) 120.6(4) 121.9(4) 127.9(3) 116.3(3) 116.8(3) 109.0(3) C2 C4 C6 C6 Se2 C8 C1 P1 C12 C3 C5 C5 C7 C9 C9 C10 C11 C11 C4 C6 C10 C8 C8 C10 C9 C12 C13 119.3(4) 117.7(3) 121.0(3) 119.9(4) 112.1(3) 119.8(3) 126.9(3) 108.5(3) 110.6(2) S33 Table S2.19. Bond angles involving hydrogens (°) atom atom atom angle atom atom atom angle C1 C2 C3 C5 C6 C7 P1 C2 C3 C4 C6 C7 C8 C11 H2 H3 H4 H6 H7 H8 H11 118.8 120.3 119.7 119.7 120.1 119.0 109.6 C3 C4 C5 C7 C8 C9 C12 C2 C3 C4 C6 C7 C8 C11 H2 H3 H4 H6 H7 H8 H11 118.8 120.3 119.7 119.7 120.1 119.0 109.6 C13 C11 H12A H12B C11 H13A H13B C11 C12 C12 C12 C13 C13 C13 H11 H12B H12B H12C H13B H13B H13C 109.6 109.5 109.5 109.5 109.5 109.5 109.5 C11 C11 H12A C11 C11 H13A C12 C12 C12 C13 C13 C13 H12A H12C H12C H13A H13C H13C 109.5 109.5 109.5 109.5 109.5 109.5 S34 Table S2.20. Torsion angles (°) atom1 atom2 atom3 atom4 angle atom1 atom2 atom3 atom4 angle P1 C1 P1 C9 Se1 Se2 Se1 Se1 Se1 Se2 Se2 P1 P1 C1 C1 P1 C9 P1 C11 C11 C2 C2 Se2 C8 Se1 C12 C12 C3 –147.30(12) –55.27(9) 147.83(12) 55.76(10) –169.60(14) –69.46(17) –174.71(16) P1 C1 P1 C9 Se1 Se2 Se1 Se1 Se1 Se2 Se2 P1 P1 C1 C1 P1 C9 P1 C11 C11 C10 C10 C11 C10 C11 C13 C13 C5 36.26(18) 49.35(9) –36.83(19) –49.71(10) 69.94(19) 170.08(15) 175.57(14) Se1 C2 C1 C3 C4 C4 C6 C5 C7 C1 C1 C2 C4 C5 C5 C5 C6 C8 C10 C10 C3 C5 C6 C10 C10 C7 C9 C9 C9 C4 C6 C7 C9 C9 C8 Se2 –5.4(3) 178.5(2) –1.9(4) –179.7(2) –179.2(2) 179.86(19) 0.8(3) –1.1(4) 174.63(19) C2 C10 C2 C3 C4 C6 C10 C6 C7 C1 C1 C3 C4 C5 C5 C5 C7 C8 C10 C2 C4 C5 C10 C10 C6 C8 C9 C5 C3 C5 C10 C1 C1 C7 C9 C10 –0.6(3) 2.1(3) 0.2(4) 1.2(4) –1.0(3) 179.92(19) –0.1(3) 1.8(4) –1.1(3) Se2 C8 C9 C9 C10 C10 C1 C1 5.8(3) –179.2(2) Se2 C8 C9 C9 C10 C10 C5 C5 –175.16(14) –0.1(3) Torsion angles > 160° and <120° are excluded Table S2.21. Intramolecular contacts less than 3.60 Å atom atom distance atom atom distance Se1 Se2 C1 C2 C5 C7 C9 C1 C4 C5 C8 C10 3.516(4) 3.503(4) 2.793(5) 2.761(5) 2.772(5) 2.842(5) Se1 Se2 C1 C3 C6 C9 C13 C12 C11 C10 C9 C11 3.594(3) 3.556(3) 3.454(4) 2.844(5) 2.808(6) 3.440(4) S35 Table S2.22. Intramolecular contacts less than 3.60 Å involving hydrogen atom atom distance atom atom distance Se1 Se1 Se2 P1 P1 C1 C1 H2 H13A H11 H12A H13A H3 H13A 2.720 3.062 3.194 2.880 2.896 3.275 3.588 Se1 Se2 Se2 P1 P1 C1 C2 H11 H8 H12A H12C H13B H11 H4 3.214 2.732 3.011 2.872 2.881 2.873 3.234 C4 C5 C6 C8 C9 C10 C10 C10 C12 H2 H3 H4 H6 H11 H2 H6 H11 H13B 3.224 3.271 2.581 3.245 2.855 3.294 3.329 2.846 2.701 C4 C5 C6 C9 C9 C10 C10 C12 C12 H6 H7 H8 H7 H12A H4 H8 H13A H13C 2.586 3.268 3.231 3.287 3.553 3.321 3.300 3.355 2.701 C13 C13 H3 H6 H11 H11 H11 H12A H12B H12A H12C H4 H7 H12A H12C H13B H13B H13A 3.355 2.701 2.312 2.293 2.375 2.877 2.877 3.592 3.592 C13 H2 H4 H7 H11 H11 H11 H12A H12B H12B H3 H6 H8 H12B H13A H13C H13C H13B 2.701 2.326 2.379 2.345 2.385 2.375 2.385 3.592 2.987 H12B H12C H13C H13B 2.522 2.522 H12C H12C H13A H13C 3.592 2.987 S36 Table S2.23. Intermolecular contacts less than 3.60 Å