Reverse Kocheshkov reaction - Redistribution reactions between RSn(OCH2CH2NMe2)2Cl (R = Alk, Ar) and PhSnCl3: Experimental and DFT study

Article abstract of DOI:10.1016/j.jorganchem.2008.09.043

A series of organotin compounds bearing two intramolecular N → Sn coordination bonds RSn(OCH₂CH₂NMe₂)₂Cl (R = Me (4), n-Bu (5), Mes (6)) were synthesized in good yields. These compounds as well as 2 (R = Ph) react with PhSnCl₃ to give redistribution products RPhSnCl₂ and (Me₂NCH₂CH₂O)₂SnCl ₂ (3). The direction of redistribution reactions is reverse to Kocheshkov reaction. DFT calculations have shown that the driving force of the reactions is formation of intramolecular N → Sn coordination bonds in (RO)₂SnCl₂ (3), the Lewis acid stronger than RSn(OR)₂Cl (2, 4-6). The mechanism of the redistribution reaction between 2 and PhSnCl₃ consists of two steps: (1) initial exchange of OCH₂CH₂NMe₂ and Cl to give PhSn(OCH₂CH₂NMe₂)Cl₂ (7) followed by (2). Ph and OCH₂CH₂NMe₂ exchange.

Full text of DOI:10.1016/j.jorganchem.2008.09.043

Journal of Organometallic Chemistry 693 (2008) 3847–3850
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Reverse Kocheshkov reaction – Redistribution reactions between
RSn(OCH2CH2NMe2)2Cl (R = Alk, Ar) and PhSnCl3: Experimental and DFT study
Ivan A. Portnyagin a,b, Valery V. Lunin a,b, Mikhail S. Nechaev a,b,
*
a Department of Chemistry, M. V. Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow, 119991, Russian Federation
b A. V. Topchiev Institute of Petrochemical Synthesis, RAS, Leninsky Prosp., 29, Moscow 119991, Russian Federation
a r t i c l e i n f o
a b s t r a c t
Article history:
A series of organotin compounds bearing two intramolecular N ? Sn coordination bonds RSn(OCH2CH2N-
Me2)2Cl (R = Me (4), n-Bu (5), Mes (6)) were synthesized in good yields. These compounds as well as 2
(R = Ph) react with PhSnCl3 to give redistribution products RPhSnCl2 and (Me2NCH2CH2O)2SnCl2 (3).
The direction of redistribution reactions is reverse to Kocheshkov reaction. DFT calculations have shown
that the driving force of the reactions is formation of intramolecular N ? Sn coordination bonds in
(RO)2SnCl2 (3), the Lewis acid stronger than RSn(OR)2Cl (2, 4–6). The mechanism of the redistribution
reaction between 2 and PhSnCl3 consists of two steps: (1) initial exchange of OCH2CH2NMe2 and Cl to
give PhSn(OCH2CH2NMe2)Cl2 (7) followed by (2). Ph and OCH2CH2NMe2 exchange.
Received 19 August 2008
Received in revised form 23 September
2008
Accepted 24 September 2008
Available online 1 October 2008
Keywords:
Kocheshkov reaction
Substituent redistribution
Intramolecular coordination
DFT
Ó 2008 Elsevier B.V. All rights reserved.
Reaction mechanism
1. Introduction
Disproportionation of organotin compounds bearing intramolec-
ular coordination bonds was shown for (2,6-(Me2NCH2)C6H3)-
One of the most widely used methods of synthesis of organotin
compounds is the Kocheshkov reaction. Redistribution of hydro-
carbon and halogen substituents at tin yields symmetrical organo-
tin compounds at elevated temperatures (Scheme 1) [1].
Such order of redistribution of hydrocarbon substituents at tin
atom takes place in all cases when tin is tetracoordinated. The in-
crease of coordination number of tin due to interaction with elec-
trodonating species (intermolecular complexes) or donor groups in
side chains (intramolecular complexes) may lead to changes in
activity of organotin compounds in respect to redistribution [2]
or even change the direction of redistribution reactions.
