Novel heteroleptic stannylenes with intramolecular O,C,O-donor stabilization

Article abstract of DOI:10.1021/om000452k

The heteroleptic organotin(II) halides {2,6-[P(O)(OEt)₂]₂-4-tert-Bu-C₆H₂}SnX (1, X = Cl; 2, X = Br) have been prepared starting from {2,6-[P(O)(OEt)₂]₂-4-tert-Bu-C₆H₂}Li and SnX₂ and have been used as precursors for the preparation of the heteroleptic stannylenes {2,6-[P(O)(OEt)₂]₂-4-tert-Bu-C₆H₂}SnX (4, X = SPh; 5, X = CH(SiMe₃)₂; 6, X = SiPh₃; 7, X = SnPh₃; 7a, X = SnMe₃), the tetravalent monorganotin derivatives {{2,6-[P(O)(OEt)₂]₂-4-tert-Bu- C₆H₂}SnCl(μ-S)}₂ (8) and {2,6-[P(O)(OEt)₂]₂-4-tert-Bu-C₆ H₂}SnBr₃ (9), the diorganotin cation {2,6-[P(O)(OEt)₂]₂-4-tert-Bu-C₆ H₂}(Ph₃C)(Cl)Sn⁺PF₆^- (10), and the metal-stannylene complexes {2,6-[P(O)(OEt)₂]₂-4- tert-Bu-C₆H₂}(Cl)Sn[M(CO)_n] (11, M = W, n = 5; 12, M = Cr, n = 5; 13, M = Fe, n = 4). Multinuclear (¹H, ¹³C, ³¹P, ¹¹⁹Sn) NMR of all compounds, ¹¹⁹Sn Mossbauer spectra of 1 and 10, and single-crystal X-ray structure analyses of 6, 8, and 12 are reported. The derivatives 6, 7, and 7a are rare examples of compounds containing Sn-(II)-Si(IV) and Sn(II)-Sn(IV) bonds, respectively.

Full text of DOI:10.1021/om000452k

Organometallics 2000, 19, 4613-4623
4613
Novel Heter olep tic Sta n n ylen es w ith In tr a m olecu la r
O,C,O-Don or Sta biliza tion †,‡
Michael Mehring, Christian Lo¨w, Markus Schu¨rmann, Frank Uhlig, and
Klaus J urkschat*
Lehrstuhl fu¨r Anorganische Chemie II der Universita¨t Dortmund,
D-44221 Dortmund, Germany
Bernard Mahieu
Laboratoire de Chimie Physique Mole´culaire et de Cristallographie (CPMC),
B-1348 Louvain-la-Neuve, Belgium
Received May 30, 2000
The heteroleptic organotin(II) halides {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnX (1, X ) Cl;
2, X ) Br) have been prepared starting from {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}Li and SnX2
and have been used as precursors for the preparation of the heteroleptic stannylenes {2,6-
[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnX (4, X ) SPh; 5, X ) CH(SiMe3)2; 6, X ) SiPh3; 7, X )
SnPh3; 7a , X ) SnMe3), the tetravalent monorganotin derivatives {{2,6-[P(O)(OEt)2]2-4-tert-
Bu-C6H2}SnCl(µ-S)}2 (8) and {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnBr3 (9), the diorganotin
cation {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}(Ph3C)(Cl)Sn+PF6- (10), and the metal-stannylene
complexes {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}(Cl)Sn[M(CO)n] (11, M ) W, n ) 5; 12, M )
Cr, n ) 5; 13, M ) Fe, n ) 4). Multinuclear (1H, 13C, 31P, 119Sn) NMR of all compounds, 119Sn
Mo¨ssbauer spectra of 1 and 10, and single-crystal X-ray structure analyses of 6, 8, and 12
are reported. The derivatives 6, 7, and 7a are rare examples of compounds containing Sn-
(II)-Si(IV) and Sn(II)-Sn(IV) bonds, respectively.
In tr od u ction
transition metal interactions in stannylenes are well
known,24 there seems to be renewed interest in com-
pounds of this type25-28 and also in compounds contain-
ing a bond between tin(II) and a main group metal.29-32
Furthermore, in the past decade there has been growing
Almost 80 years ago homoleptic stannylenes had been
suggested to occur as reactive intermediates in the
reaction of phenylmagnesium bromide with SnCl2 giving
polymeric (Ph2Sn)n,1 but it was only in 1976 that the
first homoleptic diorganostannylene [(Me3Si)2CH]2Sn2,3
was fully characterized. Since then numerous homolep-
tic diorganostannylenes which are stabilized either by
bulky substituents4-16 and/or intramolecular donor
coordination have been reported.17-23 Although tin(II)-
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* Corresponding author. Fax: +49(0)231/755-5048. E-mail: kjur@
platon.chemie.uni-dortmund.de.
† Dedicated to Professor Horst Weichmann on the occasion of his
60th birthday.
‡ This work includes parts of the Ph.D. thesis of M.M., Dortmund
University, 1998, and of the intended Ph.D. thesis of C.L.
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10.1021/om000452k CCC: $19.00 © 2000 American Chemical Society
Publication on Web 09/29/2000

4614 Organometallics, Vol. 19, No. 22, 2000
Mehring et al.
Ch a r t 1
interest in σ-bonded heteroleptic stannylenes.20,33-37
Compounds of the type RSnX (X ) NR2, Cl; R ) alkyl,
aryl)12,19,35,38-45 are very useful as starting materials for
the preparation of diverse heteroleptic stannylenes
RR′Sn. Intramolecular donor stabilization has led to the
isolation of monomeric stannylenes RSnX,19,38-41 whereas
stabilization by bulky, monodentate ligands gave mono-
mers43 as well as dimers,12,42 the latter resulting from
intermolecular Cl‚‚‚Sn interactions. Research on com-
pounds of the type RSnCl has focused mainly on
structural characterization, and surprisingly, reports on
reactivity at the Sn-Cl function are scarce.35,39,44,46
Recently, the first examples of heteroleptic, silyl-
substituted stannylenes {Sn[C6H3-2,6-(NMe2)2]{Si-
t
[(-NCH2 Bu)2-1,2-C6H4]R}} (R ) C6H3-2,6-(NMe2)2 or
N(SiMe3)2) A,20 {Sn[2,4,6-CF3(C6H2)][Si(SiMe3)3] B,33
and {Sn[2-(Me3Si)2C-C5H4N][Si(SiMe3)3]} C37 have been
reported. The first compound containing a Sn(II)-Sn-
(IV) bond, [(2-C6H4CH2PPh2)3Sn-SnCl] E,47 was re-
ported in 1986 followed by [(Me2NCH2CH2CMe2-
SnCl)3SnCl2)] F 40 in 1989 and {Sn[2-(Me3Si)2C-C5H4N]-
[Sn(SiMe3)3]} D37 in 1998 (Chart 1). These compounds
were characterized by NMR37,40,47 and Mo¨ssbauer spec-
troscopy,40,47 and in the case of the two latter compounds
also by single-crystal X-ray analyses.37,40 On the basis
of the 119Sn Mo¨ssbauer spectrum (isomer shift, IS )
2.15, 3.24 mm s-1), compound F might be regarded as
a borderline case between a Sn(II)-Sn(IV) compound
and a Sn(II)-Sn(II) adduct. The tin-tin bond distances
in F of 2.882(3), 2.873(3), and 3.156(3) Å compare well
with those of previously reported asymmetric distan-
nenes29,32,41 as well as those of the tin(II)-tin(IV)
compound D.
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17, 5602.
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We recently reported the synthesis of the O,C,O-
coordinating pincer-type ligand {2,6-[P(O)(OEt)2]2-4-tert-
Bu-C6H2}- and its application in organosilicon and
organotin chemistry.48-50 Since a long time we have
been interested in intramolecularly donor stabilized
divalent tin compounds,40,47,51-53 and since intramolecu-
lar stabilization of organostannylenes is mainly focused
on nitrogen and phosphorus rather than oxygen donors,
we explored the potential of the O,C,O-coordinating
(47) J urkschat, K.; Abicht, H. P.; Tzschach, A. J . Organomet. Chem.
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Organomet. Chem. 1986, 304, 107.

Novel Heteroleptic Stannylenes
Organometallics, Vol. 19, No. 22, 2000 4615
Ta ble 1. Selected 31P a n d 119Sn NMR Da ta ;a R )
{2,6-[P (O)(OEt)2]2-4-ter t-Bu -C6H2}
Hz) and δ -68 (J (119Sn-31P) ) 116 Hz), respectively,
which are low frequency shifted as compared with the
related intramolecularly donor-stabilized heteroleptic
stannylenes [C6H3(NMe2)2-2,6]SnCl (δ 380),39 [C6H3(CH2-
NMe2)2-2,6]SnCl (δ 156),38 {C9H6N[CH(SiMe3)]-8}SnCl
(δ 327),41 and {C9H6N[CH(SiMe3)]-8}SnBr (δ 354).41 The
31P NMR spectra of 1 and 2 show single resonances at
δ 39.1 (J (119Sn-31P) ) 113 Hz) and δ 38.8 (J (119Sn-
31P) ) 115 Hz), respectively, which are high frequency
shifted as compared with related compounds listed in
Table 1. The osmometric molecular weight determina-
tion in benzene shows the stannylene 1 to be monomeric
in solution. However, the 119Sn MAS NMR of 1 shows a
broad resonance at δ -160 (ν1/2 ) 760 Hz), which is
significantly shifted to lower frequency, and thus, it is
most likely that compound 1 is a dimer in the solid state
via intermolecular Sn‚‚‚Cl interactions (Chart 2).
δ(31P)
δ(119Sn)
compound
[J (31P-119Sn)]
[J (119Sn-31P)]
R-SnCl (1)
39.1 [113]
38.8 [115]
37.4 [95]
33.5 [107]
34.5 [95]
35.4 [99]
37.7 [21, 95]
26.7 [86]
23.8 [236]
-100 [116]
-68 [116]
R-SnBr (2)
R-Sn(SPh) (4)
R-SnCH(SiMe3)2 (5)
R-SnSiPh3 (6)
R-SnSnPh3 (7)
R-SnSnMe3 (7a )
R-Sn(Cl)(µ-S)]2 (8)
R-SnBr3 (9)
2 [96]
259 [106]
192 [96][b]
109 [98], -43 [21]c
217 [93], 11 [21]d
-439 [84]
-885 [230]
R-Sn(CPh3)(Cl)+PF6- (10) 24.8 [52], -143.5 -322 [52]
R-Sn(Cl)W(CO)5 (11)
R-Sn(Cl)Cr(CO)5 (12)
R-Sn(Cl)Fe(CO)4 (13)
33.9 [161]
32.8 [175]
30.5 [161]
-74 [161]e
131 [179]
54 [165]
a
Coupling constants J are given in Hz and chemical shifts δ in
ppm. δ(29Si) 7.9, 1J (29Si-117/119Sn) ) 674/708 Hz. c 1J (119Sn-
b
117/119Sn) ) 9130/9550 Hz. 1J (119Sn-117/119Sn) ) 7976/8346 Hz.
d
e 1J (119Sn-182W) ) 1372 Hz.
