Facile access of stable divalent tin compounds with terminal methyl, amide, fluoride, and iodide substituents

Article abstract of DOI:10.1021/ic8015639

The stable β-diketiminate tin(ll) complexes LSnX [L = HC(CMeNAr) ₂, Ar = 2,6-/Pr₂C₆H₃] with terminal methyl, amide, fluoride, and iodide (X = Me, N(SiMe₃)₂, F, I) are described. LSnMe (2) i

Full text of DOI:10.1021/ic8015639

Inorg. Chem. 2009, 48, 193-197
Facile Access of Stable Divalent Tin Compounds with Terminal Methyl,
Amide, Fluoride, and Iodide Substituents
Anukul Jana, Herbert W. Roesky,* Carola Schulzke, Alexander Do¨ring, Tobias Beck, Aritra Pal,
and Regine Herbst-Irmer
Institut fu¨r Anorganische Chemie, UniVersita¨t Go¨ttingen, Tammannstrasse 4,
37077 Go¨ttingen, Germany
Received August 15, 2008
The stable ꢀ-diketiminate tin(II) complexes LSnX [L ) HC(CMeNAr)2, Ar ) 2,6-iPr2C6H3] with terminal methyl,
amide, fluoride, and iodide (X ) Me, N(SiMe3)2, F, I) are described. LSnMe (2) is synthesized by salt metathesis
reaction of LSnCl (1) with MeLi and can be isolated in the form of yellow crystals in 88% yield. Compound
LSnN(SiMe3)2 (3) was obtained by treatment of LH with 2 equiv of KN(SiMe3)2 in THF followed by adding 1 equiv
of SnCl2. Reaction of 2 and 3 respectively with Me3SnF in toluene provided the tin(II)fluoride LSnF (4) with a
terminal fluorine as colorless crystals in 85% yield. 4 is highly soluble in common organic solvents. The reaction
of LLi(OEt2) with 1 equiv of SnI2 in diethyl ether afforded the LSnI (5). Compounds 2, 3, 4, and 5 were characterized
by microanalysis, multinuclear NMR spectroscopy, and X-ray structural analysis. Single crystal X-ray structural
analyses indicate that all the compounds (2, 3, 4, 5) are monomeric and the tin center resides in a trigonal-
pyramidal environment.
Introduction
reaction of 2,6-Trip2H3C6Sn(II)Cl (Trip ) C6H2-2,4,6-iPr3)
with MeLi. They obtained 2,6-Trip2H3C6Sn(II)-Sn(IV)(Me)2-
C6H3-2,6-Trip2 instead of 2,6-Trip2H3C6Sn(II)Me.7 Moreover
it is mentioned that the dimethylstannylene (SnMe2) is a
transient species at room temperature, which is generated in
situ under special experimental conditions from a variety of
substrates, and some aspects of its chemistry in solution and
gas phase have been reported.8-10 The organometallic
fluorides of the heavier group 14 elements are important
because of their industrial applications, synthetic methodol-
ogy, and theoretical implications.11-13 To the best of our
knowledge there are only two organotin(II)fluorides known
in literature14 although there are reports on a number of
organotin(IV)fluorides.15 Herein we report on the preparation
There has been considerable interest over the past three
decades in the chemistry of dialkyl and diaryl Sn(II)
compounds.1-5 But remarkably little is known about the
chemistry of simpler heteroleptic derivatives such as L′Sn(II)R
(L′ ) chelating ligand or bulky aryl ligand, and R a small
substituent). Recently our group reported the synthesis and
structure of LSn(II)H [L ) HC(CMeNAr)2, Ar ) 2,6-
iPr2C6H3].6 Now we are interested in the synthesis of
heteroleptic Sn(II) derivatives containing a Me, F, and I
substituent, respectively. The methyl derivative LSn(II)Me
(2) is synthesized by the nucleophilic substitution reaction
of LSn(II)Cl with MeLi. Power and Eichler reported on the
* To whom correspondence should be addressed. E-mail: hroesky@
gwdg.de. Fax: +49-551-393373.