SnPh2X (1). These compounds ( Scheme 2) are unstable in
chloroform solution upon standing at room temperature. In two
weeks the solution contains about 20% of disproportionation prod-
ucts [5]. Recently (Scheme 3) we have shown that interaction of
hypercoordinated tin compound 2 with phenyltrichlorostannane
leads to formation of dichlorodialkoxy derivative 3 and Ph2SnCl2 [6].
The above mentioned reactions are all reverse to Kocheshkov
reaction because hydrocarbon and acceptor radicals are collected
at different tin atoms. Since the data on this type of reactions are
fragmentary, we performed more detailed experimental and theo-
retical investigation of reactions of 2 and its analogs RSn(OCH2-
CH2NMe2)2Cl (R = Me (4), n-Bu (5), Mes (6)) with PhSnCl3. The scope
of the substituents R under study was dictated by experimental data
on relative migration ability of hydrocarbon groups in Kocheshkov
reaction: n-Bu < Me < Ph < Mes. Higher alkyl substituents, such as
n-Bu, are the most reluctant to migrate, while bulky aryl groups
(Mes) are the most active in redistribution reactions [1,7].
It was shown with the use of multinuclear NMR spectroscopy
that phenyltrihalogenestannanes PhSnHal3 (Hal = Cl, Br) subjected
to fluoride ions or tributylphosphane disproportionate in solution
with the formation of Ph2SnHal2LnÀ and SnHal4LnÀ (L = F, m =
m
m
n = 1,2; L = PBu3, m = 1, 2; n = 0) [3]. Later, the analogous dispropor-
tionation of monoorganotrichlorostannanes RSnCl3 (R = Me, n-Bu,
Ph) in presence of cis-1,2-bis(diphenylphosphino)-ethylene
cis-Ph2PCH@CHPPh2 was observed in solution [4]. It was found that
migration of phenyl group is faster than of aliphatic (Me and n-Bu)
groups.
2. Results and discussion
2.1. Synthesis
* Corresponding author. Address: Department of Chemistry, M. V. Lomonosov
Moscow State University, Leninskie Gory 1/3, Moscow, 119991, Russian Federation.
Tel./fax: +7 495 9392677.
Compounds 4–6 were obtained in good yields by the reaction of
monoorganotin trichlorides with 2 equiv. of b-(N,N,-dimethyl)-
aminoethoxytriethylstannane (Scheme 4).
E-mail address: nechaev@nmr.chem.msu.ru (M.S. Nechaev).
0022-328X/$ - see front matter Ó 2008 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2008.09.043

3848
I.A. Portnyagin et al. / Journal of Organometallic Chemistry 693 (2008) 3847–3850
13C NMR. According to NMR data, the main products of the reac-
200 oC
R4Sn
+
SnCl4
R3SnCl
+
RSnCl3
R2SnCl2
tions are 3 [6] and RPhSnCl2 (R = Ph [8], Me [9], Bu [10], Mes
[11]). The yields are 76–89%. Small amounts of starting materials
were also found in solution. Thus it was found that in presence
of two dimethylaminoethoxy groups both alkyl and aryl radicals
undergo redistribution under mild conditions.
R = Alk, Ar
Scheme 1.
NMe2
NMe2
NMe2
SnPh3
NMe2
2.2. DFT thermodynamics
r.t.
14 days
SnPh2X
SnPhX2 +
NMe2
To elucidate the reasons why the reverse Kocheshkov reactions
take place we performed DFT study of the reactions of 2, 4–6 with
PhSnCl3. In all cases the exchange of R and Cl groups is energeti-
NMe2
1a X = Cl
cally favorable. Calculated Gibbs free energies
D
GÀ1 lie in a range
b X = Et2NCS2
from À7.4 to À22.6 kcal/mol (Scheme 5, Table 1). Contrary, if all
N ? Sn coordination bonds are broken in RSn(OCH2CH2NMe2)2Cl
(2, 4–6) and (Me2NCH2CH2O)2SnCl2 (3), calculated Gibbs free ener-
Scheme 2.
gies
D
GÀ2 are positive, 1.4–8.1 kcal/mol.
It was found that the breaking of N ? Sn coordination bonds in
RSn(OCH2CH2NMe2)2Cl, except mesityl derivative 6, is unfavorable.