Ch a r t 2
pincer-type ligand in stannylene chemistry. Recently we
described the reaction of {2,6-[P(O)(OEt)2]2-4-tert-Bu-
C6H2}SnCl (1) with SnCl4 to give {2,6-[P(O)(OEt)2]2-4-
tert-Bu-C6H2}SnCl3,50 and in continuation of this work
we now report the synthesis of the mononuclear, het-
eroleptic stannylenes {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}-
SnX (1, X ) Cl; 2, X ) Br) and demonstrate their
versatility as precursors of the novel divalent organotin
compounds {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnX (4, X
) SPh; 5, X ) CH(SiMe3)2; 6, X ) SiPh3; 7 ) SnPh3; 7a
) SnMe3), the tetravalent monoorganotin derivatives
{{2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnCl(µ-S)}2 (8) and
{2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnBr3 (9), the dior-
ganotin cation {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}(Ph3C)-
(Cl)Sn+PF6- (10), and the metal-stannylene complexes
{2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}(Cl)Sn[M(CO)n] (11,
M ) W, n ) 5; 12, M ) Cr, n ) 5; 13, M ) Fe, n ) 4).
All compounds have been fully characterized by multi-
nuclear NMR spectroscopy. Single-crystal X-ray struc-
ture analyses of 6, 8, and 12 were determined. The
identity of 7 and 7a in solution was unambiguously
established by NMR spectroscopy and here especially
by determination of the tin(II)-tin(IV) coupling con-
stant, the second of its kind reported so far.
The IR spectra of 1 and 2 both show ν(PdO) absorp-
tions at 1171 cm-1, which are accompanied by a
shoulder at 1192 cm-1 and hint at two slightly different
coordinating modes for the phosphonate groups in the
solid state. This is in agreement with the 31P MAS NMR
spectrum, which shows two chemical shifts of equal
intensity at δ 40.0 and δ 37.1. The divalent nature of
tin in 1 is confirmed by the 119Sn Mo¨ssbauer spectrum
(IS ) 3.24 mm s-1). Similar values have been reported
for the tin(II) moiety in the mixed valence compound
[(2-C6H4CH2PPh2)3Sn-SnCl] (IS ) 3.15 mm s-1 47
and
)
the heteroleptic stannylenes 2-(OCH3)C6H4SnCl (IS )
3.29 mm s-1), 2-(iso-PrO)C6H4SnCl (IS ) 3.19 mm s-1),
and 2,4,6-(OCH3)3C6H2SnCl (IS ) 3.25 mm s-1),9 which
all rapidly oxidize on contact with air. In contrast, the
oxidation of 1 as monitored by Mo¨ssbauer spectroscopy
is very slow, and after exposure to air for one week only
38% of the stannylene 1 was oxidized, giving rise to an
additional signal at IS ) -0.11 mm s-1, which is
characteristic for a tin(IV) compound. Furthermore,
compound 1 is stable in solution after heating at reflux
in toluene for 2 h, whereas the related heteroleptic
stannylenes [C6H3(NMe2)2-2,6]SnCl39 and (Me2NCH2-
CH2CMe2)SnCl40 disproportionate in solution at room
temperature to give R2SnCl2 and elemental tin. It is
noteworthy that the 119Sn and 31P NMR spectra of 1 in
[d8]toluene to which a few drops of water had been
added did not change, even after 1 day of vigorous
stirring at room temperature.
Resu lts a n d Discu ssion
P r ep a r a tion a n d Ch a r a cter iza tion of {2,6-[P (O)-
(OEt)2]2-4-ter t-Bu -C6H2}Sn X (1, X ) Cl; 2, X ) Br ).
The organolithium reagent {2,6-[P(O)(OEt)2]2-4-tert-Bu-
C6H2}Li was reacted with SnCl2 and SnBr2, respec-
tively, in thf to give the heteroleptic stannylenes {2,6-
[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnX (1, X ) Cl; 2, X ) Br)
as colorless solids (eq 1).
To the best of our knowledge there are no spectro-
scopic data on heteroleptic stannylenes containing a
Sn-F bond, which might be the result of the poor
solubility of SnF2 and the lack of appropriate, water-
free fluorinating reagents. However, the 119Sn NMR
spectrum of {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnCl (1)
The 119Sn NMR spectra in [d8]toluene of 1 and 2
exhibit triplet resonances at δ -100 (J (119Sn-31P) ) 116

4616 Organometallics, Vol. 19, No. 22, 2000
Mehring et al.
in [d8]toluene at -40 °C to which had been added 1
molar equiv of Bu4NF‚3H2O showed a doublet of triplets
resonance at δ -208 (J (119Sn-31P) ) 112 Hz, 1J (119Sn-
19F) ) 3140 Hz, integral 0.8), which is indicative of the
formation of either the monomeric anionic complex {2,6-
[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnClF- (3a ) or the orga-
notin(II) fluoride {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnF
(3b). An additional broad signal at δ -111 (ν1/2 ) 290
Hz, integral 0.2) is assigned to 1. At room temperature
only the signal of compound 1 was observed. The 31P
NMR spectrum of this solution at low temperature
showed a broad signal at δ 45.2 ppm (ν1/2 ) 80 Hz) and
a signal of minor intensity (2%) at δ 23.8. It is note-
worthy that a complex of the type {2,6-[P(O)(OEt)2]2-
Nu cleop h ilic Su bstitu tion s a t th e Sn -Cl F u n c-
tion . The colorless organotin(II) thiophenolate {2,6-
[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnSPh (4) was prepared
from {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnCl (1) and
NaSPh in appropriate stoichiometry (Scheme 1). Its
119Sn NMR spectrum exhibits a triplet resonance at δ
2 (J (119Sn-31P) ) 96 Hz), and the 31P NMR spectrum
displays a single resonance at δ 37.4 (J (119Sn-31P) )
95 Hz).
The reaction of {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}-
SnCl (1) with LiCH(SiMe3)2 and LiSiPh3 gave the
heteroleptic stannylenes {2,6-[P(O)(OEt)2]2-4-tert-Bu-
C6H2}SnCH(SiMe3)2 (5) and {2,6-[P(O)(OEt)2]2-4-tert-
Bu-C6H2}SnSiPh3 (6), respectively (Scheme 1).
Attempts to prepare a heteroleptic tin(II) triflate
starting from 1 and AgOTf failed and gave a silver
mirror, 1,3-[P(O)(OEt)2]2-4-tert-Bu-C6H3, and unidenti-
fied products instead. On the other hand, the synthesis
of the amidotin(II) triflate [Sn(NR2)(OTf)]n (R ) SiMe3,
OTf ) -OSO2CF3), starting from [Sn(NR2)(Cl)]2 and
AgOTf, has been reported recently.57 These results show
that the redox potential of Sn(II) species can be tuned
by appropriate ligands.
-
4-tert-Bu-C6H2}SnF2 was not observed, even after
addition of a second equivalent of Bu4NF‚3H2O. At-
tempts to isolate an analytically pure organotin(II)
fluoride 3a or 3b from this reaction mixture failed.
Furthermore, the reaction of 1 with a suspension of CsF
in toluene gave the ligand precursor 1,3-[P(O)(OEt)2]2-
5-tert-Bu-C6H3 instead of the organotin fluoride 3b.
Cleavage of Sn-Ph bonds by fluoride has been reported
for organotin(IV) compounds.54,55
The 119Sn NMR chemical shift of 1 in CD2Cl2 is
temperature dependent (T ) 20 °C, δ -100; T ) -10
°C, δ -106) and strongly influenced by the addition of
[(Ph3P)2N]+Cl- (1/[(Ph3P)2N]+Cl- ) 1/1, T ) -10 °C, δ
-125, T ) -50 °C, δ -163; 1/[(Ph3P)2N]+Cl- ) 1/2, T )
-10 °C, δ -158, T ) -50 °C, δ -212), whereas the 31P
NMR chemical shift is temperature independent and not
influenced by the addition of chloride anions (δ 38.8
(J (31P-119Sn) ) 116 Hz), which shows that the coordi-
native PdO‚‚‚Sn bonds are not broken.
The molecular structure of the heteroleptic stannylene
6 is illustrated in Figure 2. Crystallographic data are
given in Table 2, and selected bond lengths and angles
are listed in Table 3. The coordination geometry at tin
is best described as that of a distorted trigonal bipyra-
mid with C(1), Si(1), and the lone pair being in equa-
torial positions, and O(1) and O(2) being axial. The
C(1)-Sn(1)-Si(1) bond angle of 96.35(9)° is significantly
smaller than the corresponding C-Sn-Si angles in the
related compounds A {Sn[C6H3-2,6-(NMe2)2]{Si[(-NCH2-
tBu)2-1,2-C6H4][C6H3-2,6-(NMe2)2]} (107.0(2)°)20 and C
{Sn[2-(Me3Si)2C-C5H4N][Si(SiMe3)3]} (113.5(2)°).37 The
Sn(1)-Si(1) bond distance of 2.751(1) Å is longer than
the corresponding distances of 2.636(2) and 2.724(2) Å
in the stannylenes A and C, respectively (Chart 1). The
bond angle O(1)-Sn(1)-O(2) of 150.97(9) Å is smaller
than in 8 (159.0(1)°), 11 (154.9(1)°), and previously
reported hypercoordinate compounds containing the
same O,C,O-coordinating pincer-type ligand (average
160.7°),48,50 which is a result of the long Sn(1)-C(1) bond
of 2.229(3) Å.
Multinuclear NMR spectroscopy shows that com-
pounds 5 and 6 have similar molecular structures in
solution and that the structure of 6 in thf solution is
similar to that in the solid state. The 31P NMR spectra
of 5 and 6 display single resonances at δ 33.5 (J (119Sn-
31P) ) 107 Hz) and δ 34.5 (J (119Sn-31P) ) 95 Hz; J (29Si-
31P) ) 64 Hz), respectively. The 119Sn NMR spectra of
5 and 6 exibit triplet resonances at δ 259 (J (119Sn-31P)
) 106 Hz) and at δ 192 (J (119Sn-31P) ) 96 Hz),
respectively, and the Sn(II)-Si(IV) bond in 6 is evi-
denced by the 29Si resonance at δ 7.9, showing 1J (29Si-
117/119Sn) couplings of 674/708 Hz.
