Synthesis of hetero-binuclear complexes from bisgermavinylidene

Article abstract of DOI:10.1021/ic400056f

Bisgermavinylidene [(Me₃SiN=PPh₂)₂C= Ge→Ge=C(PPh₂=NSiMe₃)₂] (1) has been used as a source of unstable germavinylidene for the synthesis of a series of heterobinuclear complexes. The reaction of 1 with stoichiometric amounts of transition metal chlorides MCl₂ (M = Mn, Fe) yielded [(Me ₃SiN=PPh₂)₂(GeCl)CMn(μ-Cl)]₂ (2) and [(Me₃SiN=PPh₂)₂(GeCl)CFeCl] (3), respectively. Treatment of 1 with Me₃SiN₃ gave the [2 + 3] cycloaddition product [(Me₃SiN=PPh₂) ₂CGeN(SiMe₃)N=N] (4). While similar reaction of 1 with (ⁿBu)₃SnN₃ (ⁿBu = n-butyl) and water-borane adduct H₂O → B(C₆F₅) ₃ afforded the 1,2-addition products [(Me₃SiN=PPh ₂){(ⁿBu)₃Sn}CPPh₂NSiMe ₃GeN₃] (5) and [HC(PPh₂=NSiMe₃) ₂Ge(OH)B(C₆F₅)₃] (6), respectively. The results suggested that the germanium-carbon bond in germavinylidene is capable of forming addition reaction products. The X-ray structures of 2-6 have been determined.

Full text of DOI:10.1021/ic400056f

Article
pubs.acs.org/IC
Synthesis of Hetero-Binuclear Complexes from Bisgermavinylidene
Wing-Por Leung,* Kwok-Wai Kan, Yuk-Chi Chan, and Thomas C. W. Mak
Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
S
* Supporting Information
ABSTRACT: Bisgermavinylidene [(Me3SiNPPh2)2CGe→
GeC(PPh2NSiMe3)2] (1) has been used as a source of
unstable germavinylidene for the synthesis of a series of
heterobinuclear complexes. The reaction of 1 with stoichio-
metric amounts of transition metal chlorides MCl2 (M = Mn,
Fe) yielded [(Me3SiNPPh2)2(GeCl)CMn(μ-Cl)]2 (2) and
[(Me3SiNPPh2)2(GeCl)CFeCl] (3), respectively. Treatment
of 1 with Me3SiN3 gave the [2 + 3] cycloaddition product
[(Me3SiNPPh2)2CGeN(SiMe3)NN] (4). While similar
reaction of 1 with (nBu)3SnN3 (nBu = n-butyl) and water-
borane adduct H2O → B(C6F5)3 afforded the 1,2-addition
products [(Me3SiNPPh2){(nBu)3Sn}CPPh2NSiMe3GeN3]
(5) and [HC(PPh2NSiMe3)2Ge(OH)B(C6F5)3] (6), respec-
tively. The results suggested that the germanium−carbon bond
in germavinylidene is capable of forming addition reaction
products. The X-ray structures of 2−6 have been determined.
Lewis base properties8,9 of germavinylidene have been reported.
The existence of monomeric germavinylidene intermediate in
INTRODUCTION
■
Germenes are compounds containing a double bond between
solution was shown by the synthesis of manganese−
germanium and carbon (>CGe<). They have been the focus
of several reviews.1 Synthetic methods and structures of stable
germenes R2GeCR′2 have been reported.2 The most
common routes for the synthesis of germene are the
addition-elmination reaction of tert-butyllithium with haloviny-
ligermane and the germylene−carbene coupling reaction. The
1,2-addition or [2 + n] cycloaddition reactions of germene have
been studied extensively.3 In contrast, the reactivity of
germavinylidenes (>CGe:) is not known. It is due to the
low stability of intermediate germavinylidene can only be
detected by laser-induced fluorescence spectroscopy.4
The unusual structure and the reactivity of germavinylidenes
have attracted our interest. We have communicated the
synthesis and structure of bisgermavinylidene [(Me3SiN
PPh2)2CGe→GeC(PPh2NSiMe3)2] (1).5 The Ge−Ge
interaction is considered to be weak. It is proposed that
bisgermavinylidene is a potential source to generate the reactive
monomeric germavinylidene. It can serve as a synthon to
synthesize heterobinuclear metal−germavinylidene complexes.
In the solution state, it is proposed that it may exist as
bisgermavinylidene (A), monomeric germavinylidene (B or C,
where C is a possible resonance structure of B (Scheme 1)).
It is anticipated that germavinylidene can react (i) as a Lewis
acid, (ii) as a Lewis base, (iii) undergoing addition reaction,
(iv) undergoing oxidative addition reaction, or (v) as a ligand
transfer reagent. The different reactive centers of germaviny-
lidene are shown in Scheme 2. The addition reaction,6,9−11
oxidative addition reaction,7,10 ligand transfer reaction,6 and the
germavinylidene complex [(Me3SiNPPh2)2CGe→Mn-
(CO)2Cp] (Cp  η5-C5H5).9 Germavinylidene can also act
as a starting compound for the preparation of various germenes
by cycloaddition reaction with the germanium(II) center.10 The
reactivity of the germanium−carbon bond in germavinylidene
has been demonstrated by the synthesis of (Me3SiN
PPh2)2{(cod)RhCl}CGeCl] (cod =1,5-cyclooctadiene)9 and
[2 + 2] cycloaddition reaction of germavinylidene with
AdNCO (Ad = adamantyl).11 Herein, the reactive center ii of
bisgermavinylidene is demonstrated. We here report the
synthesis and structures of novel heterobinuclear complexes
from bisgermavinylidene. The [2 + 3] cycloaddition and 1,2-
addition reaction of germavinylidene with Me3SiN3,
(Bun)3SnN3, and B(C6F5)3·H2O are also reported.
RESULTS AND DISCUSSION
■
Treatment of bisgermavinylidene 1 with stoichiometric
amounts of transition metal chlorides MCl2 (M = Mn, Fe)
yielded [(Me3SiNPPh2)2(GeCl)CMn(μ-Cl)]2 (2) and
[(Me3SiNPPh2)2(GeCl)CFeCl] (3) (Scheme 3). The X-
ray structural determination of the products obtained have
shown that the MCl bond (M = Mn, Fe) adds to the GeC
bond of germavinylidene to form compounds 2 and 3.