(7) Eichler, B. E.; Power, P. P. Inorg. Chem. 2000, 39, 5444–5449.
(8) Bleckmann, P.; Maly, H.; Minkwitz, R.; Neumann, W. P.; Watta, B.
Tetrahedron Lett. 1982, 23, 4655–4658.
(9) Watta, B.; Neumann, W. P.; Sauer, J. Organometallics 1982, 4, 1954.
(10) Becerra, R.; Gaspar, P. P.; Harrington, C. R.; Leigh, W. J.; Vargas-
Baca, I.; Walsh, R.; Zhou, D. J. Am. Chem. Soc. 2005, 127, 17469–
17478.
(1) Neumann, W. P. Chem. ReV. 1991, 91, 311–334.
(2) Driess, M.; Gru¨tzmacher, H. Angew. Chem. 1996, 108, 900–929;
Angew. Chem., Int. Ed. Engl. 1996, 35, 828-856.
(3) Weidenbruch, M. Eur. J. Inorg. Chem. 1999, 373–381.
(4) Tokitoh, N.; Okazaki, R. Coord. Chem. ReV. 2000, 210, 251–277.
(5) Boganov, S. E.; Egorov, M. V.; Faustov, V. I.; Nefedov, O. M. In
The Chemistry of Organic Germanium, Tin and Lead Compounds;
Rappoport, Z., Ed.; John Wiley and Sons: New York, 2002; Vol. 2,
pp 749-839.
(6) Pineda, L. W.; Jancik, V.; Starke, K.; Oswald, R. B.; Roesky, H. W.
Angew. Chem. 2006, 118, 2664–2667; Angew. Chem., Int. Ed. 2006,
45, 2602-2605.
(11) Murphy, E. F.; Murugavel, R.; Roesky, H. W. Chem. ReV. 1997, 97,
3425–3468.
(12) Roesky, H. W.; Haiduc, I. J. Chem. Soc., Dalton Trans. 1999, 2249–
2264.
(13) Roesky, H. W. Inorg. Chem. 1999, 38, 5934–5943.
(14) Chorley, R. W.; Ellis, D.; Hitchcock, P. B.; Lappert, M. F. Bull. Soc.
Chim. Fr. 1992, 129, 599–604.
10.1021/ic8015639 CCC: $40.75  2009 American Chemical Society
Inorganic Chemistry, Vol. 48, No. 1, 2009 193
Published on Web 12/05/2008

Jana et al.
Scheme 1
Figure 1. Molecular structure of 2. Selected bond lengths [Å] and angles
[deg]; anisotropic displacement parameters are depicted at the 50%
probability level, and all restrained refined hydrogen atoms are omitted for
clarity except Sn-Me hydrogens: Sn1-C1 2.253(2), Sn1-N1 2.2091(18),
N1-C141.331(3);N1-Sn1-C192.95(8),N2-Sn1-C192.69(9),N1-Sn1-N2
84.69(7).
and characterization of the monomeric LSn(II)Me (2),
LSn(II)N(SiMe3)2 (3), LSn(II)F (4), and LSn(II)I (5).
Results and Discussion
Generally organotin(IV) fluorides are prepared by the
substitution of chloride with KF in the presence of a phase
transfer catalyst. Therefore the known compound
[HC(CMeNAr)2SnCl] (Ar ) 2,6-iPr2C6H3) (1) was used as
a precursor.16 Compound 1 is soluble in common organic
solvents. A complete reaction of 1 with Me3SnF in toluene
even after refluxing for several days was not observed.
Consequently we changed the method for the preparation of
compound 4. It is well-known that Me4Sn and Cl4Sn
depending on the molecular ratio and temperature show
metathesis and give in high yield Me3SnCl, Me2SnCl2, and
MeSnCl3 respectively.17 The question was whether it is
possible to apply this type of reaction to Me-Sn(II) and
F-Sn(IV) species. It was therefore reasonable to prepare
LSn(II)Me (2) from LSn(II)Cl with MeLi. Furthermore we
prepared LSn(II)N(SiMe3)2 and studied the reaction with
Me3SnF.