The 1H NMR spectrum of the stannylene 1 in [d8]-
toluene at room temperature shows a broad signal for
the CH3 groups of the phosphonate units which splits
into triplet resonances of equal intensity at -20 °C. In
[d6]DMSO at room temperature and in C2D2Cl4 solution
at 72 °C, only one triplet resonance is observed for this
group. The NMR spectroscopic data for the stannylene
1 suggest an inversion of the configuration at tin, the
rate of which is influenced by Lewis bases. Compound
1 shows no conductivity in CH2Cl2 and a value of 55 S
cm2 mol-1 in CH3CN, which demonstrates 1 to be
virtually a nonelectrolyte. Thus, we suggest that inver-
sion of configuration at tin takes place in noncoordinat-
ing solvents via dimeric intermediates of the type
[RSnCl]2. Upon the addition of Cl-, inversion occurs via
anionic complexes of the type [RSnCl2]- and in coordi-
nating solvents via neutral hypercoordinate stannylene
complexes of the type [RSnCl][Donor]. Similar observa-
tions have been reported for [C6H3(CH2NMe2)2-2,6]-
SnCl.56
The reaction of the heteroleptic stannylene 1 with
LiSnPh3 in thf gave a crude reaction mixture, the 119Sn
NMR spectrum of which displayed an ABXY2-type
pattern with two triplet resonances of equal integral
(56) J astrzebski, J . T. B. H. Ph.D. Thesis, University of Utrecht,
Netherlands, 1991.
(54) Dakternieks, D.; Zhu, H. Organometallics 1992, 11, 3820.
(55) Dakternieks, D.; Zhu, H. Inorg. Chim. Acta 1992, 196, 19.
(57) Hitchcock, P. B.; Lappert, M. F.; Lawless, G. A.; de Lima, G.
M.; Pierssens, L. J .-M. J . Organomet. Chem. 2000, 601, 142.

Novel Heteroleptic Stannylenes
Organometallics, Vol. 19, No. 22, 2000 4617
F igu r e 1. General view (SHELXTL) of a molecule of 6
showing 30% probability displacement ellipsoids and the
atom-numbering scheme.
F igu r e 2. General view (SHELXTL) of a molecule of 8
showing 30% probability displacement ellipsoids and the
atom-numbering scheme.
ratio at δ -43 (J (119Sn-31P) ) 21 Hz, Sn(IV) moiety)
and δ 109 (J (119Sn-31P) ) 98 Hz, Sn(II) moiety) associ-
1
ated with J (119Sn-117/119Sn) couplings of 9550 and 9130
Hz, respectively. These signals are assigned to the Sn-
(IV)-substituted heteroleptic stannylene {2,6-[P(O)-
(OEt)2]2-4-tert-Bu-C6H2}SnSnPh3 (7). In addition, the
spectrum showed resonances at δ -94 and -143, which
are assigned to 1 and Ph3SnSnPh3, respectively. The
assignment of the tin sites in compound 7 is based
mainly on 119Sn-31P coupling arguments as compared
with the silylated stannylene 6.
The 31P NMR spectrum showed resonances at δ 39.3
(J (119Sn-31P) ) 117 Hz) (1), δ 35.4 (J (119Sn-31P) ) 99
Sch em e 1

4618 Organometallics, Vol. 19, No. 22, 2000
Ta ble 2. Cr ysta llogr a p h ic Da ta for 6, 8, a n d 12
Mehring et al.
6
8
12
formula
C
36H46O6P2SiSn‚
C36H62O12P4S2Sn2
‚2C6H6
1339.35
monoclinc
0.25 × 0.20 × 0.18
P2(1)/c
14.654(1)
12.465(1)
17.677(1)
90
101.918(1)
90
3159.3(4)
2
1.408
1.093
1368
C23H31ClCrO11P2Sn
0.5C4H8O
819.50
triclinic
0.25 × 0.15 × 0.13
P1h
11.958(1)
13.058(1)
15.948(1)
73.454(1)
94.268(1)
67.725(1)
2180.0(3)
2
fw
751.56
cryst syst
cryst size, mm
space group
a, Å
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
monoclinic
0.15 × 0.12 × 0.12
P2(1)/c
10.692(1)
17.372(1)
17.794(1)
90
90.684(1)
90
3304.8(4)
4
Z
F
calcd, Mg/m3
1.248
0.727
848
1.510
1.311
1512
µ, mm-1
F(000)
θ range, deg
3.43-25.37
-14 e he14
-14 e k e 15
-18 e l e 19
28 128
92.6
7405/0.022
4449
2.60-24.37
-16 e h e 16
-14 e k e 14
-20 e l e 20
37 657
99.7
5429/0.039
3264
3.63-27.57
-13 e h e 13
-22 e k e 22
-22 e l e 22
42 667
98.6
7543/0.030
2851
index ranges
no. of reflns collcd
completeness to θmax
no. of indep reflns/Rint
no. of reflns obsd with (I>2σ(I))
no. refined params
GooF (F2)
463
0.893
366
0.941
399
0.841
R1 (F) (I>2σ(I))
0.0373
0.0967
<0.001
0.847/-0.394
0.0364
0.0952
<0.001
0.423/-0.320
0.0301
0.0631
<0.001
0.331/-0.291
wR2 (F2) (all data)
(∆/ σ)max
largest diff peak/hole, e/Å3
Ta ble 3. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for 6 a n d 12
demonstrates a closer electronic relationship of the
latter stannylene to the zwitterionic Sn(II)δ--Sn(II)δ+
compound (tBu3Si)2SnSn(SitBu3)2 (δ 413, -690),14 the
Sn(II)-Sn(II) donor-acceptor complex {C9H6N-[CH-
(SiMe3]-8}2SnfSnCl2 (δ 1264, -637),41 and compound
6, X ) Si(1)
12, X ) Cl(1)
Sn(1)-Cr(1)
Sn(1)-O(1)
Sn(1)-O(2)
Sn(1)-X
2.5835(6)
2.335(2)
2.354(2)
2.394(2)
2.174(3)
1.492(2)
1.481(2)
1.862(4)
1.862(5)
1.858(4)
1.861(4)
1.844(4)
2.543(3)
2.446(2)
2.751(1)
2.229(3)
1.468(3)
1.479(2)
F
[(Me2NCH2CH2CMe2SnCl)3SnCl2)] (δ 412, -119)
(Chart 1),40 rather than to the heteroleptic stannylene
Sn(1)-C(1)
P(1)-O(1)
7.
P(2)-O(2)
In analogy with the reaction of the stannylene 1 with
CsF (see above), the nucleophilic substitutions giving
the stannylene derivatives 4-7a (Scheme 1) are ac-
companied with tin-carbon bond cleavage and, after
protonation under the reaction conditions employed,
formation of 1,3-[P(O)(OEt)2]2-5-tert-BuC6H3, as was
evidenced by the 31P NMR spectra of the corresponding
crude reaction mixtures.
Cr(1)-C(11)
Cr(1)-C(12)
Cr(1)-C(13)
Cr(1)-C(14)
Cr(1)-C(15)
O(1)-Sn(1)-O(2)
O(1)-Sn(1)-Cr(1)
O(1)-Sn(1)-X
O(1)-Sn(1)-C(1)
O(2)-Sn(1)-Cr(1)
O(2)-Sn(1)-X
O(2)-Sn(1)-C(1)
Cr(1)-Sn(1)-Cl(1)
Cr(1)-Sn(1)-C(1)
X-Sn(1)-C(1)
150.97(9)
154.9(1)
100.24(5)
89.25(6)
77.65(9)
102.19(5)
89.17(6)
78.08(9)
119.99(3)
139.23(8)
100.76(8)
88.38(7)
74.9(1)
89.16(7)
76.7(1)
In solution, the heteroleptic stannylenes 4-7a show
triplet resonances in the 119Sn NMR spectra and exhibit
only one 31P NMR signal as a result of two identical Pd
96.35(9)
1
O‚‚‚Sn interactions. The room-temperature 13C and H
NMR spectra of the phenylthio derivative 4, the dior-
ganostannylene 5, and the silylated stannylene 6 each
show two signals for the CH3 groups of the -P(O)(OEt)2
moieties. These results suggest that the tin atoms in
4-6 adopt a pseudo-trigonal-bipyramidal configuration
with the oxygen atoms occupying the axial, and the lone
pair and the ipso-carbon and the sulfur (4), the carbon
(5), or the silicium (6), respectively, occupying the
equatorial positions. In contrast with {2,6-[P(O)(OEt)2]2-
4-tert-Bu-C6H2}SnCl (1), no inversion of configuration
Hz) (7), and δ 18.5, the latter being assigned to 1,3-
[P(O)(OEt)2]2-5-tert-Bu-C6H3. Attempts at isolating ana-
lytically pure 7 from this solution failed. The same holds
for the trimethylstannyl-substituted derivative {2,6-
[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnSnMe3 (7a ), the detailed
NMR data of which are given in the Experimental
Section.
The 119Sn NMR chemical shifts in the Sn(II)-Sn(IV)
compound E [(2-C6H4CH2PPh2)3Sn-SnCl] (Chart 1)47
are at δ -102 [Sn(IV)] and δ -226 [Sn(II)], which is
comparable with the values observed for 7. In contrast,
essentially different chemical shifts of δ 897 and δ -502
have been reported for the Sn(II)-Sn(IV) derivative D
{Sn[2-(Me3Si)2CC5H4N][Sn(SiMe3)3]} (Chart 1),37 which
1
at tin is observed on the H and 13C NMR time scales.
