[3+2] Cycloaddition reactions of the phospha-alkyne, ButCP, with a transition metal trisulphide containing terminal thio ligands: Syntheses, crystal and molecular structures of [W(η5-(C5Me5)(S)(S2PCtBu)]2 and [W(η5-(C5Me5)(S)(S2C2 Ph2)]2

Article abstract of DOI:10.1016/S0022-328X(98)00687-1

The trisulphido complex [PPh₄][W(η⁵-(C₅Me₅)(S)₃], reacts with the phospha-alkyne Bu^tCP and O₂ to afford the dimeric complex [W(η⁵-(C₅Me₅)(S)(S₂PC^tBu)]₂. Analogous reactions occur with the alkyne Ph₂C₂ to give [W(η⁵-(C₅Me₅)(S)(S₂C₂ Ph₂)]₂. The molecular structures of both complexes are presented and discussed.

Full text of DOI:10.1016/S0022-328X(98)00687-1

Journal of Organometallic Chemistry 564 (1998) 189–191
[3+2] Cycloaddition reactions of the phospha-alkyne, ButCP, with a
transition metal trisulphide containing terminal thio ligands: syntheses,
crystal and molecular structures of [W(p5-(C5Me5)(S)(S2PCtBu)]2 and
[W(p5-(C5Me5)(S)(S2C2Ph2)]2
Sarah E. d’Arbeloff a, Peter B. Hitchcock a, John F. Nixon a,*, Takayuki Nagasawa b,
Hiroyuki Kawaguchi b, Kazuyuki Tatsumi b
a School of Chemistry, Physics and En6ironmental Science, Uni6ersity of Sussex, Brighton BN1 9QJ, Sussex, UK
b Department of Chemistry, Graduate School of Science, Nagoya Uni6ersity, Furo-cho, Chikusa-ku, Nagoya 464-01, Japan
Received 5 March 1998; received in revised form 11 May 1998
Abstract
The trisulphido complex [PPh4][W(p5-(C5Me5)(S)3], reacts with the phospha-alkyne ButCP and O2 to afford the dimeric complex
[W(p5-(C5Me5)(S)(S2PCtBu)]2. Analogous reactions occur with the alkyne Ph2C2 to give [W(p5-(C5Me5)(S)(S2C2Ph2)]2. The
molecular structures of both complexes are presented and discussed. © 1998 Elsevier Science S.A. All rights reserved.
Keywords: Cycloaddition; Thio ligands; Trisulfide
There is considerable current interest in the study of
metal sulphides, in view of their biological importance
and their potential in the design of new materials [1,2].
The reactivity of certain transition metal sulphides to-
wards alkenes [3] and alkynes [4,5] has been discussed,
but a very recent report by Goodman and Rauchfuss
[6], which describes the addition of nitriles to the tetra-
sulphido anion [ReS4]−, prompts us to report the first
example of the ready addition of the phospha-alkyne,
ButCP, 1, to the anionic mononuclear trisulphido com-
plex [PPh4][W(p5-(C5Me5)(S)3] 2, containing three ter-
minal WꢀS bonds.
* Corresponding author. Tel.: +44 273 678536; fax: +44 273
677196; e-mail: j.nixon@sussex.ac.uk
0022-328X/98/$19.00 © 1998 Elsevier Science S.A. All rights reserved.
PII S0022-328X(98)00687-1