Treatment of 1 with MeLi in diethyl ether at -78 °C then
allowed the solution to reach ambient temperature and, kept
for 3 h at this temperature, afforded the corresponding methyl
derivative [HC(CMeNAr)2SnMe] (Ar ) 2,6-iPr2C6H3) (2)
in high yield (88%) (Scheme 1). Yellow crystals of 2 suitable
for single crystal X-ray analysis were obtained from a
n-hexane solution at -30 °C after 2 days. Compound 2 is
thermally stable. No decomposition was observed at tem-
peratures below its melting point (170 °C) under an inert
atmosphere. EI-MS of 2 gave the corresponding monomeric
molecular ion peak M+. The 1H NMR spectrum of 2 consists
of a triplet resonance (0.59 ppm) for Sn-CH3 with the
coupling constant 33.07 Hz. Also the 119Sn NMR spectrum
exhibits a singlet resonance (δ ) 192.65 ppm), which is very
much different from the parent compound [HC(CMeN-
Ar)2SnCl] (Ar ) 2,6-iPr2C6H3) (1), where the tin shows a
resonance at δ ) -224 ppm. This change was expected
because of the different electronic nature of the substituents
on the tin atoms. The other resonances of the H NMR
spectrum and elemental analyses are in accordance with 2
as formulated.
The yellow compound 2 was also characterized by single
crystal X-ray structural analysis. The molecular structure is
depicted in Figure 1 and reveals the monomeric feature in
the solid state. The Sn-N and Sn-C bond lengths are
comparable to those found in literature.16
The well-defined compound LSn(II)N(SiMe3)2 (3) was
obtained in high yield from the reaction of LH with 2 equiv
of KN(SiMe3)2 followed by the reaction with 1 equiv of
SnCl2 at room temperature in tetrahydrofuran (THF, Scheme
1).
1
Compound 3 is a yellow solid soluble in benzene, THF,
n-hexane, and n-pentane and shows no decomposition on
exposure to air for a short period of time. 3 was characterized
1
by H, 13C, 29Si, and 119Sn NMR spectroscopy, EI mass
spectrometry, elemental, and X-ray structural analysis. The
1H NMR spectrum of compound 3 shows a singlet at 5.01
ppm for the γ-CH proton, two septets (3.73 and 3.16 ppm)
corresponding to the CH protons of the iPr moieties, and
singlets at 0.46 and 0.24 ppm for the two nonequivalent
SiMe3 groups. The 119Sn NMR 3 of exhibits a singlet at
134.54 ppm. The most abundant ion peak in the EI mass
spectrum appeared at m/z 537.
Maintaining a n-hexane solution of 3 for 1 day at 0 °C
resulted in slightly yellow single crystals suitable for X-ray
structural analysis. Compound 3 crystallizes in the ortho-
rhombic space group Pnma, with half a molecule in the
asymmetric unit. The coordination environment of the central
Sn atom exhibits a distorted tetrahedral geometry (see
Supporting Information). The LSn(II)NMe2 compound has
already been reported, and the 119Sn NMR exhibits a singlet
at -172.44 ppm.18
(15) (a) Mehring, M.; Vrasidas, I.; Horn, D.; Schu¨rmann, M.; Jurkschat,
K. Organometallics 2001, 20, 4647–4653. (b) Leung, W.-P.; Kwok,
W.-H.; Zhou, Z.-Y.; Mak, T. C. W. Organometallics 2003, 22, 1751–
ˇ
1755. (c) Svec, P.; Nova´k, P.; Na´dvorn´ık, M.; Padeˇlkova´, Z.; C´ısaˇrova´,
I.; Kolárˇova´, L.; Ru˚zˇicˇka, A.; Holecˇek, J. J. Fluorine Chem. 2007,
128, 1390–1395. (d) Varga, R. A.; Jurkschat, K.; Silvestru, C. Eur.
