Kirill P. Birin, Yulia G. Gorbunova, Aslan Yu. Tsivadze
Lviv, 2010
Heteroleptic lanthanide (porphyrinato)(phthalocyaninates) as promising starting
materials for development of molecular information storage devices.
Multi-step complicated synthesis…
4 stable redox states!
J. Org. Chem. 2000, 65, 7379-7390
J. Mater. Chem., 2002, 12, 808–828
Inorg. Chem. 2006, 45, 5479-5492, etc.
6 stable redox
states!
K.P. Birin et al. J. Porphyrins Phthalocyanines, 2009, 13, № 2, 283-290.
Stage 1
Stage 2
K.P. Birin et al. J. Porphyrins Phthalocyanines, 2009, 13, № 2, 283-290.
Stage 3
Single isomer of triple-decker complex!
K.P. Birin et al. J. Porphyrins Phthalocyanines, 2009, 13, № 2, 283-290.
Extended Huckel calculation of HOMO of MM+ optimized molecule of doubledecker complex for explanation of selectivity
(Pc)Y(An4P)
((MeO)8Pc)Y(An4P)
61% of HOMO is localized at Pc-ligand
66% of HOMO is localized at Pc-ligand
K.P. Birin et al. J. Porphyrins Phthalocyanines, 2009, 13, № 2, 283-290.
Ln(acac)3
R=
corresp.
porphyrin
H
TPPH2
OMe
An4PH2
Br
Br4TPPH2
R’=
corresp.
phthalocyanine
H
PcH2
OMe
(MeO)8PcH2
OBu
(BuO)8PcH2
fused 15-crown-5
(15C5)4PcH2
Ln=La-Eu
Porphyrin
meso-substituents
Phthalocyanine
substituents
H
OMe
OBu
H
(15C5)
Nd
Br
Nd
OMe
Nd
Nd
Nd
La, Nd, Eu
La-Eu
Only double-decker complexes are
obtained.
Triple-decker complexes are
obtained for the whole La-Eu series
Crucial influence of electron-donating
substituents in Pc-macroycle
Synthesis is independent from
porphyrin meso-substituents
All synthesized complexes are characterized with:
MALDI-TOF mass-spectrometry
UV-Vis spectroscopy
1H-
and 13C-NMR
NMR of [An4P]La[(15C5)4Pc]La[An4P]
K.P. Birin et al. Magn. Reson. Chem., 2010, 48, 505-515.
NMR of [An4P]La[(15C5)4Pc]La[An4P] and [Br4TPP]La[(15C5)4Pc]La[Br4TPP]
X = Br
X = OMe
NMR of series of [An4P]Ln[(15C5)4Pc]Ln[An4P] complexes
Lanthanide-induced paramagnetic shifts complicate the spectra
K.P. Birin et al. Magn. Reson. Chem., 2010, 48, 505-515.
LIS results from magnetic interaction between felectrons of lanthanide and observed nuclei
LIS: Dd = dpara – ddia
In turn, two mechanisms are possible for
interaction:
through-bond, or contact (Ddcon)
through-space, or dipolar (Dddip)
LIS is a function of molecular structure
Finally, LIS is considered as
Dd = Ddcon + Dddip
C. Piguet, C.F.G.C. Geraldes. Handbook on the physics of
rare earths, vol. 33, ch. 215, 353-463.
Contact contribution is presumed to be negligible
if lanthanide and observed nuclei is separated
by 5 or more s-bonds
Dipolar contribution is bound to geometry of the
molecule and decreases as 1/R3, where R –
distance between lanthanide and nuclei
Contact and dipolar terms for each lanthanide ion
are tabulated values, designated as <Sz>Ln and
DLn, respectively
Dd = Fi<Sz>Ln + A20GiDLn
3Cos   1
2
Gi 
R
3
If more than one lanthanide
center is present, resulting
LIS is a combination of
contributions.
In order to explain the particular behavior of each peak in spectra upon LIS, MM+
calculation of structure of complex was performed.
Averaged coordinates of protons are plotted with Gi-diagram
12
10
8
mo
6
oo
mo
oo
OMe
OMe
Pyrr
4
mi
R, A
2
Pyrr
oi
mi
oi
Ln1
0
oi
mi
-2
oi
Pyrr
-4
mi
Ln2
Pyrr
OMe
OMe
mo
-6
oo
oo
mo
-8
-10
-12
-12 -10
-8
-6
-4
-2
0
2
4
6
8
10
12
R, A
K.P. Birin et al. Magn. Reson. Chem., 2010, 48, 505-515.
Two opposite aims:
Explanation of features of NMR spectra from
structural parameters of molecules
Determination of structural parameters of molecules
in solution from features of NMR spectra
Utilization of dipolar contribution of LIS as
structural probe
Separation of contact and dipolar
contributions is unavoidable
Separation of contributions of LIS is possible
through statistical analysis of series of NMR
datasets for isostructural complexes
Model compounds [An4P]Ln[(15C5)4Pc]Ln[An4P]
Ln=La-Eu, 5 paramagnetic lanthanides and La
complex as diamagnetic reference
First step is verification of isostructurality of the
series of compounds.
Datasets for all types of protons in the molecule
are plotted in DdHi/<Sz>Ln vs DdHj/<Sz>Ln
coordinates. Linearization equation is
D d i , Ln
Sz
Ln
  F i  F j R ij   R ij
Dd
j , Ln
Sz
Ln
Fine linearization of datasets testifies
the isostructurality of the whole
series of compounds.
K.P. Birin et al. Magn. Reson. Chem., 2010, 48, 505-515.
Next step is separation of contact and dipolar
contributions
Datasets are plotted as DdHi/<Sz>Ln and
their linearization is performed according
to equation
D d i , Ln
Sz
Ln
 Fi  A G i
0
2
D Ln
Sz
Ln
Here the slope of gives the value of dipolar
term and intercept corresponds to contact
term.
Finally, tables of contact and dipolar
contributions of LIS for each proton of
each complex are obtained.
K.P. Birin et al. Magn. Reson. Chem., 2010, 48, 505-515.
Starting point for structure determination – coordinates of protons of (15C5)4Pcligand in symmetrical environment
[Pc]Sm[(15C5)4Pc]Sm[Pc]
A. G. Martynov et al. Eur. J. Inorg. Chem., 2007, 30, 4800.
K.P. Birin et al. Magn. Reson. Chem., 2010, 48, 505-515.
Determination of lanthanides positions
Ln…Ln = 3.886A
Ln

