Synthesis and characterization of tungsten alkenyl-carbyne and alkenyl-ketenyl complexes containing dithio ligands. X-ray crystal structure and MO analyses of [(dppe){κ3(S,C,S)-S2CPCy 3}W≡CCH=C(CH2)3CH2][BF 4]

Article abstract of DOI:10.1021/om970291t

The reaction of [(dppe)(CO)₂(MeCN)W≡CCH=CCH₂(CH₂) _nCH₂CH₂][BF₄] (dppe = 1,2-bis-(diphenylphosphino)ethane; n = 1 (1a), 4 (1b)) with S₂CPCy₃ in methanol for 10 min affords [(dppe)(CO)₂{κ(S)-S₂CPCy ₃}W≡CCH=CCH₂(CH₂)_nCH ₂CH₂][BF₄] (n = 1 (2a), 4 (2b)). Similarly, the complexes [(dppe)(CO)₂{κ(S)-S₂P(OEt) ₂}W≡CCH=CCH₂(CH₂)_nCH ₂CH₂] (n = 1 (3a), 4 (3b)) have been prepared by the reaction with [NBu₄][S₂P(OEt)₂]. When 1a and 1b are reacted with S₂CPCy₃ in methanol for 24 h, the complexes [(dppe){κ³(S,C,S)-S₂CPCy ₃}-W≡CCH=CCH₂(CH₂)CH₂CH ₂][BF₄] (n = 1 (4a), 4 (4b)) are formed. Moreover, when 1a and 1b are reacted with NaS₂CNR₂ (R = Me, Et), the ketenyl complexes [(dppe)(CO){κ²(S,S)-S₂CNR₂}W{κ ²(C,C)=C-(C=O)CH=CCH₂(CH₂)_nCH ₂CH₂}] are formed (R = Me, n = 1 (5a), 4 (5b); R = Et, n = 1 (5c), 4 (5d)) subsequent to the coupling between the carbyne group and carbon monoxide. IR and ¹H, ³¹P, and ¹³C NMR data are reported for all of the species. The molecular structure of compound 4a, determined by X-ray diffraction methods, shows that the S₂CPCy₃ ligand is bound to the metal in a pseudoallylic κ³(S,C,S) fashion. The metal coordination is completed by the W≡C triple bond of the alkenyl-carbyne group and by two additional W-P bonds. Since the metal center in 4a is formally a deficient 16-electron species and since the synthetic route has clearly indicated that an additional CO ligand is preferentially rejected by the metal, a reasonable interpretation of the bonding has been sought by means of EHMO calculations. Not only has the coexistence between the dithiocarboxylate and the carbyne ligands been elucidated, but also the strength of the W-S bonds is accounted for in comparison with the weaker W-S bonds observed in other saturated W complexes containing a κ³(S,C,S) dithio ligand. Finally, qualitative theoretical considerations are presented for the different behavior of the dithiocarbamate ligand.

Full text of DOI:10.1021/om970291t

Organometallics 1997, 16, 4099-4108
4099
Syn th esis a n d Ch a r a cter iza tion of Tu n gsten
Alk en yl-Ca r byn e a n d Alk en yl-Keten yl Com p lexes
Con ta in in g Dith io Liga n d s. X-r a y Cr ysta l Str u ctu r e a n d
MO An a lyses of
[(d p p e){K3(S,C,S)-S2CP Cy3}WtCCHdC(CH2)3CH2][BF 4]
Lei Zhang, M. Pilar Gamasa, and J ose´ Gimeno*
Instituto Universitario de Qu´ımica Organometa´lica “Enrique Moles” (Unidad Asociada al
CSIC), Departamento de Quı´mica Orga´nica e Inorga´nica, Facultad de Quı´mica,
Universidad de Oviedo, 33071 Oviedo, Spain
Agust´ın Galindo
Departamento de Quı´mica Inorga´nica, Universidad de Sevilla,
Aptdo 553, 441071 Sevilla, Spain
Carlo Mealli
Instituto per lo Studio della Stereochimica ed Energetica dei Composti di Coordinazione
(ISSECC-CNR), Via J . Nardi 39, 50132 Firenze, Italy
Maurizio Lanfranchi and Antonio Tiripicchio
Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica,
Universita` di Parma, Centro di Studio per la Strutturistica Diffrattometrica del CNR,
I-43100 Parma, Italy
Received April 8, 1997X
The reaction of [(dppe)(CO)2(MeCN)WtCCHdCCH2(CH2)nCH2CH2][BF4] (dppe ) 1,2-bis-
(diphenylphosphino)ethane; n ) 1 (1a ), 4 (1b)) with S2CPCy3 in methanol for 10 min affords
[(dppe)(CO)2{κ(S)-S2CPCy3}WtCCHdCCH2(CH2)nCH2CH2][BF4] (n ) 1 (2a ), 4 (2b)). Simi-
larly, the complexes [(dppe)(CO)2{κ(S)-S2P(OEt)2}WtCCHdCCH2(CH2)nCH2CH2] (n ) 1 (3a ),
4 (3b)) have been prepared by the reaction with [NBu4][S2P(OEt)2]. When 1a and 1b are
reacted with S2CPCy3 in methanol for 24 h, the complexes [(dppe){κ3(S,C,S)-S2CPCy3}-
WtCCHdCCH2(CH2)nCH2CH2][BF4] (n ) 1 (4a ), 4 (4b)) are formed. Moreover, when 1a
and 1b are reacted with NaS2CNR2 (R ) Me, Et), the ketenyl complexes [(dppe)(CO){κ2(S,S)-
S2CNR2}W{κ2(C,C)dCs(CdO)CHdCCH2(CH2)nCH2CH2}] are formed (R ) Me, n ) 1 (5a ),
4 (5b); R ) Et, n ) 1 (5c), 4 (5d )) subsequent to the coupling between the carbyne group
1
and carbon monoxide. IR and H, 31P, and 13C NMR data are reported for all of the species.
The molecular structure of compound 4a , determined by X-ray diffraction methods, shows
that the S2CPCy3 ligand is bound to the metal in a pseudoallylic κ3(S,C,S) fashion. The
metal coordination is completed by the WtC triple bond of the alkenyl-carbyne group and
by two additional W-P bonds. Since the metal center in 4a is formally a deficient 16-electron
species and since the synthetic route has clearly indicated that an additional CO ligand is
preferentially rejected by the metal, a reasonable interpretation of the bonding has been
sought by means of EHMO calculations. Not only has the coexistence between the
dithiocarboxylate and the carbyne ligands been elucidated, but also the strength of the W-S
bonds is accounted for in comparison with the weaker W-S bonds observed in other saturated
W complexes containing a κ3(S,C,S) dithio ligand. Finally, qualitative theoretical consid-
erations are presented for the different behavior of the dithiocarbamate ligand.
In tr od u ction
byne group 6 low-valent metal complexes (Fischer-type)
are genuine examples, and to date, a large number of
them have been prepared. Although carbyne complexes
of this type are readily accessible through a number of
well-established synthetic methodologies,2a,c,e only a few
complexes bearing unsaturated substituents on the
carbyne functionality have been described.3 We have
Since the discovery1 of the first carbyne complex by
E. O. Fischer in 1973, the chemistry of metal-carbon
triple bonds has been extensively investigated.2 Car-
X Abstract published in Advance ACS Abstracts, August 15, 1997.
S0276-7333(97)00291-4 CCC: $14.00 © 1997 American Chemical Society

4100 Organometallics, Vol. 16, No. 19, 1997
Zhang et al.
Ch a r t 1
The X-ray crystal structure of the complex [(dppe)-
{κ3(S,C,S)-S2CPCy3}WtCCHdC(CH2)3CH2][BF4] (4a ) is
reported to highlight the features of an interesting
organometallic species with a formal electron shortage
(16 electrons) and in which a η3-coordinated dithio acid
coexists with a triple WtC bond. In order to elucidate
in some detail the electronic nature of 4a , extended
Hu¨ckel calculations (EHMO method)5 have been carried
out for a simplified model of the complex, namely
[(PH3)2{κ3(S,C,S)-S2CPH3}W(tCCHdCH2)]+.
Resu lts a n d Discu ssion
Alk en yl-Ca r byn e Com p lexes. The addition of an
equimolar amount of S2CPCy3 to a solution of [(dppe)-
(CO)2(MeCN)WtCCHdCCH2(CH2)nCH2CH2][BF4] (1a
and 1b) in methanol at room temperature (Scheme 1,
eq 1a) in 10 min leads to substitution of the acetonitrile
ligand giving the cationic alkenyl-carbyne complexes
2a and 2b, isolated as the tetrafluoroborate salts (90%
yield). They are orange air-sensitive solids that are not
stable over -20 °C. Similarly, the reaction of 1a and
1b with [NBu4][S2P(OEt)2] (eq 1b) affords neutral
complexes 3a and 3b (82-85% yield), isolated as yellow
air-stable solids.
recently reported4 an efficient route for the synthesis
of cationic alkenyl-carbyne complexes of the type
[(dppe)(CO)2LWtCCHdCCH2(CH2)nCH2CH2][BF4] (L )
CO, MeCN; dppe ) 1,2-bis(diphenylphosphino)ethane;
n ) 1, 4) (A, Chart 1), which have been proven to be
good precursors for the preparation of cationic [(dppe)-
The conductance data of acetone solutions show that
complexes 2a and 2b are 1:1 electrolytes. The IR spec-
tra (CH2Cl2) (Table 1) of all of the complexes exhibit the
two typical ν(CO) carbonyl stretching absorptions in the
range of 2000-1930 cm-1 for cis-dicarbonyl complexes,
indicating the substitution of the acetonitrile ligand.