J. Inorg. Chem. 2008, 708–716.
(16) Ding, Y.; Roesky, H. W.; Noltemeyer, M.; Schmidt, H.-G.; Power,
P. P. Organometallics 2001, 20, 1190–1194.
(17) Thoonen, S.; Deelman, B.-J.; Koten, G. V. Chem. Commun. 2001,
1840–1841.
Treatment of 2 with Me3SnF in toluene at room temper-
ature, after refluxing the suspension for 3 h afforded the
corresponding fluoride HC(CMeNAr)2SnF (Ar ) 2,6-
194 Inorganic Chemistry, Vol. 48, No. 1, 2009

Stable DiWalent Tin Compounds
tetrahedral geometry with one lone pair. The sum of angles
around the tin atom is 266.68°. The terminal Sn-F bond
distance (1.988 Å) in 4 is quite short when compared with
that of the bridging one of Sn-F-Sn (2.156 Å).14 The Sn-N
bond lengths in 2 and 4 are similar.
The reaction of the ꢀ-diketiminato lithium salt LLi(OEt2)
with SnI2 in diethyl ether provided the monomeric complex
LSn(II)I (5), (Scheme 1). Maintaing a diethyl ether solution
of 5 for 1 day at -32 °C resulted in colorless crystals suitable
for X-ray structural analysis. Compound 5 crystallizes in the
j
triclinic space group P1, with one monomer in the asym-
metric unit. The coordination environment of the central Sn
atom exhibits a distorted tetrahedral geometry. (See Sup-
porting Information). In the 119Sn NMR spectrum the
resonance arises at δ ) -107.33 ppm, which is very different
from that of the terphenyl iodide 2,6-Trip2C6H3Sn(II)I (δ )
1140 ppm).19 The different chemical shifts might be due to
the different coordination environment around both the Sn(II)
atoms.
Figure 2. Molecular structure of 4. Selected bond lengths [Å] and angles
[deg]; anisotropic displacement parameters are depicted at the 50%
probability level, and all restrained refined hydrogen atoms are omitted for
clarity: Sn1-F1 1.988(2), Sn1-N1 2.178(3), N1-C13 1.333(4); N1-Sn1-F1
90.26(9), N2-Sn1-F1 90.20(9), N1-Sn1-N2 86.22(10).
iPr2C6H3) (4) in high yield (85%, Scheme 1). Compound 4
is thermally stable. No decomposition was observed at
temperatures below the corresponding melting point (130 °C)
under an inert atmosphere. Compound 4 is also obtained by
treating 3 with Me3SnF under the same conditions (Scheme
1).
Summary and Conclusion
In this contribution we report the syntheses and charac-
terization of four novel well-defined monomeric tin(II)
compounds supported by the bulky ꢀ-diketiminate ligand.
The synthetic strategy takes advantage of the recently
synthesized stable HC(CMeNAr)2SnCl (Ar ) 2,6-iPr2C6H3)
(1) precursor. By using the concept of nucleophilic displace-
ment reaction with MeLi and Me3SnF respectively afforded
the monomeric organotin(II) fluoride compound in high yield
which is highly soluble in common organic solvents. The
latter is the first example of a divalent monomeric organotin
fluoride compound.