Oxid a tive Ad d ition s of RSn Cl a n d RSn Br to
Give [RSn Cl(µ-S)]2 (8), RSn Br 3 (9), a n d RSn (CP h 3)-

Novel Heteroleptic Stannylenes
Organometallics, Vol. 19, No. 22, 2000 4619
Ta ble 4. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for 8
Oxidative addition of Br2 to {2,6-[P(O)(OEt)2]2-4-tert-
Bu-C6H2}SnBr (2) gave the monorganotin tribromide
{2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnBr3 (9) (eq 3), the
119Sn NMR spectrum of which shows a triplet resonance
at δ -885 (J (119Sn-31P) ) 230 Hz). On the basis of
multinuclear NMR (119Sn, 31P, 1H, 13C) and IR spectros-
copy, compound 9 is likely to adopt a similar, monomeric
molecular structure as previously reported for {2,6-
[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnCl3.50
Sn(1)-C(1)
Sn(1)-O(1)
Sn(1)-O(2)
Sn(1)-S(1)
2.149(4)
2.260(3)
2.267(3)
2.357(1)
Sn(1)-S(1a)
P(1)-O(1)
P(2)-O(2)
2.533(1)
1.494(3)
1.497(3)
C(1)-Sn(1)-Cl(1)
C(1)-Sn(1)-O(1)
C(1)-Sn(1)-O(2)
C(1)-Sn(1)-S(1)
C(1)-Sn(1)-S(1a)
S(1)-Sn(1)-Cl(1)
S(1)-Sn(1)-O(1)
S(1)-Sn(1)-O(2)
S(1)-Sn(1)-S(1a)
Cl(1)-Sn(1)-O(1)
87.8(1)
Cl(1)-Sn(1)-O(2)
Cl(1)-Sn(1)-S(1a)
O(1)-Sn(1)-O(2)
O(1)-Sn(1)-S(1a)
O(2)-Sn(1)-S(1a)
Sn(1)-S(1)-S(1a)
C(2)-P(1)-O(1)
C(6)-P(2)-O(2)
P(1)-O(1)-Sn(1)
P(2)-O(2)-Sn(1)
87.9(1)
177.0(1)
159.0(1)
93.3(1)
91.9(1)
90.1(1)
108.7(2)
107.9(2)
116.5(2)
116.3(2)
79.8(1)
80.0(1)
179.0(1)
89.2(1)
93.1(1)
100.7(1)
99.6(1)
89.9(1)
85.9(1)
-
(Cl)+P F 6 (10) (R ) {2,6-[P (O)(OEt)2]2-4-ter t-Bu -
C6H 2}), r esp ect ively. Although stannathiones of
the type [R2SnS]n (n ) 1, 2; R ) alkyl, aryl) are well
known,6,13,58-61 to the best of our knowledge there is no
report on similar compounds of the type [RSnClS]n.62
The reaction of elemental sulfur with the heteroleptic
stannylene {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnCl (1)
gave the novel dimeric stannathione [{2,6-[P(O)(OEt)2]2-
4-tert-Bu-C6H2}SnCl(µ-S)]2 (8) as a colorless crystalline
solid (Scheme 1). The molecular structure of 8 is shown
in Figure 2, and crystallographic data and relevant bond
angles and distances are given in Tables 2 and 4. The
stannathione 8 consists of a centrosymmetric dimer with
a planar [SnS]2 ring. The Sn(1)-S(1) and Sn(1)-S(1a)
bond lengths of 2.357(1) and 2.533(1) Å are comparable
with those of {[C9H6N(CH(SiMe3)2)-8]2Sn(µ-S)}2 (Sn-S
2.402(3), 2.528(2) Å)58 and [Me2NCH2CH2CH2)2Sn(µ-S)]2
(Sn-S 2.441(1), 2.482(1) Å).60 The S-Sn-S angles in 8
are 89.89(4)° and 90.11(4)°. The tin atom in 8 adopts a
distorted octahedral configuration, and the distortion
from the ideal octahedral geometry is reflected in the
trans angles C(1)-Sn(1)-S(1), Cl(1)-Sn(1)-S(1a), and
O(1)-Sn(1)-O(2) of 179.0(1)°, 177.0(1)°, and 159.0(1)°,
respectively. The deviation of the latter from the ideal
value of 180° results from the ligand constraint, as was
previously observed for the hexacoordinate diorganotin
dichloride {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnCl2Ph (O-
Sn-O 161.2°)48 and the organotin trichloride {2,6-[P(O)-
(OEt)2]2-4-tert-Bu-C6H2}SnCl3 (O-Sn-O 161.1°).50 The
intramolecular Sn(1)-O(1) and Sn(1)-O(2) distances of
2.260(3)/2.267(3) Å are comparable with the correspond-
ing values measured for the dichloro-substituted deriva-
tive {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnCl2Ph (2.203-
(5), 2.278(6) Å). The identity of the dimer is retained in
solution, as evidenced by osmometric molecular weight
determination. A symmetric coordination of the phos-
phonate groups is established by a triplet resonance at
δ -439 (J (119Sn-31P) ) 84 Hz) in the 119Sn NMR
spectrum and a single resonance at δ 26.7 (J (119Sn-
31P) ) 86 Hz) in the 31P NMR spectrum.
The reaction of {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}-
-
SnCl (1) with Ph3C+PF6 gave the tin(IV) cation {2,6-
[P(O)(OEt)2]2-4-tert-Bu-C6H2}Sn(Ph3C)(Cl)+PF6- (10) in
high yield (Scheme 1). To the best of our knowledge,
this reaction is unprecedented in stannylene chemistry
and can formally be interpreted as a Lewis base-Lewis
acid complex or as oxidative addition of the trityl cation
to the stannylene. The Mo¨ssbauer spectrum of the cation
10 shows an isomer shift of IS ) 1.44 mm s-1, typical
for R2Sn(IV) derivatives.63 The IR spectrum of 10 shows
a ν(PdO) at 1178 cm-1, which is comparable with those
reported for the tetravalent organotin derivatives 8
(ν(PdO) 1174 cm-1) and 9 (ν(PdO) 1169 cm-1). In
solution, the 31P NMR resonance for the organotin
cation in 10 is observed at δ 24.8 (J (119Sn-31P) ) 52
Hz) and for the PF6 anion at δ -143.5 (J (31P-19F) )
-
706 Hz), and the 119Sn NMR spectrum displays a triplet
resonance at δ -322 (J (119Sn-31P) ) 52 Hz). The 13C
NMR spectrum exhibits a triplet resonance at δ 79.8
1
(J (13C-31P) ) 4 Hz, J (13C-117/119Sn) 758/788 Hz) for
the quaternary aliphatic carbon of the CPh3 moiety.
Attempts to prepare the isoelectronic BPh3 adduct of 1
failed.
Tr a n sition Meta l Com p lexes of th e Heter olep tic
Sta n n ylen e RSn Cl (1): RSn (Cl)M(CO)n (R ) {2,6-
[P (O)(OEt)2]2-4-ter t-Bu -C6H2}, M ) W, n ) 5 (11);
M ) Cr , n ) 5 (12); M ) F e, n ) 4 (13)). {2,6-[P(O)-
(OEt)2]2-4-tert-Bu-C6H2}SnCl (1) was reacted with
M(CO)5thf (M ) W, Cr) in thf to give {2,6-[P(O)(OEt)2]2-
4-tert-Bu-C6H2}Sn(Cl)M(CO)5 (M ) W, 11; M ) Cr, 12)
(Scheme 1) as pale yellow and pale green solids,
respectively. {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}Sn(Cl)-
Fe(CO)4 (13) was prepared in toluene starting from 1
and Fe2(CO)9 (Scheme 1). The 31P NMR resonances of
the metal stannylene complexes (11, δ ) 33.9, J (119Sn-
31P) ) 160 Hz; 12, δ 32.8, J (119Sn-31P) ) 175 Hz; 13, δ
30.5, J (119Sn-31P) ) 161 Hz) are significantly low
frequency shifted as compared with that for the hetero-
leptic stannylene 1 (δ 39.1, J (119Sn-31P) ) 113 Hz). In
the 119Sn NMR spectra of the stannylene complexes 11,
12, and 13 triplet resonances are observed at δ -74
(J (119Sn-31P) ) 161 Hz), δ 131 (J (119Sn-31P) ) 179 Hz),
and δ 54 (J (119Sn-31P) ) 165 Hz), respectively. The
(58) Leung, W.-P.; Kwok, W.-H.; Law, L. T. C.; Zhou, Z.-Y.; Mak, T.
C. W. J . Chem. Soc., Chem. Commun. 1996, 505.
(59) Matsuhashi, Y.; Tokitoh, N.; Okazaki, R.; Goto, M. Organome-
tallics 1993, 12, 2573.
(60) J urkschat, K.; van Dreumel, S.; Dyson, G.; Dakternieks, D.;
Bastow, D. J .; Smith, M. E.; Dra¨ger, M. Polyhedron 1992, 11, 2747.
(61) Schneider, J . J .; Hagen, J .; Heinemann, O.; Bruckmann, J .;
Kru¨ger, C. Thin Solid Films 1997, 304, 144.
(62) Organometallic compounds with a similar substitution pattern
{[Cp(Ph3P)2M]SnClS}2 (M ) Ni(a), Ru(b)) have been reported. (a) Kraus,
H.; Merzweiler, K. Z. Naturforsch. 1997, 52b, 635 (b) Hauser, R. Ph.D.
Thesis, University of Halle-Wittenberg, 1998.
(63) Barbieri, R.; Huber, F.; Pellerito, L.; Ruisi, G.; Silvestri, A. In
119Sn Mo¨ssbauer Studies on Tin Compounds; Smith, P. J ., Ed.; Blackie
Academic & Professional: New York, 1998; pp 496-540.

4620 Organometallics, Vol. 19, No. 22, 2000
Mehring et al.
single bond (2.85 Å)65 and close to the Sn-Cr bond
lengths in the three-coordinate stannylenes (CO)5-
66
CrSn[CH(SiMe3)2]2
(2.562(2) Å) and (CO)5CrSn-
(2,4,6-tBuC6H2)(CH2C(CH3)2-3,5-tBu2C6H3)67 (2.614(1)
Å). Slightly longer Sn-Cr bond distances have been
reported for (CO)5CrSn(tBu)2‚pyridine (Sn-Cr 2.653(3)
Å),68 (CO)5CrSn(SCH2CH2)2NtBu (Sn-Cr 2.62(1) Å),52
and (CO)5CrSn(SCH2CH2)2PPh‚pyridine (Sn-Cr 2.618-
(1) Å),69 which is attributed to the additional N-Sn
donor interaction. A relatively short Sn-Cr bond has
been reported for (salen)SnCr(CO)5 (2.558(1) Å),25 in
which the tin center is coordinated by a tetradentate
ligand in a distorted square-pyramidal geometry. Both
the 13C NMR chemical shifts for the carbonyl carbons
at δ 219.9 and 226.3 and the ν(CO) of 1927 and 2051
cm-1 indicate the stannylene fragment in 12 to have a
similar π-acceptor capacity as reported for the stanna-
(II)bicyclooctanes RN(CH2CH2X)2Sn (R ) Me, tBu; X )
O, S)70 and for (salen)Sn.25
Con clu sion
F igu r e 3. General view (SHELXTL) of a molecule of 12
showing 30% probability displacement ellipsoids and the
atom-numbering scheme.
In this contribution we have demonstrated the ver-
satility of the O,C,O-coordinating ligand {2,6-[P(O)-
(OEt)2]2-4-tert-Bu-C6H2}- in stannylene chemistry. The
rigid backbone of the ligand including the coordinating
PdO donor groups stabilizes the tin(II) fragments,
especially in the heteroleptic stannylene 1, which is to
the best of our knowledge the most stable compound of
the type RSnCl reported so far. However, the O,C,O-
coordinating ligand does not fully compensate for the
electron deficiency at the tin(II) center, which still acts
as a Lewis acid toward anions and as a Lewis base
toward transition metal fragments. The stannylene 1
was demonstrated to be a reasonable precursor for the
preparation of Sn(II)-M compounds with M ) Si, Sn,
Cr, W, and Fe. The air-stable heterobimetallic stan-
nylenes 11-13 containing a Sn-Cl function should
allow the preparation of heterotrimetallic compounds.
signal of the tungsten derivative 11 is only slightly high
frequency shifted in comparison with the heteroleptic
stannylene 1 (δ -100, J (119Sn-31P) ) 116 Hz), whereas
the chromium derivative 12 and the iron complex 13
show a significant high-frequency shift. A similar effect
of the transition metal fragment on the 119Sn chemical
shift was reported for other metal-stannylene com-
plexes,24 e.g., M(CO)5SnCl2‚thfx (M ) W, δ -209; M )
Cr, δ ) 55) compared with SnCl2‚thfx (δ -238). The
1J (119Sn-183W) coupling in 11 amounts to 1372 Hz,
which lies between the values reported for compounds
of the type W(CO)5SnX2‚thfx (X ) Cl, Br, 1J (119Sn-183W)
) 1440-1610 Hz)64 and intramolecularly donor stabi-
lized tungsten-diorganostannylene adducts of the type
W(CO)5SnR2 (1J (119Sn-183W) ) 892-976 Hz).18,47,51
Exp er im en ta l Section
The molecular structure of {2,6-[P(O)(OEt)2]2-4-tert-
Bu-C6H2}Sn(Cl)Cr(CO)5 (12) is shown in Figure 3,
crystallographic data are given in Table 2, and selected
bond lengths and angles are summarized in Table 3.