The presence of the dithio ligands is assessed by the
31P NMR spectra (Table 1). Thus, the phosphorus
resonance of S2CPCy3 in complexes 2a and 2b appears
as a singlet signal at 31.7 ppm, as expected for a formal
phosphonium character,6 while the corresponding reso-
nance of the dithiophosphate ligand in complexes 3a and
3b appears as a triplet at δ 107.9 ppm (3J (P-P) ) 21.0-
20.5 Hz) due to the coupling of the two equivalent
phosphorus nuclei of dppe in a cis position. The spectra
also show the resonances of dppe at δ 42.4 s ppm (2a ,b)
(CO)2LWtCCHdCCH2(CH2)nCH2CH2][BF4] and neu-
tral [(dppe)(CO)2XWtCCHdCCH2(CH2)nCH2CH2] (X )
Cl, Br, I) derivatives. As an extension of the synthetic
applications of the precursor complexes (A), we have
obtained a number of novel tungsten derivatives con-
taining dithio ligands. The series of complexes is as
follows: (i) alkenyl-carbyne complexes (B) containing
monodentate ligands such as κ1(S) diethyldithiophos-
phate [S2P(OEt)2]- and the zwitterionic tricyclohexyl-
phosphonium dithiocarboxylate S2CPCy3, (ii) alkenyl-
carbyne complexes (C) with the S2CPCy3 ligand bonded
in a tridentate κ3(S,C,S) coordination mode, and (iii)
alkenyl-ketenyl complexes (D) which in contrast to the
aforementioned complexes (B) and (C) result from the
reactions of complexes A with dithiocarbamate ligands
3
and 38.2-38.1 ppm (d, J (P-P) 21.0-20.5 Hz) (3a ,b),
-
indicating the chemical equivalence of the phosphorus
atoms in accordance with the trans carbyne-dithio
ligand arrangement.
S2CNR2 (R ) Me, Et) through the coupling of the
carbyne group and carbon monoxide (formal insertion
of a carbonyl group into the metal-carbon triple bond).
When complexes 1a and 1b are allowed to react in
methanol with S2CPCy3 for 24 h, a gradual change of
color to red is observed along with the precipitation of
a red crystalline solid identified as [(dppe){κ3(S,C,S)-
(1) Fischer, E. O.; Kreis, G.; Kreiter, C. G.; Mu¨ller, J .; Huttner, G.;
Lorenz, H. Angew. Chem. 1973, 85, 618; Angew. Chem., Int. Ed. Engl.
1973, 12, 564.
(2) (a) Fischer, H.; Hofmann, P; Kreissl, F. R.; Schrock, R. R.;
Schubert, U.; Weiss, K. Carbyne Complexes; VCH Publishers: Wein-
heim, Germany, 1988. (b) Mayr, A. Comm. Inorg. Chem. 1990, 10, 227.
(c) Mayr, A.; Hoffmeister, H. Adv. Organomet. Chem. 1991, 32, 227.
(d) Mayr, A.; Bastos, C. Prog. Inorg. Chem. 1992, 40, 1. (e) Transition
Metal Carbyne Complexes; Kluwer Academic Publishers: Dordrecht,
Boston, London, 1993. (f) Engel, P. F.; Pfeffer, M. Chem. Rev. 1995,
95, 2281.
(3) (a) Alkynyl-carbyne complexes, [(CO)4XWtCCtCPh]: Fischer,
E. O.; Kalder, H. J .; Ko¨hler, F. H. J . Organomet. Chem. 1974, 81, C23.
[M(tCCtCBut)(CO)2L2{OC(O)CF3}] and [M(tCCtCBut)(CO)2L3] (M
) Mo, W): Hart, I. J .; Hill, A. F.; Stone, F. G. A. J . Chem. Soc., Dalton
Trans. 1989, 2261. (b) Alkenyl-carbyne complexes of group 6 metals
S2CPCy3}WtCCHdCCH2(CH2)nCH2CH2][BF4] (n ) 1
(4a ) and 4 (4b)) (90% yield) (Scheme 1, eq 1c). Alter-
natively, these complexes can be also obtained in similar
yield when solutions of 2a and 2b in methanol are
stirred at room temperature for 24 h. IR spectra of 4a
and 4b show no ν(CO) carbonyl stretching absorptions,
confirming the total substitution of the carbonyl ligands.
The analytical data and mass spectra (FAB) (see
Experimental Section) are in accordance with this
formulation. The 13C and 31P NMR spectra (Tables 1
and 2) are also consistent with this geometry, indicating
of the type [(CO)4XMtCdCH(CH2)2CH2] (M ) Cr, Mo, W): Fischer,
E. O.; Wagner, W. R.; Kreissl, F. R.; Neugebauer, D. Chem. Ber. 1979,
112, 1320. [(CO)4XWtCCHdC(NMe2)Ph]: see ref 3a. (c) A trinuclear
cluster of tungsten and rhenium containing an alkenyl-carbyne group
has also been described: Peng. J . J .; Peng, S. M.; Lee, G. H.; Chi, Y.
Organometallics 1995, 14, 626.
(4) Zhang, L.; Gamasa, M. P.; Gimeno, J .; Carbajo, R. J .; Lo´pez-
Ortiz, F.; Lanfranchi, M.; Tiripicchio, A. Organometallics 1996, 15,
4274.
(5) (a) Hoffmann, R. J . Chem. Phys. 1963, 39, 1397. (b) Hoffmann,
R.; Lipscomb, W. N. J . Chem. Phys. 1962, 36, 2179, 2872.
(6) See for example: Miguel, D.; Riera, V.; Miguel, J . A.; Go´mez,
M.; Sola´ns, X. Organometallics 1991, 10, 1683.

Synthesis of Tungsten Complexes
Organometallics, Vol. 16, No. 19, 1997 4101
Sch em e 1
Ta ble 1. IRa a n d 31P {1H} a n d 1H NMRb Da ta for th e Alk en yl-Ca r byn e Com p lexes
31P{1H}
IR ν(CO)
P(CH2)2P
S2CPCy3 or S2P(OEt)2
1H CâH
2a
2b
3a
3b
4a
4b
2000 s, 1936 vs
1999 s, 1936 vs
2001 vs, 1936 vs
1999 vs, 1931 vs
42.4 s (230.1)c
31.7 s
31.7 s
5.18 s, br
4.81 s, br
4.92 s, br
4.52 s, br
4.53 s, br
4.46 s, br
42.4 s (229.4)c
38.2 d (21.0d, 226.9c)
38.1 d (20.5d, 226.8c)
62.1 d (1.7e, 294.0c)
62.2 d (1.5e, 294.0c)
107.9 t (21.0d)
107.9 t (20.5d)
35.2 t (1.7e)
35.2 t (1.5e)
a
b
Spectra recorded in CH2Cl2, ν (cm-1). Abbreviations: s, strong; vs, very strong. Spectra recorded in CDCl3
(
31P{1H} NMR spectra
of 4a and 4b recorded on a Bruker AMX400 spectrometer in CD2Cl2), δ in ppm, J in Hertz. Abbreviations: s, singlet; d, doublet; t, triplet;
br, broad. c J (P-W). 3J (P-P). e J (P-P).
d
Ta ble 2. 13C{1H} NMR Da ta for th e
Alk en yl-Ca r byn e Com p lexesa
carboxylate complexes.7 The 31P{1H} NMR spectra also
show resonances due to the dppe ligand (ca. δ 62.1 ppm,
d, 3J (P-P) ) 1.7-1.5 Hz; J (P-W) ) 294.0 Hz), as
expected for an AX2 spin system.
13C{1H}
2 cis COb
S2CPCy3
b
c
CR
Câ
Cγ
166.5 s 214.5 dd
(33.4, 8.6)
165.2 s 214.7 dd
(33.1, 7.8)
164.0 s 213.7 m
The reactions can be monitored by 31P NMR in CDCl3,
which shows a stepwise acetonitrile-carbonyl substitu-
tion through the formation of complexes 2a and 2b as
intermediate species. The first reaction step seems to
be very fast, since after 5 min the signal of the starting
complex (e.g., 1a ) at δ 47 ppm is no longer observed and
two new singlet signals at δ 31.7 and 42.4 ppm appear
attributable in complex 2a (vide supra) to the phospho-
rus atoms of the dithio ligand and dppe, respectively.