Received: January 15, 2013
Published: March 25, 2013
© 2013 American Chemical Society
4571
dx.doi.org/10.1021/ic400056f | Inorg. Chem. 2013, 52, 4571−4577

Inorganic Chemistry
Article
Scheme 1
The reaction of bisgermavinylidene 1 with 2 equiv of
(Bun)3SnN3 in THF afforded [(Me3SiNPPh2){(Bun)3Sn}-
CPPh2NSiMe3GeN3] (5). The X-ray structure determination of
5 has shown that (Bun)3SnN3 underwent a 1,2-addition
reaction with germavinylidene in solution, followed by a
rearrangement process in which the GeC bond was cleaved
with the subsequent formation of GeN bond to give
heterobinuclear compound 5 (Scheme 5). This contrasts with
Scheme 2. Different Reactive Centers in Germavinylidene:
(i) Lewis Acid, (ii) Lewis Base, (iii) Addition Reaction, (iv)
Oxidative Addition Reaction, or (v) as a Ligand Transfer
Reagent
Scheme 5
Scheme 3
the result found in the reaction of 1 with Me3SiN3 in which the
azide bond underwent a [2 + 3] cycloaddition reaction with
germavinylidene to yield 5. The different results may be due to
the fact that the weaker metal-azide bond in (Bun)3SnN3 favors
a 1,2-addition reaction. Similar examples with bis-
(iminophosphorano)methanediide ligand such as
[(AlMe)2{μ2-C(Ph2PNSiMe3)2-κ4C,C′,N,N′}]13 and [Cr-
{μ2-C(Ph2PNSiMe3)2- κ4C,C′,N,N′}]214 have been reported.
Treatment of bisgermavinylidene 1 with 2 equiv of borane−
water adduct H2O→B(C6F5)3 in THF afforded the borane-
stabilized germanium(II) hydroxide complex [HC(PPh2
NSiMe3)2Ge(OH)B(C6F5)3] (6). It is proposed that the C
Ge bond in germavinylidene underwent a 1,2-addition with
H2O from H2O→B(C6F5)3, followed by a rearrangement
process in which the GeC bond was cleaved with the
subsequent formation of GeN bond to yield 6. Attempts to
Treatment of bisgermavinylidene 1 with stoichiometric
amounts of Me3SiN3 in THF gave a cycloaddition product
[(Me3SiNPPh2)2CGeN(SiMe3)NN] (4) (Scheme 4). It is
proposed that the GeC bond in 1 underwent a [2 + 3]
cycloaddition reaction with the NNN moiety of
azidotrimethylsilane to yield 4. The X-ray structure determi-
nation of 4 has shown that the GeC bond lengthened as the
bond order decreased from two to one via the cycloaddition
reactions. This further supports that the germanium−carbon
bond in germavinylidene is a GeC bond. Similar results have
been observed in the [2 + 2] cycloaddition reactions of
[MCl2{C(PPh2NSiMe3)2-κC,κ2N,N′}] (M = Zr, Hf) with
heteroallenes.12
Scheme 4
4572
dx.doi.org/10.1021/ic400056f | Inorg. Chem. 2013, 52, 4571−4577

Inorganic Chemistry
Article
Figure 1. Molecular structure of [(Me3SiNPPh2)2(GeCl)CMn(μ-Cl)]2 (2) (30% ellipsoids probability). Hydrogen atoms and CH2Cl2 molecules
are omitted for clarity. Selected bond distances (Å) and angles (deg): Ge1N1 1.985(2), Ge1C4 2.024(3), Ge1Cl1 2.549(9), Mn1N2
2.128(2), Mn1Cl1 2.457(9), Mn1Cl2 2.418(9) Mn1Cl2A 2.517(9), Mn1C4 2.584(3), N1Ge1C4 77.3(1), N1Ge1Cl1 96.9(7),
C4Ge1Cl1 93.5, N2Mn1Cl2 116.5(7), N2Mn1Cl1 125.7(7), Cl2Mn1Cl1 114.5(4), N2- Mn1Cl2A 88.8(3), Cl2Mn1
Cl2A 92.7(3), N2Mn1C4 67.5(8), Cl2Mn1C4 104.6(6), Cl2AMn1-C4 166.6(6), Mn1Cl1Ge1 83.5(3), Ge1C4Mn1 91.9(1).
prepare compound 6 with 2 equiv of H2O was not successful;
only H2C(PPh2NSiMe3)2 was obtained. To the best of our
knowledge, it is the first reported synthetic method for the
synthesis of germanium(II) hydroxide via the addition reaction
of H2O with germavinylidene. Similar germanium(II) hydrox-
ide was prepared from the substitution reaction of heteroleptic
germanium(II) chloride with H2O in the presence of N-
heterocyclic carbene.15
of δ −249.5 ppm in [Sn{CH(SiMe3)C9H6N-8}2Cl2].16 The 1H
NMR spectrum of compound 6 displayed two sets of singlet at
δ −0.19 ppm and δ 0.15 ppm which correspond to two
different SiMe3 groups. The methanide proton displayed a
signal at δ 3.91 ppm. The multiplet signal at δ 4.96 ppm is due
to the hydroxyl proton coupled to boron from B(C6F5)3. The
31P NMR spectrum of 6 showed two signals at δ −7.2 and δ
20.9 ppm. The 11B NMR spectrum of 6 showed one signal at δ
−2.9 ppm. Both spectra are consistent with the X-ray structure.
From the IR spectrum of compound 6, an absorption around
3400 cm−1 can be assigned to the O−H stretching frequency,
which is comparable to the absorption band at 3571 cm−1 in
[HC{(CMe)(2,6-iPr2C6H3N)}2 GeOH].41
X-ray Structures. Molecular structures with atom number-
ing schemes and selected bond distances and angles for
compounds 2−6 are shown in Figure 1−5, respectively.