Compound 4 is a white solid that is soluble in benzene,
toluene, n-hexane, and THF, in contrast to the fluorinating
agent Me3SnF, which is only slightly soluble in these
1
solvents. 4 was characterized by H, 13C, 19F, 119Sn NMR
spectroscopy, EI mass spectrometry, elemental analysis, and
1
X-ray structural analysis. The H NMR spectrum of com-
pound 3 shows a singlet (δ ) 4.99 ppm) for the γ-CH
protons and two septets (δ ) 3.84 and 3.09 ppm) corre-
sponding to the two different types of CH protons of the iPr
moieties. Also, the complete disappearance of the resonance
arising from Sn-CH3 (δ ) 0.59 ppm) in 2 and the resonance
arising from Sn-N(Si(CH3)3)2 (δ ) 0.46 and 0.24 ppm) in
3 clearly indicates the formation of compound 4. The 19F
NMR spectrum of 4 shows a singlet at -125.29 ppm. Also
the 119Sn NMR spectrum exhibits a doublet resonance (δ )
-371.52 ppm). This value is very much different from the
precursor 2 (δ ) 192.65 ppm), but this was expected when
compared with that of compound 1 (δ ) 224 ppm). The
Sn-F coupling constant of J(119Sn-19F) ) 3100 Hz is quite
large when compared with the previously reported Sn-F
coupling constant.14 EI-MS of 4 gave the corresponding
monomeric molecular ion peak M+.
The molecular structure of 4 has been determined by single
crystal X-ray diffraction analysis (Figure 2) which demon-
strates that the complex exists as a monomer. Colorless
crystals of 4 suitable for single crystal X-ray analysis were
obtained from a n-hexane solution at -30 °C after 1 day.
Compound 4 crystallizes in the monoclinic space group P21/
c, with one monomer in the asymmetric unit. The coordina-
tion polyhedron around the tin atom features a distorted
Experimental Section
All manipulations were performed under a dry and oxygen free
atmosphere (N2) using standard Schlenk techniques or inside a
MBraun MB 150-GI glovebox. All solvents were distilled from
Na/benzophenone prior to use. The starting material 1 was prepared
using literature procedures.16 Other chemicals were purchased
commercially and used as received. H, 13C, 19C, and 119Sn NMR
1
spectra were recorded on a Bruker Avance DRX 500 MHz
instrument and referenced to the deuterated solvent in the case of
the 1H and 13C NMR spectra. 19F and 29Si NMR spectra were
referenced to BF3 ·Et2O and TMS, and those of 119Sn NMR to
SnMe4. Elemental analyses were performed by the Analytisches
Labor des Instituts fu¨r Anorganische Chemie der Universita¨t
Go¨ttingen. EI-MS were measured on a Finnigan Mat 8230 or a
Varian MAT CH5 instrument. Melting points were measured in
sealed glass tubes with a Bu¨chi melting point B 540 instrument
and are not corrected.
Synthesis of HC(CMeNAr)2Sn(II)Me (Ar ) 2,6-iPr2C6H3)
(2). A solution of MeLi in diethyl ether (0.63 mL, 1.6 M) was
added drop by drop to a stirred solution of 1 (0.570 g, 1 mmol) in
diethyl ether (25 mL) at -78 °C. The reaction mixture was warmed
to room temperature and was stirred for an additional 3 h. After
removal of all the volatiles, the residue was extracted with n-hexane
(20 mL), and the remaining solution concentrated to about 10 mL
(18) Dove, A. P.; Gibson, V. C.; Marshall, E. D.; Rzepa, H. S.; White,
(19) Pu, L.; Olmstead, M. M.; Power, P. P. Organometallics 1998, 17,
A. J. P.; Williams, D. J. J. Am. Chem. Soc. 2006, 128, 9834–9843.
5602–5606.
Inorganic Chemistry, Vol. 48, No. 1, 2009 195

Jana et al.
Table 1. Crystallographic Data for the Structural Analyses of
Compounds 2 and 4
(20 mL) at room temperature under stirring for another 24 h. After
removal of all the volatiles, the residue was extracted with n-hexane
(30 mL), concentrated to about 5 mL, and finally stored in a 0 °C
freezer. Yellow crystals of LSnN(SiMe3)2 suitable for X-ray
diffraction analysis are formed after 1 day. Yield (0.570 g, 82%),
2
4
empirical formula
CCDC No.
