{CH2(PPh2=NSiMe3)(PPh2=S)} and {CH(PPh2=NSiMe3)(Ph2P=S)}- as ligands in zinc chemistry: Synthesis and structures

Article abstract of DOI:10.1002/ejic.201300501

The (iminophosphoranyl)(thiophosphoranyl)methane zinc complexes [{(PPh ₂=NSiMe₃)(PPh₂=S)CH₂}ZnX ₂] (X = Cl, I) have been obtained by the reaction of {CH ₂(PPh₂=NSiMe₃)(PPh₂=S)} with the corresponding zinc dihalides ZnCl₂ and ZnI₂. The (iminophosphoranyl)(thiophosphoranyl)methane ligand coordinates as a bidentate ligand through the nitrogen and sulfur atoms to the zinc atom to form a six-membered metallacycle (N-P-C-P-S-Zn). The reaction of {CH ₂(PPh₂=NSiMe₃)(PPh₂=S)} with [Zn{N(SiMe₃)₂}₂] and ZnPh₂ resulted in the (iminophosphoranyl)(thiophosphoranyl)methanide complexes [{(PPh ₂=NSiMe₃)(PPh₂=S)CH}Zn{N(SiMe₃) ₂}] and [{(PPh₂=NSiMe₃)(PPh₂=S)CH} ZnPh], respectively. In addition to the coordination of the phosphinimine nitrogen and sulfur atoms to the zinc atom, a long contact between the methine carbon atom of the P-C-P bridge and the zinc atom was observed in these complexes. The solid-state structures of all the new compounds were established by single-crystal X-ray diffraction. [{(PPh₂=NSiMe ₃)(PPh₂=S)CH₂}ZnX₂] (X = Cl, I), [{(PPh₂=NSiMe₃)(PPh₂=S)CH}Zn{N(SiMe ₃)₂}], and [{(PPh₂=NSiMe₃)(PPh ₂=S)CH}ZnPh] have been synthesized and structurally characterized. Copyright

Full text of DOI:10.1002/ejic.201300501

FULL PAPER
DOI:10.1002/ejic.201300501
{CH2(PPh2=NSiMe3)(PPh2=S)} and
{CH(PPh2=NSiMe3)(Ph2P=S)}– as Ligands in Zinc
Chemistry: Synthesis and Structures
Magdalena Kuzdrowska,[a] Balasubramanian Murugesapandian,[a]
Larissa Hartenstein,[a] Michael T. Gamer,[a] Nicholas Arleth,[a]
Siegfried Blechert,[b] and Peter W. Roesky*[a]
Dedicated to Professor Dr. Werner Uhl on the occasion of his 60th birthday
Keywords: Chelates / N,P,S Ligands / Phosphazenes / Zinc
The (iminophosphoranyl)(thiophosphoranyl)methane zinc
complexes [{(PPh2=NSiMe3)(PPh2=S)CH2}ZnX2] (X = Cl, I)
have been obtained by the reaction of {CH2(PPh2=NSiMe3)-
(PPh2=S)} with the corresponding zinc dihalides ZnCl2 and
ZnI2. The (iminophosphoranyl)(thiophosphoranyl)methane
ligand coordinates as a bidentate ligand through the nitrogen
and sulfur atoms to the zinc atom to form a six-membered
metallacycle (N–P–C–P–S–Zn). The reaction of {CH2(PPh2=
NSiMe3)(PPh2=S)} with [Zn{N(SiMe3)2}2] and ZnPh2 resulted
in the (iminophosphoranyl)(thiophosphoranyl)methanide
complexes [{(PPh2=NSiMe3)(PPh2=S)CH}Zn{N(SiMe3)2}] and
[{(PPh2=NSiMe3)(PPh2=S)CH}ZnPh], respectively. In addition
to the coordination of the phosphinimine nitrogen and sulfur
atoms to the zinc atom, a long contact between the methine
carbon atom of the P–C–P bridge and the zinc atom was ob-
served in these complexes. The solid-state structures of all
the new compounds were established by single-crystal X-ray
diffraction.