Compound 2 crystallizes in the monoclinic space group C2/c
with two solvated CH2Cl2 molecules in the solid state. It is a
chloro-bridged dimer with “GeCl” and “MnCl” moieties
bonded to the methanediide carbon. The germanium center
is bound to one of imino group in a trigonal pyramidal
geometry, while the other is bound to the manganese center
and adopts a distorted trigonal bipyramidal geometry. The sum
of angles at the germanium is 267.7°, consistent with a
stereoactive lone-pair of electrons at the germanium center.
There is no interaction between germanium and manganese as
indicated by a long distance of 3.335 Å. The CGeMnCl
and Mn2Cl2 rings are almost planar and the dihedral angle
between the two planes is 59.4°. Similar to compound 2, the
GeC bond distance of 2.024(3) Å in 2 is lengthened as
compared to the GeC distances in 1. It is also similar to the
GeC single bond distances in [Ge{CH(SiMe3)2}2]2 (2.016
Å)17 and [Ge{CPh(SiMe3)C5H4N-2}2] (2.116 Å).18 The Ge
Cl bond distance of 2.549(9)Å in 2 is longer than those
Spectroscopic Properties. Compounds 3−5 were isolated
as yellow crystalline solids whereas compound 2 and 6 were
isolated as colorless crystalline solids. They are air and
moisture-sensitive, soluble in THF and CH2Cl2 and sparingly
soluble in Et2O. Compounds 2 and 3 have been characterized
by FAB mass spectroscopy and elemental analysis. Compounds
4−6 have been characterized by NMR spectroscopy and
elemental analysis. Compounds 2 and 3 are paramagnetic, no
satisfactory NMR spectra have been obtained. The FAB mass
spectrum of compound 2 displayed a [M/2]+ peak, suggesting
it exists as a monomer in vapor phase. The fragment due to the
[M − SiMe3]+ peak was observed in the FAB mass spectrum of
1
3. The H NMR spectrum of 4 displayed two singlets at δ
−0.09 ppm and δ 0.26 ppm which correspond to two different
SiMe3 groups. The 31P NMR spectrum (25 °C) of 4 showed
one singlet at δ 7.1 ppm, which is not agreed with the X-ray
structure. At −80 °C, the 31P NMR spectrum of 4 displayed
two signals at δ 7.1 and δ −3.2 ppm. This is due to the fluxional
coordination of imino nitrogen atoms at the germanium center
1
in solution. The H and 13C NMR spectra of compound 5
displayed two set of signals due to bis(iminophosphorano)-
methanediide ligand and the n-butyl groups. The 31P NMR
spectrum of 5 showed two singlets at δ 10.6 and 45.5 ppm due
to two different phosphorus environments as found in the
solid-state structure. The 119Sn NMR spectrum of 5 displayed
one upfield signal of δ −44.6 ppm as compared with the signal
4573
dx.doi.org/10.1021/ic400056f | Inorg. Chem. 2013, 52, 4571−4577

Inorganic Chemistry
Article
Figure 2. Molecular structure of [(Me3SiNPPh2)2(GeCl)CFeCl]
(3) (30% ellipsoids probability). Hydrogen atoms, THF, and CH2Cl2
molecules are omitted for clarity. Selected bond distances (Å) and
angles (deg): Ge1N1 1.962(4), Ge1C4 2.059(4), Ge1Cl1
2.581(2), Fe1N2 2.042(4), Fe1Cl2 2.227(2), Fe1C4 2.241(5),
Fe1Cl1 2.365(2), N1Ge1C4 76.7(2), N1Ge1Cl1 99.3(1),
C4Ge1Cl1 88.6(1), N2Fe1Cl2 113.9(1), N2Fe1C4
74.6(2), Cl2Fe1C4 143.6(1), N2Fe1Cl1 131.9(1), Cl2
Fe1Cl1 105.4(8), C4Fe1Cl1 90.1(1), Fe1Cl1Ge1
79.9(5).
Figure 4. Molecular structure of [(Me3SiNPPh2){(Bun)3Sn}-
CPPh2NSiMe3GeN3] (5) (30% ellipsoids probability). Hydrogen
atoms are omitted for clarity. Selected bond distances (Å) and angles
(deg): Ge1N1 1.979(2), Ge1N2 1.974(2), Ge1N3 2.027(3),
Sn1C4 2.157(4), N3N4 1.197(4), N4N5 1.134(5), N2
Ge1N1 97.8(1), N2Ge1N3 94.8(1), N1Ge1N3 98.9(1),
N5N4N3 175.9(5), C4Sn1C55 111.4(1), C4Sn1C59
109.2(1), C4Sn1C51 112.9(1), C59Sn1C55 108.7(2).
Figure 3. Molecular structure of [(Me3SiNPPh2)2CGeN(SiMe3)-
NN] (4) (30% ellipsoids probability) Hydrogen atoms are omitted
for clarity. Selected bond distances (Å) and angles (deg): Ge1N5
1.948(3), Ge1−C4 2.125(3), Ge1N2 2.070(3), P1N1 1.537(3),
P1C4 1.814(3), P2N2 1.606(3), P2C4 1.808(3), N3N4
1.262(4), N3C4 1.503(4), N4N5 1.387(4), N5Ge1N1
97.9(1), N5Ge1C4 78.9(1), N2Ge1C4 76.3(1), N4
N3C4 115.5(3), N3N4N5 119.2(3), N4N5Ge1 117.6(2).
Figure 5. Molecular structure of [HC(PPh2NSiMe3)2Ge(OH)B-
(C6F5)3] (6) (30% ellipsoids probability). Hydrogen atoms are
omitted for clarity. Selected bond distances (Å) and angles (deg):
Ge1O1 1.785(4), Ge1N1 2.153(4), Ge1N2 2.119(4), P1N1
1.592(4), P2N2 1.598(4), C1P1 1.805(6), C1P2 1.805(6),
O1H 0.820 O1B1 1.496(7), N1Ge1O1 97.1(2), N2
Ge1O1 98.5(2), N1Ge1N2 92.4(2), Ge1O1B1 125.9(3),
O1B1C38 109.9(5), O1B1C44 107.3(5), C32B1C44
110.2(5), C32B1C38 102.4(5).
distances in [(iPr2ATI)GeCl] [2.364(2)Å]19 (ATI = amino-
troponimato) and [HC(CMeNPh)2GeCl] [2.340(6)Å],20
which is probably owing to the chelation with manganese.