After ca. 1 h, the spectrum also shows two signals at δ
35.2 and 62.1 ppm assigned to the final complex 4a ,
which are the only ones observed after ca. 24 h of
reaction.
2a 290.9 m
d
d
d
220.9 d (40.6)
220.8 d (40.2)
2b 290.9 m
3a 276.6 m
3b 276.7 t (10.4) 134.8 s 162.7 s 213.9 m
4a 300.5 t (13.4) 158.4 s
4b 300.8 t (13.6) 135.3 s 155.8 s
d
60.6 d (71.5)
60.5 d (70.7)
a
Spectra recorded in CDCl3, δ in ppm, J in Hertz. Abbrevia-
b
tions: s, singlet; d, doublet; t, triplet; m, multiplet. 2J (C-P).
d
c J (C-P). Overlapped by the aromatic carbons.
the presence of the alkenyl-carbyne group and the
dithio ligand bonded to the metal atom in a κ3(S,C,S)
coordination mode. In particular, the carbon resonance
of the dithiocarboxylate group in the S2CPCy3 ligand
appears at a high field (ca. δ 60.5 ppm, d, J (C-P) )
70.7-71.5 Hz), and the 31P NMR spectra show a low-
field triplet signal at ca. δ 35.2 (3J (P-P) ) 1.7-1.5 Hz)
typical of a quaternary phosphorus atom bearing a
formal positive charge. These values can be compared
to those shown by other κ3(S,C,S) phosphonium dithio-
X-r a y Cr ysta l Str u ctu r e of 4a . The crystal struc-
ture of complex 4a consists of cationic complexes and
-
of BF4 anions. The structure of the cationic complex
(7) (a) Galindo, A.; Gutie´rrez-Puebla, E.; Monge,A.; Pastor, A.;
Pizzano, A.; Ruiz, C.; Sa´nchez, L.; Carmona, E. Inorg. Chem. 1993,
32, 5569. (b) Carmona, E.; Gutie´rrez-Puebla, E.; Monge, A.; Pe´rez, P.;
Sa´nchez, L. Inorg. Chem. 1989, 28, 2120. (c) Galindo, A.; Mealli, C.;
Cuya´s, J .; Miguel, D.; Riera, V.; Pe´rez-Mart´ınez, J .; Bois, C.; J eannin,
Y. Organometallics 1996, 15, 2735.

4102 Organometallics, Vol. 16, No. 19, 1997
Zhang et al.
Ta ble 3. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for Com p lex 4a
W-S(1)
2.404(4)
2.401(4)
2.474(4)
2.463(4)
P(3)-C(41)
1.829(11)
1.821(12)
1.42(2)
1.36(2)
1.52(3)
1.51(3)
1.50(5)
1.51(5)
1.51(4)
1.43(2)
1.36(3)
1.52(4)
1.51(3)
1.50(5)
1.52(6)
1.51(4)
W-S(2)
P(3)-C(47)
W-P(2)
W-P(3)
W-C(1A)
W-C(1B)
W-C(8)
S(1)-C(8)
S(2)-C(8)
P(1)-C(8)
P(1)-C(9)
P(1)-C(15)
P(1)-C(21)
P(2)-C(27)
P(2)-C(29)
P(2)-C(35)
P(3)-C(28)
C(1A)-C(2A)
C(2A)-C(3A)
C(3A)-C(4A)
C(3A)-C(7A)
C(4A)-C(5A)
C(5A)-C(6A)
C(6A)-C(7A)
C(1B)-C(2B)
C(2B)-C(3B)
C(3B)-C(4B)
C(3B)-C(7B)
C(4B)-C(5B)
C(5B)-C(6B)
C(6B)-C(7B)
1.811(15)
1.808(16)
2.142(10)
1.747(11)
1.766(11)
1.823(11)
1.820(11)
1.824(13)
1.862(14)
1.867(15)
1.831(12)
1.814(12)
1.825(12)
C(1B)-W-C(8)
C(1A)-W-C(8)
C(1A)-W-C(1B)
P(3)-W-C(8)
P(3)-W-C(1B)
P(3)-W-C(1A)
P(2)-W-C(8)
P(2)-W-C(1B)
P(2)-W-C(1A)
P(2)-W-P(3)
S(2)-W-C(8)
S(2)-W-C(1B)
S(2)-W-C(1A)
S(2)-W-P(3)
S(2)-W-P(2)
S(1)-W-C(8)
S(1)-W-C(1B)
S(1)-W-C(1A)
S(1)-W-P(3)
S(1)-W-P(2)
S(1)-W-S(2)
103.9(7) W-C(1A)-C(2A)
166(1)
107.6(6) C(1A)-C(2A)-C(3A) 126(2)
18.3(7) C(2A)-C(3A)-C(7A) 124(2)
139.5(3) C(2A)-C(3A)-C(4A) 130(2)
92.4(6) C(4A)-C(3A)-C(7A) 105(2)
78.1(6) C(3A)-C(4A)-C(5A) 102(2)
136.9(3) C(4A)-C(5A)-C(6A) 108(3)
85.2(6) C(5A)-C(6A)-C(7A) 101(3)
94.0(6) C(3A)-C(7A)-C(6A) 110(2)
F igu r e 1. View of the molecular structure of the cat-
ionic complex of [(dppe){κ3(S,C,S)-S2CPCy3}WtCCHd
80.4(1) W-C(1B)-C(2B)
170(2)
45.3(3) C(1B)-C(2B)-C(3B) 129(2)
110.9(6) C(2B)-C(3B)-C(7B) 121(2)
126.6(6) C(2B)-C(3B)-C(4B) 125(2)
154.9(1) C(4B)-C(3B)-C(7B) 112(2)
C(CH2)3CH2][BF4] (4a ), with the atom-numbering scheme.
Only one of the two disordered positions of the alkenyl-
carbyne ligand are shown.
91.9(1) C(3B)-C(4B)-C(5B)
98(3)
44.7(3) C(4B)-C(5B)-C(6B) 107(3)
125.1(6) C(5B)-C(6B)-C(7B) 100(3)
114.7(6) C(3B)-C(7B)-C(6B) 102(2)
is shown in Figure 1, together with the atom-numbering
scheme; selected bond distances and angles are given
in Table 3.
95.7(1) S(2)-C(8)-P(1)
149.8(1) S(1)-C(8)-P(1)
79.0(1) S(1)-C(8)-S(2)
120.9(6)
117.1(6)
120.8(6)
The W atom displays a roughly square pyramidal
coordination with the triply-bonded C(1) atom from the
alkenyl-carbyne group lying at the apical site. Two cis
basal sites are occupied by the phosphorus atoms of the
dppe chelate, while the other two sites are jointly
spanned by the S2C unit of the tricyclohexylphospho-
nium dithiocarboxylate ligand. The apical alkenyl-
carbyne ligand has been found disordered over two
positions (A and B) with a separation between the
carbynic C(1A) and C(1B) atoms of 0.57 Å. For the sake
of clarity, only the ligand in the position A is shown in
Figure 1. The structural parameters relative to the
carbyne ligand are W-C(1A) ) 1.811(15) Å, W-C(1B)
) 1.808(16) Å, W-C(1A)-C(2A) ) 166(1)°, and W-C-
(1B)-C(2B) ) 170(2)°. The W-C bond lengths are
comparable with that found, 1.830(3) Å, in the neutral,
18-electron complex trans-[(dppe)(CO)2ClWtCCHd
C(1A)WC(8)P(1) and C(1B)WC(8)P(1) being 6(1)° and
-13(1)°, respectively. It is noteworthy that the bonding
of the S2C fragment to the tungsten atom in 4a differs
significantly from that observed in the metal-saturated
complex7a [W{κ3(S,C,S)-S2CPMe3}(CO)2(PMe3)2] where
the W-S bond lengths, 2.505(8) and 2.541(7) Å, are
definitely longer and the W-C one is only slightly
shorter, 2.12(2) Å. Another structure which is closely
related to the present one is that of the formal 16-
electron complex8 [W(tCBut)(CHBut)(CH2But)(dmpe)].
Also, in the latter the carbyne group occupies the apex
of the square pyramid (WtC ) 1.785(8) Å) while in the
basal plane there are, besides the two phosphine donors
of the chelate, adjacent alkyl and alkylidene groups.
Keten yl Com p lexes. The facile substitution of the
carbonyl groups with dithio ligands in complexes 1a and
1b prompted us to investigate their reactivity with
dialkyldithiocarbamate, a typical monoanionic chelate
C(CH2)3CH2].4 Remarkably, in the latter, the W-C-C
angle is much closer to linearity, i.e., 178.9(2)°. Also,
the W-P(2) and W-P(3) bond distances in 4a appear
shorter (2.474(4) and 2.463(4) Å) than those in the above
reference complex (2.539(1) and 2.524(1) Å, respec-
tively). The five-membered rings in positions A and B
display envelope and twist conformations, respectively.
