Syntheses and crystal structures of tungsten complexes with various ligands containing (1,3-dithioliumyl)diphenylphosphine

Article abstract of DOI:10.1021/om001032y

The (dithioalkylcarbonyl)diphenylphosphinotungsten complexes W(CO)₅[PPh₂(CS₂R)] (2-5) (R = CH₂C≡CH; CH₂C≡CD; CH₂C≡N; CH(CH₃)C≡N) are accessible by the alkylation reactions of the

Full text of DOI:10.1021/om001032y

2604
Organometallics 2001, 20, 2604-2610
Syn th eses a n d Cr ysta l Str u ctu r es of Tu n gsten
Com p lexes w ith Va r iou s Liga n d s Con ta in in g
(1,3-Dith ioliu m yl)d ip h en ylp h osp h in e
Kuang-Hway Yih,*,† Gene-Hsiang Lee,‡ and Yu Wang§
Department of Applied Cosmetology, Hung Kuang Institute of Technology, Shalu,
Taichung Hsien, Taiwan 433, Republic of China, Instrumentation Center, College of Science,
National Taiwan University, Taiwan 106, Republic of China, and Department of Chemistry,
National Taiwan University, Taiwan 106, Republic of China
Received December 4, 2000
The (dithioalkylcarbonyl)diphenylphosphinotungsten complexes W(CO)5[PPh2(CS2R)]
(2-5) (R ) CH2CtCH; CH2CtCD; CH2CtN; CH(CH3)CtN) are accessible by the alkylation
reactions of the complex [Et4N][W(CO)5PPh2CS2] (1) with unsaturated organic halides.
Protonation of 2-5 with HBF4 at room temperature causes intramolecular cyclization to
form the cationic complexes W(CO)5[PPh2CSC(R)C(R′)S][BF4] (6-9) (R, R′ ) H, CH3; H,
CH2D; H, NH2; CH3, NH2). The complex W(CO)5[PPh2CSCHC(NHCPh3)S][BF4] (10) is
produced by the reaction of 4 or 8 with Ph3CBF4. In complexes 6-10, proton-induced
intramolecular cyclization was followed by an unprecedented 1,3-hydrogen shift, forming
five-membered cationic 1,3-dithiolium rings. The 1,3-hydrogen shift process did not occur
in similar organic compound but in this metal-assisted system. The mechanism was confirmed
both by the reactions of 4 with Ph3CBF4 and by deuterium-labeling experiments. The
protonation reaction of 2 to 6 is not reversible, but deprotonation of 8 by n-BuLi or PPh3
gives 4 quantitatively. Treatment of 8 with n-Bu4NF yielded complex W(CO)5PPh2F and 4
in a 1:1 ratio, but in the reaction of 6 and n-Bu4NF only compound W(CO)5PPh2F is formed.
Complexes 6, 8, and 10 are determined by single-crystal X-ray diffraction analyses.
In tr od u ction
(S)NPh- ligands, and those compounds bring up some
novel chemistry.5 As an extension of our recent work
on the preparation of the various (thiazoliumyl)diphen-
ylphosphine ligands6 by protonation of the Ph2PC(SR)-
NPh ligands, herein we report a simple synthesis of the
various (1,3-dithioliumyl)diphenylphosphine ligands by
an unprecedented 1,3-hydrogen shift. Three X-ray crys-
tal structure analyses of the (1,3-dithioliumyl)diphen-
ylphosphinotungsten complexes have been carried out
to provide accurate structural parameters.
Dithioles, mesoionic dithioles, and dithiolium deriva-
tives have widely served as excellent building blocks for
construction of many heterocycles.1 The 1,3-dithiolium2
is of special interest in the synthetic chemistry of
organic materials due to its reactivity, unusual charge
distribution, and possible aromatic properties of the five-
membered ring. In the literature, there are two unam-
biguous examples of the metal-carbene dithiole com-
plexes, which are known at least for iron3 and platinum.4
However, until now the formation of a metal 1,3-di-
thiolium complex has been poorly investigated.
Resu lts a n d Discu ssion
We have been interested in the tungsten complexes
containing P-coordination of the Ph2PCS2- and Ph2PC-
P r ep a r a tion of th e Neu tr a l Dip h en yl(d ith io-
alkylcar bon yl)ph osph in otu n gsten Com plexes. Kun-
ze, Ambrosius, et al.7 have synthesized the anionic
heteroallyl ligands containing phosphorus such as
R2P(X)C(Y)NR- and R2PC(Y)NR- (X ) O or S, Y ) O
* Corresponding author. E-mail: khyih@sunrise.hkc.edu.tw. Fax:
886-4-6523724, 886-4-6318652-699.
† Hung Kuang Institute of Technology.
‡ Instrumentation Center, College of Science, National Taiwan
University.
§ Department of Chemistry, National Taiwan University.
(1) (a) Huisgen, R.; Gotthardt, H.; Bayer, H. O.; Schaefer, F. C.
Angew. Chem., Int. Ed. Engl. 1964, 3, 136. (b) Breslow, D.; Skolnik,
D. Multi-sulfur and Sulfur-oxygen Five- and Six-Membered Hetero-
cycles; Pergamon Press: Oxford, 1966; p 546. (c) Huisgen, R.; Gotthardt,
H.; Bayer, H. O.; Schaefer, F. C. Chem. Ber. 1970, 103, 2611.
(2) (a) Klingsberg, E. J . Am. Chem. Soc. 1961, 83, 2934. (b) Boberg,
F. Annalen 1964, 679, 107. (c) Behringer, H.; Wiedenmann, R.
Tetrahedron Lett. 1965, 3705. (d) Prinzbach, H.; Futterer, E. Adv.
Heterocycl. Chem. 1966, 7, 39. (e) Olofson, R.; Landesberg, J .; Berry,
R.; Leaver, D.; Robertson, W.; McKinnon, D. Tetrahedron 1966, 22,
2119. (f) Campaigne, E.; Hamilton, R. Q. Rep. Sulfur Chem. 1970, 5,
275. (g) Hendrickson, A.; Martin, R. J . Org. Chem. 1973, 38, 2548.