The MnC bond distance of 2.584(3)Å in 2 is significantly
longer than some reported MnC bond distances ranging
from 2.010 to 2.108 Å.21 It is suggested that the MnC bond
is lengthened in order to release the steric crowding at the
methanediide carbon. The average MnCl bond distance of
2.467 Å in 2 is similar to those (μ-Cl)2-bridges in [Mn(μ-
Cl){C(SiMe3)2(SiMe2-NMe2)}]2 (2.428 Å),22 [Mn(THF)(μ-
Cl){C(SiMe3)2 (SiMe2OMe2)}]2 (2.488 Å),22 and [LMn(μ-
4574
dx.doi.org/10.1021/ic400056f | Inorg. Chem. 2013, 52, 4571−4577

Inorganic Chemistry
Article
Cl)2 Mn(THF) (μ-Cl)2 MnL] (L
=
HC{CMeN-
average SnC bond distance of 2.162 Å in 5 is similar to those
distances for a Sn(IV)C single bond of 2.134 Å in
(2,6-iPr2C6H3)}2) (2.402 Å).23 The Mn−N bond distance of
2.128(2) Å in 2 is similar to that of some β-diketiminato
manganese(II) complexes.24
[ { P h 2 P ( C H 2 ) 3 } 2 S n C l 2 ] 3 7 a n d 2 . 1 3 6
Å
i n
[nBuSnCl2{C6H3(CH2NMe2)2-2,6}].38 The azide moiety in 5
are almost linear as indicate from the NNN bond angle of
175.9(5)°. The bonding in the GeN3 may be described by
two canonical forms: GeNNN and GeNNN. It
was found that the dominant canonical form of the GeN3
moieties in [(nPr2ATI)GeN3] (ATI = aminotroponimato)39
and [(Mes2DAP)GeN3] (Mes2DAP = 2,4-dimethyl-N,N′-bis-
(2,4,6-trimethylphenyl)-1,5-diazapentadienyl)40 is GeN
NN. The GeNazide bond distance of 2.027(3) Å in 5 is
close to that of 2.047(2) Å in [(nPr2ATI)GeN3]39 and that of
1.979(5) Å in [(Mes2DAP)GeN3].40 The NN bond
distances in 5 [1.197(4), 1.134(5) Å] are also similar to
those found in [(nPr2ATI)GeN3]37 [1.197(3), 1.144(4) Å] and
[(Mes2DAP)GeN3]40 [1.199(7), 1.152(8) Å]. Thus, the NN
bond lengths in 5 suggest that the dominant canonical form of
the GeN3 moiety is GeNNN. This is also consistent
with the results from theoretical calculations.39
Compound 3 is a monomer solvated with 1/4 CH2Cl2 and
1/2 THF molecules in the solid state structure. It is comprised
of “GeCl” and “FeCl” moieties bonded to the methanediide
carbon. The geometry at the germanium and iron center are
trigonal pyramidal and distorted tetrahedral respectively. The
C−Fe−Cl−Ge ring is almost planar as shown by the sum of
angles of 353.8°. The Ge−Fe distance of 3.179 Å shows that no
interaction between the two metal centers. The Ge−C bond
distance of 2.059(4) Å in 3 is within the range of some reported
Ge−C single bond distances [1.98−2.14 Å].25 The Ge−Cl
bond distance of 2.581(1) Å in 3 is longer than those in
[Ge(C6H3-2,6-Trip2)Cl] [2.203(1) Å]26 and [HC-
(CMeNPh)2GeCl] [2.340(6) Å].20 The Fe−C bond distance
of 2.241(5) Å in 3 is longer than that of 2.051(1) Å in
27
Fe[C(SiMe3)3]2 and that of 2.045(4) Å in Fe(Tsi)2 (Tsi =
tris(trimethylsilyl)-methyl),28 which may be due the steric
crowding at the methanediide carbon. The Fe−Clterminal bond
distance of 2.227(2) Å is similar to those found in LFeCl (L =
2,4-bis(2,6-diisopropylphenylimido) pentyl) [2.172(1) Å].29
The Fe−Clbridging bond distance of 2.345(2) Å is similar to
that of 2.324(1) and 2.338(1) Å in LFe(μ-Cl)2-Li(THF)2.29
The Fe−N bond distance of 2.042(2) Å in 3 is similar to those
distances found in some bis(iminophosphorano)methanide
iron(II) complexes.30
Compound 6 is comprised of a germanium(II) hydroxide
coordinated to the imino group of bis(iminophosphorano)-
methane and the oxygen atom in OH group is coordinated to
the tris(pentafluorophenyl)borane. The angle sum of 289.5° at
the germanium center deviates from a normal sp3 tetrahedral
geometry. Therefore, the germanium center adopts a trigonal
pyramidal geometry and is consistent with a stereoactive lone
pair at the germanium center. The angle sum of 429.8° at the
boron atom is comparable to a normal sp3 tetrahedral
geometry, so the boron atom adopts a tetrahedral geometry.