atom atom distance atom atom distance Se1 C2 C5 C9 Se11 C83 C12 C32 3.5369(8) 3.590(4) 3.485(3) 3.501(4) C1 C3 C8 C52 C92 C24 3.485(3) 3.501(4) 3.590(4) Symmetry operators: (1) –X+1, –Y+2, –Z+1 (3) X+1, Y, Z (2) –X, –Y+1, –Z+1 (4) X–1, Y, Z S37 Table S2.24. Intermolecular contacts less than 3.60 Å involving hydrogens atom atom distance atom atom distance Se1 Se2 P1 C1 C2 C2 C3 H61 H42 H32 H12B4 H35 H86 H25 3.509 3.355 3.207 3.091 3.403 3.201 3.091 Se2 Se2 P1 C2 C2 C2 C3 H31 H13A3 H42 H25 H76 H12B4 H76 3.590 3.452 3.134 3.136 3.571 3.116 3.175 C3 C4 C5 C6 C7 C7 C7 C8 C8 H12B4 H12C4 H13C4 H13B4 H23 H12A8 H13C4 H12A8 H13C4 3.216 3.491 3.208 3.447 3.519 3.186 3.125 3.244 3.014 C4 C5 C6 C6 C7 C7 C8 C8 C9 H12B4 H12B4 H13B7 H13C4 H33 H13B7 H23 H12B8 H31 3.227 3.160 3.117 3.202 3.246 3.519 3.106 3.599 3.540 C9 C10 C11 C12 C12 C13 C13 H2 H2 H13C4 H13C4 H12B4 H78 H114 H69 H114 C25 C76 3.044 3.157 3.316 3.027 3.123 3.169 3.166 3.136 3.519 C10 C11 C11 C12 C12 C13 C13 H2 H2 H12B4 H114 H13C4 H88 H13C4 H86 H12B4 C35 C86 3.121 3.030 3.357 3.264 3.492 3.566 3.492 3.091 3.106 H2 H2 H3 H3 H3 H3 H4 H4 H6 H6 H25 H76 Se21 C25 C91 H76 P110 H12C10 C137 H13A7 2.572 3.534 3.590 3.403 3.540 2.869 3.134 3.142 3.169 3.320 H2 H2 H3 H3 H3 H4 H4 H6 H6 H6 H35 H86 P110 C76 H25 Se210 H12A10 Se11 H611 H13B7 2.491 2.834 3.207 3.246 2.491 3.355 3.379 3.509 3.479 2.288 S38 H7 C23 3.571 H7 C33 3.175 H7 H7 H7 H7 H8 H8 H8 H8 H8 H11 C128 H33 H12B8 H12C8 C23 C133 H12A8 H13A3 H13C4 C124 3.027 2.869 3.035 2.890 3.201 3.566 2.740 2.779 3.480 3.123 H7 H7 H7 H7 H8 H8 H8 H8 H11 H11 H23 H12A8 H12C7 H13B7 C128 H23 H12B8 H13C3 C114 C134 3.534 2.652 3.454 3.130 3.264 2.834 2.910 3.526 3.030 3.166 H11 H11 H12A H12A H12A H12A H12B H12B H12B H114 H12B4 C78 H42 H88 H13C4 C24 C44 C88 2.574 2.458 3.186 3.379 2.740 3.288 3.116 3.227 3.599 H11 H11 H12A H12A H12A H12B H12B H12B H12B H12A4 H13C4 C88 H78 H114 C14 C34 C54 C104 3.563 2.513 3.244 2.652 3.563 3.091 3.216 3.160 3.121 H12B H12B H12B H12B H12C H12C H13A H13A H13B C114 H78 H114 H13C4 H42 H78 Se26 H86 C69 3.316 3.035 2.458 3.278 3.142 2.890 3.452 2.779 3.117 H12B H12B H12B H12C H12C H12C H13A H13A H13B C134 H88 H13A4 C44 H79 H12C12 H69 H12B4 C64 3.492 2.910 3.314 3.491 3.454 3.164 3.320 3.314 3.447 H13B H13B H13C H13C H13C H13C H13C H13C C79 H79 C64 C84 C104 C124 H84 H12A4 3.519 3.130 3.202 3.014 3.157 3.492 3.480 3.288 H13B H13C H13C H13C H13C H13C H13C H13C H69 C54 C74 C94 C114 H86 H114 H12B4 2.288 3.208 3.125 3.044 3.357 3.526 2.513 3.278 S39 Symmetry operators: (1) –X, –Y+1, –Z+1 (3) X–1, Y, Z (5) –X+1, –Y+1, –Z+1 (7) X–1, Y–1, Z (9) X+1, Y+1, Z (11) –X, –Y+1, –Z+2 (2) X, Y+1, Z (4) –X+1, –Y+2, –Z+2 (6) X+1, Y, Z (8) –X, –Y+2, –Z+2 (10) X, Y–1, Z (12) –X+1, –Y+3, –Z+2 F1. Least Squares function minimized: (SHELXL2013) w(Fo2 – Fc2)2, where w is the Least Squares weights. F2. Goodness of fit is defined as [w(Fo2 – Fc2)2/(No – Nv)]1/2, where No is the number of observations and Nv is the number of variables. S40 