But the energy of breaking of N ? Sn bonds in 3 is higher,
22.1 kcal/mol. Thus the calculations clearly show that the driving
force of R and Cl exchange is the formation of intramolecular
N ? Sn coordination bonds in (RO)2SnCl2 (3), the Lewis acid stron-
ger than RSn(OR)2Cl (2, 4–6). Indeed, according to thermodynamic
cycle in Scheme 5, the energy difference between two reactions
equals the difference between energies of breaking N ? Sn bonds:
NMe2
NMe2
Cl
Cl
O
O
Ph
Cl
O
O
+ PhSnCl3
+ Ph2SnCl2
Sn
Sn
NMe2
2
NMe2
3
Scheme 3.
DDG =
D
G-1 À
D
G-2 = À22.1 À
DG-C.
2.3. DFT mechanism
NMe2
THF
O
O
R
Sn
2 Et3SnOCH2CH2NMe2 + RSnCl3
+2Et3SnCl
The mechanism of substituent redistribution reaction was stud-
ied for interaction of PhSn(OCH2CH2NMe2)2Cl (2) and PhSnCl3
(Fig. 1 and Table S1). It was found that direct exchange of Ph and
Cl groups is associated with high lying transition state TS-B
Cl
reflux, 30 min
NMe2
4, R = Me; 5, R = n-Bu; 6, R = Mes
(DG(TS-B) = 40.0 kcal/mol). In this transition state one of N ? Sn
Scheme 4.
coordination bond in 2 is broken. Ph group from 2 and Cl atom
from PhSnCl3 are bridging between two tin atoms (Fig. S1).
The alternative way consists of two steps: (1) initial exchange of
OCH2CH2NMe2 group from 2 and Cl atom from PhSnCl3 with the
formation two molecules of PhSn(OCH2CH2NMe2)Cl2 (7); (2) dis-
proportionation of 7 via Ph and OCH2CH2NMe2 exchange. The ini-
Compounds 2, 4–6 were reacted with PhSnCl3. Equimolar
amounts of RSn(OCH2CH2NMe2)2Cl and PhSnCl3 were mixed in
THF solution and refluxed for 30 min. After solvent evaporation
in vacuo solid residues were collected and analyzed using 1H and
tial step is slightly energetically favorable,
D
G(7) = À1.9 kcal/mol.
N
N
O
O
Cl
R
O
O
Cl
+
RPhSnCl2
ΔG-1
+
PhSnCl3
Sn
N
Sn
N
Cl
22.1 kcal/mol
ΔG-C
ΔΔG
N
N
N
N
O
O
Cl
O
O
Cl
ΔG-2
+
RPhSnCl2
+
PhSnCl3
Sn
Sn
R
Cl
Scheme 5.

I.A. Portnyagin et al. / Journal of Organometallic Chemistry 693 (2008) 3847–3850
3849
Table 1
compounds bearing different aryl groups ArAr’SnX2, which were
not readily accessible previously.
Free energies of the reactions in Scheme 5 (kcal/mol)
R
D
G-C
D
G-1
D
G-2
DDG
Me
Bu
Ph
8.0
7.6
12.3
À9.6
À9.4
À10.9
À7.4
3.7
2.5
1.4
8.1
À13.1
À13.5
À8.7
4. Experimental
4.1. General procedures
Mes
À22.6
À30.7
All manipulations were carried out under purified argon using
standard Schlenk and high-vacuum-line techniques. The commer-
cially available solvents were purified by conventional methods
and distilled immediately prior to use. PhSnCl3 [7], MeSnCl3 [7],
BuSnCl3 [7], MesSnCl3 [11] and Et3Sn(OCH2CH2NMe2) [12] were
synthesized as described earlier. NMR spectra were recorded on
an AVANCE-400 NMR spectrometer at 400.13 MHz (1H) and
100.62 MHz (13C) in THF-d8. Chemical shifts are indirectly refer-
enced to tetramethylsilane (SiMe4) via the solvent signals. The
accuracy of chemical shift measurements is 0.01 ppm (1H) and
0.05 ppm (13C). Elemental analyses were performed on a Carlo
Erba EA1108 CHNS-O elemental analyzer.
The potential energy surface along the reaction pathway is very
flat. Thus we were unable to localize the corresponding transition
state. In other words, 7 is formed from 2 and PhSnCl3 with virtually
no barrier.