{CH2(Ph2PNSiMe3)2} with ZnPh2 in toluene gave the bis-
(phosphinimino)methanide complex [{(Me3SiNPPh2)2CH}-
ZnPh][40] in which the ligand is deprotonated. Addition of
the heterocumulenes di-(p-tolyl)carbodiimine and di-
phenylketene to [{(Me3SiNPPh2)2CH}ZnPh] resulted in
tripodal phenylzinc complexes [{(Me3SiNPPh2)2CH}-
{(pTol)N=C–N(pTol)}ZnPh] and [{(Me3SiNPPh2)2CH}-
(Ph2C=C–O)ZnPh]. Reaction of the related amido complex
[{CH(Ph2PNSiMe3)2}Zn{N(SiMe3)2}], which was prepared
Introduction
For many years we and others have been using zinc com-
pounds as catalysts in the hydroamination reaction.[1–39]
Most of the reported zinc catalysts show, besides their good
catalytic activity and selectivity, high tolerance towards po-
lar functional groups. Some of them are also stable towards
air and moisture, but it seems that high stability is not bene-
ficial for high catalytic activity. We have recently developed,
among others, various aminotroponiminate zinc alkyl and
amido complexes as catalysts for the hydroamination reac-
tion.[8–18] We have also reported on bis(phosphinimino)-
methanide zinc complexes.[40,41] Bis(phosphinimino)meth-
ane {CH2(Ph2PNSiMe3)2} reacted with the zinc dihalides
ZnCl2 and ZnI2 to form the corresponding bis(phosphin-
imino)methane complexes [{(Me3SiNPPh2)2CH2}ZnCl2]
and [{(Me3SiNPPh2)2CH2}ZnI2]. In contrast, treatment of
by
the
reaction of
{CH2(Ph2PNSiMe3)2}
and
[Zn{N(SiMe3)2}2] with BH3·THF, resulted in the borohyd-
ride/borane complex [{CH(Ph2PNSiMe3)2}(κ1-BH3)Zn-
(BH4)].[41]
Recently, our attention has been attracted by the (imino-
phosphoranyl)(thiophosphoranyl)methanide
ligand
{CH(PPh2=NR)(Ph2P=S)}–, which is isoelectronic with the
bis(phosphinimino)methanide ligand. The synthesis of
{CH2(PPh2=NSiMe3)(PPh2=S)} by the reaction of
{Ph2PCH2(PPh2=NSiMe3)} with sulfur in toluene at reflux
was reported by So and co-workers.[42] Deprotonation of
{CH2(PPh2=NSiMe3)(PPh2=S)} with nBuLi gave the lith-
ium(iminophosphoranyl)(thiophosphoranyl)methanide [Li-
{CH(PPh2=NSiMe3)(PPh2=S)}]. Furthermore, the corre-
sponding dianion [Li2{C(PPh2=NSiMe3)(PPh2=S)}] was
obtained by the reaction of [CH2(PPh2=NSiMe3)(PPh2=S)]
with tBuLi. Moreover, complexes of Mg,[43] Al,[43] Sn,[44,45]
[a] Institut für Anorganische Chemie and Helmholtz Research
School: Energy-Related Catalysis, Karlsruhe Institute of
Technology (KIT),
Engesserstrasse 15, 76131 Karlsruhe, Germany
E-mail: roesky@kit.edu
Homepage: http://www.aoc.kit.edu/AK%20Roesky.php
[b] Institut für Chemie, Technische Universität Berlin,
Straße des 17. Juni 135, 10623 Berlin, Germany
E-mail: blechert@chem.tu-berlin.de
Homepage: http://www.chemie.tu-berlin.de/blechert/menue/
home/
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Ru,[46] Pt,[47] and the rare-earth elements[48] with the above
ligands have been synthesized.
Herein we report on (iminophosphoranyl)(thiophosphor-
anyl)methane {CH2(PPh2=NSiMe3)(PPh2=S)} and (imino-
phosphoranyl)(thiophosphoranyl)methanide {CH(PPh2=
NSiMe3)(PPh2=S)}– as ligands in zinc chemistry. The syn-
thesis of the complexes [{(PPh2=NSiMe3)(PPh2=S)-
CH2}ZnX2] (1 and 2; X = Cl, I), [{(PPh2=NSiMe3)-
(PPh2=S)CH}Zn{N(SiMe3)2}] (3), and [{(PPh2=NSiMe3)-
(PPh2=S)CH}ZnPh] (4) are described as well as their struc-
tural characterization and a catalytic study.
Figure 1. Solid-state structure of 1. The hydrogen atoms have been
omitted for clarity. Only one of two independent molecules is
shown. Selected bond lengths [Å] and angles [°]: Zn1–N1 2.036(5),
Zn1–Cl1 2.223(2), Zn1–Cl2 2.251(2), Zn1–S1 2.420(2), Zn2–N2
2.042(5), Zn2–Cl3 2.246(2), Zn2–Cl4 2.228(2), Zn2–S2 2.424(2),
N1–P2 1.584(6), N2–P4 1.596(6), P1–S1 1.982(2), P1–C13 1.827(6),
P2–C13 1.819(7), P3–S2 1.985(2), P3–C41 1.815(6), P4–C41
1.825(7); N1–Zn1–Cl1 116.2(2), N1–Zn1–Cl2 108.8(2), N1–Zn1–
S1 100.3(2), Cl1–Zn1–Cl2 116.23(8), Cl1–Zn1–S1 104.21(7), Cl2–
Zn1–S1 109.60(8), N2–Zn2–Cl3 108.6(2), N2–Zn2–Cl4 115.9(2),
N2–Zn2–S2 100.8(2), Cl3–Zn2–Cl4 116.15(8), Cl3–Zn2–S2
109.76(8), Cl4–Zn2–S2 104.31(7), P1–C13–P2 118.3(3), P3–C41–P4
118.5(3).