The PN bond distances of 1.592(4) and 1.598(4) Å and the
CP bond distances of 1.805(6) Å in 6 are different from
those of [(Me3SiNPPh2)2CH2] [PN = 1.536(2) Å; CP
= 1.825(1) Å],34 suggesting that considerable delocalization
throughout the NPCPN backbone of the ligand. The GeO
bond distance of 1.785 Å is in good agreement with
[HC{(CMe)(2,6-iPr2C6H3N)}2GeOH] [1.828 Å]15 and the
theoretical value of 1.804 Å in Ge(OH)2.41 The OH bond
distance of 0.820 Å in compound 6 is comparable to
[HC{(CMe)(2,6-iPr2C6H3N)}2GeOH] [0.795(7) Å]15 but
significantly shorter than the theoretical value of 0.972 Å in
Ge(OH)2.41
Compound 4 is comprised of a five-membered CNN
NGe ring. The germanium center of 4 displays a trigonal
pyramidal geometry as indicated by the sum of angles of 253.17
at Ge1, which is consistent with a stereoactive lone pair at the
germanium center. The Ge1C4 bond distance of 2.125(3) Å
in 4 is similar to that of 2.135(4) Å in Ge[CPh(SiMe3)(C5H4N-
18
2)]2 and that of 2.067(1) Å in [Ge{CH(SiMe3)2}{C-
(SiMe3)3}],31 but longer than the GeC distances of
1.905(8) and 1.908(7) Å in 1, showing that the bond order
of GeC bond changed from two to one. The Ge1N5 bond
distance of 1.948(3) Å in 4 is similar to those found in
ArGeN(SiMe3)2 [Ar = 2,6-bis((diethylamino)methyl)phenyl]
[1.956(1) Å]32 and [Ge{C (C5H4N-2)C(Ph)N(SiMe3)2}{N-
(SiMe3)C(Ph)(SiMe3)-(C5H4N-2)}] [1.940(2) Å].33 The
N3N4 bond distance in 4 is assignable to a NN bond.
The C4N3 and N4N5 bond distances in 4 are normal.
The Ge1N2 bond distance of 2.070(3) Å in 4 is similar to
those reported N → Ge bond distances.
CONCLUSIONS
■
Heterobinuclear complex consisting of main-group metalloid
chloride and transition metal chloride, [(Me3SiN
PPh2)2(GeCl)CMn(μ-Cl)]2 (2) and [(Me3SiNPPh2)2
(GeCl)CFeCl] (3) have been prepared from bisgermavinyli-
dene. Bisgermavinylidene underwent a [2 + 3] cycloaddition
reaction to yield [(Me3SiNPPh2)2CGeN(SiMe3)NN] (4).
While the reaction of bisgermavinylidene with (nBu)3SnN3 (nBu
= n-butyl) and water−borane adduct H2O→B(C6F5)3 afforded
1,2-addition product [(Me3SiNPPh2){(nBu)3Sn}-
CPPh2NSiMe3GeN3] (5) and [HC(PPh2NSiMe3)2Ge(OH)-
B(C6F5)3] (6), respectively. The results demonstrated that
germanium−carbon bond in germavinylidene is capable of
forming addition reaction products.
Compound 5 is a heterobinuclear complex containing a
germanium(II) azide and a tin(IV) tetraalkyl. The ligand is
bonded in a N,N′-chelate fashion to the germanium center
which displays a trigonal pyramidal geometry. The tin center is
bonded to the methanediide carbon and adopts a tetrahedral
geometry. The GeNPCPN metallacycle in 5
displays a distorted boat conformation. There is no interaction
between germanium and the methanediide carbon. The PN
bond distances of 1.636(3) and 1.633(3) Å and the CP bond
distances of 1.720(3) and 1.711(3) Å in 5 are different from
those of [(Me3SiNPPh2)2CH2] [PN = 1.536(2)Å; CP
= 1.825(1)Å],34 suggesting that considerable charge delocaliza-
tion is present in the NPCPN backbone of the ligand. The
GeN distances of 1.974(2) and 1.979(2) Å in 5 are similar to
those of 1.983(4) and 2.002(4) Å found in [(Me3SiN
PPh2)2CHGeCl]35 and those of 1.971(4) and 1.959(4) Å
found in [HC(CMeNAr)2GeCl] (Ar = 2,6-Pri2C6H3).36 The
EXPERIMENTAL SECTION
■
General Procedures. All manipulations were carried out under an
inert atmosphere of dinitrogen gas by standard Schlenk techniques.
Solvents were dried over and distilled from CaH2(hexane) and/or Na
(Et2O, toluene, and THF). The bis(germavinylidene) [(Me3SiN
4575
dx.doi.org/10.1021/ic400056f | Inorg. Chem. 2013, 52, 4571−4577

Inorganic Chemistry
Article
PPh2)2CGe→GeC(PPh2NSiMe3)2]5 and borane−water ad-
d8, 25 °C): δ = −0.15 (s, 9H, SiMe3), 0.19 (s, 9H, SiMe3), 3.91 (m,
1H, CH), 4.96 (m, 1H, OH), 7.28−7.32 (m, 4H, Ph), 7.34−7.39 (m,
6H, Ph), 7.59−7.64 (m, 2H, Ph), 7.67−7.72 (m, 5H, Ph), 7.76−7.87
(m, 3H). 13C{1H} NMR (THF-d8, 25 °C): δ = 3.7, 4.5 (SiMe3), 129.3,
129.8, 130.3, 131.2, 131.8, 132.4, 133.0, 133.2, 133.8, 135.5 (Ph),
136.7, 139.1, 148.1, 150.5 (C6F5). 31P{1H} NMR (THF-d8, 25 °C): δ
42
duct H2O→B(C6F5)3 were prepared by literature procedures.
n
MnCl2, FeCl2, Me3SiN3, and Bu3SnN3 were purchased from Aldrich
Chemicals and used without further purification. The 1H, 13C, 31P, 11B,
and 119Sn NMR spectra were recorded on Bruker WM-300 and Varian
400 spectrometers. The NMR spectra were recorded in THF-d8, and
= 20.9, −7.2. 11B NMR (THF-d , 25 °C): δ = −2.9. IR (KBr): v =
1
the chemical shifts are relative to SiMe4 and 85% H3PO4 for H, 13C,
̃
8
and 31P, respectively.
3401, 3068, 2957, 2888, 2588, 2346, 1971, 1921, 1828, 1641, 1591,
1512, 1460, 1440, 1391, 1382, 1357, 1323, 1271, 1255, 1182, 1121,
1084, 1028, 1000, 962, 841, 798, 774, 767, 759, 747, 705, 694, 683,
658, 598, 528, 509, 488, 470.
Reaction of 1 with MnCl2. A solution of 1 (0.64g, 0.51 mmol) in
THF (20 mL) was added slowly to MnCl2 (0.13g, 1.02 mmol)
suspension in THF (20 mL) at 0 °C. The reaction mixture was stirred
at room temperature for 46 h. Volatiles in the mixture were removed
under reduced pressure, and the residue was extracted with CH2Cl2.