T [K]
C30H44N2Sn
697820
133(2)
C29H41FN2Sn
697821
133(2)
1
mp 202 °C. H NMR (300 MHz, C6D6): δ ) 6.98-7.21 (m, 6H,
crystal system
space group
a [Å]
b [Å]
c [Å]
triclinic
P1
monoclinic
P21/C
9.0047(18)
9.6328(19)
32.308(6)
90
89.92(3)
90
2802.4(9)
4
Ar-H), 5.01 (s, 1H, γ-CH), 3.73 (sept, 2H, CH(CH3)2), 3.16 (sept,
2H, CH(CH3)2), 1.52 (s, 6H, CH3), 1.45 (d, 6H, CH(CH3)2), 1.22
(q, 12H, CH(CH3)2), 1.13 (d, 6H, CH(CH3)2), 0.46 (s, 9H, Si(CH3)3),
0.24 (s, 9H, Si(CH3)3) ppm; 13C {1H} NMR (75.47 Hz, C6D6): δ
) 167.25 (CN), 145.38, 144.00, 128.09, 124.72 (Ar-C), 102.23 (γ-
C), 28.77 (CHMe2), 26.55 (CHMe2), 25.80 (CHMe2), 23.40 (Me),
7.98 (SiMe3), 6.55 (SiMe3) ppm; 29Si{1H} NMR (99.36 Hz, C6D6):
δ ) 0.61 (SiMe3), -4.70 (SiMe3) ppm; 119Sn {1H} NMR (112.00
Hz, C6D6): δ ) -134.54 ppm. EI-MS (70 eV): m/z (%): 682 (100)
[M - Me]+. Anal. Calcd for C35H59N3SnSi2(697): C, 60.33; H, 8.54;
N, 6.03. Found C, 60.20; H, 8.49; N, 5.88.
j
8.6420(17)
11.638(2)
14.986(3)
98.08(3)
98.62(3)
105.76(3)
1407.9(5)
2
R [deg]
ꢀ [deg]
γ [deg]
V [Å3]
Z
Dcalcd [g cm-3
]
1.301
0.926
576
1.316
0.936
1152
µ [mm-1
F(000)
]
θ range [deg]
1.85-27.14
1.26-25.63
reflections collected
independent reflections
data/restraints/parameters
R1, wR2 [I > 2σ(I)]a
R1, wR2 (all data)a
GoF
13371
20990
Synthesis of HC(CMeNAr)2Sn(II)F (Ar ) 2,6-iPr2C6H3) (4).
Method A: A solution of 2 (0.550 g, 1 mmol) in toluene (20 mL)
was added to a stirred suspension of Me3SnF (0.200 g, 1.1 mmol)
in toluene (10 mL), and the reaction mixture was refluxed for 3 h.
After removal of all the volatiles the residue was extracted with
n-hexane (30 mL), and the resulting solution was concentrated to
about 10 mL and stored in a -30 °C freezer. Colorless crystals of
4 suitable for X-ray diffraction analysis are formed after 1 day.
Yield: 0.470 g (85%).
6051
5251
6051/0/312
0.0295, 0.0606
0.0412, 0.0636
0.998
5251/0/311
0.0350, 0.0827
0.0506, 0.0874
0.960
∆F(max), ∆F(min) [e Å-3
a
]
0.628, -0.705
0.640, -1.230
R1 ) ∑||Fo| - |Fc||/∑|Fo|; wR2 ) (∑[w(Fo - Fc2)2]/∑w(Fo )2)1/2
.
2
2
Table 2. Selected Bond Distances (Å) and Angles (deg) for
Compounds 2 and 4
Method B: A solution of 3 (0.700 g, 1 mmol) in toluene (20
mL) was added to a stirred suspension of Me3SnF (0.200 g, 1.1
mmol) in toluene (10 mL), and the reaction mixture was refluxed
for 3 h. After removal of all the volatiles the residue was extracted
with n-hexane (30 mL), and the resulting solution was concentrated
to about 10 mL and stored in a -30 °C freezer. Colorless crystals
of 4 suitable for X-ray diffraction analysis are formed after 1 day.