The coordination of the S2CPCy3 ligand is of the
pseudoallylic κ3(S,C,S)-type with W-S(1), W-S(2), and
W-C(8) bond lengths of 2.404(4), 2.401(4), and 2.142-
(10) Å, respectively, and with the C-S bond lengths
practically equal to each other, 1.747(11) vs 1.766(11)
Å. Also, the P(1)-C(8) distance of 1.82(1) Å is compa-
rable to the typical P-Cy distances, in the range 1.82-
(1)-1.86(1) Å. The latter linkage is practically eclipsed
to the carbynic W-C(1) linkage, the dihedral angles
ligand. The addition of a stoichiometric amount of NaS2
-
CNR2 (R ) Me, Et) to a solution of 1a and 1b in
methanol at -20 °C gives a purple solution from which
ketenyl complexes 5a -d are obtained in good yields
(Scheme 2). These complexes have been isolated as
brown solids, and they are stable under N2 atmosphere.
They have been characterized by elemental analyses,
mass spectrometry (FAB) (see Experimental Section),
and IR and NMR spectroscopies (Tables 4 and 5).
The IR spectra (CH2Cl2) (Table 4) show two ν(CO)
stretching carbonyl absorptions, one very strong at
(8) Churchill, M. R.; Youngs, W. J . Inorg. Chem. 1979, 18, 2454.

Synthesis of Tungsten Complexes
Organometallics, Vol. 16, No. 19, 1997 4103
Sch em e 2
Ta ble 4. IRa a n d 31P {1H} NMRb Da ta for th e
Alk en yl-Keten yl Com p lexes
that cis-dicarbonyl complexes containing monodentate
dithiocarbamate ligands are formed (Scheme 2).9b The
ability of dithiocarbamate ligands to chelate probably
favors the substitution of an additional carbonyl ligand,
promoting the coupling of the carbyne group and carbon
monoxide to give the κ2-alkenyl-ketenyl moiety. In
contrast to this behavior, complexes 3a and 3b remain
unchanged even when their solutions in methanol are
heated under reflux. This probably indicates the un-
favorable “bite angle” of the S2P(OR)2 ligands, although
tungsten complexes in which dithiophosphate is acting
as a chelate ligand have been reported.10
31P{1H}c
IR
P trans to
ν(CO) ν(CdCdO)
κ2-ketenyl
P trans to S
5a 1869 vs
1731 m
1729 m
1729 m
1727 m
18.4 d (19.0, 72.3) 45.5 d (19.0, 312.7)
17.6 d (16.8, 67.9) 46.0 d (16.8, 315.1)
17.4 d (19.8, 73.1) 46.3 d (19.8, 310.8)
16.6 d (18.1, 68.1) 46.4 d (18.1, 313.3)
5b 1870 vs
5c 1869 vs
5d 1870 vs
Spectra recorded in CH2Cl2, ν (cm-1). Abbreviations: m,
a
b
medium; vs, very strong. Spectra recorded in CDCl3, δ in ppm,
J in Hertz. Abbreviations: d, doublet. c J (P-P) and J (P-W).
MO An a lyses of Com p lexes 4a ,b. The unit S2-
CPR3, formally resulting from the aggregation of carbon
disulfide and a tertiary phosphine, is found to be a
versatile ligand. The metal complexes show a variety
of coordination modes, and up to four electron pairs can
be involved in the bonding with the metal(s). In
particular, the trihapto binding mode, M(κ3-S,C,S), has
been structurally characterized in a number of mono-
nuclear7 and binuclear6,11 complexes. The trihapto
coordination of S2CPCy3 in complexes 4a ,b is particu-
larly interesting because it coexists with a carbyne
group bonded to the same metal center. Also, the case
is peculiar because a significant amount of back-
donation into the empty π* level of S2CPCy3 (see I) is
expected to occur from a somewhat electron-deficient
metal species (16 electrons). The EHMO calculations
1869-1870 cm-1, assigned to the terminal carbonyl
ligand, and a second medium intensity absorption at
1729-1731 cm-1, indicating the presence of the ketenyl
group.9 This is confirmed by the ketenyl carbon reso-
nance in the 13C NMR spectra (Table 5) which appears
as an unresolved multiplet at δ 199.4-201.4 ppm due
to the coupling with the unequivalent phosphorus
nuclei. An additional doublet of doublets at δ 187.9-
2
190.4 ppm (dd, J (C-P) ) 18, 10 Hz) are assigned to
the R carbon of the ketenyl group [W{κ2(C,C)dCs(CdO)-
CHdCCH2(CH2)nCH2CH2}]. Further resonances at-
tributable to the rest of the carbon nuclei of the alkenyl
moieties and dithiocarbamate and dppe ligands can also
be assigned (see Experimental Section). The 31P NMR
spectra of complexes 5a -d (Table 4) consist of two
doublets (2J (P-P) ) 16.8-19.8 Hz) along with the 183
W
satellites. As expected for the high trans influence of
the κ2-ketenyl ligand, small values of J (P-W) coupling
constants are observed (δ 16.6-18.4, 1J (P-W) ) 67.9-
1
72.3 Hz, P trans to κ2-ketenyl; δ 45.5-46.4, J (P-W) )
310.8-315.1 Hz, P trans to S).9a Significantly, the
former coupling constants are lower than those shown
by the alkenyl-carbyne ligand.4
When the reactions are monitored by IR in the carbo-
nyl region, the formation of an intermediate complex is
observed. Thus, after 5 min the spectra show two new
have been performed mainly based on the structural
results obtained for 4a . The working model II has the
imposed Cs symmetry with the terminal alkenyl group,
hanging from the carbyne, fixed in the mirror plane. No
ν(CO) stretching absorptions at 1997 and 1933 cm-1
.
The reactions are allowed to proceed until these absorp-
tions totally disappear to give those corresponding to
the final complexes 5a -d . Although all attempts to
isolate these intermediate species have failed, we believe
(9) (a) Similar data have been reported for analogous tungsten
ketenyl complexes: Birdwhistell, K. R.; Tonker, T. L.; Templeton, J .
L. J . Am. Chem. Soc. 1985, 107, 4474 and references therein. (b) An
analogous intermediate has been postulated in the formation of related
ketenyl complexes also generated by the reaction of tungsten carbonyl-
carbyne complexes with dithiocarbamate ligands (see ref 9a). (c) Hill,
A. F.; Malget, J . M.; White, A. J . P.; Williams, D. J . J . Chem. Soc.,
Chem. Commun. 1996, 721. (d) Brower, D. C.; Stoll, M.; Templeton, J .
L. Organometallics 1989, 8, 2786. (e) Mayr, A.; Chang, R. T.; Lee, T.
Y.; Cheung, O. K.; Kjelsberg, M. A.; McDermott, G. A.; Engen, D. V.
J . Organomet. Chem. 1994, 479, 47.
significant barrier is detected for a free rotation of the
(10) Haiduc, I.; Sowerby, D. B.; Lu, S. F. Polyhedron 1995, 14, 3389.

4104 Organometallics, Vol. 16, No. 19, 1997
Ta ble 5. Selected 13C{1H} NMR Da ta for th e Alk en yl-Keten yl Com p lexesa
13C{1H}
Zhang et al.
WdCRdCdOb
Câ
Cγ
2 cis COb
CRdCdO
S2CNR2
5a
5b
5c
5d
190.0 dd (18.6, 10.5)
190.4 dd (18.7, 9.7)
187.9 dd (17.8, 11.1)
190.1 dd (18.4, 9.8)
119.5 s
124.5 s
119.6 s
124.9 s
150.0 s
148.5 s
149.9 s
147.1 s
221.9 dd (10.0, 2.8)
222.4 dd (10.4, 2.4)
221.5 m
199.4 m
201.4 m
201.2 m
199.6 m
211.8 s
211.3 s
211.5 s
211.2 s
221.8 dd (10.8, 3.6)
a
b
Spectra recorded in CDCl3, δ in ppm, J in Hertz. Abbreviations: s, singlet; d, doublet; m, multiplet. In parenthesis 2J (C-P).
proper dπ symmetry (xz, yz orbitals) to interact with the
pπ orbitals of a formally trianionic carbyne. The inter-
actions are also at the origin of the WtC triple bond
(the bonding/antibonding combinations are highlighted
in Figure 2).
By considering the carbyne group as a formal trianion
(π-donor), versus monocationic (π-acceptor) or a neutral
moiety,14 the metal can be regarded as a d2 species.
Indeed, several theoretical studies have already been
devoted to octahedral metal-carbyne complexes,15 but
the situation may be simplified by thinking that the
unique electron pair of the d2 metal is hosted in the third
t2g orbital (x2-y2), hence, it is available for back-donation
into the empty π*-S2C FMO. The bonding combination
(the strongest observed in terms of overlap population
between fragment orbitals) gives rise to the HOMO of
the molecule, shown in III. It is noteworthy that the
F igu r e 2. Diagram of the interactions between the dithio
ligand S2CPH3 and the fragment [W(tCCHdCH2)(PH3)2]+.
alkenyl-carbyne fragment about the extended WtC-C
vector nor do the main electronic features seem to be
affected by the substitution of the terminal CHdCH2
group with a single H atom.