S3. Full experimental 77Se NMR parameters Table S3.1 gives the NMR parameters extracted from the 77Se solution-state and solid-state NMR spectra of 1 and 2. The spectra were recorded at 14.1 T, with 31P continuous wave decoupling at 12.5 kHz MAS. The principal components of the CSA tensor are defined according to the convention, 11 > 22 > 33.S14 For 1, it was also possible to get a fit of similar precision that resulted in the values shown in Table S3.2. It was not possible to distinguish between these two fits with the data shown. While multiple-field data may be useful to solve this problem, probe hardware capable of 31P/77Se double resonance experiments (and simultaneous 1H decoupling) was only available at 14.1 T. Table S3.1 Experimental 77Se NMR parameters (solution-state isotropic chemical shift, isosoln, solid-state isotropic chemical shift, iso, principal tensor components, ii, span, , and skew, ) extracted from solution- and solid-state NMR spectra of 1 and 2. Species 1 Se1 Se2 2 Se isosoln iso 11 22 33 (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) 179 (1) 492 (5) 23 (5) 23 (5) 470 (5) –1.0 (0.1) 213 (1) 505 (5) 77 (5) 58 (5) 447 (5) –0.9 (0.1) 280 (1) 672 (5) 84 (5) 83 (5) 589 (5) –1 (0.1) 210.2 270.2 S41 Table S3.2 Experimental 77Se NMR parameters (solution-state isotropic chemical shift, isosoln, solid-state isotropic chemical shift, iso, principal tensor components, ii, span, , and skew, ) extracted from solution-state and solid-state NMR spectra of 1 (alternative fitting). Species 1 Se1 Se2 isosoln iso 11 22 33 (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) 179 (1) 495 (5) 43 (5) –1 (5) 496 (5) –0.8 (0.1) 213 (1) 507 (5) 92 (5) 40 (5) 467(5) –0.8 (0.1) 210.2 For 2, the change in the shape of the isotropic 77Se resonance with external field indicates the presence of two Se signals with slightly different isotropic shifts, both of which experience a J coupling to 31P in an AA’X spin system. In such a case, where the resonances are overlapped, the total linewidth in Hz will be (JAX + JA’X)/2 + 0(iso(A) – iso(A’)), where 0 is the Larmor frequency (= B0) of A and A’, and the isotropic shift difference scales linearly with external field strength. In ppm, the linewidth will be (JAX + JA’X)/20 + (iso(A) – iso(A’)) and the J coupling contribution scales inversely with external field strength. Therefore, a plot of linewidth in Hz against 0 will yield a straight line with gradient (iso(A) – iso(A’)) and y intercept (JAX + JA’X)/2, whereas a plot of linewidth in ppm against 1/0 will yield a straight line with gradient (JAX + JA’X)/2 and y intercept (iso(A) – iso(A’)). Both of these plots for 2 are shown in Figure S3.1 and, together, yield approximate values for JSe1P + JSe2P = 616(54) Hz and isoSe1 – isoSe2 = 1.5(2) ppm, where the majority of the uncertainty comes from the difficulty in determining (particularly at 9.4 T) the width of the idealised “stick diagram” lineshape