190
S.E. d’Arbeloff et al. / Journal of Organometallic Chemistry 564 (1998) 189–191
The close similarity in the structures of 7 and 8 is
self-evident from an inspection of the bond length and
bond angle data summarised in Figs. 1 and 2. The
W···W, WꢁS and WꢀS distances in the two complexes
are identical within experimental error. The WS2PC
and WS2C2 ring systems are planar in 7 and 8, respec-
tively. This could be interpreted as involving some
y-delocalisation as expected for 1,2-phospha-ene thio-
lato and 1,2-enethiolato coordination; however the
˚
C(1)ꢁP distance, 1.66(2) A in 7, and the C(11)ꢁC(18)
˚
distance, 1.358(5) A in 8, are consistent with localised
PꢀC and CꢀC double bonds, respectively.
The ready [3+2] cycloaddition reaction of these
anionic trithio complexes with phospha-alkynes, sug-
gests that other metal sulphides containing terminal
MꢀS bonds may also form this type of compound.
Complex 6 also readily reacts with metal carbonyl
compounds, in the presence of an excess of ButCP, to
give the cage compound P2C2But2CO, (previously ob-
tained by Cowley et al. [17] from the reaction of
ButCP and [Ti(p5-(C5H5)(CO)2]), and a mixture of the
1,2,4- and 1,3,4-thiadiphospholes P2SC2But2. The 1,2,4-
thiadiphosphole was first reported by Lindner et al.
[18] in an unusual reaction involving ButCP and p2-
thiophosphinato cobalt and manganese complexes, but
the 1,3,4-isomer has not been previously reported, and
it will be the subject of a separate publication [19].
Previously [7,8], we showed that the addition of the
alkyne Ph2C2 to complex 2 and its molybdenum ana-
logue 3, afforded mononuclear complexes 4 (M=W)
and 5 (M=Mo), respectively, which were both fully
characterised.
In view of the well-known similarity in behaviour of
alkynes and phospha-alkynes towards transition
metals [9–12] and the previously reported synthesis of
several five-membered heterocyclic compounds by [3+
2] cycloaddition reactions involving phospha-alkynes,
it was of interest to study the reaction of the anionic
trisulphide complex 2 with the phospha-alkyne ButCP.
Monitoring the r.t. reaction between 2 and one equiv-
alent of ButCP in acetonitrile by 31P-NMR spec-
troscopy, showed the rapid development of a new
signal (lP=210.3 ppm) assigned to complex 6, which
has not yet been possible to isolate. The same complex
is obtained in the presence of five equivalents of
ButCP.
However, when dry O2 was passed through a solu-
tion of 6, the green–brown complex [W(p5-
(C5Me5)(S)(S2PCtBu)]2
7 was readily formed and
isolated, (lP=101.4 ppm, 2J(WP)=26.8 Hz) (52%)
[13]. A single crystal X-ray diffraction study of the
CH2Cl2 solvate, revealed the dimeric structure shown
in Fig. 1 [14].
In a similar way, the green solution of 4 reacted
with dioxygen, instantly turning purple. The purple
intermediate has not yet been characterised but it
seems to be paramagnetic. After 1 day at r.t., the
colour of the solution gradually changed to green and
deposited crystals (41%) of the dark-green dimeric
complex 8 [15], whose structure, also determined by a
single crystal X-ray diffraction study, is shown in Fig.
2 [16].
Fig. 1. Molecular structure of 7 together with selected bond length
o
˚
(A) and bond angle ( ) data: W···W 3.068(2), WꢁS(1) 2.404(6),
WꢁS(2) 2.403(4), WꢁS(3) 2.337(5), WꢁS(3)% 2.324(5), S(1)ꢁP 2.039(7),
S(2)ꢁC(1) 1.74(2), C(1)ꢁP 1.66(2); WꢁS(3)ꢁW 82.3(2), S(2)ꢁWꢁS(1)
79.9(2), WꢁS(2)ꢁC(1) 116.1(6), WꢁS(1)ꢁP 116.3(3), S(2)ꢁC(1)ꢁP
122.4(9), S(1)ꢁPꢁC(1) 102.8(7).