The next step, Ph and OCH2CH2NMe2 exchange between two
molecules of 7, goes via transition state TS-A
(DG(TS-A) =
24.8 kcal/mol; Fig. S1). In TS-A both tin atoms are hexacoordinated
and each has N ? Sn coordination bond. There are a number of
coordination isomers of TS-A possible. We performed optimization
of more than 20 possible structures. The one presented is the
lowest in energy.
Transition state TS-A is 15.2 kcal/mol lower in energy than TS-B.
Thus we propose that the ligand exchange reaction goes solely via
two-step mechanism with initial formation of 7 and further ex-
change of Ph and OCH2CH2NMe2 groups. Moreover the calculated
barrier of the reaction (24.8 kcal/mol) is consistent with the exper-
imental result: the reaction proceeds to completion in 30 min. in
refluxing THF (ꢀ66 °C). We also suppose that exchange reactions
between 4 and 6 and PhSnCl3 proceed via the same mechanism.
4.2. MeSn(OCH2CH2NMe2)2Cl (4)
A solution of Et3Sn(OCH2CH2NMe2) (6.65 g, 23.33 mmol) in Et2O
(20 mL) was added dropwise to a stirred solution of MeSnCl3
(2.80 g, 11.66 mmol) in Et2O (30 mL). After 2 h of stirring an abun-
dant white precipitate has formed. This was filtered, washed with
hexane, and dried in vacuo. The yield was 2.49 g (61.8%). M.p. 139–
140 °C. 1H NMR (400.1 MHz, CD2Cl2, ppm): d = 0.71 (br, s,
2JSnH = 99.0/103.6 Hz, 3 H, MeSn), 2.57 (br, s, 12 H, Me2N), 2.70
(br, 4H, CH2N), 3. 78 (br, m, 4 H, CH2O). 13C NMR (100.61 MHz,
CD2Cl2, ppm): d = 10.80 (MeSn), 46.27 (Me2N), 58.74 (br, CH2N),
63.61 (br, CH2O). Anal. calc. for C9H23ClN2O2Sn (345.45): C,
31.29; H, 6.71; N, 8.11. Found: C, 31.05; H, 6.80; N, 7.97%.
3. Conclusion
We have shown that the presence of intramolecularly coordi-
nating groups OCH2CH2NMe2 at tin atom dramatically increase
the mobility of substituents. Both higher alkyl as well as aryl
groups in RSn(OCH2CH2NMe2)Cl2 readily redistribute in refluxing
THF, while the exchange reaction between Ph3SnCl and PhSnCl3
yielding Ph2SnCl2 demands heating up to 200 °C.
4.3. BuSn(OCH2CH2NMe2)2Cl (5)
A solution of Et3Sn(OCH2CH2NMe2) (3.42 g, 11.63 mmol) in THF
(25 mL) was added dropwise to a stirred solution of BuSnCl3
(1.64 g, 5.82 mmol) in THF (30 mL). The mixture was stirred for
2 h and stored overnight. The solvent was removed in vacuo to
about one sixth of the initial volume, then 50 mL of hexane was
added to give a white crystalline precipitate. This was filtered un-
der argon, washed with hexane, and dried in vacuo. The yield was
1.53 g (68%). 1H NMR (400.1 MHz, CDCl3, ppm): d = 0.75–0.79 (m,
3H, SnCH2CH2CH2CH3), 1.17–1.25 (m, 2H, SnCH2CH2CH2CH3),
1.41–1.55 (m, 4H, SnCH2CH2CH2CH3), 2.58 (s, 12H, Me2N), 2.64–
2.69 (br, m, 4H, CH2N), 3.36–3.81 (br, m, JSnH = 66.3 Hz, 4H,
CH2O). 13C NMR (100.61 MHz, CDCl3, ppm): d = 13.35
(SnCH2CH2CH2CH3), 26.16 (SnCH2CH2CH2CH3), 29.43 (JSnC = 48.3
Hz), 30.53 (SnCH2CH2CH2CH3), 46.01 (Me2N), 58.32 (CH2N), 63.12
(CH2O). Anal. Calc. for C12H29ClN2O2Sn (387.51): C, 37.19; H,
7.54; N, 7.23. Found: C, 37.05; H, 7.76; N, 7.14%.