(3) Lagadec, A.; Misterkiewicz, B.; Darchen, A.; Grandjean, D.;
Mousser, A.; Patin, H. Organometallics 1988, 7, 242.
(4) Michelin, R. A.; Facchin, G. J . Organomet. Chem. 1985, 279, C34.
(b) Michelin, R. A.; Ros, R.; Guadalupi, G.; Bombieri, G.; Benetollo,
F.; Chapuis, G. Inorg. Chem. 1989, 28, 840. (c) Michelin, R. A.; Bertani,
R.; Mozzon, M.; Bombieri, G.; Benetollo, F.; Guedes da Silva, M. F. C.;
Pombeiro, A. J . L. Organometallics 1993, 12, 2372.
(5) Yih, K. H.; Lin, Y. C.; Cheng M. C.; Wang, Y. J . Chem. Soc.,
Chem. Commun. 1993, 1380. (b) Yih, K. H.; Lin, Y. C.; Cheng M. C.;
Wang, Y. Organometallics 1994, 13, 1561. (c) Yih, K. H.; Lin, Y. C.;
Cheng M. C.; Wang, Y. J . Organomet. Chem. 1994, 474, C34. (d) Yih,
K. H.; Lin, Y. C.; Lee, G. H.; Wang, Y. J . Chem. Soc., Chem. Commun.
1995, 223. (e) Yih, K. H.; Lin, Y. C.; Cheng M. C.; Wang, Y. J . Chem.
Soc., Dalton Trans. 1995, 1305.
(6) Yih, K. H.; Yeh, S. C.; Lin, Y. C.; Lee G. S.; Wang, Y.
Organometallics 1998, 17, 513.
10.1021/om001032y CCC: $20.00 © 2001 American Chemical Society
Publication on Web 05/17/2001

Tungsten Complexes with Various Ligands
Organometallics, Vol. 20, No. 12, 2001 2605
Sch em e 1
Sch em e 2
or S), and no metal complex includes phosphorus
coordination of these ligands. The synthesis of the
tungsten complex containing the P-coordination of the
Ph2PCS2CH2CtCH ligand and the cyclization product
has been reported in a previous communication,5b and
the detailed procedure is given in the Experimental
Section together with a full spectroscopic and analytical
characterization. Treatment of complex [Et4N][W(CO)5-
PPh2CS2] (1) with propargyl bromide, BrCH2CtCH, in
dichloromethane leads to formation of an S-C bond,
affording the thiopropargyl complex W(CO)5[PPh2-
(CS2CH2CtCH)] (2) (Scheme 1) in 78% isolated yield.
Compound 2 is a red crystalline product and moderately
soluble in diethyl ether and n-hexane.
[PPh2CS2CH(CH3)CtN] (5), both with high yields. The
similar alkylated complex W(CO)5[PPh2(CS2Me)]5e was
structurally confirmed by X-ray diffraction analysis in
a previous report.
Syn th eses of Va r iou s 1,3-Dith ioliu m Tu n gsten
Com p lexes. The methodology of the facile synthesis
of various thiazolium6 tungsten complexes can be ap-
plied to prepare dithiolium complex. Thus, protonation
of 2 by HBF4 in diethyl ether at 0 °C results in the
formation of the 1,3-dithiolium complex W(CO)5-
[PPh2CSCHC(CH3)S][BF4] (6) in 87% yield exclusively
(Scheme 2). Compound 6 is an air-stable, brown solid
and is readily soluble in polar organic solvents such as
dichloromethane and acetonitrile but is insoluble in
diethyl ether and n-hexane.
The spectroscopic and analytical data of 2 are in
agreement with the formulation. The FAB mass spec-
trum of 2 exhibits a base peak corresponding to the
molecular mass. In the IR spectrum of 2, three terminal
carbonyl stretchings appear at 2073(m), 1957(m), and
1919(vs) cm-1, a typical pattern for an LM(CO)5 unit in
octahedral geometry. The higher frequencies compared
to those of 1 indicate that 2 is a neutral complex. The1H
NMR spectrum of 2 exhibits a doublet resonance at δ
The identification of 6 as W(CO)5[PPh2CSCHC-
(CH3)S][BF4] is according to the spectroscopic data. The
FAB mass spectrum of 6 shows a base peak at m/z 625,
which corresponds to a fragment formed by loss of the
BF4- group from 6. In the H NMR spectrum, the vinyl
1
proton and methyl protons are observed at δ 8.98 and
4
4
4.04 and a triplet resonance at δ 2.47 with J H-H ) 2.89
2.85, respectively, with coupling constants J H-H of 1.0
Hz, and the corresponding resonances in the 13C{1H}
NMR spectrum appear at δ 145.8 and 16.9, respectively.
Notably, the relative downfield 13C{1H} resonance of
the vinylic carbon reveals the cationic property. The
31P{1H} NMR resonance of 6 appears at δ 30.4 with a
pair of tungsten satellites (1J W-P ) 261.8 Hz), which
shifted from δ 60.4 of 2. This significant upfield shift of
the 31P{1H} NMR of 6 would suggest a shielding of the
phosphorus nucleus caused by the contribution from the
resonance structure of the 1,3-dithiolium.
Hz assignable to the S-methylene and terminal methyne
proton of the propargyl group, respectively. The corre-
sponding 13C{1H} NMR signals appear at δ 26.6 and
72.7, respectively. In the 13C{1H} NMR spectrum of 2,
two resonances with an integration ratio of 1:4 at δ
198.7 and 196.8 are attributed to the trans and cis
carbonyl groups, respectively. In the 31P{1H} NMR
spectrum of 2, a resonance at δ 60.4 with a pair of
tungsten satellites (1J W-P ) 240.0 Hz) indicates the
P-coordination of the PPh2C(S)SCH2CtCH ligand.