Figure 2 shows the diagram for the interaction
between the dithiocarboxylate ligand and the remaining
part of the molecule. The frontier molecular orbitals
(FMOs) of the ligand S2CPH3 (on the right side of the
figure) have been described recently.7c,12 Essentially,
these consist of two major in-plane combinations of
sulphur lone pairs (in-phase σip and out-of-phase, σop),
and three of the π-S2C system containing four electrons.
Besides the empty π*-S2C level, these include the π-S2C
and πn-S2C combinations.
The fragment of the type ML3 (with pseudo C3v
symmetry) is somewhat atypical because of the triple
linkage between the metal and one of the ligands
(WtCR). In any case, by adopting a classic strategy13
the frontier orbitals can still be thought to descend from
an octahedron following the removal of three fac σ
donors. Accordingly, there are two main subsets of
levels, namely a lower t2g and higher eg + σhybrid. Two
levels of the former subset, considered empty, have the
total energy as well as that of the HOMO are optimized
for a value of the Ccarbyne-W-Cdithioligand bond angle very
close to the experimental one (ca. 105°).
Previous MO studies7c,12 on the interaction between
the ligand S2CPH3 and metal fragments such as [Fe-
(CO)3] and [W(CO)2(PH3)2] also pointed out the extra
stability of the back-donation into the FMO I, which
adds to the four-electron donation involving the S2C π
system. The rest of metal orbitals lying above the t2g
set are also shown in Figure 2. One of them, xy,
interacts more strongly with the πn-S2C antisymmetric
combination. Finally, there are two possible candidates
(see IV and V) which, being empty, can potentially
interact with the symmetric π-S2C bonding combination.
(11) See for example: (a) Miguel, D.; Pe´rez-Mart´ınez, J . A.; Riera,
V.; Garc´ıa-Granda, S. Organometallics 1994, 13, 4667. (b) Barrado,
G.; Li, J .; Miguel, D.; Pe´rez-Mart´ınez, J . A.; Riera, V.; Bois, C.; J eannin,
Y. Organometallics 1994, 13, 2330. (c) Miguel, D.; Pe´rez-Mart´ınez, J .
A.; Riera, V.; Garc´ıa-Granda, S. Organometallics 1994, 13, 1336. (d)
Miguel, D.; Pe´rez-Mart´ınez, J . A.; Riera, V.; Garc´ıa-Granda, S. Orga-
nometallics 1993, 12, 2888. (e) Miguel, D.; Pe´rez-Mart´ınez, J . A.; Riera,
V.; Garc´ıa-Granda, S. Organometallics 1993, 12, 1394. (f) Miguel, D.;
Pe´rez-Mart´ınez, J . A.; Riera, V.; Garc´ıa-Granda, S. Angew. Chem. 1992,
31, 76.
(14) Neutral formalism avoids the oxidation state assignment, see
for example: (a) Wilker, C. N.; Hoffmann, R.; Eisenstein, O. Nouv. J .
Chim. 1983, 7, 535. (b) Hoffmann, R.; Wilker, C. N.; Eisenstein, O. J .
Am. Chem. Soc. 1982, 104, 632.
(12) Galindo, A.; Mealli, C. Inorg. Chem. 1996, 35, 2406.
(13) See for example: Albright, T. A.; Burdett, J . K.; Whangbo, M.-
H. Orbital Interactions in Chemistry; Wiley: New York, 1985.

Synthesis of Tungsten Complexes
Organometallics, Vol. 16, No. 19, 1997 4105
The higher level σhy (IV) has sp hybrid character while
the lower has dπ character (V). Since the main lobe of
the latter points opposite to the WtC linkage, it is
indicated as z2 in Figure 2.
dihapto bonded. It is worth pointing out that although
in the present complex the metal is electron poor (recall
its apparent 16-electron configuration and, at the very
best, the extra donation from the in-plane σip S2C lone
pair), the back-donation from the unique electron pair
in dx2-y2 is a major stabilizing force.
In principle, both of the FMOs IV and V could share
the electrons donated from π-S2C and the description
of the whole complex as a 16-electron species could still
be rational.16 However, as a new piece of information
provided by the calculations, the in-plane sulfur lone
pair σip (see Figure 2) contributes somehow to the
bonding, in particular it overlaps preferentially with z2.
The 18-electron configuration can be achieved in this
manner, i.e., through the involvement of all of the nine
metal orbitals in some different interaction. Experi-
mentally, the participation of as many as three sulphur
electron pairs in bonding to the metal is supported by
the comparison of the W-S distances in the present and
other 18-electron species also containing the same di-
thio ligand κ3(S,C,S) coordinated. As discussed during
the description of the structure 4a , the W-S distance
in the 18-electron complex [W{κ3(S,C,S)-S2CPMe3}-
(CO)2(PMe3)2]7a is at least 0.1 Å longer than in our
species, a fact which is nicely rationalized by the
theoretical arguments which assign a certain double
bond character to the W-S linkages.
The fragment molecular orbital (FMO) analysis high-
lights the importance of the relative orientation of
S2CPH3 with respect to the fragment [W(tCCHd
CH2)(PH3)2]+. The dithio ligand is able to donate up to
three electron pairs (two from the π and one from the σ
system) only if the P-C bond of S2CPH3 eclipses the
W-C triple bond, as occurs in the molecular structure
of 4a . Similar preferred orientations for π-acceptor
ligands (alkenes and alkynes) have been reported in
several d2 complexes containing multiple-bonded ligands17
(mainly oxo18 and imido18b,19 derivatives). While the
metal achieves the formal 18-electron configuration, a
fourth electron pair is backdonated into the electrophilic
S2C carbon atom (I). If the dithio ligand is turned
upside down, the energetics of the system is disfavored
by ca. 0.6 eV and, importantly, the fluxionality of the
κ3 bound S2CPR3 ligand is prevented by the highest
energetics when the C-P vector is perpendicular to the
WtC linkage (∆E > 1.4 eV).
There still remains doubts on the reasons why in 4a
the ligand S2CPCy3 prefers the trihapto coordination
while the metal center could be formally saturated by
the dihapto κ2(S,S) coordination in the presence of an
extra CO ligand. Evidently (see Scheme 1), the addition
of S2CPCy3 forces the departure of as many as two CO
ligands from the coordination sphere. As a possible
explanation, if the S2CPCy3 group were dihapto coor-
dinated, there could be a significant electron repulsion
between its filled π MOs (at the sulfur atoms) and the
metal xz, yz orbitals. The latter are expected to ac-
cumulate large electron density when involved in π
interactions with the triply-bonded carbyne group.
Similar points have been raised by other authors
regarding the coexistence in the complex of a carbyne
ligand with coligands capable of donating four π elec-
trons such as an alkyne.20 Along the same lines also,
the deformation of the octahedral geometry in such
complexes has been interpreted.2b In summary, the
metal back-donation into the π*-S2C orbital at κ3-(S,C,S)
bonding and the loss of π repulsions due to the dihapto
coordination seem to be the factors counterbalancing the
loss of one carbonyl ligand. Hence, the preference for
the five-coordinated complexes 4a ,b over the six-
coordinated monocarbonyl species is reasonable.
-
The different behavior of S2CNR2 ligands versus
S2CPCy3 on coordination to the alkenyl-carbyne core
affords the ketenyl derivatives 5a -d (Scheme 2). Al-
though a theoretical analysis of such a different reactiv-
ity has not been carried out as yet, we want to comment
on the evidently different electronic properties of the
dithiocarbamate ligands vs S2CPR3. Indeed, the popu-
lation of the dithiocarbamate π system is characterized
by a total of six electrons, and the electrophilicity at the
central carbon atom is evidently diminished. This
feature is usually well-described by the VB representa-
tion VI.
The dichotomy between the κ3(S,C,S) and κ2(S,S)
coordination modes of dithio ligands in a variety of satu-
rated metal complexes has been previously addressed.7c
For the model compound [(PH3)2(S2CPH3)W(tCCHd
CH2)]+, the complex with a κ3(S,C,S) bonding mode is
more stable than the dihapto one by ca. 1 eV. The
stabilization of the HOMO due to the back-donation is
lost at the square pyramidal geometry if S2CPH3 is
Importantly, the back-donation from the metal is
greatly reduced as is the possibility of forming trihapto-
adducts analogous to those obtained with S2CPR3. Also,
since the π electron density accumulates less at the
sulfur atoms, the κ2(S,S) coordination is less hindered
and the octahedral geometry is more easily achieved.
The trihapto-pseudoallylic coordination of S2CPCy3
found in 4a ,b has been characterized by X-ray crystal-
lography in other dithio ligands (xanthate and thiox-
anthate) bonded to d2 oxo-molybdenum complexes, for
example as in [Mo(O){κ2(S,S)-S2CSPri}{κ3(S,C,S)-
S2CSPri}],21 [Mo(O){κ2(S,S)-S2CPh}{κ3-(S,C,S)-S2CPh}],22
[M o(O ){κ2 (S , S )-S 2 C (P M e 3 )O P r i }{κ3 (S , C , S )-
(15) (a) Brower, D. C.; Templeton, J . L.; Mingos, D. M. P. J . Am.