The presence of donor groups lead to desymmetrization of tin
compounds. Tin species bearing coordinating groups collect elec-
tronegative substituents and release electropositive ones. This is
due to more effective coordination of donor groups in SnX4, the
Lewis acids stronger than RSnX3 or R2SnX2.
We suppose that the activation of exchange reactions in mild
conditions with the use of intramolecularly coordinating groups
may lead to development of new methods of synthesis of organotin
TS-B
40.0
TS-A
24.8
4.4. MesSn(OCH2CH2NMe2)2Cl (6)
NMe2
A solution of MesSnCl3 (2.10 g, 6.10 mmol) in THF (30 mL) was
added dropwise to a stirred solution of Et3Sn(OCH2CH2NMe2)
(3.95 g, 13.43 mmol) in THF (25 mL). The mixture was stirred for
2 h and stored overnight. The solvent was removed in vacuo to
about one sixth of the initial volume, and then 50 mL of hexane
was added to give a white crystalline precipitate. This was filtered
under argon, washed with hexane, and dried in vacuo. The yield
was 1.78 g (65%). 1H NMR (400.1 MHz, CDCl3, ppm): 2.18 (s,
JSnH = 8.8 Hz, 3H, p-CH3), 2.22 (br, s, 12H, Me2N), 2.47 (s,
JSnH = 5.9 Hz, 6H, o-CH3), 2.66 (br, m, 4H, CH2N), 4.00 (br, t,
O
O
Ph
Cl
NMe2
Cl
Cl
NMe2
+ Ph2SnCl2
Sn
2
0.0
-1.9
NMe2
O
O
3
Sn
NMe2
+ PhSnCl3
-7.4
Cl
Cl
2
O Sn
Ph
7
Fig. 1. Potential energy surface of the reaction of 2 with PhSnCl3 (Gibbs free
energies in kcal/mol).

3850
I.A. Portnyagin et al. / Journal of Organometallic Chemistry 693 (2008) 3847–3850
JHH = 5.4 Hz, 4 H, CH2O), 6.85 (s, JSnH = 226.3 Hz, 2H, aromatic pro-
tons in Mes). 13C NMR (100.61 MHz, CDCl3, ppm):d = 20.79 (br, p-
CH3), 24.38 (JSnC = 37.7 Hz, o-CH3), 45.09 (br, Me2N), 60.39 (br,
CH2N), 61.55 (CH2O), 126.68 (Cm), 132.60 (Ci), 136.70 (Cp), 141.78
(Co). Anal. Calc. for C17H31ClN2O2Sn (449.58): C, 45.42; H, 6.95; N,
6.23. Found: C, 45.35; H, 7.06; N, 6.12%.
dient functional [13]. The triple zeta valence basis set including
polarization functions TZ2P (3,1,1/3,1,1/1,1) for Sn, Cl, C, N, O
atoms and (3,1,1/1) for H atom was used [14]. Innermost electrons
for Sn, Cl, C, N, O atoms were treated using the ECP-SBKJC relativ-
istic effective core potentials [15].
Total energies E, zero point vibration energies ZPE, E0 = E + ZPE,
H0, G0 were calculated for all stationary points corresponding to
reactants, transition states, intermediates, and products. Vibra-
tional frequencies were used to characterize stationary points
either as minima (number of imaginary frequencies i = 0) or transi-
tion states (i = 1). For reliable identification of transition states, the
IRC procedure, following the reaction path from transition state to
products/reactants, was used [16]. All calculations were performed
using the PRIRODA program [17].
4.5. General procedure for the reaction of RSn(OCH2CH2NMe2)2Cl with
PhSnCl3 (NMR experiment)
A solution of RSn(OCH2CH2NMe2)2Cl (0.6 mmol) and PhSnCl3
(0.6 mmol) in THF (10 mL) was mixed. After 30 min in refluxing
THF the solvent was removed in vacuo and CD2Cl2 (1 mL) was
introduced. The solution was transferred to a 5-mm NMR tube
and sealed.
Acknowledgements
4.6. Reaction with PhSn(OCH2CH2NMe2)2Cl (2)
This work was supported by the Russian Foundation for Basic
Research (04-03-32662-a). The authors are thankful to Prof. Yu.