S.E. d’Arbeloff et al. / Journal of Organometallic Chemistry 564 (1998) 189–191
191
[9] K.B. Dillon, F. Mathey, J.F. Nixon, Phosphorus: The Carbon
Copy, Wiley, Chichester, UK, 1998.
[10] J. F. Nixon, Coord. Chem. Revs. 145 (1995) 201; Chem. Soc.
Revs. 24 (1995) 319, and references therein.
[11] M. Regitz, P. Binger, in M. Regitz, O.J. Scherer (Eds.), Multiple
Bonds and Low Coordination in Phosphorus Chemistry, Georg
Thieme, Stuttgart, and references therein, 1991, chapter 2.
[12] J.F. Nixon, Chem. Rev. 88 (1988) 1327, and references therein.
[13] 7: 1H-NMR (360 MHz, CD3CN); l 1.82 (s, C5Me5, 30H), 0.61
(s, But, 18H).
[14] Crystal data for 7: C31H50Cl2P2S6W2, M=1115.6, monoclinic,
space group C2/c (No. 15), a=28.794(6), b=9.435(6), c=
3
˚
˚
15.074(4) A, i=107.17(2)°, U=3913(3) A , Z=4, Dcalc=1.89
g cm−3, F(000)=2716. Monochromated Mo–Kh radiation u=
0.71073 A, T=173(2) K. Data were collected on an Enraf-
˚
Nonius CAD 4 diffractometer using a crystal of 0.20×0.20×
0.05 mm. A total of 3423 independent reflections were measured
for 2BqB25o of which 2165 had I\2|I. The structure was
solved by direct methods using SHELXS-86 and refined on F2
with all non-H atoms anisotropic using SHELXL-93. Methyl-H
atoms were included in riding mode, fixed at idealised geometry,
but with the torsional angle defining the H atom positions
refined and Uiso(H)=1.5Ueq(C). The final residues were R1=
0.075 (for I\2|I) and wR2=0.203 for all data.
Fig. 2. Molecular structure of 8 together with selected bond length
o
˚
(A) and bond angle ( ) data: W···W 3.0652(3), WꢁS(1) 2.402(1),
WꢁS(2) 2.401(1), WꢁS(3) 2.348(1), WꢁS(3)* 2.344(1), S(1)ꢁC(11)
1.736(4), S(2)ꢁC(18) 1.740(4), C(11)ꢁC(18) 1.358(5); WꢁS(3)ꢁW*
[15] 8: 1H-NMR (500 MHz, CDCl3); l 2.02 (s, C5Me5, 30H), 7.2 (m,
Ph, 20H). UV-visible (umax, nm THF): 409, 542, 638. Found C,
49.01, H, 4.41, S, 15.89; C48H50W2S6 requires C, 48.57, H, 4.25,
S, 16.21%.
81.58(3),
S(2)ꢁWꢁS(1)
78.07(3),
WꢁS(2)ꢁC(18)
111.3(1),
WꢁS(1)ꢁC(11) 111.1(1), S(2)ꢁC(18)ꢁC(11) 118.3(3), S(1)ꢁC(11)ꢁC(18)
118.9(3).
[16] Crystal data for 8: C48H50S6W2, M=1186.98, triclinic, space
˚
References
(
group P1 (No. 2), a=10.5450(9), b=11.1888(8), c=9.898(1) A,
h=96.359(8), i=91.321(8), k=77.343(6) , U=1132.4(2) A ,
o
3
˚
Z=1, Dcalc=1.740 g cm−3, F(000)=582.00. Monochromated
Mo–Kh radiation u=0.71069 A, T=296 K. Data were col-
[1] E.I. Stiefel, K. Matsumoto (Eds.), Transition Metal Sulfur
Chemistry, Biological and Industrial Significance, American
Chemical Society, Washington, DC, 1996.
[2] E.I. Stiefel, D. Coucouvanis, W.E. Newton (Eds.), Molybdenum
Enzymes, Cofactors and Model Systems, American Chemical
Society, Washington, DC, 1993.
[3] M. Rakowski, B.R. DuBois, B.R. Jagirdar, S. Dietz, B.C. Noll,
Organometallics 16 (1997) 294, and references therein.
[4] A.A. Eagle, S.M. Harben, E.R.T. Tiekink, C.G. Young, J. Am.
Chem. Soc. 116 (1994) 9749.
[5] T. Shibahara, G. Sakane, S. Mochida, J. Am. Chem. Soc. 115
(1993) 10408.
[6] J.T. Goodman, T.B. Rauchfuss, Angew. Chem. Int. Ed. Engl. 36
(1997) 2083.
[7] H. Kawaguchi, K. Tatsumi, J. Am. Chem. Soc. 117 (1995) 3885.
[8] H. Kawaguchi, K. Yamada, J.-P. Lang, K. Tatsumi, J. Am.
Chem. Soc. 119 (1997) 10346.
˚
lected on a Rigaku AFC7R diffractometer using a crystal of
0.20×0.25×0.15 mm. A total of 5203 independent reflections
were measured for 2BqB25o of which 4430 had I\3|I. The
structure was solved by Patterson methods and refined by full-
matrix least-squares with all non-H atoms anisotropic using the
TEXSAN package. The final residues were R=0.023 and Rw=
0.027 (for I\3|I).
[17] A.R. Barron, A.H. Cowley, S.W. Hall, C.M Nunn, Angew.
Chem. Int. Ed. Engl. 27 (1988) 837.
[18] (a) E. Lindner, C. Haase, H.A. Meyer, M. Kemmler, R. Fawzi,
M. Steimann, Angew. Chem. Int. Ed. Engl. 32 (1993) 1424. (b)
E. Lindner, T. Schlenker, C. Haase, J. Organomet. Chem. 464
(1994) C31.
[19] S.E. d’Arbeloff, S. Krill, J.F. Nixon, L. Nyulaszi, M. Regitz,
paper in preparation.
.