Chem. Soc. 1987, 109, 5203. (b) Kostic, N. M.; Fenske, R. F. Organo-
metallics 1982, 1, 489. (c) Kostic, N. M.; Fenske, R. F. J . Am. Chem.
Soc. 1981, 103, 4677.
(16) See for example: Templeton, J . L.; Winston, P. B.; Ward, B. C.
J . Am. Chem. Soc. 1981, 103, 7713.
(17) Nugent, W. A.; Mayer, J . M. Metal Ligand Multiple Bonds;
Wiley: New York, 1988.
(18) See for example: (a) Hall, K. A.; Mayer, J . M. J . Am. Chem.
Soc. 1992, 114, 10402. (b) Su, F.-M.; Bryan, J . C.; J ang, S.; Mayer, J .
M. Polyhedron 1989, 8, 1261. (c) Templeton, J . L.; Ward, B. C.; Chen,
G. J .-J .; McDonald, J . W.; Newton, W. E. Inorg. Chem. 1981, 20, 1248.
(19) See for example: (a) Clark, G. R.; Nielson, A. J .; Rickard, C. E.
F. J . Chem. Soc., Dalton Trans. 1995, 1907. (b) Clark, G. R.; Glenny,
M. W.; Nielson, A. J .; Rickard, C. E. F. J . Chem. Soc., Dalton Trans.
1995, 1147. (c) Montilla, F.; Galindo, A.; Carmona, E. Unpublished
results.
(20) See for example: Atagi, L. M.; Mayer, J . M. Organometallics
1994, 13, 4794 and references therein.
(21) Hyde, J .; Venkatasubramanian, K.; Zubieta, J . Inorg. Chem.
1978, 17, 414.

4106 Organometallics, Vol. 16, No. 19, 1997
Zhang et al.
2H, P(CHaHb)2P), 7.30-7.73 (m, 20H, PPh2). 13C{1H} NMR
(δ, CDCl3): 23.1-35.6 (m, 22 CH2), 29.6 (m, P(CH2)2P), 32.4
(d, J (C-P) ) 36.2 Hz, P(CH(CH2)5)3), 128.1-135.7 (m, Câ,
PPh2).
S2COPri}],23 and [Mo(O){κ2(S,S)-S2C(PMe3)SPri}{κ3-
(S,C,S)-S2CSPri}].24 These complexes are closely related
with compounds 4a ,b, and all of them have been studied
through the corresponding [Mo(O){κ3-(S,C,S)-S2CX}-
(S-S)] models or, alternatively, by a general [Mo(O)-
{κ3(S,C,S)-S2CH}{κ2-(S,S)-S2CH}] model compound. The
bonding of the dithio ligand to the ML3 fragment
(pseudo C3v), containing the oxo group and the other κ2-
dithio ligand, can be described as previously done for a
model of 4a . The HOMO of the [Mo(O){κ3(S,C,S)-
S2CH}{κ2-(S,S)-S2CH}] model is formed through the
same interaction highlighted before, that is the overlap
of the π*-S2C FMO and the filled dx2-y2 orbital. Similar
preferred orientations of the κ3-S2CX group can be
understood in terms of maximum overlap between
FMOs as outlined for the carbyne example and need no
further comments.
[(d p p e )(CO)2{K(S)-S2P (OE t )2}WtCCH dCCH 2(CH 2)n -
CH2CH2] (n ) 1 (3a ), 4 (3b)). Gen er a l P r oced u r e.
A
mixture of 1a or 1b (0.2 mmol) and [NBu4][S2P(OEt)2] (0.2
mmol) in dichloromethane (10 mL) was stirred at room
temperature for 0.5 h. After evaporation of the solvent to
dryness, the residue was extracted with toluene and filtered
off on Alox. Removal of the solvent gave 3a or 3b as bright
yellow solids. Yield: 3a , 85%; 3b, 82%.
Spectral and analytical data for 3a : IR (KBr, ν(CO)) 1995
(vs), 1928 (vs). 1H NMR (δ, CDCl3): 1.20 (t, J (H-H) ) 7.1
Hz, 6H, P(OCH2CH3)2), 1,48 (m, 4H, 2 CH2), 1.93 (m, 2H, CH2),
1.99 (m, 2H, CH2), 2.60 (m, 2H, P(CHaHb)2P), 2.80 (m, 2H,
P(CHaHb)2P), 3.78 (m, 4H, P(OCH2CH3)2), 7.33-7.74 (m, 20H,
3
PPh2). 13C{1H} NMR (δ, CDCl3): 15.6 (d, J (C-P) ) 9.0 Hz,
P(OCH2CH3)2), 25.4 (s, CH2), 26.1 (s, CH2), 27.2 (m, P(CH2)2P),
31.5 (s, CH2), 34.4 (s, CH2), 61.8 (d, 2J (C-P) ) 6.6 Hz, P(OCH2-
CH3)2), 128.2-136.6 (m, Câ, PPh2). MS (FAB, m/ e): 860 [M+
- 2CO], 731 [M+ - (EtO)2PS2], 645 [M+ - 2CO - 2EtO - S -
C7H9]. Anal. Calcd for C39H43O4P3S2W: C, 51.1; H, 4.7.
Found: C, 51.0; H, 4.8.
Exp er im en ta l Section
The reactions were carried out under dry nitrogen using
Schlenk techniques. All solvents were dried by standard
methods and distilled under nitrogen before use. The com-
plexes [(dppe)(CO)2(MeCN)WtCCHdCCH2(CH2)nCH2CH2][BF4]
(n ) 1 (1a ), 4 (1b)) were prepared by the literature methods.4
[NBu4][S2P(OEt)2], NaS2CNR2 (R) Me, Et) (Aldrich Chemi-
cal Co.), and S2CPCy3 (Strem Chemical Co.) were used as
received.
Infrared spectra were recorded on a Perkin-Elmer 1720-XFT
spectrometer. Mass spectra (FAB) were recorded using a VG-
Autospec spectrometer, operating in the positive mode; 3-ni-
trobenzyl alcohol (NBA) was used as the matrix. The conduc-
tivities were measured at room temperature, in ca. 10-3 mol
dm-3 acetone solutions, with a J enway PCM3 conductivimeter.
The C, H, and N analyses were carried out with a Perkin-
Elmer 240-B microanalyzer.
Spectral and analytical data for 3b: IR (KBr, ν(CO)) 1991
(vs), 1921 (vs). 1H NMR (δ, CDCl3): 1.19 (t, J (H-H) ) 7.0
Hz, 6H, P(OCH2CH3)2), 1.42 (m, 4H, 2 CH2), 1.50 (m, 4H, 2
CH2), 1.77 (m, 4H, 2 CH2), 2.38 (m, 2H, CH2), 2.60 (m, 2H,
P(CHaHb)2P), 2.80 (m, 2H, P(CHaHb)2P), 3.77 (m, 4H, P(OCH2-
CH3)2), 7.33-7.70 (m, 20H, PPh2). 13C{1H} NMR (δ, CDCl3):
3
15.7 (d, J (C-P) ) 9.2 Hz, P(OCH2CH3)2), 25.5 (s, CH2), 26.8
(s, CH2), 27.0 (s, 3 CH2), 27.4 (m, P(CH2)2P), 31.8 (s, CH2), 35.9
(s, CH2), 62.0 (d, 2J (C-P) ) 6.7 Hz, P(OCH2CH3)2), 128.3-
136.4 (m, PPh2). MS (FAB, m/ e): 902 [M+ - 2CO], 773 [M+
- (EtO)2PS2], 645 [M+ - 2CO - 2EtO - S - C10H15]. Anal
Calcd for C42H49O4P3S2W: C, 52.6; H, 5.2. Found: C, 52.8;
H, 4.8.
NMR spectra were run on a Bruker AC300 spectrometer at
300 MHz (1H), 121.5 MHz (31P), or 75.5 MHz (13C) using CDCl3
as solvent. The spectral references used were tetramethylsi-
lane for 1H and 13C NMR measurements and 85% H3PO4 for
31P NMR measurements.
[(d p p e ){K3(S ,C,S )-S 2C P C y 3}WtC C H dC C H 2(C H 2)n -
CH2CH2][BF 4] (n ) 1 (4a ), 4 (4b)). Gen er a l P r oced u r e. A
mixture of complex 1a or 1b (0.2 mmol) and S2CPCy3 (0.2
mmol) in methanol (20 mL) was stirred at room temperature
for 24 h. The color of the solution changed from orange to
deep red, and a red crystalline solid precipitated. Complete
precipitation took place by addition of diethyl ether (20 mL).
The solvent was decanted, and the resulting solid was washed
with diethyl ether (5 mL) and hexane (2 × 5 mL) to give the
compounds 4a or 4b as red crystalline solids. Yield: 4a and
4b, 90%. Conductivity (acetone, 20 °C, Ω-1 cm2 mol-1): 4a ,
121; 4b, 118.