The synthetic method mentioned above is applicable
to primary organic halides with various substituents.
Thus, the reaction of 1 with BrCH2CtCD (98% deute-
rium labeling at the terminal alkyne) in CH2Cl2 affords
W(CO)5[PPh2(CS2CH2CtCD)] (3) in 73% yield. The
The same procedure was used to prepare other 1,3-
dithiolium complexes W(CO)5[PPh2CSCHC(NH2)S][BF4]
(8) and W(CO)5[PPh2CSC(CH3)C(NH2)S][BF4] (9) with
95% and 90% yields, respectively. In the FAB mass
spectra, two base peaks with the typical W isotope
distribution are respectively in agreement with the [M+
- BF4-] molecular masses of 8 and 9. The 31P{1H} NMR
1
31P{1H} NMR resonance of 3 (δ 59.6 with J W-P ) 237.0
Hz) is similar to that of 2. The same procedure was used
to prepare W(CO)5[PPh2(CS2CH2CtN)] (4) and W(CO)5-
1
spectra of 8 (δ 21.8 with J W-P ) 259.6 Hz) and 9 (δ
1
(7) Ambrosius, H. P. M. M.; Bosman, W. P.; Gras, J . A. J . Orga-
nomet. Chem. 1981, 215, 201. (b) Ambrosius, H. P. M. M.; Van Der
Linden, A. H. I. M.; Steggerda, J . J . J . Organomet. Chem. 1980, 204,
211. (c) Ambrosius, H. P. M. M.; Cotton, F. A.; Falvello, L. R.; Hintzen,
J . M. H. T.; Melton, T. J .; Schwotzer, W.; Tomas, M.; Van Der Linden,
J . G. M. Inorg. Chem. 1984, 23, 1611. (d) Ambrosius, H. P. M. M.;
Willemse, J .; Cras, J . A.; Bosman, W. P.; Noordik, J . H. Inorg. Chem.
1984, 23, 2672. (e) Ambrosius, H. P. M. M.; Van Hemert, A. W.;
Bosman, W. P.; Noordik, J . H.; Ariaans, G. J . A. Inorg. Chem. 1984,
23, 2678. (f) Antoniadis, A.; Kunze, U.; Moll, M. J . Organomet. Chem.
1982, 235, 177. (g) Kunze, U.; Brunsa, A.; Rehder, D. J . Organomet.
Chem. 1984, 268, 213. (h) Kunze, U.; Bruns, A. J . Organomet. Chem.
1985, 292, 349. (i) Kunze, U.; J awad, H.; Burghardt, R.; Tittmann, R.;
Kruppa, V. J . Organomet. Chem. 1986, 302, C30.
20.2 with J W-P ) 259.7 Hz) are similar to that of 6.
To distinguish the mechanism of formation of the
dithiolium complex, an intramolecular rearrangement8
of the S-propargyl group to the S-alleneyl group, or 1,3-
hydrogen shift, the following experiments were carried
out. The reaction of 2 and CH3COOD was monitored
(8) Danheiser, R. L.; Carini, D. J .; Basak, A. J . Am. Chem. Soc. 1981,
113, 1604. (b) Boger, D. L.; Brotherton, C. E. J . Am. Chem. Soc. 1984,
106, 805. (c) Yamago, S.; Nakamura, E. J . Am. Chem. Soc. 1989, 111,
7285.

2606 Organometallics, Vol. 20, No. 12, 2001
Yih et al.
Sch em e 3
Sch em e 4
Sch em e 5
[Et2NCSCHC(CH3)S][BF4], the cationic 1,3-dithiolylidene
[Et2NCSCH2C(CdCH2)S][BF4] was isolated (Scheme 5).
1
The H NMR spectrum shows three multiples at δ 4.61,
5.62, and 5.84 with a 2:1:1 ratio, which are assigned to
the SCH2 protons and to two methylene protons.
From the discussion of the spectroscopic data of 6-10,
it is clear that there is a cationic 1,3-dithiolium ring.
While the dithiolium organic compounds have been
extensively studied, very little has been reported about
the dithiolium metal complex. Because of the unknown
nature of the 1,3-dithiolium complex, we performed
X-ray diffraction analyses of three kinds of 1,3-dithio-
lium complex, i.e., 6, 8, and 10. The ORTEP9 diagrams
with atomic labeling are shown in Figures 1, 2, and 3
for 6, 8, and 10, respectively. Table 2 contains selected
bond distances and angles. The coordination geometry
around the tungsten metal center in 6, 8, and 10 is
pseudooctahedral with the (1,3-dithiolium)diphenylphos-
phine ligand bound to tungsten through the phosphorus
atom. The most remarkable features of the three
structures are the five-membered cationic 1,3-dithiolium
rings. In 6, 8, and 10, the three kinds of 1,3-dithiolium
rings are all planar. The deviations from the average
plane for five atoms are less than 0.025(11) Å in 6,
0.021(12) Å in 8, and 0.022(14) Å in 10. Notably, the
sulfur-carbon bond lengths in the dithiolium ring of 6
(1.650(10)-1.711(11) Å), 8 (1.648(9)-1.713(10) Å), and
10 (1.635(12)-1.699(11) Å) have a range of regular
partial double bond character. These parameters are
indicative of delocalized bonding in the five-membered
ring. Significantly, the C(7)-C(8) bond distances of 6
(1.331(17) Å), 8 (1.371(13) Å), and 10 (1.406(16) Å) have
significant differences, but are all in the range of a
regular aromatic C-C bond. The C(6)-P and W-P bond
distances of 1.852(10) and 2.518(3) Å in 6 are sim-
ilar to 1.820(9) and 2.498(2) Å in 8 and 1.840(12) and
2.496(3) Å in 10.
by 1H NMR at -20 °C, giving W(CO)5[PPh2CSCHC-
(CH2D)S][BF4] (7) (Scheme 3) with 87% deuterium
labeling at the methyl site. Complex 7 can also be
obtained by the reaction of the deuterium-labeled
complex W(CO)5[PPh2(CS2CH2CtCD)] (3) and HBF4.