The O,C,O-pincer-type ligand in 12 is bonded in a
tridentate fashion with C(1)-Sn(1), O(1)-Sn(1), and
O(2)-Sn(1) bond lengths of 2.174(3), 2.335(2), and 2.354-
(2) Å, respectively. The latter are somewhat shortened
in comparison with O-Sn bond lengths in the silyl-
substituted stannylene 6 (2.546(3), 2.443(3) Å). The
coordination geometry at the tin center is best described
as a distorted trigonal bipyramid with the oxygens O(1)
and O(2) occupying the axial sites and C(1), Cr(1), and
Cl(1) the equatorial positions. The tin atom lies nearly
perfectly in the equatorial plane (∆ ) 0.014(1) Å). The
Cr(1)-Sn(1)-Cl(1) (139.2(1)°) and Cl(1)-Sn(1)-C(1)
(100.8(8)°) angles deviate from 120 °C as a result of
steric repulsion by the Cr(CO)5 fragment. The O(1)-
Sn(1)-O(2) angle amounts to 154.9(1)° and lies between
the O-Sn-O angles in 6 (O-Sn-O 150.8(1)°) and 8 (O-
Sn-O 159.0(1)°). The Sn(1)-Cr(1) bond length of 2.5835-
(6) Å is remarkably short in comparison with a Sn-Cr
Gen er a l Meth od s. All reactions were carried out under an
atmosphere of dry nitrogen. The solvents were purified by
distillation from appropriate drying agents under nitrogen.
[{2,6-Bis(diethoxyphosphonyl)-4-tert-butyl}phenyl]lith-
72
ium,48 Ph3SiLi,71 and Ph3SnLi were prepared according to
the literature, and tetrabutylammonium fluoride trihydrate
and [(Ph3P)2N]+Cl- were commercial products.
Elemental analyses were performed on an instrument from
Carlo Erba Strumentazione (Model 1106), and the molecular
weight determinations were measured osmometrically on a
Knauer Dampfdruckosmometer.
(65) Struchkov, Y. T.; Anisimov, K. N.; Osipova, O. P.; Kolobova,
N. E.; Nesmeyanov, A. N. Proc. Acad. Sci. (USSR) 1967, 172, 15.
(66) Cotton, J . D.; Davidson, P. J .; Lappert, M. F. J . Chem. Soc.,
Dalton Trans. 1976.
(67) Weidenbruch, M.; Stilter, A.; Peters, K.; von Schnering, H. G.
Z. Anorg. Allg. Chem. 1996, 622, 534.
(68) Brice, M. D.; Cotton, F. A. J . Am. Chem. Soc. 1973, 95, 4529.
(69) J urkschat, K.; Tzschach, A.; Meunier-Piret, J .; van Meersche,
M. J . Organomet. Chem. 1988, 349, 143.
(70) Zschunke, A.; J urkschat, A.; Scheer, M.; Vo¨ltzke, M.; J urkschat,
K.; Tzschach, A. J . Organomet. Chem. 1986, 308, 325.
(71) Gilman, H.; Lichtenwalter, G. D. J . Am. Chem. Soc. 1960, 82,
3319.
(72) Quintard, J .-P.; Pereye, M. In Reviews on Silicon, Germanium,
Tin and Lead Compounds; Gielen, M., Ed.; Freund Publishing House
Ltd.: Tel Aviv, 1980; Vol. IV/3, p 151.
(64) du Mont, W.-W.; Kroth, H. J . Z. Naturforsch. 1980, 35b, 700.

Novel Heteroleptic Stannylenes
Organometallics, Vol. 19, No. 22, 2000 4621
NMR spectra were recorded on Bruker DRX400 and Bruker
DPX300 FT NMR spectrometers with broad band decoupling
of 119Sn at 149.21 and 111.92 MHz, respectively, and of 13C at
(400.13 MHz, [d8]toluene): δ 1.14 (s, ν1/2 ) 16 Hz, 12H, CH3),
1.24 (s, 9H, CH3), 4.04 (s, ν1/2 ) 25 Hz, 4H, CH2), 4.32 (s, ν1/2
) 20 Hz, 2H, CH2), 4.54 (ν1/2 ) 20 Hz, 2H, CH2), 8.18 (complex
pattern, 2H, HPh). 1H NMR (400.13 MHz, [d8]toluene, -20
°C): δ 1.14 (t, 6H, CH3), 1.20 (t, 6H, CH3), 1.23 (s, 9H, CH3),
3.93-4.00 (complex pattern, 4H, CH2), 4.32-4.41 (complex
pattern, 2H, CH2), 4.63-4.71 (complex pattern, 2H, CH2), 8.27
(complex pattern, 2H, HPh). 13C{1H} NMR (100.63 MHz, [d8]-
toluene): δ 16.8 (s, 2C, CH3), 16.9 (s, 2C, CH3), 31.5 (s, 3C,
CH3), 35.3 (s, 1C, C), 63.7 (s, ν1/2 ) 30 Hz, 2C, CH2), 64.3 (s,
ν1/2 ) 30 Hz, 2C, CH2), 132.2 (dd, 1J (13C-31P) ) 193 Hz, 3J (13C-
31P) ) 24 Hz, 2C, C2,6), 132.4 (complex pattern, 2C, C3,5), 151.9
(t, 3J (13C-31P) ) 13 Hz, 1C, C4), 188.2 (t, 2J (13C-31P) ) 37 Hz,
1C, C1). 119Sn{1H} NMR (149.18 MHz, [d8]toluene): δ -100
(t, J (119Sn-31P) ) 116 Hz). 31P{1H} NMR (161.98 MHz, [d8]-
toluene): δ 39.1 (J (31P-119Sn) ) 113 Hz). IR (KBr): ν ) 1192
cm-1 (PdO); 1171 cm-1 (PdO). Anal. Calcd for C18H31ClO6P2-
Sn (559.6): C, 38.6; H, 5.6; Cl, 6.3. Found: C, 38.2; H, 5.8; Cl,
6.3. Molecular weight determination (benzene, 45 °C): 506 g
mol-1. Mo¨ssbauer spectroscopy: QS ) 3.51 mm s-1, IS. ) 3.24
mm s-1. Compound 1 was exposed to air for 8 days, and
Mo¨ssbauer spectra of this sample were measured after 0, 3,
75, and 179 h.
1
100.61 MHz, using external and internal deuterium lock. H,
13C, and 119Sn NMR chemical shifts δ are given in ppm and
referenced to external Me4Sn (119Sn) and Me4Si (13C, 1H),
respectively. Temperatures were maintained using a Bruker
control system. The NMR spectra were recorded at room
temperature if not otherwise stated.
IR spectra were obtained using a Bruker FT-IR IFS 113v
spectrometer.
The Mo¨ssbauer spectra were recorded in constant-accelera-
tion mode on a homemade instrument, designed and built by
the Institut voor Kernen Stralingsfysica (IKS), Leuven. The
isomer shifts refer to a source of Ca119mSnO3 from Amersham,
U.K., samples being maintained at 90 ( 2 K. The data were
treated with a least-squares iterative program deconvoluting
the spectrum into a sum of Lorentzians.
Cr ysta llogr a p h y. Intensity data for the crystals were
collected on a Nonius KappaCCD diffractometer with graphite-
monochromated Mo KR (0.71069 Å) radiation at 291 K (6, 12)
and 203 K (8). The data collection covered almost the whole
sphere of reciprocal space with 360 frames via ω-rotation (∆/ω
) 1°) at two times, 10 s (8) and 20 s (6, 12), per frame. The
crystal-to-detector distance was 2.8 cm (6), 2.9 cm (8), and 3.0
cm (12) with a detector-θ-offset of 5° (12). Crystal decay was
monitored by repeating the initial frames at the end of data
collection. The data were not corrected for absorption effects.
Analyzing the duplicate reflections, there was no indication
for any decay. The structure was solved by direct methods
using SHELXS9773 and successive difference Fourier synthe-
ses. Refinement applied full-matrix least-squares methods
using SHELXL97.74
The H atoms were placed in geometrically calculated
positions using a riding model (C-Hprim. 0.96 Å, C-Hsec. 0.97
Å; Haryl C-H 0.93). The H atom isotropic temperature factors
of 6 are constrained to be 1.5 times those of the carrier atom
for aliphatic C atoms and refined with a common isotropic
temperature factor (Uiso 0.101(3) Å2), those of 8 are refined
with a common isotropic temperature factor (Uiso 0.160(5) Å2)
for aromatic C atoms, and those of 12 are refined with common
isotropic temperature factors for Haryl (Uiso 0.050(6) Å2) and
for Halkyl (Uiso 0.214(5) Å2).
Disordered tetramethylene, tert-butyl (12), and iso-butyl (8)
groups were found with occupancies of 0.3333 (C(43′), C(44′)),
0.5 (C(3), C(5), C(3′), C(5′)), and 0.6666 (C(43), C(44)) in 12
and of 0.15 (C(32′)) and 0.85 (C(32)) in 8. The solvent molecule
thf (6) was isotropically refined with an occupancy of 0.5.
Atomic scattering factors for neutral atoms and real and
imaginary dispersion terms were taken from International
Tables for X-ray Crystallography.75 The figures were created
by SHELXTL.76 Crystallographic data are given in Table 2,
and selected bond distances and angles for 6 and 12 are given
in Table 3 and for 8 in Table 4.
Syn t h esis of {[2,6-Bis(d iet h oxyp h osp h on yl)-4-ter t-
bu tyl]p h en yl}tin (II) Br om id e, {2,6-[P (O)(OEt)2]2-4-ter t-
Bu C6H2}Sn Br (2). [{2,6-Bis(diethoxyphosphonyl)-4-tert-butyl}-
phenyl]lithium (1.53 g, 3.71 mmol) was added in small portions
at -30 °C to a suspension of SnBr2 (1.14 g, 4.09 mmol) in thf
(30 mL). The suspension was stirred for 4 h at -30 °C and 12
h at room temperature. The solvent was evaporated, the
residue was extracted four times with hot hexane (240 mL),
and then the solution was concentrated to a volume of 60 mL.