affected only by isotropic shifts and J couplings. S42 Figure S3.1 plots of the linewidth of the isotropic 77Se resonance in (a) Hz and (b) ppm as a function of (a) 0 and (b) 1/0. The lines of best fit and their formulae are shown in both parts. The case of two doublets in an AA’X system can readily be distinguished from other possible cases that would lead to the triplet-like appearance of the 77Se spectra of 2 at higher fields (14.1 and 20.0 T). A true triplet arising from an AX 2 system would have only one isotropic shift and, therefore, the linewidth in Hz will be 2JAX and independent of field. A doublet of doublets arising from AXX’ (i.e., as observed for Se1 of 1) would also contain a single isotropic shift and the linewidth in Hz would be JAX+JAX’, and independent of field. While both of these cases would give a linewidth in ppm that would be inversely proportional to the external field strength, a plot of linewidth in ppm against 1/0 would yield a straight line that passed through the origin (as there is no shift difference contribution to the linewidth). S43 S4. 13C and 31P solid-state NMR spectra and variable-temperature 77Se NMR Figure S4.1 shows the 13C CP MAS NMR spectra of compounds 1 and 2, acquired using the parameters given in Table S1.1. Figure S4.1 13C CP MAS NMR spectra of (a) 1 and (b) 2, acquired using the parameters given in Table S1.1. Spinning sideband are marked *. Figure S4.2 shows the 31P MAS NMR spectra of compounds 1 and 2, acquired using the parameters given in Table S1.1. The coupling to the S44 77Se (7.6% abundance) is not resolved, and no improvement in resolution is obtained when 1H decoupling is also applied in acquisition. a 1 50 1 0 0 50 0 −50 −1 0 0 −50 −1 0 0 −1 50 δ (ppm) b 1 50 1 0 0 50 0 −1 50 δ (ppm) Figure S4.2 31P MAS NMR spectra of (a) 1 and (b) 2, acquired using the parameters given in Table S1.1. Figures S4.3 and S4.4 show 77Se CP MAS NMR spectra of 1 and 2, recorded as a function of temperature. A significant shift to higher is observed as the temperature increases (accounting for the differing resonance positions in the spectra in Figure 1 of the main text, where different rotor sizes and different spinning speeds were used). A very small variation in the coupling may also be observed, but this is much more difficult to S45 measure quantitatively owing to the change in linebroadening as the temperature increases. Figure S4.3 77Se (14.1 T, 12.5 kHz) MAS NMR spectra of 1, acquired at varying temperatures. S46 Figure S4.4 77Se (14.1 T, 12.5 kHz) MAS NMR spectra of 2, acquired at varying temperatures. S47 S5. DFT calculations and electronic coupling deformation density Periodic planewave density functional theory (DFT) calculations were carried out using the CASTEP code, version 8.0.S4 J coupling calculations, performed at both the nonrelativistic (Schrödinger) and scalar-relativistic levels of theory using the ZORA method,S6 are given in Table S5.1. Using