After filtration and concentration of the filtrate, 2 was obtained as
colorless crystals. Yield: 0.27g (35%). Mp: 210.2 °C (dec). Anal found:
C, 49.57; H, 5.27; N, 3.86. Calcd for C62H76Cl4Ge2Mn2N4P4Si4: C,
49.30; H, 5.07; N, 3.71. MS (FAB): m/z 756 (60, [M/2]+).
Reaction of 1 with FeCl2. A solution of 1 (0.68g, 0.54 mmol) in
THF (20 mL) was added slowly to FeCl2 (0.14g, 1.08 mmol)
suspension in THF (20 mL) at 0 °C. The reaction mixture was stirred
at room temperature for 39 h. Volatiles in the mixture were removed
under reduced pressure, and the residue was extracted with 1:1
mixture of Et2O/CH2Cl2. After filtration and concentration of the
filtrate, 3 was obtained as pale yellow crystals. Yield: 0.38g (47%). Mp:
152.3−154.2 °C. Anal found: C, 48.92; H, 5.24; N, 3.67. Calcd for
C31H38Cl2GeFeN2P2Si2: C, 49.24; H, 5.07; N, 3.70. MS (FAB): m/z
684 (17, [M − SiMe3]+).
X-ray Crystallography. Single crystals were sealed in Lindemann
glass capillaries under nitrogen. X-ray data of 2−6 were collected on a
Rigaku R-AXIS II imaging plate using graphite-monochromatized Mo
́
Kα radiation (λ = 0.71073 Å) from a rotating-anode generator
operating at 50 kV and 90 mA. Crystal data are summarized in Tables
6 and 7 (Supporting Information). The structures were solved by
direct phase determination using the computer program SHELXTL-
PC on a PC 486 and refined by full-matrix least-squares with
anisotropic thermal parameters for the non-hydrogen atoms.43
Hydrogen atoms were introduced in their idealized positions and
included in structure factor calculations with assigned isotropic
temperature factor calculations. Full details of the crystallographic
analysis of 2−6 are given in the Supporting Information.
ASSOCIATED CONTENT
* Supporting Information
■
S
Reaction of 1 with SiMe3N3. A solution of 1 (0.72g, 0.57 mmol)
in THF (20 mL) was added slowly to Me3SiN3 (0.20 mL, 1.52 mmol)
in THF (20 mL) at 0 °C. The resultant pale yellow solution was raised
to room temperature and stirred for 31 h. The volatiles were removed
under reduced pressure. The residue was extracted with Et2O. After
filtration and concentration of the filtrate, compound 4 was obtained
as pale yellow crystals. Yield: 0.15g (42%). Mp: 111.7−112.5 °C. Anal
found: C, 54.74; H, 6.37; N, 9.12. Calcd for C34H47GeN5P2Si3: C,
Details about the X-ray crystal structures in CIF format,
including tables of selected bond distances and angles, and
tables of crystal data for 2−6. This material is available free of
charge via the Internet at http://pubs.acs.org.
AUTHOR INFORMATION
Corresponding Author
*E-mail: kevinleung@cuhk.edu.hk. Fax: +852 2609 5057.
■
1
54.84; H, 6.36; N, 9.41. H NMR (THF-d8, 25 °C): δ = −0.09, (s,
18H, SiMe3), −0.26, (s, 9H, SiMe3), 7.23−7.26 (m, 3H, Ph), 7.27−
7.30 (m, 5H, Ph), 7.31−7.33 (m, 4H, Ph), 7.38−7.45 (m, 2H, Ph),
7.46−7.49 (m, 2H, Ph), 7.74−7.81 (m, 4H, Ph). 13C{1H} NMR
(THF-d8, 25 °C): δ = −0.04 (SiMe3), 3.6 (SiMe3), 125.9, 126.1, 126.2,
126.5, 128.9, 129.8, 129.8, 130.0, 130.2, 130.4, 130.7, 131.6, 131.9,
132.1, 132.2 (Ph). 31P{1H} NMR (THF-d8, 25 °C): δ = 7.1, (THF-d8,
−80 °C): δ = 7.1, −3.2.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
This work was supported by The Hong Kong Research Grant
Council (Reference No. CUHK 402210)
■
Reaction of 1 with (Bun)3SnN3. A solution of 1 (0.73g, 0.58
mmol) in THF (20 mL) was added slowly to the (Bun)3SnN3 (0.35
mL, 1.27 mmol) in THF (20 mL) at 0 °C. The resultant yellow
solution was raised to room temperature and stirred for 18 h. The
volatiles were removed under reduced pressure. The residue was
extracted with Et2O. After filtration and concentration of the filtrate,
compound 5 was obtained as yellow crystals. Yield: 0.31g (28%). Mp:
80.6 °C (dec). Anal found: C, 53.77; H, 7.07; N, 6.65. Calcd for
REFERENCES
■
(1) For selected recent reviews and examples of germenes, see:
(a) Barrau, J.; Escudie,
́
J.; Satge,
́
J. Chem. Rev. 1990, 90, 283.
(b) Driess, M.; Grutzmacher, H. Angew. Chem., Int. Ed. Engl. 1996, 35,
̈
828. (c) Escudie,
44, 113. (d) Couret, C.; Escudie,
Soc. 1987, 109, 4411. (e) Anselme, G.; Escudie,
J. Organomet. Chem. 1991, 403, 93. (f) Lazraq, M.; Couret, C.; Escudie,
J.; Satge, J. Polyhedron 1991, 10, 1153. (g) Lee, V. Y.; Sekiguchi, A.
́
J.; Ranaivonjatovo, H. Adv. Organomet. Chem. 1999,
J.; Satge, J.; Lazraq, M. J. Am. Chem.
J.; Couret, C.; Satge, J.