During the reactive period, the 1H NMR spectrum
reveals two doublet resonances at δ 3.89 and 2.76 with
2J H-H ) 12.8 Hz and one singlet at δ 4.92, which
confirms the proposed structure of 7′. The 1H NMR
spectrum also shows one triplet resonance at δ 2.85 and
one multiplet at δ 8.98 assignable to CH2D protons and
the vinyl proton. The increased ratio of 7 corresponds
with the decreased ratio of 7′ by the reaction time. No
deuterium labeling at the vinylic site of the dithiolium
ring of 7 was found.
In the reaction of 4 and triphenyl carbenium tet-
rafluoroborate, Ph3CBF4, in acetonitrile at room tem-
perature, no abstracted hydride product of 4 could be
detected; instead, a 1,3-dithiolium complex, W(CO)5-
[PPh2CSCHC(NHCPh3)S][BF4] (10) (Scheme 4), was
isolated with 96% yield. Compound 10 can also be
prepared by the reaction of 8 with Ph3CBF4. The1H
NMR spectrum of 10 exhibits a singlet resonance at δ
8.51 assignable to the vinyl proton, and the correspond-
ing 13C{1H} NMR signal appears at δ 168.8. The
1
31P{1H} NMR resonance of 10 (δ 21.5 with J W-P
)
259.0 Hz) is similar to that of 8. Clearly, the result is
rather unexpected, as is the formation of 10 through a
1,3-hydrogen shift process.
In an attempt to prepare six- or seven-membered
1,3-dithiolium complexes, we treated W(CO)5[PPh2CS2-
(CH2)nCN]5e (n ) 2 or 3) with HBF4, yielding no reaction
under reaction conditions similar to 8. However, in the
reaction of organic compound Et2NCS2CH2CtCH and
HBF4, instead of cationic 1,3-dithiolium compound
(9) J ohnson C. K. ORTEP, Report ORNL-5138; Oak Ridge National
Laboratory: Oak Ridge, TN, 1976.

Tungsten Complexes with Various Ligands
Organometallics, Vol. 20, No. 12, 2001 2607
Ta ble 1. Cr ysta l Da ta a n d Refin em en t Deta ils for Com p lexes W(CO)5[P P h 2CSCHC(CH3)S][BF 4] (6),
W(CO)5[P P h 2CSCHC(NH2)S][BF 4] (8), a n d W(CO)5[P P h 2CSCHC(NHCP h 3)S][BF 4] (10)a
6
8
10
mol formula
fw
cryst syst
cryst dimens, mm
space group
a, Å
b, Å
c, Å
C
21H14BF4O5PS2W
C20H13BF4NO5PS2W
713.07
monoclinic
0.50 × 0.50 × 0.40
P21/c
16.1947(20)
8.0236(20)
19.580(4)
C40.5H30.5BF4NO5PS2W
973.4
triclinic
0.35 × 0.35 × 0.30
P1h
13.270(6)
15.250(6)
19.993(7)
98.42(3)
94.50(3)
93.78(4)
3978(3)
4
712.08
triclinic
0.35 × 0.30 × 0.20
P1h
8.745(6)
9.662(9)
15.421(11)
87.31(8)
74.07(5)
85.36(7)
1248.6(16)
2
R, deg
â, deg
90.550(12)
γ, deg
V, Å3
2544.1(9)
4
1.862
49.153
0-45
25
Z
dcalcd, g cm-3
1.894
1.625
µ(Mo KR), cm-1
2θ range, deg
T, °C
50.067
0-45
25
31.539
0-45
25
total no. of rflns
no. of unique data with I g 2σ(I)
no. of variables
Rb
3274
2644
317
0.034
0.036
1.44
3331
2646
353
0.025
0.028
1.50
10 406
7201
974
0.043
0.046
c
Rw
Sd
1.87
a
b
10 contains two independent molecules in the unit cell and no essential structural difference between them. R ) ∑||Fo| - |Fc||/∑|Fo|.
c Rw ) [∑w(|Fo| - | Fc|)2]1/2; w ) 1/σ2(|Fo|). Quality-of-fit ) [∑w(|Fo| - |Fc|)2/(Nobserved - Nparameters)]1/2
.
d
Ta ble 2. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for 6, 8, a n d 10
bond lengths
bond angles
Compound 6
S(1)-C(6)-S(2)
W-P(1)
2.519(3)
1.852(9)
1.678(9)
1.686(11)
1.650(10)
1.713(10)
1.332(16)
1.508(17)
114.7(5)
97.4(5)
114.3(8)
116.9(8)
96.6(5)
C(6)-P(1)
C(6)-S(1)
C(7)-S(1)
C(6)-S(2)
C(8)-S(2)
C(7)-C(8)
C(8)-C(9)
C(6)-S(2)-C(8)
S(2)-C(8)-C(7)
C(8)-C(7)-S(1)
C(7)-S(1)-C(6)
C(9)-C(8)-C(7)
C(9)-C(8)-S(2)
125.6(10)
120.0(9)
Compound 8
W-P(1)
2.4951(16)
1.825(6)
1.684(5)
1.721(6)
1.648(6)
1.656(6)
1.373(9)
1.343(8)
S(1)-C(6)-S(2)
C(6)-S(2)-C(8)
S(2)-C(8)-C(7)
C(8)-C(7)-S(1)
C(7)-S(1)-C(6)
N(1)-C(7)-C(8)
N(1)-C(7)-S(1)
114.3(3)
98.7(3)
116.5(5)
113.4(4)
97.0(3)
C(6)-P(1)
C(6)-S(1)
C(7)-S(1)
C(6)-S(2)
C(8)-S(2)
C(7)-C(8)
C(7)-N(1)
F igu r e 1. ORTEP drawing with 30% thermal ellipsoids
and atom-numbering scheme for the cationic complex
113.4(4)
120.3(5)
W(CO)5[PPh2CSCHC(CH3)S]+ (6).