A. Ustynyuk for the critical discussions during the preparation of
the manuscript.
According to the 1H and 13C NMR spectra, the solution con-
tained (Me2NCH2CH2O)2SnCl2 (3) and Ph2SnCl2 [8] (89%) as the
main products. Ph2SnCl2: 1H NMR (400.1 MHz, CD2Cl2, ppm):
d = 7.60–7.67 (m, 3 H, Ph), 7.81–7.84 (m, 2 H, Ph). 13C NMR
(100.61 MHz, CDCl3, ppm): d = 130.32 (3JSnC = 85.1 Hz, Cm), 132.48
(4JSnC = 18.4 Hz, Cp), 135.57 (2JSnC = 63.6 Hz, Co), 137.50 (Ci).
Appendix A. Supplementary material
Calculated structures, energetic parameters. Supplementary
data associated with this article can be found, in the online version,
at doi:10.1016/j.jorganchem.2008.09.043.
4.7. Reaction with MeSn(OCH2CH2NMe2)2Cl (4)
According to the 1H and 13C NMR spectra, the solution con-
tained (Me2NCH2CH2O)2SnCl2 (3) and MePhSnCl2 [9] (85%) as the
main products. MePhSnCl2: 1H NMR (400.1 MHz, CD2Cl2, ppm):
d = 1.35 (s, CH3), 7.52–7.68 (m, 5 H, Ph). 13C NMR (100.61 MHz,
CDCl3, ppm): d = 4.80 (CH3), 129.6 (Cm), 131.7 (Cp), 134.6 (Co),
138.8 (Ci).
References
[1] A.G. Davies, Organotin Chemistry, 2nd ed., Wiley-VCH, Weinheim, 2004.
[2] (a) S.H.L. Thoonen, H. van Hoek, E. de Wolf, M. Lutz, A.L. Spek, B.-J. Deelman, G.
van Koten, J. Organomet. Chem. 691 (2006) 1544;
(b) J. Beckmann, D. Dakternieks, A. Duthie, E.R.T. Tiekink, Dalton Trans. (2003)
755;
(c) P. Novák, Z. Padelková, L. Kolárová, I. Císarová, A. Ruzicka, J. Holecek, Appl.
Organomet. Chem. 19 (2005) 1101;;
4.8. Reaction with BuSn(OCH2CH2NMe2)2Cl (5)
According to the 1H and 13C NMR spectra, the solution con-
tained (Me2NCH2CH2O)2SnCl2 (3) and BuPhSnCl2 [10] (76%) as
the main products. BuPhSnCl2: 1H NMR (400.1 MHz, CD2Cl2,
ppm): d = 0.85–0.91 (m, 3H, SnCH2CH2CH2CH3), 1.30–1.36 (m, 2H,
SnCH2CH2CH2CH3), 1.45–1.62 (m, 4H, SnCH2CH2CH2CH3), 7.26–
7.35 (m, 3 H, Ph), 7.60–7.67 (m, 2 H, Ph). 13C NMR (100.61 MHz,
CDCl3, ppm): d = 13.85 (SnCH2CH2CH2CH3), 25.24, 25.53
(SnCH2CH2CH2CH3), 27.94 (SnCH2CH2CH2CH3), 127.27 (Cm),
127.86 (4JSnC = 21.5 Hz, Cp), 134.89 (2JSnC = 66 Hz, Co), 136.22 (Ci).
(d) P. Novák, I. Císarová, L. Kolárová, A. Ruzicka, J. Holecek, J. Organomet.
Chem. 692 (2007) 4287;
(e) Z. Padelková, T. Weidlich, L. Kolárová, A. Eisner, I. Císarová, T.A. Zevaco, A.
Ruzicka, J. Organomet. Chem. 692 (2007) 5633.
[3] (a) R. Colton, D. Dakternieks, Inorg. Chim. Acta 143 (1988) 151;;
(b) D. Dakternieks, H. Zhu, Organometallics 11 (1992) 3820;;
(c) C.H. Yoder, L.A. Margolis, J.M. Horne, J. Organomet. Chem. 633 (2001) 33.
[4] M.M. Ebrahim, H. Stoeckli-Evans, K. Panchanatheswaran, J. Organomet. Chem.