Compound 2
Sn(1)-N(1)
Sn(1)-N(2)
Sn(1)-C(1)
N(1)-C(14)
N(2)-C(17)
2.2091(18)
2.218(2)
2.253(2)
1.331(3)
1.4338(3)
C(14)-C(16)
C(16)-C(17)
C(14)-C(15)
C(17)-C(18)
1.404(4)
1.407(3)
1.517(3)
1.511(3)
N(1)-Sn(1)-N(2)
N(1)-Sn(1)-C(1)
N(2)-Sn(1)-C(1)
84.69(7)
92.95(8)
92.69(9)
Sn(1)-N(1)-C(14)
Sn(1)-N(2)-C(17)
122.26(16)
123.21(16)
1
Yield: 0.390 g (70%); mp 130 °C. H NMR (500 MHz, C6D6): δ
) 7.04-7.17 (m, 6H, Ar-H), 4.99 (s, 1H, γ-CH), 3.84 (sept, 2H,
CH(CH3)2), 3.09 (sept, 2H, CH(CH3)2), 1.63 (s, 6H, CH3), 1.41 (d,
6H, CH(CH3)2), 1.18 (q, 12H, CH(CH3)2), 1.09 (d, 6H, CH(CH3)2),
ppm. 13C {1H} NMR (125.75 MHz, C6D6): δ ) 165.14 (CN),
145.71, 142.75, 141.55, 127.42, 125.18, 123.91 (Ar-C), 98.75 (γ-
C), 28.85 (CHMe2), 27.70 (CHMe2), 26.70 (CHMe2), 24.99 (Me),
ppm; 19F {1H} NMR (188.31 MHz, C6D6): δ ) -125.29 ppm (J19F-
119Sn ) 3100 Hz); 119Sn {1H} NMR (186.50 MHz, C6D6): δ )
-371.52 ppm. EI-MS: m/z (%) 521 (100) [M+ - F. Me]. Anal.
Calcd for C29H41FN2Sn (556.23): C, 62.72; H, 7.44; N, 5.04. Found
C, 62.38; H, 8.67; N, 5.00.
Compound 4
Sn(1)-F(1)
Sn(1)-N(1)
Sn(1)-N(2)
N(1)-C(13)
N(2)-C(16)
1.988(2)
2.178(3)
2.178(3)
1.333(4)
1.335(4)
C(13)-C(15)
C(15)-C(16)
C(13)-C(14)
C(16)-C(17)
1.399(5)
1.391(5)
1.506(5)
1.514(4)
F(1)-Sn(1)-N(1)
F(1)-Sn(1)-N(2)
N(1)-Sn(1)-N(2)
90.20(9)
90.26(9)
86.22(10)
Sn(1)-N(1)-C(13)
Sn(1)-N(2)-C(16)
119.6(3)
124.7(2)
and stored in a -30 °C freezer. Yellow crystals of 2 suitable for
X-ray diffraction analysis are formed after 2 days. Yield: 0.485 g
(88%); mp 170 °C. H NMR (500 MHz, C6D6): δ ) 7.10-7.15
1
Synthesis of {HC(CMeNAr)2}Sn(II)I (Ar ) 2,6-iPr2C6H3)
(5). A solution of LLi(OEt2) (0.498 g, 1 mmol) in diethyl ether
(20 mL) was added drop by drop to a stirred suspension of SnI2
(0.375 g, 1 mmol) in diethyl ether (10 mL) at -78 °C. The reaction
mixture was warmed to room temperature, and stirring was
continued for another 12 h. The precipitate was filtered, and the
solvent was partially reduced (ca. 20 mL). Storage of the remaining
solution in a -32 °C freezer overnight afforded colorless crystals
of 5 suitable for X-ray diffraction analyses. Yield (0.510 g, 77%);
(m, 6H, Ar-H), 4.86 (s, 1H, γ-CH), 3.59 (sept, 2H, CH(CH3)2),
3.37 (sept, 2H, CH(CH3)2), 1.60 (s, 6H, CH3), 1.35 (d, 6H,
CH(CH3)2), 1.22 (d, 6H, CH(CH3)2), 1.19 (d, 12H, CH(CH3)2), 0.59
(t, 3H, Sn-CH3) ppm. 13C {1H} NMR (125.75 MHz, C6D6): δ )
165.81 (CN), 144.90, 143.28, 126.69, 124.45 (Ar-C), 97.94 (γ-C),
29.02 (CHMe2), 27.68 (CHMe2), 24.89 (CHMe2), 23.95 (Me), 16.24
(Sn-CH3) ppm; 119Sn {1H} NMR (186.50 MHz, C6D6): δ ) 192.65
ppm. EI-MS: m/z (%) 537 (100) [M+ - Me]. Anal. Calcd for
C30H44N2Sn (552.25): C, 65.35; H, 8.04; N, 5.08. Found C, 64.96;
H, 8.64; N, 5.09.