Crystallization at -20 °C afforded 0.22 g (10%) of 2 as colorless
1
solid, mp 105-106 °C. H NMR (400.13 MHz, [d8]toluene): δ
1.02 (t, 12H, CH3), 1.11 (s, 9H, CH3), 3.93-4.00 (complex
pattern, 4H, CH2), 4.00-4.19 (complex pattern, 4H, CH2), 8.27
(complex pattern, 2H, HPh). 13C{1H} NMR (100.63 MHz, [d8]-
3
toluene): δ 15.9 (d, J (13C-31P) ) 7 Hz, 4C, CH3), 30.5 (s, 3C,
CH3), 34.3 (s, 1C, C), 63.1 (d, 2J (13C-31P) ) 5 Hz, 4C, CH2),
131.2 (dd, 1J (13C-31P) ) 193 Hz, 3J (13C-31P) ) 24 Hz, 2C, C2,6),
131.4 (complex pattern, 2C, C3,5), 151.0 (t, 3J (13C-31P) ) 13
2
Hz, 1C, C4), 185.8 (t, J (13C-31P) ) 36 Hz, 1C, C1). 119Sn{1H}
NMR (149.18 MHz, [d8]toluene): δ -68 (t, J (119Sn-31P) ) 116
Hz). 31P{1H} NMR (161.98 MHz, [d8]toluene): δ 38.8 (J (31P-
119/117Sn) ) 115/111 Hz). IR (KBr): ν ) 1192 cm-1 (PdO), 1171
cm-1 (PdO). Anal. Calcd for C18H31BrO6P2Sn (604.0): C, 35.8;
H, 5.2; Br, 13.2. Found: C, 36.2; H, 5.6; Br, 13.1.
Reaction of {[2,6-Bis(dieth oxyph osph on yl)-4-ter t-bu tyl]-
p h en yl}tin (II) Ch lor id e (1) w ith Bu 4NF ‚3H2O. To a solu-
tion of {2,6-[P(O)(OEt)2]2-4-tert-BuC6H2}SnCl (1) (65 mg, 0.12
mmol) in [d8]toluene (0.5 mL) was added Bu4NF‚3H2O (37 mg,
0.12 mmol) at room temperature. 119Sn{1H} NMR spectra of
this solution were recorded at room temperature and at -40
°C. 119Sn{1H} NMR (149.18 MHz, [d8]toluene): δ -98 (ν1/2
)
1000 Hz). 119Sn{1H} NMR (149.18 MHz, [d8]toluene, -40 °C):
δ -111 (ν1/2 ) 290 Hz, integral 0.2), -208 (J (119Sn-31P) ) 112
Hz, 1J (119Sn-19F) ) 3140 Hz, integral 0.8). 31P{1H} NMR
(161.98 MHz, [d8]toluene, -40 °C): δ 45.2 (ν1/2 ) 80 Hz).
Reaction of {[2,6-Bis(dieth oxyph osph on yl)-4-ter t-bu tyl]-
p h en yl}tin (II) Ch lor id e (1) w ith [(P h 3P )2N]+Cl-. To a
solution of {2,6-[P(O)(OEt)2]2-4-tert-BuC6H2}SnCl (1) (105 mg,
0.19 mmol) in [d8]toluene (0.4 mL) was added [(Ph3P)2N]+Cl-
in a 1:2 (214 mg, 0.38 mmol) and 1:1 (107 mg, 0.19 mmol)
molar ratio at room temperature. 119Sn{1H} and 31P{1H} NMR
spectra of these solutions were recorded at different temper-
atures.
Syn t h esis of {[2,6-Bis(d iet h oxyp h osp h on yl)-4-ter t-
bu tyl]p h en yl}tin (II) Ch lor id e, {2,6-[P (O)(OEt)2]2-4-ter t-
Bu C6H2}Sn Cl (1). [{2,6-Bis(diethoxyphosphonyl)-4-tert-butyl}-
phenyl]lithium (5.55 g, 13.50 mmol) was added in small
portions at -30 °C to a solution of SnCl2 (2.65 g, 13.98 mmol)
in thf (90 mL). The resulting suspension was stirred for 4 h
at -30 °C and 2 h at room temperature. The solvent was
evaporated, the residue was extracted four times with hot
hexane (320 mL), and the combined solutions were concen-
trated to a volume of 80 mL. Crystallization at -20 °C afforded
5.10 g (68%) of 1 as a colorless solid, mp 107-109 °C. 1H NMR
(73) Sheldrick, G. M. Acta Crystallogr. 1990, A46, 467.
(74) Sheldrick, G. M. SHELXL97; University of Go¨ttingen: 1997.
(75) International Tables for Crystallography; Kluwer Academic
Publishers: Dordrecht, 1992.
(76) Sheldrick, G. M. SHELXTL, Release 5.1 Software Reference
Manual; Bruker AXS, Inc.: Madison, WI, 1997.
Syn t h esis of {[2,6-Bis(d iet h oxyp h osp h on yl)-4-ter t-
bu tyl]p h en yl}(th iop h en ola te)tin (II), {2,6-[P (O)(OEt)2]2-
4-ter t-Bu -C6H2}Sn SP h (4). NaSPh (220 mg, 1.67 mmol) was
added to a solution of {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnCl
(550 mg, 0.98 mmol) in toluene (25 mL). After stirring the

4622 Organometallics, Vol. 19, No. 22, 2000
Mehring et al.
2
suspension for 17 h at 80 °C, the solvent was removed in vacuo,
and the resulting residue was extracted twice with 25 mL of
hot n-hexane and filtered. The filtrate was reduced to a volume
of 15 mL. Crystallization at -25 °C yielded 450 mg (72%) of 4
as a pale yellow solid, mp 250 °C. 1H NMR (400.13 MHz,
CDCl3): δ 1.22 (t, 6H, CH3), 1.24 (t, 6H, CH3), 1.28 (s, 9H,
CH3), 3.94-4.34 (complex pattern, 8H, CH2), 6.92 (t, 1H,
13 Hz, 1C, C4), 185.5 (t, J (13C-31P) ) 36 Hz, 1C, C1). 119Sn-
{1H} NMR (121.49 MHz, thf/D2O-cap.): δ 192 (t, J (117/119Sn-
31P) ) 96 Hz). 29Si{1H} NMR (59.63 MHz, thf/D2O-cap.): δ 7.9
(s, 1J (29Si-117/119Sn) ) 674/708 Hz). 31P{1H} NMR (161.98 MHz,
[d8]toluene): δ 34.5 (J (119Sn-31P) ) 95 Hz). Anal. Calcd for
C
36H46O6P2SiSn (783.5): C, 55.2; H, 5.9. Found: C, 55.9; H,
6.7.
In Situ Syn th eses of {[2,6-Bis(d ieth oxyp h osp h on yl)-
H
Ph,para), 7.04 (t, 2H, HPh,meta), 7.45 (d, 2H, HPh,ortho), 7.79 (d,
3J (1H-31P) ) 14 Hz, 2H, Haryl). 13C{1H} NMR (100.63 MHz,
CDCl3): δ 16.7 (d, 3J (13C-31P) ) 9 Hz, 2C, CH3), 16.8 (d,
3J (13C-31P) ) 9 Hz, 2C, CH3), 31.6 (s, 3C, CH3), 35.3 (s, 1C,
Cq), 63.2 (d, 2J (13C-31P) ) 6 Hz, 2C, CH2), 64.2 (d, 2J (13C-31P)
) 5 Hz, 2C, CH2), 124.1 (s, 1C, CPh,para), 128.4 (s, 2C, CPh,meta),
131.9 (dd, 1J (13C-31P) ) 193 Hz, 3J (13C-31P) ) 24 Hz, 2C, C2,6),
4-ter t-b u t yl]p h en yl}(t r ior ga n ost a n n yl)t in (II) Der iva -
tives, {2,6-[P (O)(OEt)2]2-4-ter t-Bu -C6H2}Sn Sn P h 3 (7) a n d
{2,6-[P (O)(OEt)2]2-4-ter t-Bu -C6H2}Sn Sn Me3 (7a ). A solution
of R3SnLi (7, R ) Ph; 7a , R ) Me; 2.70 mmol) in thf (15 mL)
was added dropwise at -40 °C to a solution of {2,6-[P(O)-
(OEt)2]2-4-tert-Bu-C6H2}SnCl (1.00 g, 1.79 mmol) in thf (15
mL). Stirring for 15 h at -40 °C gave a red-brown solution,
the volume of which was reduced in vacuo at -20 °C to about
5 mL. From this solution 31P and 119Sn NMR spectra were
recorded.
2
4
132.2 (dd, J (13C-31P) ) 17 Hz, J (13C-31P) ) 4 Hz, 2C, C3,5),
3
133.2 (s, 2C, CPh,ortho), 142.0 (s, 1C, CPh,ipso), 151.5 (t, J (13C-
3
31P) ) 13 Hz, 1C, C4), 182.7 (t, J (13C-31P) ) 35 Hz, 1C, C1).
119Sn{1H} NMR (111.92 MHz, toluene/D2O-cap.): δ 2 (t,
J (119Sn-31P) ) 96 Hz). 31P{1H} NMR (121.49 MHz, toluene/
D2O-cap.): δ 37.4 (s, J (13P-117/119Sn) ) 95 Hz). IR (Nujol): ν
) 1164 cm-1 (PdO). Anal. Calcd for C24H36O6P2SSn (633.3):
C, 45.5; H, 5.7. Found: C, 45.5; H, 5.7.
Com p ou n d 7. 119Sn{1H} NMR (111.92 MHz, thf/D2O-
cap.): δ 109 (t, J (119Sn-31P) ) 98 Hz, 1J (119Sn-117/119Sn) )
9130/9550 Hz, Sn(II) of 7), -43 (t, J (119Sn-31P) ) 21 Hz,
1J (119Sn-117/119Sn) ) 9125/9545 Hz, Sn(IV) of 7), -94 (ν1/2
)
400 Hz, 1), -143.4 (Ph3SnSnPh3). 31P{1H} NMR (121.49 MHz,
thf/D2O-cap.): δ 39.2 (s, J (31P-117/119Sn) ) 112 Hz, 1), 35.4 (s,
J (31P-117/119Sn) ) 99 Hz), 18.5 (1,3-[P(O)(OEt)2]2-4-tert-Bu-
C6H3).