Compound 10
W(1)-P(1)
C(6)-P(1)
C(6)-S(1)
C(7)-S(1)
C(6)-S(2)
C(8)-S(2)
C(7)-C(8)
C(8)-N(9)
2.497(3)
S(1)-C(6)-S(2)
C(6)-S(2)-C(8)
S(2)-C(8)-C(7)
C(8)-C(7)-S(1)
C(7)-S(1)-C(6)
N(9)-C(8)-C(7)
N(9)-C(8)-S(2)
114.6(6)
97.3(5)
113.8(7)
115.2(7)
99.1(5)
at the carbon of the nitrile moiety. It is obvious that
the dithiolium compounds are induced by a proton and
followed by a 1,3-hydrogen shift process. To the best of
our knowledge, there is no previous report of formation
a 1,3-dithiolium metal complex through the phenom-
enon of unprecedented 1,3-hydrogen shift.
Remarkably, the protonation reaction of 2,3 with
HBF4 in THF at room temperature gave 6,7 im-
mediately, and the protonations of 2,3 to 6,7 are not
reversible, but deprotonation of 8 by n-BuLi or PPh3 in
THF at room temperature produced 4 quantitatively.
To examine the reactivity of the cationic 1,3-dithiolium
complex, we carried out the reactions of complex 6 and
8 with several nucleophiles. Treatment of 8 with anhy-
drous n-Bu4NF in THF at room temperature yielded
complex W(CO)5PPh2F6 and 4 in a 1:1 ratio (Scheme
6). Interestingly, under similar reactive conditions,
treatment of the analogous species 6 with n-Bu4NF gave
only W(CO)5PPh2F quantitatively. Clearly, the n-Bu4-
1.843(10)
1.635(10)
1.674(10)
1.690(9)
1.707(10)
1.395(14)
1.345(12)
122.9(9)
123.2(7)
A lot of 1,3-dithiolium organic compounds2 are known,
but their preparations do not involve protonation of a
precursor or an unprecedented 1,3-hydrogen shift. In
the reaction of 2 with acid, protonation takes place at
the terminal carbon of the propargyl moiety of 2 to
afford a cationic complex, followed by nucleophilic attack
of the sulfur atom of the thiocarbonyl group at the center
carbon of the propargyl unit to form the cationic 1,3-
dithiolium ring. Similarly, formation of the products 8
and 9 is believed to proceed via protonation at the
nitrogen atom of the nitrile group, followed by nucleo-
philic attack of the sulfur atom of the thiocarbonyl group

2608 Organometallics, Vol. 20, No. 12, 2001
Yih et al.
diethyl ether, THF, and benzene were distilled from sodium
benzophenone. Acetonitrile and dichloromethane were dis-
tilled from calcium hydride, and methanol was distilled from
magnesium. All other solvents and reagents were of reagent
grade and used as received. The compounds [Et4N][W(CO)5-
(PPh2CS2)] (1)5a and W(CO)5(PPh2CS2CH2CN) (4)5e were pre-
pared according to the literature methods. Elemental analyses
and X-ray diffraction studies were carried out at the Regional
Center of Analytical Instrument located at the National
Taiwan University. W(CO)6 and PPh2H were purchased from
Strem Chemical; CS2, ICH(CH3)CN, ICH2CN, BrCH2CtCH,
HBF4, n-BuLi, PPh3, CH3COOD, and anhydrous n-Bu4NF were
purchased from Merck.
P r ep a r a tion of 2. Propargyl bromide, BrCH2CtCH (0.08
mL, 1.1 mmol), was added to a solution of 1 (0.715 g, 1.0 mmol)
in CH2Cl2 (20 mL), and the mixture was stirred at room
temperature for 2 min. The solvent was removed under
vacuum, the residue was extracted with diethyl ether (2 × 10
mL), and the extracts were filtered through Celite. The fil-
trate was removed under vacuum to give the red product. The
crude product was recrystallized from CH2Cl2/n-hexane (1:10)
at -20 °C to give microcrystalline complex W(CO)5[PPh2-
(CS2CH2CtCH)], 2 (0.49 g, 78%). Spectroscopic data of 2 are
as follows. IR (KBr, cm-1): ν(CO) 2073(m), 1957(m), 1919(vs).
31P{1H} NMR (81 MHz, CDCl3, 298 K): δ 60.4 (J W-P ) 240.0
Hz). 1H NMR (200 MHz, CDCl3, 298 K): δ 2.47 (t, 1H, CH,
F igu r e 2. ORTEP drawing with 30% thermal ellipsoids
and atom-numbering scheme for the cationic complex
W(CO)5[PPh2CSCHC(NH2)S]+ (8).
4
4J H-H ) 2.89 Hz), 4.04 (d, 2H, SCH2, J H-H ) 2.89 Hz), 7.48
(m, 6H, Ph), 7.69 (m, 6H, Ph). 13C{1H} NMR (50 MHz, CDCl3,
298 K): δ 26.6 (s, SCH2), 72.7 (s, CH), 75.8 (s, CH2C), 128.6
3
(d, meta-C of Ph, J P-C ) 15.4 Hz), 131.2 (s, para-C of Ph),
2
133.7 (d, ortho-C of Ph, J P-C ) 11.8 Hz), 134.7 (d, ipso-C of
2
Ph, J P-C ) 30.7 Hz), 196.8 (d, cis-CO, J P-C ) 6.0 Hz), 198.7
(d, trans-CO, 2J P-C ) 25.0 Hz). MS (FAB, NBA, m/z): 625 (M+),
597 (M+ - CO), 569 (M+ - 2CO), 541 (M+ - 3CO), 513 (M+
-
4CO), 485 (M+ - 5CO). Anal. Calcd for C21H13O5PS2W: C,
40.40; H, 2.10. Found: C, 40.51; H, 2.27.