Synthesis of [HC(CMeNAr)2Sn(II)N(SiMe3)2] (Ar ) 2,6-iPr2-
C6H3) (3). A solution of LH (0.418 g, 1 mmol) in THF (15 mL)
was added drop by drop to a stirred suspension of KN(SiMe3)2
(0.400 g, 2 mmol) in THF (10 mL) at room temperature, and stirring
was continued overnight. The resulting solution was added drop
by drop to a stirred suspension of SnCl2 (0.190 g, 1 mmol) in THF
1
mp 197 °C. H NMR (300 MHz, C6D6): δ ) 7.01-7.15 (m, 6H,
Ar-H), 5.20 (s, 1H, γ-CH), 4.05 (sept, 2H, CH(CH3)2), 3.09 (sept,
2H, CH(CH3)2), 1.59 (s, 6H, CH3), 1.42 (d, 6H, CH(CH3)2), 1.17
(q, 12H, CH(CH3)2), 1.06 (d, 6H, CH(CH3)2) ppm; 13C {1H} NMR
(75.47 Hz, C6D6): δ ) 167.11 (CN), 146.46, 143.23, 141.40, 125.74,
124.07(Ar-C), 102.79 (γ-C), 29.39 (CHMe2), 29.25 (CHMe2), 28.15
(CHMe2), 24.71 (CHMe2), 23.90 (Me) ppm; 119Sn {1H} NMR
(112.00 Hz, C6D6): δ ) -107.33 ppm. EI-MS (70 eV): m/z (%):
196 Inorganic Chemistry, Vol. 48, No. 1, 2009

Stable DiWalent Tin Compounds
663 (100) [M]+. Anal. Calcd for C29H41IN2Sn(664): C, 52.51; H,
6.23; N, 4.22. Found C, 51.55; H, 5.78; N, 4.06.
disordered. The hydrogen atoms were refined isotropically on
calculated positions using a riding model. Crystallographic data are
presented in Table 1, and selected bond distances and angles in
Table 2.
Crystallographic Details for Compounds 2 and 4. Suitable
crystals of 2 and 4 were mounted on a glass fiber and data was
collected on an IPDS II Stoe image-plate diffractometer (graphite
monochromated Mo KR radiation, λ ) 0.71073 Å) at 133(2) K.
The data was integrated with X-Area. The structures were solved
by Direct Methods (SHELXS-97)20 and refined by full-matrix least-
squares methods against F2 (SHELXL-97).20 All non-hydrogen
atoms were refined with anisotropic displacement parameters. One
of the eight isopropyl groups in both 2 and 4 was found to be
Acknowledgment. This work was supported by the
Deutsche Forschungsgemeinschaft.
Supporting Information Available: X-ray data for 2, 3, 4, and
5 (CIF) and tables of crystallographic and structural refinement data
of 3 and 5 (PDF). This material is available free of charge via the
Internet at http://pubs.acs.org.
(20) Sheldrick, G. M. Acta Crystallogr., Sect. A 2008, 64, 112–122.
IC8015639
Inorganic Chemistry, Vol. 48, No. 1, 2009 197