Syn t h esis of {[2,6-Bis(d iet h oxyp h osp h on yl)-4-ter t-
bu tyl]p h en yl}[bis(tr im eth ylsilylm eth yl)]tin , {2,6-[P (O)-
(OEt)2]2-4-ter t-Bu -C6H2}Sn CH(SiMe3)2 (5). To a solution of
{2,6-[P(O)(OEt)2]2-4-tert-BuC6H2}SnCl (1) (932 mg, 1.67 mmol)
in diethyl ether (12 mL) at -78 °C was added (Me3Si)2CHLi
(278 mg, 1.68 mmol) in small portions. The resulting suspen-
sion was stirred overnight at room temperature, the solid was
filtered, and all volatiles were evaporated to give 1.03 g (91%)
Com p ou n d 7a . 119Sn{1H} NMR (111.92 MHz, thf/D2O-
cap.): δ 217 (t, J (119Sn-31P) ) 93 Hz, 1J (119Sn-117/119Sn) )
7976/8346 Hz, Sn(II) of 7a ), 11 (t, J (119Sn-31P) ) 21 Hz,
1J (119Sn-117/119Sn) ) 9125/9545 Hz, Sn(IV) of 7a ), -75.0 (ν1/2
) 122 Hz, not assigned), -106 (Me3SnSnMe3). 31P{1H} NMR
(121.49 MHz, thf/D2O-cap.): δ 37.7 (s, J (31P-117/119Sn) ) 21,
95 Hz, 7a ), 20.9 (1,3-[P(O)(OEt)2]2-4-tert-Bu-C6H3).
1
of 5 as a pale yellow solid, 90 °C (dec). H NMR (400.13 MHz,
[d8]toluene): δ 0.29 (s, 1H, CH), 0.61 (s, 18H, SiMe3), 1.11 (t,
6H, CH3), 1.36 (s, 9H, CH3), 1.38 (t, 6H, CH3), 3.85-3.95
(complex pattern, 2H, CH2), 4.04-4.14 (complex pattern, 2H,
CH2), 4.22-4.39 (complex pattern, 4H, CH2), 8.13 (complex
pattern, 2H, HPh). 13C{1H} NMR (100.63 MHz, [d8]toluene): δ
4.27 (s, 1J (13C-29Si) ) 48 Hz, 4J (13C-119Sn) ) 15 Hz, 6C,
SiMe3), 15.7 (d, 3J (13C-31P) ) 7 Hz, 2C, CH3), 15.8 (d, 3J (13C-
31P) ) 7 Hz, 2C, CH3), 30.6 (s, 3C, CH3), 34.1 (s, 1C, C), 62.1
Syn t h esis of {[2,6-Bis(d iet h oxyp h osp h on yl)-4-ter t-
bu tyl]p h en yl}tin Ch lor id e Su lfid e, {{2,6-[P (O)(OEt)2]2-
4-ter t-Bu C6H2}Sn (S)Cl}2 (8). Sulfur (19 mg, 0.59 mmol) was
added at -78 °C to a solution of {2,6-[P(O)(OEt)2]2-4-tert-
BuC6H2}SnCl (1) (305 mg, 0.55 mmol) in thf (5 mL). The
reaction mixture was stirred at room temperature overnight,
and the solvent was evaporated. The residue was crystallized
from toluene/CHCl3 at 4 °C to give 226 mg (69%) of 8 as
2
2
(d, J (13C-31P) ) 7 Hz, 2C, CH2), 62.2 (d, J (13C-31P) ) 5 Hz,
2C, CH2), 130.9 (complex pattern, 2C, C3,5), 132.2 (dd, 1J (13C-
31P) ) 195 Hz, 3J (13C-31P) ) 24 Hz, 2C, C2,6), 149.4 (t, 3J (13C-
1
colorless crystals, mp > 350 °C. H NMR (400.13 MHz, [d8]-
31P) ) 13 Hz, 1C, C4), 189.8 (t, J (13C-31P) ) 37 Hz, 1C, C1).
2
toluene): δ 1.12 (s, 9H, CH3), 1.16 (t, 6H, CH3), 1.38 (t, 6H,
CH3), 4.30-4.33 (complex pattern, 2H, CH2), 4.53-4.62 (com-
plex pattern, 4H, CH2), 4.98-5.01 (complex pattern, 2H, CH2),
8.03 (complex pattern, 2H, HPh). 13C{1H} NMR (100.63 MHz,
[d8]toluene): δ 15.8 (complex pattern, 2C, CH3), 16.0 (complex
pattern, 2C, CH3), 30.5 (s, 3C, CH3), 34.3 (s, 1C, C), 64.6 (s,
119Sn{1H} NMR (149.18 MHz, [d8]toluene): δ 259 (t, J (119Sn-
31P) ) 106 Hz). 31P{1H} NMR (161.98 MHz, [d8]toluene): δ
33.5 (J (31P-119Sn) ) 107 Hz). Anal. Calcd for C25H50O6P2Si2-
Sn (683.5): C, 43.9; H, 7.4. Found: C, 43.5; H, 7.1.
Syn t h esis of {[2,6-Bis(d iet h oxyp h osp h on yl)-4-ter t-
bu t yl]p h en yl}(t r ip h en ylsilyl)t in (II), {2,6-[P (O)(OE t )2]2-
4-ter t-Bu -C6H2}Sn SiP h 3 (6). A solution of Ph3SiLi (2.70
mmol) in thf (40 mL) was added dropwise at -40 °C to a
solution of {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnCl (1.50 g, 2.69
mmol) in thf (15 mL). Stirring for 15 h at -40 °C yielded a
red-brown solution, which was then evaporated to dryness in
vacuo at -20 °C. The resulting brown solid was extracted and
filtered four times with 25 mL of cold n-hexane. The filtrates
were combined and reduced to a volume of 25 mL. Crystal-
lization at -25 °C yielded 300 mg (14%) of 6 as an orange solid,
1
2C, CH2), 65.5 (s, 2C, CH2), 125.8 (dd, J (13C-31P) ) 180 Hz,
3J (13C-31P) ) 19 Hz, 2C, C2,6), 130.7 (complex pattern, 2C, C3,5),
3
2
152.3 (t, J (13C-31P) ) 13 Hz, 1C, C4), 177.5 (t, J (13C-31P) )
19 Hz, 1C, C1). 119Sn{1H} NMR (149.18 MHz, [d8]toluene): δ
-439 (t, J (119Sn-31P) ) 84 Hz). 31P{1H} NMR (161.98 MHz,
[d8]toluene): δ 26.7 (J (31P-119/117Sn) ) 86/82 Hz). IR (KBr): ν
) 1174 cm-1 (PdO). Anal. Calcd for C36H62Cl2O12P4S2Sn2
(1183.3): C, 36.5; H, 5.3. Found: C, 36.0; H, 4.8. Molecular
weight determination (CHCl3, 36 °C): 1166 g mol-1
.
Syn t h esis of {[2,6-Bis(d iet h oxyp h osp h on yl)-4-ter t-
bu tyl]p h en yl}tin Tr ibr om id e, {2,6-[P (O)(OEt)2]2-4-ter t-
Bu C6H2}Sn Br 3 (9). Bromine (0.1 mL, 0.20 mmol) was added
at 0 °C to a solution of {2,6-[P(O)(OEt)2]2-4-tert-BuC6H2}SnBr
(2) (100 mg, 0.16 mmol) in toluene (3 mL). The reaction
mixture was stirred at room temperature overnight, and the
resulting residue was filtered and crystallized from CH2Cl2/
hexane by slow evaporation of CH2Cl2 at room temperature
1
mp 77-79 °C. H NMR (400.13 MHz, [d8]thf): δ 0.94 (t, 6H,
CH3), 1.22 (t, 6H, CH3), 1.42 (s, 9H, CH3), 3.07 (complex
pattern, 2H, CH2), 3.33 (complex pattern, 2H, CH2), 3.96
(complex pattern, 2H, CH2), 4.05 (complex pattern, 2H, CH2),
3
7.05-7.30 (complex pattern, 15H, Ph3Si), 7.77 (d, J (1H-31P)
) 13 Hz, 2H, Haryl). 13C{1H} NMR (100.63 MHz, thf/D2O-
cap.): δ 15.6 (d, 3J (13C-31P) ) 7 Hz, 2C, CH3), 15.7 (d, 3J (13C-
31P) ) 7 Hz, 2C, CH3), 30.7 (s, 3C, CH3), 34.4 (s, 1C, Cq), 62.0
1
to give 45 mg (37%) of 9 as a colorless solid, mp > 350 °C. H
3
3
(d, J (13C-31P) ) 6 Hz, 2C, CH2), 62.3 (d, J (13C-31P) ) 5 Hz,
NMR (400.13 MHz, CDCl3): δ 1.36 (t, 12H, CH3), 1.36 (s, 9H,
CH3), 4.25-4.35 (complex pattern, 4H, CH2), 4.42-4.52 (com-
plex pattern, 4H, CH2), 7.92 (complex pattern, 2H, HPh). 13C-
{1H} NMR (100.63 MHz, CDCl3): δ 16.2 (complex pattern, 4C,
CH3), 31.3 (s, 3C, CH3), 35.5 (s, 1C, C), 66.1 (complex pattern,
2C, CH2), 126.8 (s, 6C, CPh,meta), 127.1 (s, 3C, CPh,para), 131.0
(dd, J (13C-31P) ) 17 Hz, J (13C-31P) ) 4 Hz, 2C, C3,5), 131.7
2
4
(dd, 1J (13C-31P) ) 194 Hz, 3J (13C-31P) ) 24 Hz, 2C, C2,6), 136.6
(s, 6C, CPh,ortho), 141.7 (s, 3C, CPh,ipso), 149.4 (t, J (13C-31P) )
3

Novel Heteroleptic Stannylenes
Organometallics, Vol. 19, No. 22, 2000 4623
1
3
4C, CH2), 122.7 (dd, J (13C-31P) ) 186 Hz, J (13C-31P) ) 18
(CdO). Anal. Calcd for C23H31ClO11P2SnW (883.4): C, 31.3;
H, 3.5. Found: C, 31.5; H, 3.4.
Hz, 2C, C2,6), 131.2 (complex pattern, 2C, C3,5), 154.7 (t, 3J (13C-
31P) ) 13 Hz, 1C, C4), 175.0 (t, J (13C-31P) ) 18 Hz, 1C, C1).
Syn t h esis of {[2,6-Bis(d iet h oxyp h osp h on yl)-4-ter t-
bu tyl]p h en yl}tin Ch lor id e Ch r om iu m P en ta ca r bon yl,
{2,6-[P (O)(OEt)2]2-4-ter t-Bu -C6H2}{Cl}Sn [Cr (CO)5] (12). A
solution of Cr(CO)6 (1.00 g, 4.54 mmol) in thf (270 mL) was
irradiated (UV light, Hg high-pressure lamp) until 100 mL (4.1
mmol) of CO was produced (1.5 h). From this solution, 140
mL (2.35 mmol Cr(CO)5(thf)) was added dropwise at room
temperature to a solution of {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}-
SnCl (1) (1.00 g, 1.79 mmol) in thf (30 mL). After stirring the
mixture for 17 h, the solvent was evaporated, and the excess
Cr(CO)6 was sublimed in vacuo at 40 °C. Crystallization of the
residue from n-hexane/toluene (15:1) yielded 310 mg (23%) of
12 as a pale green solid, mp 163-165 °C. 1H NMR (400.13
MHz, C6D6): δ 0.91 (t, 6H, CH3), 1.01 (complex pattern, 15H,
2
119Sn{1H} NMR (149.18 MHz, CDCl3): δ -885 (t, J (119Sn-31P)
) 230 Hz). 31P{1H} NMR (121.50 MHz, CDCl3): δ 23.8 (J (31P-
119/117Sn) ) 236/225 Hz). IR (KBr): ν ) 1169 cm-1 (PdO). Anal.