P r ep a r a tion of 3. The synthesis and workup were similar
to those used in the preparation of complex 2. The complex
W(CO)5[PPh2(CS2CH2CtCD)] (3) was isolated in 73% yield as
a red microcrystalline solid. Spectroscopic data of 3 are as
follows. IR (CH2Cl2, cm-1): ν(CO) 2072(m), 1940(vs). 31P{1H}
F igu r e 3. ORTEP drawing with 30% thermal ellipsoids
and atom-numbering scheme for the cationic complex
W(CO)5[PPh2CSCHC(NHCPh3)S]+ (10).
1
NMR (81 MHz, CDCl3, 298 K): δ 59.6 (J W-P ) 237.0 Hz). H
NMR (200 MHz, CDCl3, 298 K): δ 3.96 (s, 2H, SCH2), 7.45
(m, 6H, Ph), 7.69 (m, 6H, Ph).
NF acts as not only a nucleophile but also a deproton
reagent. Attempted reactions of complex 6 or 8 with
cyclopentadiene, PhCtCH, and I2 in refluxing THF
gave no reaction but with other nucleophiles such as
Et2NCS2Na, Et2NH, KSCN, and NaBH4 in THF at room
temperature gave more than 10 complexes, although
these reactions were not pursued further.
In conclusion, through a series of investigation of the
cyclization reactions of mesoionic compounds, we have
shown that the reactions of this type can be useful for
the preparation of five-membered cationic 1,3-dithiolium
tungsten complexes.
P r ep a r a tion of 5. The synthesis and workup were similar
to those used in the preparation of complex 2. The complex
W(CO)5[PPh2CS2CH(CH3)CN] (5) was isolated in 88% yield as
a red microcrystalline solid. Spectroscopic data of 5 are as
follows. IR (CH2Cl2, cm-1): ν(CO) 2074(m), 1936(vs). 31P{1H}
1
NMR (81 MHz, CDCl3, 298 K): δ 62.1 (J W-P ) 254.3 Hz). H
NMR (200 MHz, CDCl3, 298 K): δ 1.70 (dd, 3H, CH3, 3J H-H
)
)
5
3
7.30 Hz, J P-H ) 1.10 Hz), 4.85 (dd, 1H, SCH, J H-H
4
7.30 Hz, J P-H ) 1.20 Hz), 7.48 (m, 6H, Ph), 7.69 (m, 6H, Ph).
13C{1H} NMR (50 MHz, CDCl3, 298 K): δ 16.0 (s, CH3), 33.8
3
(s, SCH), 117.5 (s, CN), 128.9 (d, meta-C of Ph, J P-C ) 10.9
Hz), 131.7 (s, para-C of Ph), 132.9 (d, ipso-C of Ph, J P-C ) 38.9
2
Hz), 133.7 (d, ortho-C of Ph, J P-C ) 11.9 Hz), 196.7 (d, cis-
CO, 2J P-C ) 6.7 Hz), 198.7 (d, trans-CO, 2J P-C ) 25.0 Hz), 235.3
(s, CS2). MS (FAB, NBA, m/z): 640 (M+), 611 (M+ - CO), 583
Exp er im en ta l Section
(M+ - 2CO), 555 (M+ - 3CO), 527 (M+ - 4CO), 499 (M+
-
Gen er a l P r oced u r es. All manipulations were performed
under nitrogen using vacuum-line, drybox, and standard
Schlenk techniques. NMR spectra were recorded on a Bruker
AM-200 or on an AM-300 WB FT-NMR spectrometer and are
reported in units of parts per million with residual protons in
the solvent as an internal standard (CDCl3, δ 7.24; CD3CN, δ
1.93; C6D6, δ 7.15; C2D6CO, δ 2.04). IR spectra were measured
on a Perkin-Elmer 983 instrument and referenced to polysty-
rene standard, using cells equipped with calcium fluoride
windows. MS spectra were recorded on a J EOL SX-102A
spectrometer. Solvents were dried and deoxygenated by re-
fluxing over the appropriate reagents before use. n-Hexane,
5CO), 443 (M+ - 5CO - CHCH3CN), 369 (M+ - 5CO -
CHCH3CN - CS2). Anal. Calcd for C21H14NO5PS2W: C, 39.54;
H, 2.21; N, 2.19. Found: C, 39.62; H, 2.42; N, 2.25.
P r ot on a t ion of 2. To a flask containing a diethyl ether
solution of W(CO)5[PPh2(CS2CH2CtCH)] (2) (0.625 g, 1.0
mmol) was added an aliquot of HBF4 (0.25 mL of a 54%
solution in diethyl ether, 1.23 mmol) at 0 °C. The solution was
stirred for 5 min at 0 °C and slowly warmed to room tem-
perature. A brown precipitate formed, which was filtered off
(G4) and washed with diethyl ether (2 × 10 mL) to give the
crude product. The crude product was further purified by

Tungsten Complexes with Various Ligands
Organometallics, Vol. 20, No. 12, 2001 2609
Sch em e 6
recrystallization from CH2Cl2/n-hexane (1:10) to give complex
C21H15BF4NO5PS2W: C, 34.68; H, 2.08; N, 1.93. Found: C,
34.82; H, 2.22; N, 1.98.
P r ep a r a tion of 10. Method A: MeCN (30 mL) was added
W(CO)5[PPh2CSCHC(CH3)S][BF4] (6) (0.62 g, 0.87 mmol) as
a brown powder in 87% yield. Spectroscopic data of 6 are as
follows. IR (KBr, cm-1): ν(CO) 2076(m), 2007(m), 1951(s),
1923(vs). 31P{1H} NMR (81 MHz, CDCl3, 298 K): δ 30.4 (J W-P
) 261.8 Hz). 1H NMR (200 MHz, CDCl3, 298 K): δ 2.85 (d,
to a flask (100 mL) containing W(CO)5[PPh2CSCHC(NH2)S]-
[BF4] (8) (0.71 g, 1.0 mmol) and Ph3CBF4 (0.33 g, 1.0 mmol).