Results and Discussion
The reaction of {CH2(PPh2=NSiMe3)(PPh2=S)} with the
zinc dihalides ZnCl2 and ZnI2 in a 1:1 molar ratio in THF
afforded the corresponding (iminophosphoranyl)(thiophos-
phoranyl)methane complexes [{(PPh2=NSiMe3)(PPh2=S)-
CH2}ZnCl2] (1) and [{(PPh2=NSiMe3)(PPh2=S)CH2}ZnI2]
(2) as colorless crystals in good yields (88 and 81%, respec-
tively; Scheme 1), which were fully characterized. Owing to
their poor solubility, no useful NMR spectroscopic data
could be obtained for compounds 1 and 2.
Compound 2 crystallizes in the monoclinic space group
P21/c with two independent molecules of compound 2 and
one molecule of THF in the asymmetric unit (Figure 2). As
observed for compound 1, the {(PPh2=NSiMe3)(PPh2=S)-
CH2} ligand coordinates as a bidentate ligand through the
nitrogen and sulfur atoms to the zinc atom. The six-mem-
bered metallacycle (N–P–C–P–S–Zn), which shows no
carbon–zinc contact, adopts a twist-boat conformation.
The zinc atom is at the center of a distorted tetrahedral
polyhedron. The observed Zn–S and Zn–N bond lengths
are in the expected range [Zn1–S1 2.4150(11) Å, Zn2–S2
2.4132(11) Å, Zn1–N1 2.035(3) Å, Zn2–N2 2.031(3) Å].
The bonding parameters are similar to those of the related
bis(phosphinimino)methane complex [{(Me3SiNPPh2)2-
CH2}ZnI2] [e.g., Zn–N1 2.061(5) Å, Zn–N2 2.033(6) Å].[40]
Scheme 1. Synthesis of [{(PPh2=NSiMe3)(PPh2=S)CH2}ZnX2] [X
= Cl (1), I (2)].
Single crystals of compounds 1 and 2 were obtained from
hot THF directly from the reaction mixture. Compound 1
crystallizes in the monoclinic space group Cc with two inde-
pendent molecules of 1 in the asymmetric unit (Figure 1).
Some THF solvent molecules were suppressed by using the
SQUEEZE routine in PLATON.[49] The (iminophosphor-
anyl)(thiophosphoranyl)methane ligand coordinates as a bi-
dentate ligand through the nitrogen and sulfur atoms to the
zinc atom to form a six-membered metallacycle (N–P–C–
P–S–Zn). The Zn–N bonds lengths of Zn1–N1 [2.036(5) Å]
and Zn2–N2 [2.042(5) Å] are slightly shorter than those in
the
related
bis(phosphinimino)methane
complex
[{(Me3SiNPPh2)2CH2}ZnCl2] [Zn1–N1 2.055(3) Å, Zn1–
N2 2.061(3) Å, Zn2–N3 2.064(3) Å, Zn2–N4 2.046(2) Å].[40]
Although there is no carbon–zinc contact, the metallacycle
adopts a twist-boat conformation, presumably as a result
of the crystal packing. Thus, the zinc atom is tetracoordi-
nated by the {(PPh2=NSiMe3)(PPh2=S)CH2} ligand and
the two chlorine atoms. The N–Zn–S bite angles of the li-
gands inside the {(PPh2=NSiMe3)(PPh2=S)CH2} moiety
are smaller than in a regular tetrahedron [N1–Zn1–S1
100.3(2)°, N2–Zn2–S2 100.8(2)°].
Figure 2. Solid-state structure of 2. The hydrogen atoms have been
omitted for clarity. Only one of two independent molecules is
shown. Selected bond lengths [Å] and angles [°]: Zn1–I1 2.5797(5),
Zn1–I2 2.6052(5), Zn1–S1 2.4150(11), Zn1–N1 2.035(3), Zn2–I3
2.5687(5), Zn2–I4 2.5816(5), Zn2–S2 2.4132(11), Zn2–N2 2.031(3),
P1–C13 1.801(4), P2–C13 1.819(3), N1–Zn1–S1 104.22(9), N1–
Zn1–I1 119.07(8), S1–Zn1–I1 98.62(3), N1–Zn1–I2 108.49(8), S1–
Zn1–I2 112.99(3), I1–Zn1–I2 112.83(2), N2–Zn2–S2 103.24(9),
N2–Zn2–I3 117.67(8), S2–Zn2–I3 98.06(3), N2–Zn2–I4 110.40(8),
S2–Zn2–I4 110.04(3), I3–Zn2–I4 115.67(2), P1–C13–P2 120.9(2).
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Scheme 2. Synthesis of [{(PPh2=NSiMe3)(PPh2=S)CH}Zn{N(SiMe3)2}] (3).