́
́
1
́
́
C43H64GeN5P2Si2Sn: C, 53.72; H, 6.81; N, 7.28. H NMR (THF-d8,
́
25 °C): δ = −0.16, (s, 9H, SiMe3), −0.08, (s, 9H, SiMe3), 0.30 (m,
6H, CH2-nBu), 0.80 (t, 9H, CH3-nBu, JH−H = 6 Hz), 0.30 (m, 12H,
C2H4-nBu), 7.10−7.14 (m, 4H, Ph), 7.20−7.25 (m, 2H, Ph), 7.29−
7.48 (m, 10H, Ph), 7.87−7.91 (m, 4H, Ph). 13C{1H} NMR (THF-d8,
25 °C): δ = 3.5 (SiMe3), 4.7 (SiMe3), 14.1, 17.5, 28.2, 30.0 (nBu), 38.1
(PCP), 130.2, 130.8, 131.0, 131.2, 131.8, 132.0, 132.1, 132.2, 132.8,
132.9, 134.0, 136.4, 144.4, 144.8 (Ph). 31P{1H} NMR (THF-d8, 25
°C): δ = 10.6, 45.5. 119Sn{1H} NMR (THF-d8): δ = −44.6.
́
Organometallics 2004, 23, 2822. (h) Lee, V. Y.; Sekiguchi, A.
Organometallic Compounds of Low-Coordinate Si, Ge, Sn and Pb:
From Phantom Species to Stable Compounds; Wiley: Chichester, 2010;
Chapter 5.
(2) (a) Meyer, H.; Baum, G.; Massa, W.; Berndt, A. Angew. Chem.,
Int. Ed. Engl. 1987, 26, 798. (b) Lazraq, M.; Escudie,
Satge, J.; Drager, M.; Dammel, R. Angew. Chem., Int. Ed. Engl. 1988, 27,
828. (c) Couret, C.; Escudie,
́
J.; Couret, C.;
́
̈
Reaction of 1 with H2O→B(C6F5)3. A solution of 1 (1.34g, 1.06
mmol) in THF (20 mL) was added to a solution of B(C6F5)3·H2O
(1.13g, 2.13 mmol) in THF (10 mL) at −90 °C. The reaction mixture
turned colorless, and it was stirred at room temperature for 1 h. A
colorless solution was formed. All the volatiles in the reaction mixture
were removed under reduced pressure and the residue was extracted
with Et2O (20 mL). After filtration and concentration of the filtrate,
compound 6 was isolated as colorless crystals. Yield: 1.43g (57.7%).
Mp: 128.5 °C. Anal found: C, 51.22; H, 3.96; N, 2.54. Calcd For
́
́
J.; Delpon-Lacaze, G.; Satge, J.
Organometallics 1992, 11, 3176. (d) Bravo-Zhivotovskii, D.; Zharov,
I.; Kapon, M.; Apeloig, Y. J. Chem. Soc., Chem. Commun. 1995, 1625.
(e) Tokitoh, N.; Kishikawa, K.; Okazaki, R. J. Chem. Soc., Chem.
Commun. 1995, 1425. (f) Lee, V. Y.; Ichinohe, M.; Sekiguchi, A. J. Am.
Chem. Soc. 2002, 124, 9962.
(3) (a) Escudie,
1998, 178, 565. (b) Lazraq, M.; Escudie,
Organometallics 1992, 11, 555. (c) Ech-Cherif EI Kettani, S.; Escudie,
́
J.; Couret, C.; Ranaivonjatovo, H. Coord. Chem. Rev.
́
J.; Couret, C.; Satge, J.
́
1
C49H40BF15GeN2OP2Si2: C, 50.76; H, 3.48; N, 2.42. H NMR (THF-
́
4576
dx.doi.org/10.1021/ic400056f | Inorg. Chem. 2013, 52, 4571−4577

Inorganic Chemistry
Article
J.; Couret, C.; Ranaivonjatovo, H.; Lazraq, M.; Soufiaoui, M.;
Gornitzka, H.; Cretiu Nemes, G. Chem. Commun. 2003, 1662.
(d) Ech-Cherif, E. I.; Kettani, S.; Lazraq, M.; Ranaivonjatovo, H.;
(30) (a) Evans, D. J.; Hill, M. S.; Hitchcock, P. B. Dalton Trans. 2003,
570. (b) Hill, M. S.; Hitchcock, P. B. J. Organomet. Chem. 2004, 689,
3163.
(31) Jutzi, P.; Becker, A.; Stammler, H. G.; Neumann, B.
Organometallics 1991, 10, 1647.
Escudie,
2004, 23, 5062. (e) Ech-Cherif EI Kettani, S.; Lazraq, M.;
Ranaivonjatovo, H.; Escudie, J.; Couret, C.; Gornitzka, H.; Atmani,
́
J.; Couret, C.; Gornitzka, H.; Merceron, N. Organometallics
(32) Bibal, C.; Mazier
metallics 2002, 21, 2940.
̀
es, S.; Gornitzka, H.; Couret, C. Organo-
́
A. Organometallics 2005, 24, 5364.
(33) Leung, W.-P.; So, C.-W.; Wu, Y.-S.; Li, H.-W.; Mak, T. C. W.
Eur. J. Inorg. Chem. 2005, 513.
(4) Harper, W. H.; Ferrall, E. A.; Hilliard, R. K.; Stogner, S. M.; Grev,
R. S.; Clouthier, D. J. J. Am. Chem. Soc. 1997, 119, 8361.
(5) Leung, W.-P.; Wang, Z.-X.; Li, H.-W.; Mak, T. C. W. Angew.
Chem., Int. Ed. 2001, 40, 2501.
(6) Leung, W.-P.; So, C.-W.; Wang, J.-Z.; Mak, T. C. W. Chem.
Commun. 2003, 248.
(7) Leung, W.-P.; So, C.-W.; Wang, Z.-X.; Wang, J.-Z.; Mak, T. C. W.
Organometallics 2003, 22, 4305.
(8) Leung, W.-P.; So, C.-W.; Kan, K.-W.; Chan, H.-S.; Mak, T. C. W.
Organometallics 2005, 24, 5033.
(9) Leung, W.-P.; So, C.-W.; Kan, K.-W.; Chan, H.-S.; Mak, T. C. W.