The solution was stirred for 5 min, and an IR spectrum
indicated completion of the reaction. After removal of the
solvent in vacuo, the residue was redissolved with CH2Cl2 (10
mL). n-Hexane (15 mL) was added to the solution, and a yellow
precipitate was formed. The precipitate was collected by
filtration (G4), washed with n-hexane (2 × 10 mL), and then
dried in vacuo, yielding 0.86 g (90%) of 10.
Method B: Ph3CBF4 (0.33 g, 1.0 mmol) was dissolved in
MeCN (10 mL), and the solution was added to a solution of
W(CO)5(PPh2CS2CH2CN) (0.624 g, 1.0 mmol) in MeCN (10
mL). A color change from red to yellow occurred immediately,
and an IR spectrum indicated completion of the reaction.
Subsequently the solvent was removed under vacuum. The
residue was redissolved in 5 mL of CH2Cl2. n-Hexane (15 mL)
was added to the solution, and a yellow precipitate was formed.
The precipitate was collected by filtration (G4), washed with
n-hexane (2 × 10 mL), and then dried in vacuo, yielding 0.92
4
3H, CH3, J H-H ) 1.0 Hz), 7.50 (m, 6H, Ph), 7.66 (m, 4H, Ph),
8.98 (m, 1H, dCH). 13C{1H} NMR (50 MHz, CDCl3, 298 K): δ
3
16.9 (s, CH3), 129.6 (d, meta-C of Ph, J P-C ) 9.7 Hz), 132.3
2
(s, para-C of Ph), 134.6 (d, ortho-C of Ph, J P-C ) 12.2 Hz),
134.9 (d, ipso-C of Ph, J P-C ) 36.6 Hz), 145.8 (s, dCH), 166.9
2
(s, CCH3), 196.4 (d, cis-CO, J P-C ) 7.5 Hz), 199.0 (d, trans-
2
CO, J P-C ) 25.0 Hz). MS (FAB, NBA, m/z): 625 (M+ - BF4),
597 (M+ - BF4 - CO), 569 (M+ - BF4 - 2CO), 541 (M+ - BF4
- 3CO), 513 (M+ - BF4 - 4CO), 485 (M+ - BF4 - 5CO), 369
(M+ - BF4 - 5CO - CS2C3H4). Anal. Calcd for C21H14BF4O5-
PS2W: C, 35.42; H, 1.99. Found: C, 35.59; H, 2.12.
P r ep a r a tion of 7. The synthesis and workup were similar
to those used in the preparation of complex 6. The complex
W(CO)5[PPh2CSCHC(CH2D)S][BF4] (7) was isolated in 87%
yield as a red-brown microcrystalline solid. Spectroscopic data
of 7 are as follows. IR (CH2Cl2, cm-1): ν(CO) 2077(m), 1945-
(vs). 31P{1H} NMR (81 MHz, CDCl3, 298 K): δ 30.4 (J W-P
)
g (96%) of W(CO)5[PPh2CSCHC(NHCPh3)S][BF4] (10). Spec-
troscopic data of 10 are as follows. IR (KBr, cm-1): ν(CO) 2076-
(m), 1944(vs). 31P{1H} NMR (81 MHz, CDCl3, 298 K): δ 21.5
(J W-P ) 259.0 Hz). 1H NMR (200 MHz, CDCl3, 298 K): δ 7.10-
7.60 (m, 25H, Ph), 8.51 (d, 1H, CH, 4J H-H ) 2.00 Hz). 13C{1H}
NMR (50 MHz, CDCl3, 298 K): δ 56.7 (s, NCPh3), 119-146.5
(m, C of Ph), 168.8 (s, dCH), 172.0 (s, CNHCPh3), 195.2 (d,
1
261.8 Hz). H NMR (200 MHz, CDCl3, 298 K): δ 3.06 (t, 2H,
2
CH2D, J H-H ) 1.00 Hz), 7.50 (m, 6H, Ph), 7.66 (m, 4H, Ph),
8.98 (m, 1H, dCH).
Complexes W(CO)5[PPh2CSCHC(NH2)S][BF4] (8) and W(CO)5-
[PPh2CSC(CH3)C(NH2)S][BF4] (9) were synthesized using the
same procedure as that used in the synthesis of 6 by employing
4, 5, and HBF4, respectively. The yields are 95% and 90% for
8 and 9, respectively.
2
2
cis-CO, J P-C ) 6.5 Hz), 197.5 (d, trans-CO, J P-C ) 25.0 Hz).
MS (FAB, NBA, m/z): 868 (M+ - BF4), 626 (M+ - BF4 - CPh3).
Anal. Calcd for C39H27BF4NO5PS2W: C, 49.02; H, 2.85; N, 1.47.
Found: C, 49.62; H, 2.92; N, 1.35.
Spectroscopic data of 8 are as follows. IR (KBr, cm-1):
Sin gle-Cr ysta l X-r a y Diffr a ction An a lyses of 6, 8, a n d
10. Single crystals of 6, 8, and 10 suitable from X-ray
diffraction analyses were grown by recrystallization from 20:1
n-hexane/CH2Cl2. The diffraction data were collected at room
temperature on an Enraf-Nonius CAD4 diffractometer equipped
with graphite-monochromated Mo KR (λ ) 0.71073 Å) radia-
tion. The raw intensity data were converted to structure factor
amplitudes and their esd’s after correction for scan speed,
background, Lorentz, and polarization effects. An empirical
absorption correction, based on the azimuthal scan data, was
applied to the data. Crystallographic computations were
carried out on a Microvax III computer using the NRCC-SDP-
VAX structure determination package.10
A suitable single crystal of 6 was mounted on the top of a
glass fiber with glue. Initial lattice parameters were deter-
mined from 24 accurately centered reflections with 2θ values
in the range from 19.38° to 24.16°. Cell constants and other
pertinent data were collected and are recorded in Table 1.