Next we attempted to synthesize (iminophosphor- {(PPh2=NSiMe3)(PPh2=S)CH}– ligand scaffold, the P–C13
anyl)(thiophosphoranyl)methanide zinc complexes that bond lengths of the {CH(PPh2=NSiMe3)(PPh2=S)}– ligand
have a suitable leaving group as potential catalysts for intra- are significantly shorter [P1–C13 1.736(4) Å, P2–C13
molecular hydroamination/cyclization reactions. Treatment 1.752(3) Å] than in the starting material {CH2-
of {(PPh2=NSiMe3)(PPh2=S)CH2} with an equimolar (PPh2=NSiMe3)(PPh2=S)} [1.820(3) Å, 1.831(3) Å],[42]
amount of [Zn{N(SiMe3)2}2] in toluene at reflux resulted in which indicates a certain level of delocalization.
the (iminophosphoranyl)(thiophosphoranyl)methanide zinc
complex [{(PPh2=NSiMe3)(PPh2=S)CH}Zn{N(SiMe3)2}]
(3) after 2 days (Scheme 2). During the course of the reac-
tion, {(PPh2=NSiMe3)(PPh2=S)CH2} was deprotonated.
A characteristic doublet of doublets for the methine pro-
ton is observed in the 1H NMR spectrum of 3 at δ =
2
2.87 ppm [2J(H,PN) = 3.2 Hz, J(H,PS) = 1.6 Hz]. This sig-
nal is slightly shifted upfield in comparison with
{(PPh2=NSiMe3)(PPh2=S)CH2} (δ = 3.56 ppm).[42] Other
characteristic signals are the two singlets of the SiMe3
group of the ligand and the SiMe3 group of the amide. In
the 31P{1H} NMR spectrum of 3, two doublets can be seen
at δ = 28.0 and 35.0 ppm. In the 13C{1H} NMR spectrum,
the signal of the methine carbon atom was detected at δ =
Figure 3. Solid-state structure of 3. The hydrogen atoms have been
36.9 ppm; owing to the coupling to the phosphorus atoms,
omitted for clarity. Selected bond lengths [Å] and angles [°]: Zn–S
this signal is split into a doublet of doublets [1J(C,PN) =
2.4612(11), Zn–N1 2.016(3), Zn–N2 1.906(3), Zn–C13 2.475(4),
1
Zn–P2 2.7695(9), S–P1 2.0087(13), N–P2 1.601(3), P1–C13
1.736(4), P2–C13 1.752(3), S–Zn–N1 102.52(9), S–Zn–N2
119.40(10), S–Zn–C13 76.20(9), N1–Zn–N2 132.96(12), N1–Zn–
C13 73.17(11), N2–Zn–C13 134.14(12), P1–C13–P2 119.9(2).
101.4 Hz, J(C,PS) = 71.2 Hz]. In the IR spectrum of com-
pound 3, strong bands are observed for the P=N (ν =
˜
1243 cm–1)[50] and P=S (ν = 688 cm–1)[51] stretching vi-
˜
brations.
Compound 3 crystallizes without any solvent in the tri-
The treatment of {(PPh2=NSiMe3)(PPh2=S)CH2} with
¯
clinic space group P1 with two molecules in the unit cell ZnPh2 in toluene led to the (iminophosphoranyl)(thiophos-
(Figure 3). In the solid state, the zinc atom is coordinated phoranyl)methanide complex [{(PPh2=NSiMe3)(PPh2=S)-
by the phosphinimine nitrogen and sulfur atoms [Zn–N1 CH}ZnPh] (4; Scheme 3). During the course of the reaction
2.016(3), Zn–S 2.4612(11) Å] of the {(PPh2=NSiMe3)- {(PPh2=NSiMe3)(PPh2=S)CH2} was deprotonated. The
(PPh2=S)CH}– ligand and the nitrogen atom of the new complex was characterized by standard analytical and
N(SiMe3)2 group [Zn–N2 1.906(3) Å]. The S–Zn–N1 angle spectroscopic techniques, and the solid-state structure was
of the ligand is 102.52(9)°, and the angles to the N(Si- established by single-crystal X-ray diffraction (Figure 4).
Me3)2 group, N1–Zn–N2 and S–Zn–N2, are 132.96(12) and The room temperature 1H and 31P{H} NMR spectra of
119.40(10)°, respectively. Furthermore, a long contact be- compound
4
show the expected pattern for the
tween the methine carbon atom (C13) and the zinc atom of {(PPh2=NSiMe3)(PPh2=S)CH}– ligand. In the 1H NMR
2.475(4) Å is observed. This distance is about 0.5 Å shorter spectrum, a significant downfield shift of the P–CH–P reso-
than the Zn–C distance in the related bis(phosphinimino)- nance (δ = 2.71 ppm) is observed compared with the neutral
methanide complex [{CH(Ph2PNSiMe3)2}Zn{N(SiMe3)2}] ligand (δ = 3.56 ppm).[42] This signal is split into a doublet
[2.981(2) Å].[41] By considering the Zn–C13 distance as a of doublets [2J(H,PN) = 3.4 Hz, 2J(H,PS) = 1.4 Hz] as a
bond, the coordination polyhedron of the Zn atom can be result of the two chemically different phosphorus atoms.
