Supporting Information
Victoria A. Piunova, Hans Horn, Gavin O. Jones, Julia E. Rice, Robert D. Miller
IBM Almaden Research Center, 650 Harry Rd. San Jose, CA 95120
Contents
A. Computational Details
a. Protocol
b. Results
B. Experimental Details
C. Cartesian Coordinates and Energies for Optimized Stationary Points of Different ROP
Initiators (Methanol, Neopentyl alcohol (NPA) and Trichloroethanol (TCE) and their Adducts
with TBD catalyst) and δ-VL.
D. Cartesian Coordinates and Energies for Optimized Stationary Points of ROP Reactions
1
A. Computational Details
a. Protocol
All calculations were performed with GAMESS-US1,2 using M113 density functional theory and
the lowest energy pathways reported. Geometry optimizations were performed with the 631+G(d) basis set4–6,7 followed by single-point energy calculations with the aug-cc-pVTZ basis
set.8,9 Reaction conditions were represented by a continuum dielectric representation of
toluene (ε=2.37) at room temperature with the SMD (IEF-cPCM) method.10–12 Only vibrational
free energy corrections to the electronic energy at the experimental temperature (298 K) were
used in accordance with recommendations for molecules optimized in an implicit solvent. 13
Normal modes of all structures were examined to verify that their ground states possessed no
imaginary frequencies and that transition structures possessed only one imaginary frequency
corresponding to bond formation or bond breaking. For each transition state found, intrinsic
reaction coordinate (IRC)14 calculations were performed to ascertain that reactant/product
complexes and intermediates were connected via transition states. Partial charges were
determined from a fit to the electrostatic potential15 calculated on four Connolly surfaces at 1.4,
1.6, 1.8 and 2.0 times the van der Waals radii with the M11(SMD)/aug-cc-pVTZ//6-31+G(d)
method. These charges were constrained to reproduce the dipole moment of the molecule).
b. Results
2
a)
b)
i
ii
iii
iv
v
vi
Figure S1. Structures of binary adducts between various ROP initiators and TBD
We find that both methanol and NPA have comparable partial charges at the hydroxyl oxygen (Error!
Reference source not found.) as well as comparable TBD-adduct binding energies and structural
properties (1a), which are very different from the ones for TCE (Figure S1b). In particular, TCE shows
increased OH acidity (indicated by the presence of a stable ion pair with TBD (Figure S1b.iii), ≈2
kcal/mol higher in free energy than the lowest covalent adduct, Figure b.i) as well as increased CH
acidity (Figure S1b.iv), which could, after traversing a high energy barrier (Figure S1b.v, ~ 26 kcal/mol
above the lowest covalent adduct, Figure S1b.i) eventually yield an extremely stable elimination
product (Figure S1b.vi). However, this barrier is significantly higher than that for the OROP reaction
with δ-VL and was thus not discussed in the main text.
Table S1. Computed barrier heights (free energies in kcal/mol) for the TBD-catalyzed OROP of δ-VL
with methanol, TCE and NPA in toluene as solvent (ε = 2.37)
Reaction
TS1 [kcal/mol]
TS2
TS3
δ-VL-MeOH-TBD
11.0
8.0
11.1
δ-VL-NPA-TBDa
10.9
8.0
11.1
δ-VL-TCE-TBD
9.9
11.9
15.8
3
Figure S2. Schematic representation of the bond-breaking region in TS3 (an ion pair) for δ-VL and
various initiators; charges shown are ESP partial charges 11,12
B. Experimental Details
4
PVL
PVL-tBuMA
16
19
22
25
Elution Volume, ml
Figure S3. GPC traces (RI detector) of PVL with trichloromethyl end-functionality (red) and extended
bcp produced by ATRP (blue)
Figure S4. 1H NMR spectra of PVL-macroinitiator (A) and extended bcp PVL-tBuMA (B).
5
C. Cartesian Coordinates and Energies for Optimized Stationary Points of Different ROP
Initiators (Methanol, Neopentyl alcohol (NPA) and Trichloroethanol (TCE) and their Adducts
with TBD catalyst) and δ-VL. Coordinates available upon request.
References
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(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
(15)
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