Inorg. Chem. 2005, 44, 7286.
(34) Moller, A.; Mohlen, M.; Neumuller, B.; Faza, N.; Massa, W.;
̈
̈
̈
Dehnicke, K. Z. Anorg. Allg. Chem 1999, 625, 1748.
(35) Leung, W.-P.; So, C.-W.; Wang, Z. -X.; Wang, J.-Z.; Mak, T. C.
W. Organometallics 2003, 22, 4305.
(36) Ding, Y.; Roesky, H. W.; Noltemeyer, M.; Schmidt, H.-G.;
Power, P. P. Organometallics 2001, 20, 1190.
(37) Seibert, M.; Merzweiler, K.; Wagner, C.; Weichmann, H. J.
Organomet. Chem. 2002, 650, 25.
(38) Thooen, S. H. L.; Hoek, H. V.; Wolf, E. D.; Lutz, M.; Spek, A.
L.; Deelman, B.-J.; Koten, G. V. J. Organomet. Chem. 2006, 691, 1544.
(39) Ayers, A. E.; Marynick, D. S.; Dias, H. V. R. Inorg. Chem. 2000,
39, 4147.
(10) Leung, W.-P.; Kan, K.-W.; So, C.-W.; Mak, T. C. W.
Organometallics 2007, 26, 3802.
(40) Ayers, A. E.; Klapotke, T. M.; Dias, H. V. R. Inorg. Chem. 2001,
̈
(11) Leung, W.-P.; Kan, K.-W.; So, C.-W.; Mak, T. C. W. Appl.
Organomet. Chem. 2007, 21, 814.
(12) (a) Cavell, R. G.; Babu, K. R. P.; Kasani, A.; McDonald, R. J. Am.
Chem. Soc. 1999, 121, 5805. (b) Babu, K. R. P.; McDonald, R.; Cavell,
R. G. Organometallics 2000, 19, 3462. (c) Cavell, R. G. J. Organomet.
Chem. 2001, 617, 158.
40, 1000.
(41) Johnson, J. R. T.; Panas, I. Chem. Phys. 1999, 249, 273.
(42) Bergquist, C.; Bridgewater, B. M.; Harlan, C. J.; Norton, J. R.;
Friesner, R. A.; Parkin, C. J. Am. Chem. Soc. 2000, 122, 10581.
(43) Sheldrick, G. M. SHELXL-97, Program for Crystal Structure
Refinement; University of Gottingen: Germany, 1997.
̈
(13) Aparna, K.; McDonald, R.; Ferguson, M.; Cavell, R. G.
Organometallics 1999, 18, 4241.
(14) Aparna, K.; McDonald, R.; Cavell, R. G. Chem. Commun. 1999,
1993.
(15) Pineda, L. W.; Jancik, V.; Roesky, H. W.; Neculai, D.; Neculai,
A. M. Angew. Chem., Int. Ed. 2004, 43, 1419.
(16) Leung, W.-P.; Kwok, W.-H.; Zhou, Z.-Y.; Mak, T. C. W.
Organometallics 2003, 22, 1751.
(17) Hitchcock, P. B.; Lappert, M. F.; Miles, S. J.; Thorne, A. J. J.
Chem. Soc., Chem. Commun. 1984, 480.
(18) Leung, W.-P.; Kwok, W.-H.; Weng, L.-H.; Law, L. T. C.; Zhou,
Z.-Y.; Mak, T. C. W. J. Chem. Soc., Dalton Trans. 1997, 4301.
(19) Dias, H. V. R.; Wang, Z.; Jin, W. Coord. Chem. Rev. 1998, 176,
67.
(20) Saur, I.; Miqueu, K.; Rima, G.; Barrau, J.; Lemierre, V.;
Chrostowska, A.; Sotiropoulos, J.-M.; Pfister-Guillouzo, G. Organo-
metallics 2003, 22, 3143.
(21) (a) Buttrus, N. H.; Eaborn, C.; Hitchcock, P. B.; Smith, J. D.;
Sullivan, A. C. J. Chem. Soc., Chem. Commun. 1985, 534.. (b) Andersen,
R. A.; Haaland, A.; Rypdal, K.; Volden, H. V. J. Chem. Soc., Chem.
Commun. 1985, 1807. (c) Andersen, R. A.; Berg, D. J.; Fernholt, L.;
Faegri, K.; Green, J. C.; Haaland, A.; Lappert, M. F.; Leung, W.-P.;
Rypdal, K. Acta Chem. Scand. Ser. 1998, 42, 554. (d) Wehmschulte, R.
J.; Power, P. P. Organometallics 1995, 14, 3264.
(22) Al-Juaid, S. S.; Eaborn, C.; El-Hamruni, S. M.; Hitchcock, P. B.;
Smith, J. D.; Can, S. E. S. J. Organomet. Chem. 2002, 649, 121.
(23) Chai, J.; Zhu, H.; Roesky, H. W.; Yang, Z.; Jancik, V.; Herbst-
Irmer, R.; Schmidt, H.-G.; Noltemeyer, M. Organometallics 2004, 23,
5003.
(24) Chai, J.; Zhu, H.; Roesky, H. W.; He, C.; Schmidt, H.-G.;
Noltemeyer, M. Organometallics 2004, 23, 3284.
(25) Jutzi, P.; Becker, A.; Leue, C.; Stammler, H.-G.; Neumann, B.;
Hursthouse, M. B.; Karaulov, A. Organometallics 1991, 10, 3838.
(26) Pu, L.; Olmstead, M. M.; Power, P. P.; Schiemenz, B.
Organometallics 1998, 17, 5602.
(27) LaPointe, A. M. Inorg. Chim. Acta 2003, 345, 359.
(28) Viefhaus, T.; Schwarz, W.; Hubler, K.; Locke, K.; Weidlein, J. Z.
̈
Anorg. Allg. Chem. 2001, 627, 715.
(29) Smith, J. M.; Lachicotte, R. J.; Holland, P. L. Chem. Commun.
2001, 1542.
4577
dx.doi.org/10.1021/ic400056f | Inorg. Chem. 2013, 52, 4571−4577