considered as a distorted tetrahedron. A six-membered Furthermore, for the SiMe3 group, a characteristic singlet
metallacycle (N–P1–C13–P2–S–Zn) is formed by the at δ = 0.13 ppm is observed. Compound 4 shows two dou-
{(PPh2=NSiMe3)(PPh2=S)CH}– ligand and the zinc atom. blets (δ = 26.6 and 35.5 ppm) in the 31P{1H} NMR spec-
The ring adopts a twist-boat conformation in which the trum that are significantly shifted compared with the start-
central carbon atom (C13) and the zinc atom are displaced ing material (δ = –4.8 and 36.2 ppm). On the other hand,
from the NP2S least-squares plane. Within the compound 3 (δ = 28.0 and 35.0 ppm) and the analogous
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mesityl bis(phosphinimino)methanide complex [{CH- methanide ligand, instead of the sulfur atom an additional
(Ph2PNC6H2Me3-2,4,6)2}ZnN(SiMe3)2] (δ
= 33.1 ppm) NSiMe3 group forms part of the ligand scaffold. This
show signals in the 31P{1H} NMR spectrum in a compar- NSiMe3 group forces the Zn–Ph group into a different con-
able range.[52] The IR spectrum of compound 4 is similar formation of the metallacycle. By considering
to that of compound 3; strong bands are observed for the {CH(PPh2=NSiMe3)(PPh2=S)}– as a tridentate ligand, the
P=N (ν = 1243 cm–1)[50] and P=S (ν = 688 cm–1)[51] stretch- zinc atom is tetracoordinated forming a distorted tetrahe-
˜
˜
ing vibrations.
dral polyhedron. Upon coordination to the zinc atom the
{(PPh2=NSiMe3)(PPh2=S)CH}– ligand forms a six-mem-
bered metallacycle that adopts a twist-boat conformation
showing Zn–N and Zn–S bond lengths of 2.020(2) and
2.6081(7) Å, respectively. Although the Zn–N bond length
is in the range of that of compound 3, the Zn–S bond is
significantly longer.
Because various aminotroponiminate zinc alkyl and
amido complexes have been used successfully in hydroamin-
ation/cyclization reactions,[8–12,16,18] we performed catalytic
Scheme 3. Synthesis of [{(PPh2=NSiMe3)(PPh2=S)CH}ZnPh] (4).
studies by using compound
4
as catalyst and
[PhNMe2H][B(C6F5)4] as co-catalyst in the hydroamination/
cyclization reaction. Three different amino-olefins and one
aminoalkyne were used as substrates. All experiments were
carried out under rigorously anaerobic reaction conditions
with dry, degassed substrates and 5 mol-% catalyst and
5 mol-% co-catalyst loadings. Unfortunately, we could not
obtain reproducible yields and rates under the same reac-
tion conditions. We suggest that compound 4 decomposes
under the reaction conditions. Similar behavior was
observed
for
the
lanthanide
compounds
[{CH(PPh2=NSiMe3)(PPh2=S)}Ln{N(SiHMe2)2}2], which
also decompose under the catalytic conditions of the
hydroamination/cyclization
reaction.[48]
Clearly
the
{CH(PPh2=NSiMe3)(PPh2=S)}– ligand does not coordinate
to hard metals such as zinc and the lanthanides as effec-
tively as the corresponding bis(phosphinimino)methanide
{CH(Ph2PNSiMe3)2}–.
Figure 4. Solid-state structure of 4. The hydrogen atoms have been
omitted for clarity. Selected bond lengths [Å] and angles [°]: Zn–S
2.6081(7), Zn–N 2.020(2), Zn–C13 2.343(2), Zn–C29 1.963(2), S–
P1 1.9973(8), N–P2 1.601(2), P1–C13 1.741(2), P2–C13 1.757(2),
N–Zn–C29 136.84(9), C13–Zn–C29 133.95(9), N–Zn–C13 75.34(7),
S–Zn–C29 113.05(7), N–Zn–S 103.92(6), S–Zn–C13 75.84(6), P1–
C13–P2 121.37(14).