ZORA was found to make a small difference to the predicted couplings, generally resulting in an increase. However, ZORA and nonrelativistic calculations do predict a different order for the Se2-P through-bond and through-space couplings. Table S5.1 J couplings (TB = through bond, TS = through space) in 1 and 2 predicted by DFT at the non-relativistic (NR) and scalar-relativistic ZORA levels of theory. Values given are the largest coupling of that type. Type Compound 1 Compound 2 NR J / Hz ZORA J / Hz NR J / Hz ZORA J / Hz Se1-P TB –292.9 –289.7 –272.5 –271.63 Se1-P TS 57.8 66.6 56.4 64.1 Se2-P TB –316.1 –324.0 –260.0 –261.4 Se2-P TS 306.4 348.0 95.8 109.1 P-P TS 143.2 147.6 12.5 11.5 Se1-Se2 TB 13.1 13.9 26.8 29.4 23.5 18.3 19.8 Se1-Se1 TS 109.6 123.7 121.7 136.3 Se2-Se2 TS 61.6 75.3 2.7 1.7 S48 The electronic coupling deformation density (CDD) is defined by Malkina and Malkin in Ref. S15 as ACDD , B (r ) (r , A , B ) (r , A , B ) , AB (1) where (r , A , B ) is the ground state density of the following perturbed Hamiltonian ˆ H ˆ 0 A H ˆ AFC BH ˆ BFC . H (2) Here, Ĥ 0 is the unperturbed ground-state Hamiltonian and Hˆ AFC is the Fermi-contact operator acting on nucleus A. This can be easily implemented in a pseudopotential electronic-structure code as a spin-dependent modification to the D 0 matrix of the pseudopotential of the target nuclei. The value of was chosen to be 102 . S49 S6. References S1. Fuller, A. L.; Knight, F. R.; Slawin, A. M. Z., Woollins, J. D. Eur. J. Inorg. Chem. 2010, 2010, 4043. S2. Skibsted J.; Jakobsen, H. J. J. Phys. Chem. A, 1999, 103, 7958. S3. Green, T. F. G.; Yates, J. R. J. Chem. Phys. 2014, 140, 234106. S4. Clark, S. J.; Segall, M. D.; Pickard, C. J.; Hasnip, P. J.; Probert, M. J.; Refson, K. ; Payne, M. C. Z. Kristall. 2005, 220, 567. S5. Perdew, J. P.; Burke, K.; Ernzerhof, M. Phys. Rev. Lett. 1996, 77, 3865. S6. Autschbach, J.; Ziegler, T. J. Chem. Phys. 2000, 113, 936. S7. CrystalClear: Data Collection and Processing Software, Rigaku Corporation (19982014). Tokyo 196-8666, Japan. S8. Sheldrick, G. M. Acta Cryst. 2008, A64, 112. S9. International Tables for Crystallography, Vol. C (1992). Ed. A. J. C. Wilson, Kluwer Academic Publishers, Dordrecht, Netherlands, Table 6.1.1.4, pp. 572. S10. Ibers, J. A.; Hamilton, W. C. Acta Crystallogr. 1964, 17, 781. S11. Creagh, D. C.; McAuley, W. J.; "International Tables for Crystallography", Vol. C, (A. J. C. Wilson, ed.), Kluwer Academic Publishers, Boston, Table 4.2.6.8, pages 219-222 (1992). S12. Creagh, D. C.; Hubbell, J. H. "International Tables for Crystallography", Vol. C, (A. J. C. Wilson, ed.), Kluwer Academic Publishers, Boston, Table 4.2.4.3, pages 200-206 (1992). S13. CrystalStructure 4.1: Crystal Structure Analysis Package, Rigaku Corporation (20002014). Tokyo 196-8666, Japan. S14. Mason, J. Solid State Nucl. Magn. Reson. 1992, 2, 285. S16. Malkina, O. L., Malkin, V. G., Angew. Chemie Int. Ed. 2003, 42, 4335. S50