Calcd for C18H31Br3O6P2Sn (763.8): C, 28.3; H, 4.1. Found: C,
28.6; H, 4.3.
Syn t h esis of {[2,6-Bis(d iet h oxyp h osp h on yl)-4-ter t-
bu tyl]p h en yl}(tr ip h en ylm eth yl)(ch lor o)tin Hexa flu or o-
ph osph ate, {2,6-[P (O)(OEt)2]2-4-ter t-Bu -C6H2}(P h 3C)ClSn +-
-
-
P F 6 (10). Ph3C+PF6 (600 mg, 1.54 mmol) was added in
portions to a solution of {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnCl
(1) (720 mg, 1.29 mmol) in toluene (25 mL). The suspension
was stirred for 15 h at room temperature. The resulting solid
was isolated and dried in vacuo to give 870 mg (71%) of 10 as
a cream-colored solid, mp 130 °C (dec). 1H NMR (400.13 MHz,
[d6]acetone): δ 1.17 (t, 6H, CH3), 1.35 (t, 6H, CH3), 1.45 (s,
9H, CH3), 3.79-3.94 (complex pattern, 4H, CH2), 4.20-4.39
(complex pattern, 4H, CH2), 7.26-7.44 (complex pattern, 15H,
3
CH3), 3.86-4.18 (complex pattern, 8H, CH2), 8.01 (d, J (1H-
31P) ) 14 Hz, 2H, Haryl). 13C NMR (100.63 MHz, C6D6): δ 16.1
3
3
(d, J (13C-31P) ) 3 Hz, 2C, CH3), 16.2 (d, J (13C-31P) ) 3 Hz,
2C, CH3), 30.9 (s, 3C, CH3), 35.2 (s, 1C, Cq), 64.6 (2C, CH2),
1
3
H
Ph), 8.49 (d, 3J (1H-31P) ) 15 Hz, 2H, Haryl). 13C NMR (100.63
65.1 (2C, CH2), 131.1 (dd, J (13C-31P) ) 189 Hz, J (13C-31P)
) 20 Hz, 2C, C2,6), 132.5 (complex pattern, 2C, C3,5), 154.6 (t,
3J (13C-31P) ) 12 Hz, 1C, C4), 172.8 (t, 2J (13C-31P) ) 25 Hz,
MHz, [d6]acetone): δ 15.3 (d, 3J (13C-31P) ) 3 Hz, 2C, CH3),
15.4 (d, J (13C-31P) ) 2 Hz, 2C, CH3), 30.1 (s, 3C, CH3), 35.6
3
(s, 1C, Cq), 66.5 (d, 2J (13C-31P) ) 19 Hz, 4C, CH2), 79.8 (t,
J (13C-31P) ) 4 Hz, 1J (13C-117/119Sn) ) 758/788 Hz, 1C, Cq),
1C, C1), 219.9 (s, J (13C-119Sn) ) 130 Hz, 4C, COeq), 226.3 (s,
2
1C, COax). 119Sn{1H} NMR (111.92 MHz, toluene/D2O-cap.): δ
131 (t, J (117/119Sn-31P) ) 179 Hz). 31P{1H} NMR (121.49 MHz,
toluene/D2O-cap.): δ 32.8 (s, J (31P-117/119Sn) ) 175 Hz). IR
(Nujol): ν ) 1180 cm-1 (PdO), 1927 cm-1 (CdO), 2051 cm-1
(CdO). Anal. Calcd for C23H31ClO11P2SnCr (751.6): C, 36.8;
H, 4.2. Found: C, 36.6; H, 4.3.
127.9 (s, 3C, CPh,para), 128.8 (s, J (13C-117/119Sn) ) 17 Hz, 6C,
4
C
Ph,meta), 130.0 (dd, 1J (13C-31P) ) 185 Hz, 3J (13C-31P) ) 17 Hz,
2C, C2,6), 130.5 (s, 3J (13C-117/119Sn) ) 68 Hz, 6C, CPh,ortho), 133.8
(complex pattern, 2C, C3,5), 141.5 (s, 2J (13C-117/119Sn) ) 65 Hz,
3C, CPh,ipso), 156.3 (t, 2J (13C-31P) ) 16 Hz, C1), 158.4 (t, 3J (13C-
31P) ) 13 Hz, 1C, C4). 119Sn{1H} NMR (111.92 MHz, CH2Cl2/
D2O-cap.): δ -322 (t, J (119Sn-31P) ) 52 Hz). 31P{1H} NMR
(121.49 MHz, CH2Cl2/D2O-cap.): δ 24.8 (s, J (31P-117/119Sn) )
Syn t h esis of {[2,6-Bis(d iet h oxyp h osp h on yl)-4-ter t-
b u t yl]p h en yl}t in Ch lor id e Ir on Tet r a ca r b on yl, {2,6-
[P (O)(OEt)2]2-4-ter t-Bu -C6H2}{Cl}Sn [F e(CO)4] (13). To a
solution of {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}SnCl (1) (420 mg,
0.74 mmol) in toluene (10 mL) was added Fe2(CO)9 (136 mg,
0,37 mmol). The mixture was stirred at 80 °C for 15 h. The
suspension was filtered, and n-hexane (10 mL) was added to
the filtrate. Crystallization at -30 °C gave 13 as orange
crystals, mp 250 °C (dec) (210 mg, 39%). 1H NMR (400.13 MHz,
CDCl3): δ 1.23 (t, 6H, CH3), 1.30 (t, 6H, CH3), 1.34 (s, 9H,
CH3), 3.90-4.30 (complex pattern, 8H, CH2), 7.93 (d, 3J (1H-
31P) ) 12 Hz, 2H, Haryl). 13C NMR (100.63 MHz, CDCl3): δ
16.5 (d, 3J (13C-31P) ) 3 Hz, 2C, CH3), 16.6 (d, 3J (13C-31P) ) 4
Hz, 2C, CH3), 31.5 (s, 3C, CH3), 35.8 (s, 1C, Cq), 65.2 (4C, CH2),
130.5 (dd, 1J (13C-31P) ) 187 Hz, 3J (13C-31P) ) 19 Hz, 2C, C2,6),
132.5 (complex pattern, 2C, C3,5), 155.4 (t, 3J (13C-31P) ) 13
Hz, 1C, C4), 168.4 (t, 2J (13C-31P) ) 22 Hz, 1C, C1), 215.0 (s,
2J (13C-119Sn) ) 180 Hz, CO). 119Sn{1H} NMR (111.92 MHz,
toluene/D2O-cap.): δ 54 (t, J (117/119Sn-31P) ) 165 Hz). 31P{1H}
NMR (121.49 MHz, toluene/D2O-cap.): δ 30.5 (s, J (31P-
117/119Sn) ) 161 Hz). IR (Nujol): ν ) 1154 cm-1 (PdO), 1923
cm-1 (CdO), 2026 cm-1 (CdO). Anal. Calcd for C22H31ClFeO10P2-
Sn (727.4): C, 36.3; H, 4.3. Found: C, 36.3; H, 4.2.
52 Hz, P(O)(OEt)2), -143.5 (sept, J (31P-19F) ) 706 Hz, PF6).
1
IR (Nujol): ν ) 1178 cm-1 (PdO). Mo¨ssbauer-spectroscopy: QS
) 2.99 mm s-1, IS ) 1.44 mm s-1. Anal. Calcd for C37H46
-
ClF6O6P3Sn (947.8): C, 46.9; H, 4.9. Found: C, 46.6; H, 4.5.
Syn t h esis of {[2,6-Bis(d iet h oxyp h osp h on yl)-4-ter t-
bu tyl]ph en yl}tin Ch lor ide Tu n gsten P en tacar bon yl, {2,6-
[P (O)(OEt)2]2-4-ter t-Bu -C6H2}(Cl)Sn [W(CO)5] (11). A so-
lution of W(CO)6 (1.50 g, 4.26 mmol) in thf (270 mL) was
irradiated (UV light, Hg high-pressure lamp) until 95 mL (3.90
mmol) of CO were produced (1.5 h). From this solution, 140
mL (2.20 mmol W(CO)5(thf)) was added dropwise at room
temperature to a solution of {2,6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}-
SnCl (1) (1.00 g, 1.79 mmol) in thf (30 mL). After stirring the
mixture for 17 h, the solvent was evaporated and the excess
W(CO)6 sublimed in vacuo at 40 °C. Crystallization of the
residue from n-hexane/toluene (15:1) yielded 130 mg (10%) of
11 as a pale yellow solid, mp 165-167 °C. 1H NMR (400.13
MHz, C6D6): δ 0.91 (t, 6H, CH3), 0.99 (t, 6H, CH3), 1.01 (s,
9H, CH3), 3.87-4.19 (complex pattern, 8H, CH2), 8.01 (d,
3J (1H-31P) ) 14 Hz, 2H, Haryl). 13C NMR (100.63 MHz, C6D6):
δ 14.7 (complex pattern, 4C, CH3), 29.4 (s, 3C, CH3), 33.6 (s,
Ack n ow led gm en t. We are grateful to the Deutsche
Forschungsgemeinschaft and the Fonds der Chemischen
Industrie for financial support.
1C, Cq), 63.0 (2C, CH2), 63.7 (2C, CH2), 129.6 (dd, J (13C-31P)
1
) 188 Hz, 3J (13C-31P) ) 19 Hz, 2C, C2,6), 130.7 (complex
pattern, 2C, C3,5), 152.9 (t, 3J (13C-31P) ) 12 Hz, 1C, C4), 170.4
(t, J (13C-31P) ) 25 Hz, 1C, C1), 197.3 (s, J (13C-119Sn) ) 124
Hz, 1J (13C-182W) ) 66 Hz, 4C, COeq), 200.3 (s, 1C, COax). 119Sn-
{1H} NMR (111.92 MHz, toluene/D2O-cap.): δ -74 (t, 1J (119Sn-
183W) ) 1372 Hz, J (119Sn-31P) ) 161 Hz). 31P{1H} NMR (121.49
MHz, toluene/D2O-cap.): δ 33.9 (s, J (31P-117/119Sn) ) 160 Hz).
IR (Nujol): ν ) 1179 cm-1 (PdO), 1910 cm-1 (CdO), 2064 cm-1
2
2
Su p p or tin g In for m a tion Ava ila ble: Tables of all coor-
dinates, anisotropic displacement parameters, and geometric
data for compounds 6, 8, and 12. This material is available
free of charge via the Internet at http://pubs.acs.org.
OM000452K