AF 
EXP
 G iTEOR
Gi
 TEOR  EXP
G
Gk
 k

K.P. Birin et al. Magn. Reson. Chem., 2010, 48, 505-515.
 G iEXP
 EXP
G
 k




2




2
Determination of positions of porphyrin decks
Coordinates of protons of
porphyrin deck are obtained
from MM+ optimization of
molecular geometry
K.P. Birin et al. Magn. Reson. Chem., 2010, 48, 505-515.
Pc...Por = 3.395 Å
Ln
Ln
Finally, protons of the molecule are located and may act as binding points for the
whole structure
The described procedure allows
determination of structural parameters of
complexes in solutions
Ln...Ln = 3.886 Å
Pc...Por = 3.395 Å
Ln...N4(Pc) = 1.943 Å
Ln...N4(Por) = 1.453 Å
ms-An skew = 41o
Further refinement of structure needs application of LIS data for carbon atoms of
molecular skeleton.
13C{H}
spectra of triple-decker complexes [An4P]Ln[(15C5)4Pc]Ln[An4P]
Ln = La
Ln = Nd
Assignment of 13C-NMR spectra is possible in several ways:
INEPT and DEPT techniques to determine signals of C, CH,
CH2 and CH3 fragments
Heteronuclear 13C-1H COSY to correlate directly bound 1H and
13C atoms
Pulse-field gradient techniques:
HMQC – to correlate directly bound 1H and 13C atoms
HMBC – to correlate 1H and quaternary 13C atoms
HMQC 13C-1H correlation of triple-decker complexes [An4P]Ln[(15C5)4Pc]Ln[An4P]
Carbon dimension
Ln = La
Proton dimension
Ln = Nd
Application of 13C data for structure determination allows to operate with most
atoms of molecular core, except quaternary carbons.
The developed methodology for structural analysis of heteroleptic
porphyrinato-phthalocyaninates in current state:
Allows precise determination of relative positions of atoms of molecule
Involves all protons of the molecule and most carbon atoms of molecular core
Allows to determine structural parameters of molecule in solution
This work was supported by
Russian Foundation for Basic Research (grant#08-0300835) and programs of Russian Academy of Sciences.
Thank you for your attention!