692 (2007) 2168.
ˇ ˇ
ˇ
ˇ
[5] (a) A. Ru˚ zicka, R. Jambor, J. Brus, I. Císarová, J. Holecek, Inorg. Chim. Acta 323
(2001) 163;
ˇ
ˇ
ˇ
(b) B. Kašná, R. Jambor, L. Dostál, L. Kolárová, I. Císarová, J. Holecek,
Organometallics 25 (2006) 148.
[6] I.A. Portnyagin, M.S. Nechaev, V.N. Khrustalev, N.N. Zemlyansky, I.V. Borisova,
M.Y. Antipin, Y.A. Ustynyuk, V.V. Lunin, Eur. J. Inorg. Chem. (2006) 4271–4277.
[7] K.A. Kocheshkov, N.N. Zemlyansky, N.I. Sheverdina, E.M. Panov, Germanium,
Tin, Lead, Nauka, Moscow, 1968.
[8] B. Mathiasch, Org. Magn. Reson. 17 (1981) 296.
[9] R.N. Kapoor, P. Apodaca, M. Montes, F.D. Gomez, K.H. Pannell, Appl.
Organomet. Chem. 19 (2005) 518.
[10] A. Tupciauskas, N.M. Sergeev, Y.A. Ustynyuk, Org. Magn. Reson. 3 (1971) 655.
[11] F. Jakle, I. Manners, Organometallics 18 (1999) 2628.
[12] N.N. Zemlyansky, I.V. Borisova, M.G. Kuznetsova, V.N. Khrustalev, Y.A.
Ustynyuk, M.S. Nechaev, V.V. Lunin, J. Barrau, G. Rima, Organometallics 22
(2003) 1675.
[13] (a) J.P. Perdew, K. Burke, M. Ernzerhof, Phys. Rev. Lett. 77 (1996) 3865;
(b) M. Ernzerhof, G.E. Scuseria, J. Chem. Phys. 110 (1999) 5029;
(c) C. Adamo, V. Barone, J. Chem. Phys. 110 (1999) 6158.
[14] D.N. Laikov, Ph.D. Thesis, Moscow State University, 2000.
[15] (a) W.J. Stevens, H. Basch, M. Krauss, J. Chem. Phys. (1984) 6026;
(b) W.J. Stevens, M. Krauss, H. Basch, P.G. Jasien, Can. J. Chem. (1992) 612;
(c) T.R. Cundari, W.J. Stevens, J. Chem. Phys. 98 (1993) 5555.
[16] K. Fukui, Acc. Chem. Res. 12 (1981) 363.
4.9. Reaction with MesSn(OCH2CH2NMe2)2Cl (6)
According to the 1H and 13C NMR spectra, the solution con-
tained (Me2NCH2CH2O)2SnCl2 (3) and MesPhSnCl2 [11] (80%) as
the main products. MesPhSnCl2: 1H NMR (400.1 MHz, CD2Cl2,
ppm): d = 2.29 (c, 3H, p-Me), 2.52 (s, JSnH = 10 Hz, 6H, o-Me), 6.95
(c, JSnH = 28 Hz, 2H, m-H-Mes), 7.51 (m, 3H, m-Ph, p-Ph), 7.76 (m,
2 H, o-Ph). 13C NMR (100.61 MHz, CDCl3, ppm): d = 21.1 (JSnC = 9
Hz, p-Me), 25.3 (JSnC = 48 Hz, o-Me), 129.4 (JSnC = 79/82 Hz, m-
Mes), 129.6 (JSnC = 81/84 Hz, m-Ph), 131.1 (JSnC = 17 Hz, p-Ph),
134.3 (JSnC = 62/64 Hz, o-Ph), 135.2 (i-Ph), 142.1 (JSnC = 15 Hz, p-
Mes), 142.6 (i-Mes), 144.2 (JSnC = 60/62 Hz, o-Mes).
5. Computational method
All calculations were done at the DFT level of theory. The geom-
etry optimizations were carried out using the PBE generalized gra-
[17] (a) D.N. Laikov, Chem. Phys. Lett. 281 (1997) 151;;
(b) D.N. Laikov, Y.A. Ustynyuk, Russ. Chem. Bull. Int. Ed. 54 (2005) 820.