Reflection data were collected using the θ/2θ scan method. The
final scan speed for each reflection was determined from the
net intensity gathered during an initial prescan and ranged
from 2.06 to 8.24 deg min-1. The θ scan angle was determined
for each reflection according to the equation 0.80 ( 0.35 tan
θ. Three check reflections were measured every 30 min
ν(CO) 2075(m), 1991(m), 1948(s), 1922(vs). 31P{1H} NMR (81
1
MHz, CDCl3, 298 K): δ 21.8 (J W-P ) 259.6 Hz). H NMR (200
MHz, CDCl3, 298 K): δ 7.50 (m, 6H, Ph), 7.66 (m, 4H, Ph),
4
8.12 (br, 2H, NH2), 8.20 (d, 1H, CH, J H-H ) 1.90 Hz).
13C{1H} NMR (50 MHz, CDCl3, 298 K): δ 129.6 (d, meta-C of
3
2
Ph, J P-C ) 10.5 Hz), 133.2 (d, ortho-C of Ph, J P-C ) 13.4
Hz), 133.5 (s, para-C of Ph), 133.7 (d, ipso-C of Ph, J P-C ) 43.8
2
Hz), 172.3 (s, dCH), 175.6 (s, CNH2), 196.5 (d, cis-CO, J P-C
2
) 6.6 Hz), 198.3 (d, trans-CO, J P-C ) 25.5 Hz). MS (FAB,
NBA, m/z): 626 (M+ - BF4), 598 (M+ - BF4 - CO), 570 (M+
- BF4 - 2CO), 542 (M+ - BF4 - 3CO), 514 (M+ - BF4 - 4CO),
486 (M+ - BF4 - 5CO), 369 (M+ - BF4 - 5CO - CS2C2HNH2).
Anal. Calcd for C20H13BF4NO5PS2W: C, 33.68; H, 1.84; N, 1.96.
Found: C, 33.31; H, 1.97; N, 1.85.
Spectroscopic data of 9 are as follows. IR (KBr, cm-1):
ν(CO) 2076(m), 1964(s), 1915(vs). 31P{1H} NMR (81 MHz,
1
CDCl3, 298 K): δ 20.2 (J W-P ) 259.7 Hz). H NMR (200 MHz,
CDCl3, 298 K): δ 2.67 (s, 3H, CH3), 7.50 (m, 6H, Ph), 7.66 (m,
4H, Ph), 7.80 (br, 2H, NH2). 13C{1H} NMR (50 MHz, CDCl3,
3
298 K): δ 12.0 (s, CH3), 129.8 (d, meta-C of Ph, J P-C ) 10.5
Hz), 132.3 (d, ortho-C of Ph, 2J P-C ) 13.3 Hz), 132.7 (s, para-C
of Ph), 133.3 (d, ipso-C of Ph, J P-C ) 19.0 Hz), 162.2 (s, CH3C),
2
171.4 (s, CNH2), 195.6 (d, cis-CO, J P-C ) 7.0 Hz), 197.2 (d,
2
trans-CO, J P-C ) 25.5 Hz). MS (FAB, NBA, m/z): 640 (M+
-
BF4), 512 (M+ - BF4 - CO), 584 (M+ - BF4 - 2CO), 556 (M+
- BF4 - 3CO), 528 (M+ - BF4 - 4CO), 500 (M+ - BF4 - 5CO),
369 (M+ - BF4 - 5CO - CS2C2CH3NH2). Anal. Calcd for
(10) Gabe, E. J .; Lee, F. L.; Lepage, Y. In Crystallographic Comput-
ing 3; Sheldrick, G. M., Kruger, C., Goddard, R., Eds.; Clarendon
Press: Oxford, England, 1985; p 167.

2610 Organometallics, Vol. 20, No. 12, 2001
Yih et al.
throughout the data collection and showed no apparent decay.
The merging of equivalent and duplicate reflections gave a
total of 3284 unique measured data in which 2644 reflections
with I > 2σ(I) were considered observed. The structure was
first solved by using the heavy-atom method (Patterson
synthesis), which revealed the positions of metal atoms. The
remaining atoms were found in a series of alternating differ-
ence Fourier maps and least-squares refinements. The quan-
tity minimized by the least-squares program was w(|Fo| -
|Fc|)2, where w is the weight of a given operation. The
analytical forms of the scattering factor tables for the neutral
atoms were used.11 The non-hydrogen atoms were refined
anisotropically. Hydrogen atoms were included in the structure
factor calculations in their expected positions on the basis of
idealized bonding geometry but were not refined in least
squares. All hydrogens were assigned isotropic thermal pa-
rameters 1-2 Å2 larger than the equivalent Biso value of the
atom to which they were bonded. The final residuals of this
refinement were R ) 0.034 and Rw ) 0.036. Selected bond
distances and angles are listed in Table 2.
The procedures for 8 and 10 were similar to those for 6.
The final residuals of this refinement were R ) 0.025 and Rw
) 0.028 for 8 and R ) 0.043 and Rw ) 0.046 for 10. Selected
bond distances and angles are listed in Table 2. Tables of
thermal parameters are given in the Supporting Information.
Ack n ow led gm en t. We would like to thank the
National Science Council of Taiwan, Republic of China,
and Hung Kuang Institute of Technology of Humanities
and Science Council for support.
Su p p or t in g In for m a t ion Ava ila b le: For 6, 8, and 10
tables of atomic coordinates, crystal and intensity collection
data, anisotropic thermal parameters, and bond distances and
bond angles. This material is available free of charge via the
Internet at http://pubs.acs.org.
(11) International Tables for X-ray Crystallography; Reidel: Dor-
drecht, The Netherlands, 1974; Vol. IV.
OM001032Y