Conclusions
The solid-state structure of 4 was investigated by single-
crystal X-ray diffraction and the data is in agreement with
We have introduced {CH2(PPh2=NSiMe3)(PPh2=S)} and
the NMR spectroscopic data obtained in solution. Com- {CH(PPh2=NSiMe3)(Ph2P=S)}– as ligands into zinc chem-
pound 4 crystallizes in the monoclinic space group P21/c istry. The (iminophosphoranyl)(thiophosphoranyl)methane
with four molecules in the unit cell. In the solid state, the zinc complexes [{(PPh2=NSiMe3)(PPh2=S)CH2}ZnX2] [X
zinc atom is coordinated by the phosphinimine nitrogen = Cl (1), I (2)] were obtained by the reaction of
and sulfur atoms of the {(PPh2=NSiMe3)(PPh2=S)CH}– li- {CH2(PPh2=NSiMe3)(PPh2=S)} and the corresponding
gand as well as by the phenyl group. Moreover, a long con- zinc dihalides ZnCl2 and ZnI2. The reaction of
tact between the methine carbon atom (C13) and the zinc {CH2(PPh2=NSiMe3)(PPh2=S)} with [Zn{N(SiMe3)2}2]
atom is observed. Comparison of the Zn–C bond lengths and ZnPh2 led to the (iminophosphoranyl)(thiophosphor-
within compound 4 clearly indicates that the bonding of the anyl)methanide complexes [{(PPh2=NSiMe3)(PPh2=S)-
zinc atom to the phenyl group [Zn–C29 1.963(2) Å] is much CH}Zn{N(SiMe3)2}] (3) and [{(PPh2=NSiMe3)(PPh2=S)-
tighter than the bonding to the methanide carbon atom CH}ZnPh] (4). The solid-state structures of all the new
[Zn–C13 2.343(2) Å]. The Zn–C13 distance is in the range compounds were established by single-crystal X-ray diffrac-
of the same bond in compound 3, but significantly shorter tion. In all compounds the zinc atom is coordinated by the
than in the bis(phosphinimino)methanide complex phosphinimine nitrogen and sulfur atoms of the ligand.
[{(Me3SiNPPh2)2CH}ZnPh] [2.923(2) Å].[40] The smaller Furthermore, a long contact between the methine carbon
Zn–C13 distance in 4 is a result of the reduced repulsion atom of the P–C–P bridge and the zinc atom was observed
between the Zn–Ph group and the {(PPh2=NSiMe3)- in the (iminophosphoranyl)(thiophosphoranyl)methanide
(PPh2=S)CH}– ligand in comparison with the bis(phos- complexes 3 and 4. No reproducible results were obtained
phinimino)methanide analogue. In the bis(phosphinimino)- when [{(PPh2=NSiMe3)(PPh2=S)CH}ZnPh] was used as
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Single crystals suitable for X-ray analysis were obtained from hot
heptane, yield 271 mg, 0.41 mmol, 68%. 1H NMR (300.13 MHz,
[D8]THF): δ = 0.01 [s, 9 H, Si(CH3)3], 0.05 {s, 18 H, N[Si-
catalyst for the hydroamination/cyclization reaction. We
suggest that the complex decomposes under the catalytic
conditions.
2
2
(CH3)3]2}, 2.87 [dd, J(H,PN) = 3.2, J(H,PS) = 1.6 Hz, 1 H, CH],
7.21–7.30 (m, 8 H, o-PPh), 7.31–7.39 (m, 4 H, p-PPh), 7.63–7.74
(m, 8 H, m-PPh) ppm. 13C{1H} NMR (75.48 MHz, [D8]THF): δ =
3.5 [Si(CH3)3], 6.1 {N[Si(CH3)3]2}, 36.9 [dd, 1J(C,PN) = 101.4,
1J(C,PS) = 71.2 Hz, CH], 128.8 (m, o-PPh), 131.7 (m, p-PPh), 132.3
(m, m-PPh), 135.5 (m, i-PPh) ppm. 31P{1H} NMR (121.49 MHz,
[D8]THF): δ = 28.0 [d, 2J(P,P) = 6.4 Hz, PNSi(CH3)3], 35.0 [d,
Experimental Section
General: All manipulations of air-sensitive materials were per-
formed with the rigorous exclusion of oxygen and moisture in
flame-dried Schlenk-type glassware either on a dual manifold
Schlenk line, interfaced to a high vacuum (10–3 mbar) line, or in an
argon-filled MBraun glove-box. THF was distilled under nitrogen
from potassium benzophenone ketyl prior to use. Hydrocarbon sol-
vents (toluene and n-pentane) were dried by using an MBraun sol-
vent purification system (SPS-800). All solvents were stored in
vacuo over LiAlH4 in a resealable flask. Deuteriated solvents were
obtained from Aldrich GmbH or Carl Roth GmbH + Co. KG (99
atom-% D) and were degassed, dried, and stored in vacuo over Na/
K alloy in resealable flasks. NMR spectra were recorded with a
Bruker Avance II 300 MHz or Avance 400 MHz NMR spectrome-
ter. Chemical shifts are referenced to internal solvent resonances
and are reported relative to tetramethylsilane (1H and 29Si NMR)
or 85% phosphoric acid (31P NMR). IR spectra were recorded with
a Bruker Tensor 37 spectrometer. Elemental analyses were per-
formed with an Elementar vario EL or micro cube instrument.