Spectral and analytical data for 4a : IR (KBr, ν(B-F)) 1056
(s, br). 1H NMR (δ, CDCl3): 1.28 (m, 14H, 7 CH2), 1.67 (m,
8H, 4 CH2), 1.80 (m, 10H, 5 CH2), 2.15 (m, 6H, 3 CH2), 2.70
(m, 3H, P(CH(CH2)5)3), 3.14 (m, 2H, P(CHaHb)2P), 3.52 (m, 2H,
P(CHaHb)2P), 7.13-7.96 (m, 20H, PPh2). 13C{1H} NMR (δ,
CDCl3): 25.0 (s, CH2), 25.5 (m, 3 CH2), 26.3 (s, CH2), 26.9 (d,
2J (C-P) ) 11.8 Hz, 6 CH2), 27.4 (m, 6 CH2), 29.6 (m, P(CH2)2P),
30.2 (s, CH2), 32.8 (s, CH2), 33.9 (d, J (C-P)) 41.4 Hz, P(CH-
(CH2)5)3), 128.7-132.9 (m, Câ, PPh2). MS (FAB, m/ e): 1031
[M+ - BF4], 751 [M+ - BF4 - PCy3], 646 [M+ - BF4 - PCy3
- C - C7H9]. Anal. Calcd for C52H66BF4P3S2W: C, 55.8; H,
6.0. Found: C, 55.6; H, 6.0.
Selected IR and 1H, 31P{1H}, and 13C{1H} NMR spectroscopic
data for the novel alkenyl-carbyne complexes and alkenyl-
ketenyl complexes are collected in Tables 1, 2, 4, and 5.
[(d p p e )(CO)2{K(S )-S2CP Cy3}WtCCH dCCH 2(CH 2)n -
CH2CH2][BF 4] (n ) 1 (2a ), 4 (2b)). Gen er a l P r oced u r e.
An equimolar amount of complex 1a or 1b (0.2 mmol) and
S2CPCy3 in methanol (20 mL) was stirred at room temperature
for 10 min. The color of the solution changed from orange to
red. Removal of the solvent and washing the resulting solid
with diethyl ether (5 mL) and hexane (2 × 5 mL) gave 2a or
2b as orange solids. Yield: 2a and 2b, 90%. Conductivity
(acetone, 20 °C, Ω-1 cm2 mol-1): 2a , 136; 2b, 140.
Spectral data for 2a : IR (KBr, ν(CO) and ν(B-F)) 1989 (s),
1923 (vs), 1055 (s, br). 1H NMR (δ, CDCl3): 1.09 (m, 14H, 7
CH2), 1.38 (m, 10H, 5 CH2), 1.69 (m, 10H, 5 CH2), 1.91 (m,
4H, 2 CH2), 2.35 (m, 3H, P(CH(CH2)5)3), 2.50-3.20 (m, 4H,
P(CH2)2P), 7.27-7.70 (m, 20H, PPh2). 13C{1H} NMR (δ,
CDCl3): 24.9-34.6 (m, 19 CH2), 29.5 (m, P(CH2)2P), 32.4 (d,
J (C-P) ) 36.1 Hz, P(CH(CH2)5)3), 128.1-135.0 (m, Câ, PPh2).
Spectral data for 2b: 1H NMR (δ, CDCl3) 1.12 (m, 12H, 6
CH2), 1.42 (m, 14H, 7 CH2), 1.74 (m, 16H, 8 CH2), 2.44 (m,
5H, CH2, P(CH(CH2)5)3), 2.82 (m, 2H, P(CHaHb)2P), 3.06 (m,
Spectral and analytical data for 4b: IR (KBr, ν(B-F)) 1065
(s, br). 1H NMR (δ, CDCl3): 0.84 (m, 2H, CH2), 1.10 (m, 2H,
CH2), 1.19 (m, 6H, 3 CH2), 1.29 (m, 10H, 5 CH2), 1.38 (m, 2H,
CH2), 1.46 (m, 2H, CH2), 1.70 (m, 4H, 2 CH2), 1.78 (m, 4H, 2
CH2), 1.84 (m, 6H, 3 CH2), 2.14 (m, 6H, 3 CH2), 2.72 (m, 3H,
P(CH(CH2)5)3), 3.23 (m, 2H, P(CHaHb)2P), 3.48 (m, 2H,
P(CHaHb)2P), 7.11-7.99 (m, 20H, PPh2). 13C{1H} NMR (δ,
CDCl3): 23.2 (s, CH2), 25.3 (s, CH2), 25.5 (s, CH2), 25.6 (s, 3
(22) Tatsumisago, M.; Matsubayashi, G.; Tanaka, T.; Nishigaki, S.;
Nakatsu, K. J . Chem. Soc, Dalton Trans. 1982, 121.
(23) Carmona, E.; Galindo, A.; Gutie´rrez-Puebla, E.; Monge, A.;
Puerta, C. Inorg. Chem. 1986, 25, 3804.
(24) Carmona, E.; Galindo, A.; Guille-Photin, C.; La¨ı, R.; Monge, A.;
Ruiz, C.; Sa´nchez, L. Inorg. Chem. 1988, 27, 488.
2
3
CH2), 27.0 (d, J (C-P) ) 11.7 Hz, 6 CH2), 27.6 (d, J (C-P) )

Synthesis of Tungsten Complexes
Organometallics, Vol. 16, No. 19, 1997 4107
Ta ble 6. Exp er im en ta l Da ta for th e X-r a y
Diffr a ction Stu d y of Com p lex 4a
2.1 Hz, 6 CH2), 27.9 (s, CH2), 29.7 (m, P(CH2)2P), 30.2 (s, CH2),
31.8 (s, CH2), 32.6 (s, CH2), 33.9 (d, J (C-P)) 41.6 Hz, P(CH-
(CH2)5)3), 128.8-132.8 (m, PPh2). MS (FAB, m/ e): 1073 [M+
- BF4], 793 [M+ - BF4 - PCy3], 646 [M+ - BF4 - PCy3 - C
- C7H9]. Anal. Calcd for C55H72BF4P3S2W: C, 56.9; H, 6.2.
Found: C, 56.3; H, 6.2.
formula
C52H66BF4P3S2W
1118.79
Mr
cryst syst
space group
radiation (λ,Å)
monoclinic
P21/n
graphite-monochromated
(Mo KR, 0.710 73)
16.864(4)
17.940(5)
17.506(5)
99.39(2)
5225(2)
4
1.422
[(d p p e )(C O ){K2 (S ,S )-S 2 C N R 2 }W{κ2 (C,C)dC (C dO )-
a, Å
b, Å
c, Å
â, deg
V, Å3
Z
CHdCCH2(CH2)n CH2CH2}] (R ) Me, n ) 1 (5a ), 4 (5b); R
) Et, n ) 1 (5c), 4 (5d )). Gen er a l P r oced u r e. A mixture
of 1a or 1b (0.2 mmol) and NaS2CNR2 (0.2 mmol) in methanol
(20 mL) was stirred at room temperature for 2 h. The color of
the solution changed from orange to reddish-purple. The
solvent was removed under vacuum, the solid residue was
extracted with dichloromethane, and the extract was filtered.
The solution was concentrated to ca. 2 mL, and methanol (10
mL) was added. Slow evaporation of the solvents gave 5a -d
as red solids. Yield: 5a , 85%; 5b, 80%; 5c, 80%; 5d , 88%.
D
calc, g cm-3
F(000)
2280
cryst size, mm
0.16 × 0.22 × 0.28
µ (Mo KR), cm-1
θ range, deg
24.30
3-27
no. of reflns measd
unique total no. of data
unique no. of obsd data
R ) Σ|∆F|/Σ|Fo|
(h,k,l
Spectral and analytical data for 5a : IR (KBr, ν(CO);
ν(CdCdO)) 1870 (vs); 1731 (m). 1H NMR (δ, CDCl3): 1.48 (m,
4H, 2 CH2), 2.53 (m, 4H, 2 CH2), 2.58 (s, 3H, NCH3), 2.60 (m,
2H, P(CHaHb)2P), 2.69 (s, 3H, NCH3), 3.10 (m, 2H, P(CHaHb)2P),
7.10-8.04 (m, 21H, CâH, PPh2). 13C{1H} NMR (δ, CDCl3): 24.6
(m, PCaH2CbH2P), 26.1 (s, CH2), 26.5 (s, CH2), 30.2 (m,
PCaH2CbH2P), 31.5 (s, CH2), 34.4 (s, CH2), 38.5 (s, NCH3), 39.7
(s, NCH3), 126.3-135.9 (m, PPh2). MS (FAB, m/ e): 852 [M+],
795 [M+ - 2CO - H], 702 [M+ - 2CO - H - C7H9], 646 [M+
11384
4555 [I > 2σ(I)]
0.0493
0.0558
Rw ) [Σw(∆F)2/Σw(Fo)2]1/2
Cr ysta l Str u ctu r e Deter m in a tion of Com p lex 4a . Se-
lected crystallographic data for complex 4a are listed in Table
6. Data were collected at room temperature (22 °C) on a
Philips PW 1100 single-crystal diffractometer using graphite-
monochromated Mo KR radiation. All reflections with θ in the
range 3-27° were measured; of 11 384 independent reflections,
4555, having I > 2σ(I), were considered observed and used in
the analysis. One standard reflection was monitored every
100 measurements; no significant decay was noticed over the
time of data collection. Intensities were corrected for Lorentz
and polarization effects. A correction for absorption was
applied (maximum and minimum values for the transmission
factors were 1.0 and 0.612).25
- 2CO - H - C7H9 - CNMe2]. Anal. Calcd for C38H39
-
NO2P2S2W: C, 53.6; H, 4.6; N, 1.6. Found: C, 54.1; H, 4.4; N,
1.5.
Spectral and analytical data for 5b: IR (KBr, ν(CO);
ν(CdCdO)) 1869 (vs); 1722 (m). 1H NMR (δ, CDCl3): 1.39 (m,
6H, 3 CH2), 1.59 (m, 2H, CH2), 1.73 (m, 2H, CH2), 2.00 (m,
2H, CH2), 2.20-3.50 (m, 4H, P(CH2)2P), 2.32 (m, 2H, CH2),
2.56 (s, 3H, NCH3), 2.67 (s, 3H, NCH3), 7.02-8.33 (m, 21H,
CâH, PPh2). 13C{1H} NMR (δ, CDCl3): 23.7 (m, PCaH2CbH2P),
25.5 (s, CH2), 26.3 (s, CH2), 26.5 (s, CH2), 27.3 (s, CH2), 27.4
(s, CH2), 30.1 (m, PCaH2CbH2P), 31.0 (s, CH2), 37.7 (s, CH2),
38.5 (s, NCH3), 39.7 (s, NCH3), 126.4-134.9 (m, PPh2). MS
(FAB, m/ e): 894 [M+], 838 [M+ - 2CO], 702 [M+ - 2CO - H
- C10H15], 646 [M+ - 2CO - H - C10H15 - CNMe2]. Anal.
Calcd for C41H45NO2P2S2W: C, 55.1; H, 5.1; N, 1.6. Found:
C, 54.8; H, 5.0; N, 1.5.
The structure was solved by Patterson and Fourier methods
and refined by full-matrix least-squares first with isotropic
thermal parameters and then with anisotropic thermal pa-
rameters for the non-hydrogen atoms, excluding the carbon
atoms of the alkenyl-carbyne ligand and of the phenyl rings
-
and the atoms of the BF4 anion (both the ligand and anion
were found disordered and distributed in two positions, A and
B, of equal occupancy factors). The hydrogen atoms were
placed at their geometrically calculated positions (C-H ) 0.96
Å) and refined “riding” on the corresponding carbon atoms.
The final cycles of refinement were carried out on the basis of
435 variables; after the last cycles, no parameters shifted by
more than 0.9 esd. The highest remaining peak (close to the
W atom) in the final difference map was equivalent to about
1.50 e/Å3. In the final cycles of refinement, a weighting scheme
Spectral and analytical data for 5c: IR (KBr, ν(CO);
ν(CdCdO)) 1869 (vs); 1726 (m). 1H NMR (δ, CDCl3): 0.93 (t,
J (H-H) ) 7.2 Hz, 3H, NCH2CH3), 0.96 (t, J (H-H) ) 7.2 Hz,
3H, NCH2CH3), 1.50 (m, 4H, 2 CH2), 2.05 (m, 2H, CH2), 2.50
(m, 2H, CH2), 2.50-3.30 (m, 4H, P(CH2)2P), 3.00 (m, 2H, NCH2-
CH3), 3.27 (m, 2H, NCH2CH3), 7.00-8.00 (m, 21H, CâH, PPh2).
13C{1H} NMR (δ, CDCl3): 12.19 (s, NCH2CH3), 12.24 (s,
NCH2CH3), 25.2 (m, PCaH2CbH2P), 26.2 (s, CH2), 26.6 (s, CH2),
30.2 (m, PCaH2CbH2P), 31.5 (s, CH2), 34.4 (s, CH2), 44.1 (s,
NCH2CH3), 45.3 (s, NCH2CH3), 127.1-136.3 (m, PPh2). MS
(FAB, m/ e): 880 [M+], 823 [M+ - 2CO - H], 730 [M+ - 2CO
- H - C7H9], 646 [M+ - 2CO - H - C7H9 - CNEt2]. Anal.
Calcd for C40H43NO2P2S2W: C, 54.6; H, 4.9; N, 1.6. Found:
C, 55.4; H, 5.0; N, 1.5.
2
-1
w ) K[σ2(Fo) + gFo
]
was used; at convergence the K and g
values were 0.738 and 0.0017. Final R and Rw values were
0.0493 and 0.0558, respectively. The analytical scattering
factors, corrected for the real and imaginary parts of anoma-
lous dispersion, were taken from ref 26. All calculations were
carried out on the Gould Powernode 6040 and Encore 91
computers of the Centro di Studio per la Strutturistica
Diffrattometrica del CNR, Parma, using the SHELX-76 and
SHELX-86 systems of crystallographic computer programs.27
The extended Hu¨ckel parameters were taken from ref 28,
and the graphic interpretation of the MO calculations has been
performed by using the package CACAO.29 The geometry of
the model used for the calculations is fully consistent with that
obtained from the X-ray analysis of compound 4a .
Spectral and analytical data for 5d : IR (KBr, ν(CO);
ν(CdCdO)) 1869 (vs); 1725 (m). 1H NMR (δ, CDCl3): 0.90 (t,
J (H-H) ) 7.1 Hz, 3H, NCH2CH3), 0.97 (t, J (H-H) ) 7.1 Hz,
3H, NCH2CH3), 1.42 (m, 6H, 3 CH2), 1.75 (m, 4H, 2 CH2), 2.20
(m, 2H, CH2), 2.48 (m, 2H, CH2), 2.70-3.40 (m, 4H, P(CH2)2P),
2.95 (m, 2H, NCH2CH3), 3.25 (m, 2H, NCH2CH3), 7.00-8.00
(m, 21H, CâH, PPh2). 13C{1H} NMR (δ, CDCl3): 12.2 (s,
N(CH2CH3)2), 24.7 (m, PCaH2CbH2P), 25.6 (s, CH2), 26.2 (s,
CH2), 26.4 (s, CH2), 27.3 (s, CH2), 27.5 (s, CH2), 30.3 (m,
PCaH2CbH2P), 30.9 (s, CH2), 37.8 (s, CH2), 44.0 (s, NCH2CH3),
45.2 (s, NCH2CH3), 127.0-134.5 (m, PPh2). MS (FAB, m/ e):
922 [M+], 866 [M+ - 2CO], 730 [M+ - 2CO - H - C10H15],
646 [M+ - 2CO - H - C10H15 - CNEt2]. Anal. Calcd for
Ack n ow led gm en t. This work was supported by the
DGICYT (Project No. PB93-0325) and E. U. (Human
Capital Mobility programme. Project No. ERBCHRXCT
C
43H49NO2P2S2W: C, 56.0; H, 5.4; N, 1.5. Found: C, 56.8; H,
(25) (a) Walker, N.; Stuart, D. Acta Crystallogr., Sect. A 1983, 39,
158. (b) Ugozzoli, F. Comput. Chem. 1987, 11, 109.
5.4; N, 1.4.

4108 Organometallics, Vol. 16, No. 19, 1997
Zhang et al.
isotropic thermal parameters (Table SII), anisotropic thermal
parameters (Table SIII), and complete bond distances and
angles (Table SIV) (8 pages). Ordering information is given
on any current masthead page.
940501). L.Z. thanks the Spanish Ministerio de Edu-
cacio´n y Ciencia and Ministerio de Asuntos Exteriores
(Agencia Espan˜ola de Cooperacio´n Internacional) for
grants. A bilateral Italo-Spanish research project (CNR-
CSIC) is gratefully acknowledged (A.G. and C.M.).
Preliminary MO studies have been carried out by Mr.
Rafael Ferna´ndez.
OM970291T
(27) Sheldrick, G. M. SHELX-7, Program for crystal structure
determination; University of Cambridge: Cambridge, England, 1976;
SHELXS-86, Program for the solution of crystal structures; University
of Go¨ttingen: Go¨ttingen, The Netherlands, 1986.
(28) Alvarez, S. Tables of Parameters for Extended Hu¨ckel Calcula-
tions; Departamento de Qu´ımica Inorga´nica, Universidad de Barce-
lona: Barcelona, Spain, 1989.
Su p p or tin g In for m a tion Ava ila ble: Tables of fractional
atom coordinates (Table SI), hydrogen atom coordinates and
(26) International Tables for X-ray Crystallography; Kynoch Press:
Birmingham, England, 1974; Vol IV.
(29) Mealli, C.; Proserpio, D. M. J . Chem. Educ. 1990, 67, 399.