2J(P,P) = 6.4 Hz, PS] ppm. IR (ATR): ν = 3057 (w), 2948 (w), 1699
˜
(w), 1685 (w), 1653 (w), 1576 (w), 1559 (w), 1540 (w), 1521 (w),
1507 (w), 1484 (w), 1457 (w), 1435 (w), 1303 (m), 1243 (w), 1180
(w), 1143 (m), 1122 (m), 1110 (m), 1093 (w), 1027 (w), 984 (m),
919 (w), 880 (m), 845 (s), 829 (s), 794 (m), 764 (m), 741 (s), 725
(m), 688 (s), 667 (s), 615 (m), 591 (m), 542 (m), 513 (m), 491 (s),
465 (m), 438 (m) cm–1. C34H48N2P2SSi3Zn (728.41): calcd. C 56.06,
H 6.64, N 3.85, S 4.40; found C 56.06, H 6.53, N 3.66, S 4.41.
[CH(PPh2=NSiMe3)(PPh2=S)ZnPh]
(4):
ZnPh2
(110 mg,
0.5 mmol) and [CH2(PPh2=NSiMe3)(PPh2=S)] (250 mg, 0.5 mmol)
were dissolved in toluene (10 mL) at room temperature and the
mixture was stirred for 18 h. The solution was then concentrated
until a colorless precipitate appeared and the mixture was heated
carefully until the solution became clear. The solution was allowed
to stand at room temperature to obtain the product as colorless
crystals, yield 233 mg, 0.36 mmol, 72%. 1H NMR (300.13 MHz,
C6D6): δ = 0.13 [s, 9 H, Si(CH3)3], 2.71 [dd, 2J(H,PN) = 3.4,
2J(H,PS) = 1.4 Hz, 1 H, CH], 6.81–6.98 (m, 12 H, o-, p-PPh), 7.31
(m, 1 H, Zn-p-Ph), 7.43 (m, 2 H, Zn-o-Ph), 7.65–7.75 (m, 8 H, m-
PPh), 8.15 (m, 2 H, Zn-m-Ph) ppm. 13C{1H} NMR (75.48 MHz,
C6D6): δ = 2.9 [Si(CH3)3], 29.2 [dd, 1J(C,PN) = 102.1, 1J(C,Ps) =
73.3 Hz, CH], 126.6 (Zn-o-Ph), 127.8 (Zn-p-Ph), 130.5 (m, o-PPh),
131.1 (m, p-PPh), 134.7 (m, m-PPh), 136.3 (m, i-PPh), 139.2 (Zn-
m-Ph), 153.2 (Zn-i-Ph) ppm. 31P{1H} NMR (121.49 MHz, C6D6):
δ = 26.6 [d, 2J(P,P) = 8.5 Hz, PNSi(CH3)3], 35.5 [d, 2J(P,P) =
[CH2(PPh2=NSiMe3)(PPh2=S)],[42]
ZnPh2,[53]
and
[Zn{N-
(SiMe3)2}][54] were prepared according to literature procedures.
[CH(PPh2=NSiMe3)(PPh2=S)ZnCl2] (1): ZnCl2 (68 mg, 0.5 mmol)
and [CH2(PPh2=NSiMe3)(PPh2=S)] (250 mg, 0.5 mmol) were dis-
solved in THF (10 mL) at room temperature. After 10 min a color-
less precipitate was formed. The mixture was stirred for another
10 min and then heated at reflux to obtain a colorless crystalline
solid. The product was collected by filtration, washed with n-pent-
ane (5 mL), and dried in vacuo. Single crystals suitable for X-ray
analysis were obtained from hot THF, yield 282 mg, 0.44 mmol,
8.5 Hz, PS] ppm. IR (ATR): ν = 3052 (w), 2950 (w), 1734 (w), 1699
˜
88%. IR (ATR): ν = 3058 (w), 2950 (w), 2908 (w), 2860 (w), 1589
˜
(w), 1670 (w), 1636 (w), 1576 (w), 1540 (w), 1507 (w), 1474 (w),
1436 (w), 1420 (m), 1396 (w), 1363 (w), 1299 (w), 1258 (w), 1244
(w), 1145 (w), 1127 (m), 1096 (m), 1071 (w), 1029 (w), 999 (w), 918
(w), 835 (s), 789 (m), 766 (m), 746 (m), 725 (s), 703 (s), 690 (s), 667
(m), 632 (m), 614 (m), 593 (m), 544 (m), 503 (s), 481 (s), 433
(m) cm–1. C34H35NP2SSiZn (645.13): calcd. C 63.30, H 5.47, N
2.17, S 4.97; found C 62.29, H 5.45, N 2.07, S 4.92.
(w), 1559 (w), 1507 (w), 1437 (w), 1264 (w), 1074 (w), 1029 (w),
998 (w), 839 (m), 804 (m), 794 (w), 755 (w), 735 (m), 714 (m), 690
(m), 682 (s), 670 (s), 625 (m), 587 (m), 529 (m), 504 (s), 482 (s), 474
(s), 441 (w), 419 (w), 405 (w) cm–1. C28H31Cl2NP2SSiZn (639.94):
calcd. C 52.55, H 4.88, N 2.19, S 5.01; found C 52.05, H 4.67, N
2.17, S 5.07.
[CH(PPh2=NSiMe3)(PPh2=S)ZnI2] (2): ZnI2 (160 mg, 0.5 mmol)
and [CH2(PPh2=NSiMe3)(PPh2=S)] (250 mg, 0.5 mmol) were dis-
solved in THF (10 mL) at room temperature. After 10 min a color-
less precipitate was formed. The mixture was stirred for another
10 min and then heated at reflux to obtain colorless needles suitable
for X-ray analysis. The product was collected by filtration, washed
with n-pentane (5 mL), and dried in vacuo, yield 333 mg,
X-ray Crystallographic Studies of 1–4: Crystals of 1 and 2 were
grown from hot THF, single crystals of compound 3 were obtained
from hot heptane, and crystals of compound 4 were grown from
toluene. A suitable crystal of each compound 1–4 was covered in
mineral oil (Aldrich) and mounted onto a glass fiber. The crystal
was transferred directly to a cold stream of a Stoe IPDS II dif-
fractometer.
0.41 mmol, 81%. IR (ATR): ν = 3267 (w), 3052 (w), 2917 (w), 2858
˜
(w), 1699 (w), 1685 (w), 1653 (w), 1576 (w), 1559 (w), 1540 (w),
1522 (w), 1507 (w), 1483 (w), 1434 (m), 1333 (w), 1311 (w), 1200
(w), 1175 (w), 1160 (w), 1103 (m), 1036 (m), 1021 (w), 996 (w), 845
(w), 806 (m), 790 (m), 752 (m), 740 (s), 730 (s), 716 (m), 685 (s),
669 (m), 617 (w), 582 (s), 560 (m), 518 (m), 495 (s), 478 (s), 455
(w), 415 (w) cm–1. C28H31I2NP2SSiZn (822.84): calcd. C 40.87, H
3.80, N 1.70, S 3.90; found C 40.08, H 2.85, N 1.67, S 4.27.
All structures were solved by direct or Patterson methods
(SHELXS-97[55]). The remaining non-hydrogen atoms were located
on the basis of the results of successive difference Fourier map cal-
culations. The refinements were carried out by using full-matrix
least-squares techniques on F2, minimizing the function (Fo – Fc)2,
2
the weight defined as 4F0 /2(Fo2), and Fo and Fc are the observed
and calculated structure factor amplitudes using the program
[CH(PPh2=NSiMe3)(PPh2=S)Zn{N(SiMe3)2}]
(3):
[Zn{N- SHELXL-97.[55] The hydrogen atom contributions of all com-
(SiMe3)2}2] (0.24 mL, 0.6 mmol) and [CH2(PPh2=NSiMe3)-
(PPh2=S)] (300 mg, 0.6 mmol) were dissolved in toluene (15 mL).
The solution was heated at reflux for 48 h and was then reduced
to dryness, extracted with n-pentane, filtered, and dried in vacuo.
pounds were calculated but not refined. The locations of the largest
peaks in the final difference Fourier map calculation as well as the
magnitude of the residual electron densities in each case were of
no chemical significance.
Eur. J. Inorg. Chem. 2013, 4851–4857
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© 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.eurjic.org
FULL PAPER
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Crystal Data for 1: C28H31Cl2NP2SSiZn·1.25(C4H8O), M = 730.03,
monoclinic, a = 26.904(2), b = 18.7957(12), c = 17.6028(13) Å, β =
91.129(6)°, V = 8899.7(11) Å3, T = 200(2) K, space group Cc, Z
= 8, μ(Mo-Kα) = 0.840 mm–1, 31882 reflections measured, 16220
independent reflections (Rint = 0.0615). The final R1 value was
0.0682 [IϾ2σ(I)] and the final wR(F2) value was 0.1851 (all data).
The goodness of fit on F2 was 0.980.
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monoclinic, a = 18.1297(5), b = 18.0287(5), c = 22.6015(7) Å, β =
113.101(2)°, V = 6795.0(3) Å3, T = 153(2) K, space group P21/c, Z
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= 4, μ(Mo-Kα) = 2.753 mm–1, 48891 reflections measured, 12650
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0.0324 [IϾ2σ(I)] and the final wR(F2) value was 0.0407 (all data).
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The goodness of fit on F2 was 0.846.
Crystal Data for 3: C34H48N2P2SSi3Zn, M = 728.38, triclinic, a =
10.0370(8), b = 14.1275(10), c = 14.3215(10) Å, α = 103.068(6), β
= 94.034(6), γ = 93.791(6)°, V = 1966.2(3) Å3, T = 200(2) K, space
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¯
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Crystal Data for 4: C34H35NP2SSiZn, M = 645.09, monoclinic, a
= 9.3199(6), b = 17.1584(8), c = 20.2766(12) Å, β = 98.055(5)°, V
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This work was supported by the Cluster of Excellence “Unifying
Concepts in Catalysis” coordinated by the Technical University
Berlin, the Deutsche Forschungsgemeinschaft (DFG), the Fonds
der Chemischen Industrie, the Alexander-von-Humboldt Stiftung
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of compound 4 is acknowledged.
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© 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim