Enhanced C-C bond formation of heterodinuclear methylplatinum-molybdenum complexes having a hemilabile ligand with dialkyl acetylenedicarboxylate

Article abstract of DOI:10.1021/om034162q

Heterodinuclear methylplatinum-molybdenum complexes having a hemilabile P-L ligand, (P-L)MePt-MoCp(CO)₃ (P-L = Ph₂PC₂H₄NEt₂ (1), Ph₂PC₂H₄CH=CH₂ (2)), react with dialkyl acetylenedicarboxylate to afford the novel heterodinuclear complexes (P-L)MePt-{μ-η²:η²-C(O)C₂ (CO₂R)₂}MoCp(μ-CO)(CO) (P-L = Ph₂PC₂H₄NEt₂, R = Me (5); P-L = Ph₂-PC₂H₄CH=CH₂, R = Me (6); P-L = Ph₂PC₂H₄NEt₂, R = Et (7)). An X-ray diffraction study of 5 has revealed that the complex has a unique structure containing a platinacyclobutenone framework, where the φ-bond coordinates to the molybdenum. Heating of 5 at 50°C for 2 days results in reductive elimination of methyl and alkenyl ligands followed by decarbonylation to form the new μ-alkenyl type complexes (Ph₂PC₂H₄NEt₂-κ²N,P ) {μ-MeO₂C(Me)=CCO₂-Me}Pt-MoCp(μ-CO)(CO) (8) and (Ph₂PC₂H₄NEt₂-κ¹P) (CO){μ-MeO₂C(Me)=CCO₂Me}Pt-MoCp (μ-CO)(CO) (9). Reactions of 5 with ^tBuNC or PMe₃ cause selective ligand displacement of the amino moiety in the P-N ligand to form (Ph₂PC₂H₄NEt₂-κ¹P) (L′)MePt {μ-η²:η²-C(O)C₂(CO₂ Me)₂}MoCp(μ-CO)(CO) (L′ = ^tBuNC (10), PMe₃ (11)). On the other hand, nucleophiles such as H₂NBu, HNEt₂, pyrrolidine, and KOPh add to acyl carbon to give the trisubstituted μ-alkenyl type complexes (Ph₂PC₂H₄NEt₂-κ²N,P )Me {μ-MeO₂C(R₂NCO)C=CCO₂Me}Pt-MoCp(μ-CO)(CO) (NR₂ = NHBu (12), NEt₂ (13), NC₄H₈ (14)) and K⁺[(Ph₂PC₂H₄- NEt₂-κ¹O)Me{μ-MeO₂C(PhO₂C)C =CCO₂Me}Pt-MoCp(μ-CO)(CO)]^- (15).

Full text of DOI:10.1021/om034162q

44
Organometallics 2004, 23, 44-53
En h a n ced C-C Bon d F or m a tion of Heter od in u clea r
Meth ylp la tin u m -Molybd en u m Com p lexes Ha vin g a
Hem ila bile Liga n d w ith Dia lk yl Acetylen ed ica r boxyla te
Susumu Tsutsuminai, Nobuyuki Komine, Masafumi Hirano, and
Sanshiro Komiya*
Department of Applied Chemistry, Faculty of Technology, Tokyo University of Agriculture and
Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, J apan
Received September 9, 2003
Heterodinuclear methylplatinum-molybdenum complexes having a hemilabile P-L ligand,
(P-L)MePt-MoCp(CO)3 (P-L ) Ph2PC2H4NEt2 (1), Ph2PC2H4CHdCH2 (2)), react with
dialkyl acetylenedicarboxylate to afford the novel heterodinuclear complexes (P-L)MePt-
{µ-η2:η2-C(O)C2(CO2R)2}MoCp(µ-CO)(CO) (P-L ) Ph2PC2H4NEt2, R ) Me (5); P-L ) Ph2-
PC2H4CHdCH2, R ) Me (6); P-L ) Ph2PC2H4NEt2, R ) Et (7)). An X-ray diffraction study
of 5 has revealed that the complex has a unique structure containing a platinacyclobutenone
framework, where the π-bond coordinates to the molybdenum. Heating of 5 at 50 °C for 2
days results in reductive elimination of methyl and alkenyl ligands followed by decarbon-
ylation to form the new µ-alkenyl type complexes (Ph2PC2H4NEt2-κ2N,P){µ-MeO2C(Me)dCCO2-
Me}Pt-MoCp(µ-CO)(CO) (8) and (Ph2PC2H4NEt2-κ1P)(CO){µ-MeO2C(Me)dCCO2Me}Pt-
t
MoCp(µ-CO)(CO) (9). Reactions of 5 with BuNC or PMe3 cause selective ligand displacement
of the amino moiety in the P-N ligand to form (Ph2PC2H4NEt2-κ1P)(L′)MePt{µ-η2:η2-
t
C(O)C2(CO2Me)2}MoCp(µ-CO)(CO) (L′ ) BuNC (10), PMe3 (11)). On the other hand,
nucleophiles such as H2NBu, HNEt2, pyrrolidine, and KOPh add to acyl carbon to give the
trisubstituted µ-alkenyl type complexes (Ph2PC2H4NEt2-κ2N,P)Me{µ-MeO2C(R2NCO)Cd
CCO2Me}Pt-MoCp(µ-CO)(CO) (NR2 ) NHBu (12), NEt2 (13), NC4H8 (14)) and K+[(Ph2PC2H4-
NEt2-κ1P)Me{µ-MeO2C(PhO2C)CdCCO2Me}Pt-MoCp(µ-CO)(CO)]- (15).
In tr od u ction
of hetrodinuclear organoplatinum complexes having a
hemilabile P-N ligand (2-(diphenylphosphino)triethyl-
amine), which show a facile and reversible Pt-N bond
rupture causing high reactivity toward CO.5 In the
present study, we wish to report the synthesis of new
heterodinuclear organoplatinum complexes with un-
symmetrical P-olefin and P-S ligands and reactions
of these heterodinuclear organoplatinum complexes
with dimethyl acetylenedicarboxylate to give the novel
µ-platinacyclobutenone complexes (Ph2PC2H4NEt2-κ2-
N,P)MePt{µ-η2:η2-C(O)C2(CO2Me)2}MoCp(µ-CO)(CO).
Unique thermal transformation and nucleophilic reac-
tions of these platinacyclobutenes to give heterodi-
nuclear alkenylplatinum complexes are also described.
Heterodinuclear complexes have attracted intrinsic
interest due to their possible cooperative effect of two
different metal centers in catalytic and stoichiometric
chemical reactions.1-3 Introduction of an unsymmetrical
chelating ligand into such dinuclear complexes is ex-
pected to provide a highly selective reaction environ-
ment, because preferential partial dissociation of the
chelating ligand gives a specific vacant coordination site
on a metal center.4 We recently reported the synthesis
* To whom correspondence should be addressed. E-mail: komiya@
cc.tuat.ac.jp.
(1) (a) Braunstein, P., Oro, L. A., Raithby, P. R., Eds. Metal Clusters
in Chemistry; Wiley-VCH: Weinheim, Germany, 1999. (b) Adams, R.
D., Cotton, F. A., Eds. Catalysis by Di- and Polynuclear Metal Cluster
Complexes; Wiley-VCH: New York, 1998. (c) Chetcuti, M. J . In
Comprehensive Organometallic Chemistry II; Adams, R. D., Ed.;
Pergamon Press: Oxford, U.K., 1995; Vol. 10. (d) Shriver, D. F., Kaesz,
H., Adams, R. D., Eds. The Chemistry of Metal Cluster Complexes;
VCH: New York, 1990.
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Adams, R. D.; Barnard, T. S.; Wu, Z. Li. W.; Yamamoto, J . H. J . Am.
Chem. Soc. 1994, 116, 9103. (c) Braunstein, P.; Knorr, M.; Sta¨hreldt,
J . J . Chem. Soc., Chem. Commun. 1994, 1913.
(3) (a) Komiya, S.; Endo, I. Chem. Lett. 1988, 1709. (b) Fukuoka,
A.; Sadashima, T.; Endo, I.; Ohashi, N.; Kambara, Y.; Sugiura, T.;
Komiya, S. Organometallics 1994, 13, 4033. (c) Fukuoka, A.; Sa-
dashima, T.; Sugiura, T.; Wu, X.; Mizuho, Y.; Komiya, S. J . Organomet.
Chem. 1994, 473, 139. (d) Fukuoka, A.; Sugiura, T.; Yasuda, T.;
Taguchi, T.; Hirano, M.; Komiya, S. Chem. Lett. 1997, 329. (e) Fukuoka,
A.; Fukagawa, S.; Hirano, M.; Komiya, S. Chem. Lett. 1977, 377. (f)
Yasuda, T.; Fukuoka, A.; Hirano, M.; Komiya, S. Chem. Lett. 1998,
29. (g) Komiya, S.; Muroi, S.; Furuya, M.; Hirano, M. J . Am. Chem.
Soc. 2000, 122, 170. (h) Komine, N.; Hoh, H.; Hirano, M.; Komiya, S.
Organometallics 2000, 19, 5251. (i) Fukuoka, A.; Fukagawa, S.; Hirano,
M.; Koga, N.; Komiya, S. Organometallics 2001, 20, 2065.
Resu lts a n d Discu ssion
Syn th esis of Heter od in u clea r Meth ylp la tin u m -
Molybd en u m Com p lexes Ha vin g Un sym m etr ica l
P -Olefin a n d P -S Liga n d s. We recently described
(4) (a) Braunstein, P.; Naud, F. Angew. Chem., Int. Ed. 2001, 40,
680. (b) Anderson, G. K.; Lumetta, G. J . Organometallics 1985, 4, 1542.
(c) Dekker, G. P. C. M.; Buijs, A.; Elsevier, C. J .; Vrieze, K.; Smeets,
W. J . J .; Spek, A. L.; Wang, Y. F.; Stam, C. H. Organometallics 1992,
11, 1937. (d) Mauthner, K.; Slugovc, C.; Mereiter, K.; Schmid, R.;
Kirchner, K. Organometallics 1997, 16, 1956. (e) Hayashi, T.; Kumada,
M. Acc. Chem. Res. 1982, 15, 395. (f) Pfeiffer, J .; Kickelbick, G.;
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E.; Kurahashi, T.; Nakao, Y.; Hiyama, T. Organometallics 2000, 19,
5671. (h) Mu¨ller, C.; Lachicotte, R. J .; J ones, W. D. Organometallics
2002, 21, 1975.
(5) Tsutsuminai, S.; Komine, N.; Hirano, M.; Komiya, S. Organo-
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10.1021/om034162q CCC: $27.50 © 2004 American Chemical Society
Publication on Web 12/06/2003

Heterodinuclear Methylplatinum-Molybdenum Complexes
Organometallics, Vol. 23, No. 1, 2004 45
Sch em e 1
However, when 2 was treated with CO (1 atm), facile
displacement of the coordinating olefin moiety of the
P-olefin ligand by CO took place, giving (Ph2PC2H4-
CHdCH2-κ1P)(CO)MePt-MoCp(CO)3 (4) with a mono-
dentate P-olefin ligand similar to 1, suggesting the
hemilabile nature of the P-olefin ligand (eq 3).
the synthesis of organoplatinum-molybdenum com-
plexes having a P-N ligand, (Ph2PC2H4NEt2-κ2N,P)-
MePt-MoCp(CO)3 (1; Scheme 1), which showed dy-
namic behavior arising from facile reversible Pt-N bond
rupture, and this hemilabile nature of the P-N ligand
leads to high reactivity toward CO, causing facile ligand
displacement of the N atom by CO to give (Ph2PC2H4-
NEt2-κ1P)(CO)MePt-MoCp(CO)3 with monodentate phos-
phorus coordination.5
In contrast, complex 3 did not react at all with CO,
suggesting that the P-S ligand is not hemilabile but
coordinates strongly to Pt, as observed for a symmetrical
bidentate ligand such as N,N,N ′,N ′-tetramethylethyl-
enediamine (TMEDA) or 1,2-bis(diphenylphosphino)-
ethane (DPPE).5
Rea ction s of Heter od in u clea r Meth ylp la tin u m -
Molybd en u m Com p lexes w ith Dim eth yl Acety-
len ed ica r boxyla te. Heterodinuclear organoplatinum-
molybdenum complexes having a hemilabile P-N or
P-olefin ligand (P-L)MePt-MoCp(CO)3 (P-L ) Ph2-
PC2H4NEt2, (1), Ph2PC2H4CHdCH2, (2)) reacted with
dimethyl acetylenedicarboxylate to afford the novel
heterodinuclear µ-platinacyclobutenone complexes (P-
L)MePt{µ-η2:η2-C(O)C2(CO2Me)2}MoCp(µ-CO)(CO) (P-L
) Ph2PC2H4NEt2 (5), Ph2PC2H4CHdCH2 (6)) (eq 4). In
In addition to the previously prepared complex 1,
novel platinum-molybdenum complexes having an
unsymmetrical P-L bidentate ligand such as but-3-
enyldiphenylphosphine6 and 2-(diphenylphosphino)ethyl
methyl sulfide7 (P-L)MePt-MoCp(CO)3 (P-L ) Ph2-
PC2H4CHdCH2 (2), Ph2PC2H4SMe (3)) were newly
prepared by the ligand exchange reaction of (cod)MePt-
3b
MoCp(CO)3 (eq 1) with Ph2PC2H4CHdCH2 as well as
by metathetical reactions of PtMe(NO3)(Ph2PC2H4SMe-
κ2P,S) with Na[MoCp(CO)3] (eq 2). They were charac-
terized by NMR and IR spectroscopy and elemental
analyses. The 31P{1H} NMR spectra of 2 and 3 show
singlets at δ 42.0 and 57.4 with 195Pt satellites having
contrast, complex 3 and analogous heterodinuclear
complexes with symmetrical bidentate ligands such as
N,N,N ′,N ′-tetramethylethylenediamine (TMEDA) and
1,2-bis(diphenylphosphino)ethane (DPPE), (tmeda)-
MePt-MoCp(CO)3 and (dppe)MePt-MoCp(CO)3, as well
as the mononuclear complex PtMeCl(Ph2PC2H4NEt2-
κ2N,P) did not react at all with DMAD under the same
reaction conditions. The present high reactivity of 1 and
2 may be attributed to the generation of a vacant
coordination site on the platinum center by the facile
and partial dissociation of hemilabile P-N or P-olefin
ligands, though dynamic behavior due to facile ligand
dissociation was not observed in the NMR of 2. The
coordinated DMAD is then considered to couple with
bridging CO to give the platinacyclobutenone complexes
5 and 6.
1
the large J Pt-P values 3584 and 3734 Hz, respectively,
suggesting that the phosphorus atom of these ligands
locates in a position trans to the MoCp(CO)3 moiety
similar to the previously prepared analogous complexes
with the P-N ligand 1. In the 1H NMR spectra, the
vinyl protons of the P-olefin ligand and the methyl
protons of the P-S ligand are also observed with 195Pt
satellites. The data indicate that these ligands are
coordinated to the Pt center in a bidentate fashion, but
the ligand dissociation process is not fast enough to
show dynamic behavior in NMR at ambient tempera-
ture.
(6) (a) Hursthouse, M. B.; Malik, K. M. A. Polyhedron 1996, 15, 23.
(b) Clark, P. W.; Curtis, J . L. S.; Garrou, P. E.; Hartwell, G. E. Can. J .
Chem. 1974, 52, 1714.
(7) (a) Anderson, G. K.; Kumar, R. Inorg. Chem. 1984, 23, 4064. (b)
Saleem, A. M.; Hodali, H. A. Inorg. Chim. Acta 1990, 174, 223.
The molecular structure of complex 5 was established
by an X-ray structure analysis. An ORTEP drawing of

46 Organometallics, Vol. 23, No. 1, 2004
Tsutsuminai et al.
that of the mononuclear complex (Ph3P)2Pt(OC3Ph2)
(1.31(8) Å). The observed longer CdC double bond is
considered to be due to the effective π-back-donation
from the Mo metal. Although the Pt-Mo distance 2.898-
(2) Å in 5 lies in a typical range of Pt-Mo single bonds
which have been reported for dinuclear and cluster
complexes such as (cod)PhPt-MoCp(CO)3 (2.8320(12)
Å),3b (Ph2C2H4NEt2-κ2N,P)MePt-MoCp(CO)3 (2.8989-
(9) Å),5 Cp2Mo2Pt(µ-PPh2)2(CO)5 (2.860(2), 2.872(2) Å),10a
and [(η5-C5H4Me)Mo(CO)2(µ-dppm)Pt(dppm)]+ (2.912-
(4) Å),10b no actual Pt-Mo interaction is considered to
be involved. The Mo moiety in 5 has adopted a three-
legged piano-stool type geometry with two carbonyls and
one π-bonded platinacyclobutenone ligand. To satisfy
the 18-electron rule, we could consider that one electron
is transferred from Pt to Mo, making the bond of
formally Pt(IV)+ and Mo(0)- zwitterionic character.
However, no significant molar electric conductivity was
observed in THF. If the bridging carbonyl is regarded
as a one-electron ligand for both metals as if it were a
dimetallaketone, formal oxidation states of Pt and Mo
are counted as +4 and +2. This formalism is unlikely,
because Mo(II) should have a four-legged piano-stool
geometry in general, as is typically known for 18e Mo-
(II) complexes having a Cp group such as CpMo-
(CO)3Cl.11 However, this contribution cannot be ex-
cluded, since the rare example of Mo(II) complexes
having a three-legged structure such as MCl(CF3C2-
CF3)2Cp (M ) Mo, W)12 is also precedented.
F igu r e 1. Molecular structure of (Ph2PC2H4NEt2-κ2N,P)-
MePt{µ-η2,η2-C(O)C2(CO2Me)2}MoCp(µ-CO)(CO) (5). All
hydrogen atoms are omitted for clarity, and ellipsoids
represent 50% probability.
Ta ble 1. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for 5
Pt(1)-Mo(1)
Pt(1)-P(1)
Pt(1)-C(2)
Mo(1)-C(3)
Mo(1)-C(27)
O(1)-C(2)
2.898(2)
2.328(5)
2.09(2)
2.32(2)
1.96(2)
1.18(2)
1.08(3)
1.45(2)
Pt(1)-C(1)
Pt(1)-N(1)
Pt(1)-C(6)
Mo(1)-C(6)
Mo(1)-C(28)
O(6)-C(27)
C(2)-C(3)
2.21(2)
2.43(2)
2.11(2)
2.11(2)
2.06(2)
1.18(3)
1.40(3)
O(7)-C(28)
C(3)-C(6)
IR spectra of 5 and 6 respectively show strong bands
at 1947 and 1960 cm-1 assignable to the terminal
carbonyl and bands at 1779 and 1774 cm-1 due to the
bridging carbonyl, consistent with the molecular struc-
Mo(1)-Pt(1)-C(1)
N(1)-Pt(1)-C(2)
P(1)-Pt(1)-N(1)
N(1)-Pt(1)-C(6)
Mo(1)-C(27)-O(6)
Mo(1)-C(28)-O(7)
Pt(1)-C(2)-C(3)
138.5(6)
172.2(6)
81.6(4)
107.1(6)
154(1)
P(1)-Pt(1)-C(6)
C(1)-Pt(1)-C(27)
C(1)-Pt(1)-C(6)
P(1)-Pt(1)-C(2)
Pt(1)-C(27)-O(6)
C(2)-C(3)-C(6)
Pt(1)-C(6)-C(3)
169.8(5)
179.7(8)
93.6(8)
106.1(6)
124(1)
1
ture. The H NMR spectrum of 5 in acetone-d6 shows a
178(2)
96(1)
104(1)
93(1)
methyl resonance at δ 0.67 with a 195Pt satellite, two
methoxy signals at δ 3.51 and 3.72, and a single Cp
resonance at δ 5.40. The NOESY experiment for 5
showed correlation between Cp protons and two meth-
oxy groups of the platinacyclobutenone moiety, consis-
tent with the proximity of these moieties in the geom-
etry of 5. The 1J Pt-P value of 5 observed in 31P{1H} NMR
is 2577 Hz, which is significantly smaller than that for
1 (4208 Hz). Analogous trends were also observed for
complex 6. This may be due to the decrease in s
character of the Pt-P bond by constructing d2sp3
5 is depicted in Figure 1, and selected bond distances
and angles are given in Table 1. As shown in Figure 1,
the geometry around the Pt center is octahedral, sug-
gesting a d6 electron configuration of Pt(IV). The P-N
ligand coordinates as a chelate, and the methyl group
is located in the axial position. Furthermore, one of the
carbonyl groups attached to Mo is significantly bent
(Mo(1)-C(27)-O(6) ) 154(1)°) and the C(27) atom is
located very close to the Pt center (Pt(1)-C(27) ) 2.49-
(2) Å), suggesting that the bridging carbonyl group
C(27)-O(6) occupies one of the coordination sites of Pt.
The IR spectrum shows two strong ν(CO) bands in the
(8) (a) Boag, N. M.; Goodfellow, R. J .; Green, M.; Hessner, B.;
Howard, J . A. K.; Stone, F. G. A. J . Chem. Soc., Dalton Trans. 1983,
2585. (b) Chetcuti, M. J .; Green, K. A. Organometallics 1988, 7, 2450.
(c) Finnimore, S. R.; Knox, S. A. R.; Taylor, G. E. J . Chem. Soc., Chem.
Commun. 1980, 411. (d) Finnimore, S. R.; Knox, S. A. R.; Taylor, G.
E. J . Chem. Soc., Dalton Trans. 1982, 1783. (e) Dickson, R. S.; Evans,
G. S.; Fallon, G. D. Aust. J . Chem. 1985, 38, 273. (f) Chetcuti, M. J .;
Eigenbrot, C.; Green, K. A. Organometallics 1987, 6, 2298. (g) Chetcuti,
M. J .; Grant, B. E.; Fanwick, P. E. Organometallics 1995, 14, 2937.
(h) Chetcuti, M. J .; Grant, B. E.; Fanwick, P. E. Organometallics 1996,
15, 4389.
(9) J ones, R. A. Y.; Katritzky, A. R.; Richards, A. C.; Saba, S.;
Sparrow, A. J .; Trepanier, D. L. J . Chem. Soc., Chem. Commun. 1972,
673.
(10) (a) Blum, T.; Braunstein, P. Organometallics 1989, 8, 2504. (b)
Braunstein, P.; Bellefon, C. M.; Lanfranchi, M.; Tiripicchino, A.
Organometallics 1984, 3, 1772.
(11) (a) Bueno, C.; Churchill, M. R. Inorg. Chem 1981, 20, 2197. (b)
Poli, R. Organometallics 1990, 9, 1892.
(12) (a) Davidson, J . L.; Green, M.; Sharp, D. W. A.; Stone, F. G. A.;
Welch, A. J . J . Chem. Soc., Chem. Commun. 1974, 706. (b) Davidson,
J . L.; Green, M.; Stone, F. G. A.; Welch, A. J . J . Chem. Soc., Dalton
Trans. 1976, 738. (c) Davidson, J . L.; Green, M.; Nyathi, J . Z.; Stone,
F. G. A.; Welch, A. J . J . Chem. Soc., Dalton Trans. 1977, 2246.
carbonyl region arising from both terminal (1947 cm-1
and bridging (1779 cm-1) carbonyls.
)
The CdC double bond of the platinacyclobutenone
moiety in 5 also coordinates to Mo to act as a bridging
ligand. Analogous unique structures containing π-coor-
dination of metallacyclobutenone to different metals
have been known.8 The two observed Pt-C bond dis-
tances of the platinacyclobutenone moiety (Pt(1)-C(2)
) 2.09(2) Å, Pt(1)-C(6) ) 2.11(2) Å) in 5 are similar to
the values of 2.02(3), 2.04(3) Å and 2.08(6), 2.09(4) Å
for the known platinacyclobutenone complexes Pt2{µ-
η2:η2-C(Ph)C(Ph)C(O)}(η-C5H5)2 and (Ph3P)2Pt(OC3-
8a
Ph2),9 respectively. The CdC double-bond distance in
the η2-bonded platinacyclobutenone complex 5 (1.45(2)
Å) is comparable to that of Pt2{µ-η2:η2-C(Ph)C(Ph)C(O)}-
(η-C5H5)2 (1.46(4) Å), but it is significantly longer than

Heterodinuclear Methylplatinum-Molybdenum Complexes
Organometallics, Vol. 23, No. 1, 2004 47
Ta ble 2. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for 8
hybridization of octahedral Pt(IV) for 5 and 6 in
comparison with dsp2 hybridization for the square-
planar Pt(II) complex 1. The trans influence of sp2-C
instead of Mo and the high oxidation state of Pt in 5
and 6 are also considered to decrease the coupling
constant.
Complex 1 also reacted with diethyl acetylenedi-
carboxylate to form the µ-platinacyclobutenone com-
plex (Ph2PC2H4NEt2-κ2N,P)MePt{µ-η2:η2-C(O)C2(CO2-
Et)2}MoCp(µ-CO)(CO) (7), but other alkynes such as
diphenylacetylene, 1-phenyl-1-propyne, and ethyl 2-bu-
tynoate did not react with 1 under the same reaction
conditions. This result suggests the importance of highly
electron-withdrawing substituents on acetylene for the
reaction to proceed.
Pt(1)-Mo(1)
Pt(1)-P(1)
Pt(1)-C(26)
Mo(1)-C(22)
Mo(1)-C(27)
C(26)-O(5)
2.8302(7)
2.251(2)
2.487(8)
2.341(7)
1.951(8)
1.168(10)
Pt(1)-N(1)
Pt(1)-C(19)
Mo(1)-C(19)
Mo(1)-C(26)
C(19)-C(22)
C(26)-O(6)
2.244(6)
2.021(7)
2.155(7)
1.949(8)
1.43(1)
1.16(1)
Mo(1)-Pt(1)-P(1)
Mo(1)-Pt(1)-C(19)
P(1)-Pt(1)-N(1)
P(1)-Pt(1)-C(26)
N(1)-Pt(1)-C(26)
Pt(1)-C(26)-O(5)
151.46(5) Mo(1)-Pt(1)-N(1)
124.0(2)
42.4(2)
103.1(2)
173.2(3)
87.5(3)
49.4(2)
83.3(2)
Mo(1)-Pt(1)-C(26)
P(1)-Pt(1)-C(19)
N(1)-Pt(1)-C(19)
C(19)-Pt(1)-C(26)
164.1(2)
86.8(3)
120.8(6)
Mo(1)-C(26)-O(5) 160.5(7)
Mo(1)-C(27)-O(6) 179.1(8)
Th er m a l Tr a n sfor m a tion of P la tin a cyclobu ten -
on e to a n Alk en ylp la tin u m -Molybd en u m Din u -
clea r Com p lex. Heating of the platinacyclobutenone
complex 5 at 50 °C in acetone-d6 for 2 days caused
apparent insertion of DMAD into the Pt-Me bond to
form a mixture of the new µ-alkenyl type complexes
(Ph2PC2H4NEt2-κ2N,P){µ-MeO2C(Me)dCCO2Me}Pt-Mo-
Cp(µ-CO)(CO) (8) and (Ph2PC2H4NEt2-κ1P)(CO){µ-Me-
O2C(Me)dCCO2Me}Pt-MoCp(µ-CO)(CO) (9), in the lat-
ter of which the coordinating nitrogen atom in 8 was
displaced by CO (eq 5). The rare complex 8 was isolated
F igu r e 2. Molecular structure of (Ph2PC2H4NEt2-κ2N,P)-
{µ-MeO2C(Me)CdCCO2Me}Pt-MoCp(µ-CO)(CO) (8). All
hydrogen atoms are omitted for clarity, and ellipsoids
represent 50% probability.
) 1.949(8) Å). The bridging carbonyl in 8 is bent
(Mo(1)-C(26)-O(5) ) 160.5(7)°, Pt(1)-C(26)-O(5) )
120.8(6)°), suggesting strong bridging character in 8.
The Pt-Mo bond distance of 8 is 2.8302(7) Å, which is
slightly shorter than that of complex 5. The geometry
at the Pt center is considered to be square planar with
a P-N ligand, alkenyl, and Mo-CO moieties, where the
least-squares plane consisting of Pt(1), P(1), N(1), C(19),
and the central position of Mo(1)-C(26) has a largest
deviation of only 0.14 Å from the plane. Mo and the
carbonyl carbon C(26) deviate 0.47 Å from this plane.
One possible formalism of the bonding scheme is the
side-on type coordination of the Mo-CO bond to Pt, and
the apparent oxidation states of Pt and Mo in 8 are
considered to be +2 and 0, giving again a Pt+ and Mo-
zwitterionic structure. However, contribution to the
coordination by a canonical ModCdO double bond
structure is not the case, since the CO stretching band
is similar to other cases, but the Mo-CO single bond
interacts with Pt. A five-coordinate tbp structure for-
malism of the Pt center having a chelating P-N ligand,
alkenyl carbon, Mo, and bridging carbonyl may also be
possible, with the N(1) and C(19) atoms in apical
positions, because the Pt(1), P(1), N(1), and C(19) atoms
constitute an almost complete plane. An analogous
structural feature was also observed for the indepen-
dently prepared complex (dppe)(µ-CH2dCCO2Me)Pt-
MoCp(µ-CO)(CO), obtained by the reaction of (dppe)-
(Η)Pt-MoCp(CO)3 with HCtCCO2Me.3f It is interesting
to note that the difference of oxidation states in 5 and
from the mixture by recrystallization from acetone/
hexane. The reaction is considered to proceed by initial
formation of 8 followed by coordination of the liberated
CO, since the ratio of 8 to 9 gradually decreased during
the reaction. In fact, the treatment of the isolated 8 with
1 atm of CO immediately gave 9 at room temperature.
On the other hand, when 9 was heated at 50 °C in
acetone-d6 under reduced pressure, complex 8 was
slowly regenerated. Decrease in the ratio of 8 to 9 in
the course of the reaction may indicate that initial
decarbonylation in 5 gives 8 by reductive elimination,
followed by coordination of CO. The result also suggests
that 5 is the kinetic product but µ-alkenyl type com-
plexes 8 and 9 are the thermodynamic products in the
reaction of 1 with DMAD.
The failure of the direct insertion in the reaction of 1
with DMAD may be due to the resultant trans geometry
of Me and DMAD in the initial stage of the reaction,
and thus the coupling of DMAD and bridging CO
became a favorable reaction pathway instead.
Single crystals of 8 suitable for X-ray structure
analysis were fortunately obtained by recrystallization
from acetone/hexane. Selected bond distances and angles
are summarized in Table 2, and an ORTEP drawing is
depicted in Figure 2. The alkenyl group on Pt coordi-
nates to the Mo center via the CdC double bond (C(19)-
C(22) ) 1.43(1) Å, Mo(1)-C(19) ) 2.155(7) Å, Mo(1)-
C(22) ) 2.341(7) Å), and one of the carbonyls acts as a
bridging ligand (Pt(1)-C(26) ) 2.487(8) Å, Mo(1)-C(26)

48 Organometallics, Vol. 23, No. 1, 2004
Tsutsuminai et al.
8 is reflected in their CO stretching bands, where the
values for 5 are larger than those for 8 by ca. 30 cm-1
,
being consistent with stronger back-donation in Pt(II)
than in Pt(IV), although the slight structural difference
of the Mo moiety may interfere with such a discussion.
1
The coupling constant J Pt-P for 8 in the 31P{1H} NMR
spectrum is significantly large (4010 Hz). This also
suggests an increase in s-character of the Pt-P bond
in 8 over that in 5.
Complex 9 was also characterized by NMR. The
chemical shift of the signals due to the diethylamino
moiety of the P-N ligand were almost the same as those
1
for free 2-(diphenylphosphino)triethylamine in H NMR,
suggesting the ligand displacement of an N atom by CO.
The 31P{1H} NMR spectrum showed a singlet with a
195Pt satellite (1J Pt-P ) 3136 Hz). The small 1J Pt-P value
of 9 may be due to the decrease of electron density at
Pt by the coordination of CO, and a similar trend was
observed for complex 4.
F igu r e 3. Molecular structure of (Ph2PC2H4NEt2-κ1P)-
(tBuNC)MePt{µ-η2,η2-C(O)C2(CO2Me)2}MoCp(µ-CO)(CO)
(10). All hydrogen atoms are omitted for clarity, and
ellipsoids represent 50% probability.
The present reaction is considered to proceed by a
mechanism involving cis reductive elimination of al-
kenyl and methyl ligands at Pt(IV) followed by decar-
bonylation to give a formal insertion of DMAD into the
Pt-Me bond. Initial decarbonylation providing a cis
geometry of DMAD and methyl ligands followed by
facile cis insertion is another possible mechanism.
Ta ble 3. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for 10
Pt(1)-Mo(1)
Pt(1)-C(1)
2.875(1)
2.129(9)
2.080(7)
2.104(9)
2.00(1)
2.303(8)
1.18(1)
1.12(1)
1.42(1)
Pt(1)-C(1)
2.352(4)
2.095(7)
2.526(9)
1.96(1)
2.124(9)
1.204(10)
1.16(1)
Pt(1)-C(20)
Pt(1)-C(26)
Mo(1)-C(26)
Mo(1)-C(28)
O(1)-C(25)
O(3)-C(27)
N(2)-C(21)
C(28)-C(29)
Pt(1)-C(25)
Pt(1)-C(28)
Mo(1)-C(27)
Mo(1)-C(29)
O(2)-C(26)
N(2)-C(20)
C(25)-C(29)
t
Liga n d Disp la cem en t Rea ction of 5 w ith Bu NC
a n d P Me3. The µ-platinacyclobutenone complex 5 dis-
placed the hemilabile N atom in the P-N ligand by
tBuNC or PMe3 to give corresponding complexes with a
monodentate P-N ligand, (Ph2PC2H4NEt2-κ1P)(L′)MePt-
{µ-η2:η2-C(O)C2(CO2Me)2}MoCp(µ-CO)(CO) (L′ ) tBuNC
(10), PMe3 (11)) (eq 6). Complex 10 was isolated as
1.45(1)
1.44(1)
Mo(1)-Pt(1)-C(1)
C(1)-Pt(1)-C(26)
P(1)-Pt(1)-C(20)
P(1)-Pt(1)-C(25)
Pt(1)-C(20)-N(2)
Pt(1)-C(26)-O(2)
139.3(3) P(1)-Pt(1)-C(28)
172.9(3) C(20)-Pt(1)-C(25)
95.9(2) C(20)-Pt(1)-C(28)
97.6(2) C(25)-Pt(1)-C(28)
168.6(8) C(20)-N(2)-C(21)
119.2(8) Mo(1)-C(28)-O(2)
162.7(2)
164.3(3)
99.4(3)
66.2(3)
175(1)
161.9(8)
94.3(5)
Mo(1)-C(27)-O(3) 177(1)
Pt(1)-C(28)-C(29)
Pt(1)-C(25)-C(29)
92.9(5) C(25)-C(29)-C(28) 105.9(7)
the signals for 5 and are almost similar to those of free
2-(diphenylphosphino)triethylamine. The 31P{1H} NMR
spectrum shows a single resonance at δ -12.1 with a
195Pt satellite (1J Pt-P ) 2348 Hz). A further decrease in
1J Pt-P value in comparison with 5 is the reflection of
effective back-donation to the isonitrile ligand to de-
crease the electron density at Pt.
orange crystals by recrystallization from a mixture of
acetone and hexane in the presence of an excess amount
of tBuNC. In the absence of an excess amount of tBuNC,
t
10 dissociated BuNC to regenerate 5.
The structure of 10 was confirmed by an X-ray
diffraction study (Figure 3, Table 3). There are no
significant differences in the geometry around Pt and
Mo in comparison with complex 5. The P-N ligand acts
Complex 11 was characterized spectroscopically by
1
NMR and IR. In the H NMR spectrum, the chemical
shift of the methylene group of -NCH2CH3 was close
to that of free Ph2PC2H4NEt2. The Pt-Me group ap-
pears as a double doublet at δ 0.70 with a 195Pt satellite,
indicating two magnetically inequivalent phosphorus
nuclei attached to Pt. Consistently, 31P{1H} NMR shows
t
as a monodentate ligand in 10, and BuNC was coordi-
nated to the Pt center instead of the diethylamino
moiety. The terminal isonitrile ligand exhibits ap-
proximately linear geometry (C(20)-N(2)-C(21) ) 175-
(1)°). The Pt(1)-C(20) and N(2)−C(20) distances (2.095-
(7) and 1.12(1) Å, respectively) are close to the values
found in [Pt3(µ-dppm)2(µ-PPh2)(tBuNC)]OTf (mean Pt-C
) 1.96 Å and mean C-N ) 1.15 Å)13a and [(C-N-N)-
Pt(tBuNC)]ClO4 (C-N-N ) 6-phenyl-2,2′-bipyridine;
Pt-C ) 1.936(8) Å and C-N ) 1.13(1) Å).13b
two doublets with
a small cis coupling constant
(2J P-P ) 13 Hz) having 195Pt satellites. The IR spectrum
of 11 also shows ν(CO) bands similar to those of 5 and
10.
Rea ction of 5 w ith Nu cleop h iles. The acyl group
of 5 attached to an electron-deficient Pt(IV) center was
susceptible to nucleophilic reactions. In fact, H2NBu,
HNEt2, or pyrrolidine readily attacked the Pt-acyl
carbon of the platinacyclobutenone moiety, to give a
novel hetereodinuclear complex having a bridging trisub-
stituted alkenyl group, (Ph2PC2H4NEt2-κ2N,P)Me{µ-Me-
O2C(R2NCO)CdCCO2Me}Pt-MoCp(µ-CO)(CO) (NR2 )
In the 1H NMR spectrum of 10, the methylene signals
of the -NCH2CH3 moiety shifts upfield compared with
(13) (a) Wachtler, H.; Schuh, W.; Ongania, K.; Wurst, K.; Peringer,
P. Organometallics 1998, 17, 5649. (b) Lai, S.; Lam, H.; Lu, W.; Cheung,
K.; Che, C. Organometallics 2002, 21, 226.

Heterodinuclear Methylplatinum-Molybdenum Complexes
Organometallics, Vol. 23, No. 1, 2004 49
Sch em e 2
NHBu (12), NEt2 (13), NC4H8 (14)) with evolution of
methane (Scheme 2). In contrast to these results,
sterically demanding secondary amines such as HNiPr2
and HNPh2 and a tertiary amine such as NEt3 did not
react at all with 5. This may be attributed to the steric
congestion at Pt in 5 to prevent attack of these amines.
The reaction is considered to proceed by initial nucleo-
philic reaction of dialkyl amide anion with the acyl
carbon, followed by reductive elimination of methane.
It is not clear whether a hydridoplatinum(IV) species
is formed or not as an intermediate prior to the reaction.
F igu r e 4. Molecular structure of K+[(Ph2PC2H4NEt2-κ1P)-
Me{µ-MeO2C(PhO2C)CdCCO2Me}Pt-MoCp(µ-CO)(CO)]-
(15). All hydrogen atoms, the solvent molecule, and K+
moiety are omitted for clarity, and ellipsoids represent 30%
probability.
In the IR spectrum of 13, two ν(CO) bands arising
from bridging and terminal carbonyls on Mo appeared
at 1715 and 1958 cm-1 and a new band due to the
resulting amide moiety was also observed at 1618 cm-1
.
In the 31P{1H} NMR spectrum, a singlet with a 195Pt
The structure of 15 was characterized spectroscopi-
cally as well as by preliminary X-ray structure analysis.
In the IR spectrum, a new ν(CdO) band of the resulting
CO2Ph group was observed at 1592 cm-1, in addition
to the large bands due to terminal and bridging car-
bonyls and CO2Me groups. The methylene protons of
the ethyl group were observed to be very close to those
of the free P-N ligand, similarly to 9-11 in the 1H
NMR, suggesting partial dissociation of the diethyl-
amino group to behave as a monodentate ligand. A
preliminary X-ray structure analysis supported a square-
planar geometry of 15 similar to that of 8, as depicted
in Figure 4. The bridging carbonyl carbon deviates by
0.78(3) Å from the least-squares plane consisting of P,
Me, alkenyl, and Mo (maximum deviation 0.21(2) Å).
The relatively small 1J Pt-P value for 15 (3038 Hz) in the
31P{1H} NMR compared with those of 8 and 12-14 may
reflect the stronger trans influence of alkenyl carbon
as compared to that of bridging carbonyl.
1
satellite having the large J Pt-P value of 4298 Hz was
observed, similarly to µ-alkenyl complex 8 (1J Pt-P ) 4010
1
Hz). In the H NMR spectrum of 13, two methyl groups
of the diethylamide moiety were inequivalent, showing
two broad signals at δ 1.06 and 1.13. In addition, the
corresponding methylene resonances of the diethyla-
mide group were observed as diastereotopic (3.3-3.6
(3H, br) and 3.95 (1H, br)). These results indicate the
restricted rotation of the N-C(O) bond due to the
significant contribution of carbon-nitrogen double-bond
character14 and the diastereotopic nature of methylene
protons by the π-coordination of the CdC bond to the
Mo center. From these observations, the analogous
structure of 13 is proposed as depicted in Scheme 2.
Treatments of 13 and 14 with 1 atm of hydrogen gas
at ambient temperature resulted in the hydrogenation
and hydrogenolysis of the Pt-alkenyl moiety, giving
dialkylcarbamoyl dimethylsuccinate, though unfortu-
nately the inorganic products could not be characterized
due to their extensive reduction to metal (Scheme 2).
This fact also supports the proposed structure of these
complexes.
Reaction of 15 with methyl iodide gave the dimethyl-
(alkenyl)(P-N ligand)platinum-molybdenum complex
(Ph2PC2H4NEt2-κ2N,P)Me2{µ-MeO2C(PhO2C)CdCCO2-
Me}Pt-MoCp(µ-CO)(CO) (16), where two methyl ligands
are inequivalent, indicating that they are cis to each
other. Although the detailed structure of 16 is not clear
at present, the P-N ligand is considered to coordinate
KOPh also reacted with 5 to give a new ate complex
having a µ-alkenyl group, K+[(Ph2PC2H4NEt2-κ1P)Me-
{µ-MeO2C(PhO2C)CdCCO2Me}Pt-MoCp(µ-CO)(CO)]-
(15) (eq 7).
1
in a bidentate fashon. Again the J Pt-P value (2105 Hz)
is small, suggesting Pt(IV) and Mo(0) as discussed
before. The IR spectrum of 16 shows two strong ν(CO)
bands in the carbonyl region arising from both terminal
(1925 cm-1) and bridging (1744 cm-1) carbonyls, respec-
tively, suggesting a six-coordinated structure containing
a bridging carbonyl group, as depicted in Scheme 3.
On the other hand, protonolysis of 15 with HCl/
acetone did not afford trisubstituted olefin, but the
µ-alkenyl type complex (Ph2PC2H4NEt2-κ2N,P){µ-MeO2C-
(PhO2C)CdCCO2Me}Pt-MoCp(µ-CO)(CO) (17) was
(14) Gutowsky, H. S.; Holm, C. H. J . Chem. Phys. 1956, 25, 1228.

50 Organometallics, Vol. 23, No. 1, 2004
Tsutsuminai et al.
Meter. GC-MS analysis was performed on a Shimadzu GCMS-
QP2000A using a GL Science 30 m × 0.25 mm TC-WAX
capillary column.
Sch em e 3
(P h 2P C2H4CHdCH2-K2P ,olefin )MeP t-MoCp (CO)3 (2).
(cod)MePt-MoCp(CO)3 (166.9 mg, 0.2963 mmol) was placed
in a Schlenk tube under nitrogen, and benzene was added.
Then Ph2PC2H4CHdCH2 (70 µL, 0.28 mmol) was added and
stirred at room temperature for 1 day. After the solution was
concentrated under reduced pressure, excess hexane was
added to give an analytically pure yellow powder. Yield: 81%
(181.7 mg, 0.2399 mmol). Anal. Calcd for C25H25MoO3PPt: C,
1
43.18; H, 3.62. Found: C, 42.92; H, 3.55. H NMR (C6D6): δ
3
2
1.30 (3H, d, J P-H ) 5.7 Hz, J Pt-H ) 77 Hz, Pt-Me), 1.6-1.9
3
2
(4H, m, CH2CH2), 3.89 (1H, d, J H-H ) 17.7 Hz, J Pt-H ) 32.4
3
2
Hz, CHdCH2), 4.83 (1H, d, J H-H ) 9.3 Hz, J Pt-H ) 35.1 Hz,
CHdCH2), 5.08 (5H, s, Cp), 5.41 (1H, m, CHdCH2), 7.01-7.03
(6H, m, m- and p-Ph), 7.53-7.60 (4H, m, o-Ph). 31P{1H} NMR
(C6D6): δ 42.0 (s, 1J Pt-P ) 3584 Hz). IR (KBr, cm-1): 1795 (vs),
1904 (vs).
formed with liberation of methane. The 31P{1H} NMR
of 17 showed a single resonance with a 195Pt satellite,
1
which has a large J Pt-P value (4139 Hz) similar to that
(P h 2P C2H4SMe-K2P ,S)MeP t-MoCp (CO)3 (3). PtMeCl-
(Ph2PC2H4SMe-κ2P,S) (121.9 mg, 0.2296 mmol) and AgNO3
(63.6 mg, 0.374 mmol) were dissolved in THF, and the
suspension was stirred overnight at room temperature to give
a pale yellow solution with a white precipitate of AgCl. The
precipitate was filtered off, and the resulting solution was
added dropwise to a THF solution of Na[MoCp(CO)3]15 (88.4
mg, 0.329 mmol) under -70 °C and the mixture was stirred
for 3 h at -30 °C. All volatile matter was removed by
evaporation, and the resulting brown-yellow solid was ex-
tracted with toluene at -20 °C. After the filtered solution was
concentrated under reduced pressure at -20 °C, excess hexane
was added to give an analytically pure yellow powder. The
product was filtered, washed with hexane, and dried under
vacuum at room temperature. Yield: 70% (115.2 mg, 0.1610
mmol). Anal. Calcd for C24H25MoO3PPtS: C, 40.29; H, 3.52;
S, 4.48. Found: C, 40.68; H, 3.64; S, 4.59. 1H NMR (CD3-
of the (µ-alkenyl)platinum(II) complex 8 mentioned
1
above. In the H NMR, all resonances for the coordinat-
ing P-N ligand, alkenyl group, and Cp group on Mo
were also observed, and their chemical shifts are similar
to those of 8. These results suggest that 17 has the
µ-alkenyl structure depicted in Scheme 3.
Con clu d in g Rem a r k s
In the present study, we have synthesized novel Pt-
Mo heterodinuclear organometallic complexes having an
unsymmetrical P-olefin or P-S ligand. Heterodinuclear
complexes with hemilabile ligands, 1 and 2, show higher
reactivity toward DMAD than do 3 and analogous
complexes with symmetrical bidentate ligands such as
TMEDA and DPPE, to give new metallacyclobutenone
complexes. Facile generation of a reactive vacant coor-
dination site on the Pt center caused by the hemilabile
character of the ligand and cooperative effects of the two
metals are considered to play crucial roles in the process
of coupling of CO and DMAD and the formal insertion
process, though the mechanistic details are not clear at
present.
Although further functionalizations of these alkenyl
ligands by demetalation in these heterodinuclear sys-
tems were unsuccessful, the present selective reactions
of Pt-Mo heterodinuclear complexes with hemilabile
P-N ligands are of great interest in connection with
the possible catalytic functionalization of alkynes by
bimetallic catalysts.
3
2
COCD3): δ 0.55 (3H, d, J P-H ) 5.7 Hz, J Pt-H ) 73.9 Hz, Pt-
3
Me), 2.5-3.3 (4H, br, CH2CH2), 2.56 (3H, s, J Pt-H ) 19.5 Hz,
SMe), 5.32 (5H, s, Cp), 7.5-7.8 (10H, m, Ph). 31P{1H} NMR
1
(CD3COCD3): δ 57.4 (s, J Pt-P ) 3734 Hz). IR (KBr, cm-1):
1791 (vs), 1897 (vs).
(P h 2P C2H 4CH dCH 2-K1P )(CO)MeP t -MoCp (CO)3 (4). 2
(71.0 mg, 0.104 mmol) was dissolved in toluene, and the
solution was degassed. Carbon monoxide (1 atm) was then
introduced. After the mixture was stirred for 2 h at ambient
temperature, a large amount of hexane (ca. 20 mL) was added
to the solution, and then the yellow solution was filtered and
cooled to -30 °C to give pale yellow crystals of 4. Yield: 98%
(74.0 mg, 0.102 mmol). Anal. Calcd for
C26H25MoO4PPt‚
0.5C7H8: C, 46.04; H, 3.80. Found: C, 46.18; H, 3.96. 1H NMR
(CD3COCD3): δ 0.71 (3H, d, 3J P-H ) 8.4 Hz, 2J Pt-H ) 61.8 Hz,
Pt-Me), 2.50 (2H, m, CH2CH2), 2.93 (2H, m, CH2CH2), 5.01
3
3
(1H, brd, J H-H ) 10.0 Hz, CHdCH2), 5.14 (1H, dq, J H-H
)
Exp er im en ta l Section
2
17.1 Hz, J H-H ) 4J H-H ) 1.5 Hz, CHdCH2), 5.43 (5H, s, Cp),
3
5.96 (1H, ddt, J H-H ) 17.1, 10.0, 6.3 Hz, CHdCH2), 7.54-
All manipulations were carried out under a dry nitrogen or
argon atmosphere using standard Schlenk and vacuum-line
techniques. Solvents were refluxed over and distilled from
appropriate drying agents under N2: benzene, toluene, hexane,
THF, and Et2O from sodium benzophenone ketyl; acetone from
Drierite; CH2Cl2 from P2O5. Deuterated solvents were degassed
by three freeze-pump-thaw cycles and then vacuum trans-
ferred from appropriate drying agents (C6D6 from sodium wire,
CD3COCD3 from Drierite). NMR spectra were recorded on a
7.58 (6H, m, m- and p-Ph), 7.72-7.80 (4H, m, o-Ph). 31P{1H}
1
NMR (CD3COCD3): δ 29.4 (s, J Pt-P ) 2965 Hz). IR (KBr,
cm-1): 1832 (vs), 1921 (vs), 2050 (s).
(P h 2P C2H4NEt2-K2N,P )MeP t{µ-η2:η2-C(O)C2(CO2Me)2}-
MoCp (µ-CO)(CO) (5). Dimethyl acetylenedicarboxylate (D-
MAD; 20 µL, 0.16 mmol) was added to a solution of the complex
(Et2NC2H4PPh2-κ2N,P)MePt-MoCp(CO)3 (1; 135 mg, 0.153
mmol) in acetone at -30 °C, and the reaction mixture was
stirred for 12 h at -30 °C. Then, the solution was concentrated
under reduced pressure at room temperature, and excess
hexane was added to give an analytically pure yellow powder.
Yield: 71% (97 mg, 0.11 mmol). Anal. Calcd for C33H38MoNO7-
PPt: C, 44.90; H, 4.34; N, 1.59. Found: C, 44.44; H, 4.53; N,
1.60. Molar electrical conductivity Λ (THF, 20 °C): 0.0012 S
1
J EOL LA-300 spectrometer (300.4 MHz for H, 121.6 MHz for
31P) with chemical shifts reported in ppm downfield from TMS
1
for H and from 85% H3PO4 in D2O. Product yields for reactions
in a NMR tube were calculated on the basis of internal CHPh3.
IR spectra were recorded on a J ASCO FT/IR-410 spectrometer
using KBr disks. Elemental analyses were carried out with a
Perkin-Elmer 2400 Series II CHN analyzer. The molar electri-
cal conductivity was measured on a TOA CM 7B Conduct
(15) Piper, T. S.; Wilkinson, G. J . Inorg. Nucl. Chem. 1956, 3, 104.

Heterodinuclear Methylplatinum-Molybdenum Complexes
Organometallics, Vol. 23, No. 1, 2004 51
1
3
cm2 mol-1. H NMR (CD3COCD3): δ 0.67 (3H, d, J P-H ) 6.9
Hz, 2J Pt-H ) 76.6 Hz, Pt-Me), 0.92 (6H, t, 3J H-H ) 7.5 Hz, Me
(NEt)), 2.5-3.2 (8H, m, CH2 (NEt) and CH2CH2), 3.51 (3H, s,
OMe), 3.72 (3H, s, OMe), 5.40 (5H, s, Cp), 7.3-7.4 (6H, m, m-
and p-Ph), 7.7-7.9 (4H, m, o-Ph). 31P{1H} NMR (CD3COCD3):
tallized from acetone/hexane in the presence of an excess
amount of tBuNC to give yellow crystals. Yield: 35% (21.0 mg,
0.0220 mmol). Anal. Calcd for C38H47MoN2O7PPt: C, 47.26;
H, 4.91; N, 2.90. Found: C, 47.17; H, 4.87; N, 3.08. Molar
1
electrical conductivity Λ (THF, 24 °C): 0.050 S cm2 mol-1. H
δ 7.2 (s, J Pt-P ) 2577 Hz). IR (KBr, cm-1): 1691 (vs), 1706
(vs), 1779 (vs), 1947 (vs).
NMR (CD3COCD3): δ 0.81 (6H, t, J H-H ) 6.9 Hz, Me (N-
1
3
3
Et)), 0.83 (3H, d, J P-H ) 6.3 Hz, Pt-Me), 1.25 (9H, s, Me
3
(tBu)), 2.37 (4H, q, J H-H ) 6.9 Hz CH2 (N-Et)), 2.1-2.9 (4H,
(P h 2P C2H4CHdCH2-K2P ,olefin )MeP t{µ-η2:η2-C(O)C2(CO2-
Me)2}MoCp (µ-CO)(CO) (6). Dimethyl acetylenedicarboxylate
(DMAD; 12 µL, 0.098 mmol) was added to a solution of the
complex (Ph2PC2H4CHdCH2-κ2P,olefin)MePt-MoCp(CO)3 (2;
62.8 mg, 0.0922 mmol) in acetone at -30 °C and the reaction
mixture was stirred for 12 h at -30 °C. Then, the solution
was concentrated under reduced pressure at -30 °C, and
excess hexane was added to give an analytically pure yellow
powder. Yield: 65% (50.2 mg, 0.0599 mmol). Anal. Calcd for
m, CH2CH2), 3.52 (3H, s, OMe), 3.72 (3H, s, OMe), 5.36 (5H,
s, Cp), 7.44-7.72 (10H, m, Ph). 31P{1H} NMR (CD3COCD3): δ
1
-12.1 (s, J Pt-P ) 2348 Hz). IR (KBr, cm-1): 1682 (s), 1700
(s), 1783 (s), 1959 (s), 2200 (s).
(P h 2P C2H 4NE t 2-κ1P )(P Me3)MeP t {µ-η2:η2-C(O)C2(CO2-
Me)2}MoCp (µ-CO)(CO) (11). To a solution of 5 (107.9 mg,
0.1222 mmol) in toluene was added PMe3 (15 µL, 0.14 mmol)
at -30 °C, and the solution was stirred for 5 h at -30 °C. Then,
the solution was concentrated under reduced pressure at -30
°C, and excess hexane was added to give a yellow powder.
Yield: 67% (78.7 mg, 0.0821 mmol). 1H NMR (CD3COCD3): δ
C
31H31MoO7PPt: C, 44.45; H, 3.37. Found: C, 44.89; H, 3.95.
1H NMR (CD3COCD3): δ 0.58 (3H, d, 3J P-H ) 6.9 Hz, 2J Pt-H
)
75.3 Hz, Pt-Me), 2.0-3.0 (4H, m, CH2CH2), 3.52 (3H, s, OMe),
3.76 (3H, s, OMe), 4.60 (1H, m, CHdCH2), 4.93 (1H, m, CHd
CH2), 5.49 (5H, s, Cp), 5.76 (1H, m, CHdCH2), 7.3-7.7 (10H,
3
3
0.70 (3H, d, J P-H ) 6.0, 9.3 Hz, Pt-Me), 0.80 (6H, t, J H-H
)
2
6.9 Hz, Me (N-Et)), 0.92 (9H, d, J P-H ) 5.1 Hz, Me (PMe3)),
m, Ph). 31P{1H} NMR (CD3COCD3): δ 10.5 (s, J Pt-P ) 2639
1
3
2.2-3.1 (4H, m, CH2CH2), 2.35 (4H, q, J H-H ) 6.9 Hz CH2
Hz). IR (KBr, cm-1): 1678 (s), 1702 (s), 1725 (vs), 1774 (vs),
1960 (s).
(N-Et)), 3.46 (3H, s, OMe), 3.67 (3H, s, OMe), 5.45 (5H, s,
Cp), 7.4-7.7 (10H, m, Ph). 31P{1H} NMR (CD3COCD3):
δ
)
2
1
2
(P h 2P C2H 4NE t 2-K2N,P )MeP t {µ-η2:η2-C(O)C2(CO2E t )2}-
MoCp (µ-CO)(CO) (7). Diethyl acetylenedicarboxylate (14 µL,
0.088 mmol) was added to a solution of the complex 1 (55.2
mg, 0.0745 mmol) in toluene at -30 °C, and the reaction
mixture was stirred for 4 h at -30 °C. After removal of all
volatile matters under vacuum, the resulting orange solid was
washed with hexane and recrystallized from THF/hexane to
-52.6 (d, J P-P ) 13 Hz, J Pt-P ) 1156 Hz), -16.9 (d, J P-P
13 Hz, J Pt-P ) 2310 Hz). IR (KBr, cm-1): 1695 (s), 1776 (vs),
1
1952 (vs).
(P h 2P C2H4NEt2-K2N,P ){µ-MeO2C(Bu HNCO)CdCCO2Me}-
P t-MoCp (µ-CO)(CO) (12). Complex 5 (12.6 mg, 0.0142
mmol) was placed in an NMR tube into which C6D6 was added
by vacuum distillation. The NMR tube was capped with a
rubber septum under a nitrogen atmosphere, and then NH2-
Bu (1.4 µL, 0.014 mmol) was injected into the NMR tube by
use of a hypodermic syringe. Complex 12 was characterized
1
give orange crystals. Yield: 71% (56.9 mg, 0.0624 mmol). H
3
NMR (CD3COCD3): δ 0.68 (3H, d, J P-H ) 6.6 Hz, Pt-Me),
3
3
0.93 (6H, t, J H-H ) 6.9 Hz, Me (NEt)), 1.18 (3H, t, J H-H
)
6.9 Hz, Me (OEt)), 1.29 (3H, t, 3J H-H ) 6.9 Hz, Me (OEt)), 2.7-
3.2 (8H, br, CH2 (NEt) and CH2CH2), 3.88-4.31 (4H, m, CH2
(OEt)), 5.41 (5H, s, Cp), 7.32-7.38 (6H, m, m- and p-Ph), 7.76-
7.91 (4H, m, o-Ph). 31P{1H} NMR (CD3COCD3): δ 7.4 (s,
1J Pt-P ) 2578 Hz). IR (KBr, cm-1): 1678 (s), 1712 (s), 1790 (s),
1951 (vs).
1
spectroscopically. Yield: 90%. H NMR (C6D6): δ 0.71 (3H, t,
3
3J H-H ) 6.9 Hz, Me (NEt)), 0.80 (3H, t, J H-H ) 7.4 Hz, Me
3
(Bu)), 1.06 (3H, t, J H-H ) 6.8 Hz, Me (NEt)), 1.30 (2H, m,
3
CH2 (Bu)), 1.45 (2H, q, J H-H ) 6.9 Hz, CH2 (Bu)), 1.7-2.2
(4H, m, CH2CH2), 2.33 (1H, m, CH2 (NEt)), 2.80 (3H, s, OMe),
3.17 (3H, s, OMe), 3.29 (4H, m, CH2 (NEt) and CH2 (Bu)), 3.57
(P h 2P C2H 4NE t 2-K2N,P ){µ-MeO2C(Me)CdCCO2Me}P t -
MoCp (µ-CO)(CO) (8). Complex 5 (43 mg, 0.049 mmol) was
dissolved in acetone, and the solution was heated at 50 °C for
2 days. The solution turned from yellow to red-orange. The
solution was evaporated under reduced pressure and recrys-
tallized from acetone/hexane to give yellow crystals. Yield:
31% (15 mg, 0.015 mmol). Anal. Calcd for C32H38MoNO6PPt:
C, 44.97; H, 4.48; N, 1.64. Found: C, 45.28; H, 4.41; N, 1.66.
Molar electrical conductivity Λ (THF, 24 °C): 0.069 S cm2
(1H, m, CH2 (NEt)), 5.28 (5H, s, Cp), 7.20 (6H, m, m- and p-Ph),
1
7.85 (4H, m, o-Ph). 31P{1H} NMR (C6D6): δ 40.3 (s, J Pt-P
)
4497 Hz).
(P h 2P C2H4NEt2-κ2N,P ){µ-MeO2C(Et2NCO)CdCCO2Me}-
P t-MoCp (µ-CO)(CO) (13). To a solution of 5 (113 mg, 0.129
mmol) in THF was added NHEt2 (20 µL, 0.19 mmol) and the
mixture was stirred for 5 h at ambient temperature. All the
volatile matters were removed by evaporation and the result-
ing solid was extracted with hexane. The hexane solution was
evaporated to dryness and the resulting yellow solid of 13 was
dried under vacuum. Yield 31% (383 mg, 0.0408 mmol). Anal.
Calcd for C36H45MoN2O7PPt: C, 46.01; H, 4.83; N, 2.98.
Found: C, 45.96; H, 4.96; N, 3.0. 1H NMR (C6D6): δ 0.84 (3H,
1
3
mol-1. H NMR (CD3COCD3): δ 1.02 (3H, t, J H-H ) 6.9 Hz,
3
Me (NEt)), 1.22 (3H, s, Me (alkenyl)), 1.44 (6H, t, J H-H ) 6.9
Hz, Me (NEt)), 2.82 (3H, s, OMe), 3.32 (3H, s, OMe), 2.4-3.7
(8H, m, CH2 (NEt) and CH2-CH2), 5.26 (5H, s, Cp), 7.48-7.63
(6H, m, m- and p-Ph), 7.6-7.9 (4H, m, o-Ph). 31P{1H} NMR
3
3
t, J H-H ) 7.2 Hz, Me (NEt)), 0.93 (3H, t, J H-H ) 7.2 Hz, Me
1
(CD3COCD3): δ 44.9 (s, J Pt-P ) 4010 Hz). IR (KBr, cm-1):
(NEt)), 1.06 (3H, br, Me (CONEt)), 1.13 (3H, br, Me (CONEt)),
3
1664 (s), 1685 (s), 1739 (s), 1917 (s).
1.7-2.4 (4H, m, CH2-CH2), 2.60 (1H, dq, J H-H ) 7.2 Hz,
2J H-H ) 13.2 Hz, CH2 (NEt)), 2.78 (1H, dq, J H-H ) 7.2 Hz,
3
(P h 2P C2H4NEt2-K1P )(CO){µ-MeO2C(Me)CdCCO2Me}P t-
MoCp (µ-CO)(CO) (9). Complex 8 (12.7 mg, 0.0221 mmol) was
placed in an NMR tube, and CD3COCD3 (0.6 mL) was added
by vacuum distillation. Then CO (1 atm) was introduced into
the NMR tube. Complex 9 was characterized spectroscopically.
2J H-H ) 13.2 Hz, CH2 (NEt)), 2.91 (3H, s, OMe), 3.35 (2H, m,
CH2 (NEt)), 3.3-3.6 (3H, br, CH2 (CONEt)), 3.52 (3H, s, OMe),
3.95 (1H, br, CH2 (CONEt)), 5.35 (5H, s, Cp), 7.0-7.9 (10H,
m, Ph). 31P{1H} NMR (C6D6): δ 39.6 (s, J Pt-P ) 4298 Hz). IR
1
(KBr, cm-1): 1618 (s), 1670, (s) 1687 (s), 1715 (s), 1958 (s).
(P h 2P C2H4NEt2-K2N,P ){µ-MeO2C(C4H8NCO)CdCCO2Me}-
P t-MoCp (µ-CO)(CO) (14). Complex 5 (18.3 mg, 0.0207
mmol) was placed in an NMR tube into which C6D6 was added
by vacuum distillation. The NMR tube was capped with a
rubber septum under a nitrogen atmosphere, and then pyr-
rolidine (1.8 µL, 0.022 mmol) was injected into the NMR tube
by use of a hypodermic syringe. Complex 14 was characterized
1
3
Yield: 50%. H NMR (CD3COCD3): δ 0.90 (6H, t, J H-H ) 6.9
Hz, Me (NEt)), 1.67 (3H, s, Me (alkenyl)), 2.50 (4H, q, 3J H-H
)
6.9 Hz, CH2 (NEt)), 2.5-3.0 (4H, m, CH2CH2), 3.19 (3H, s,
OMe), 3.43 (3H, s, OMe), 5.37 (5H, s, Cp), 7.5-7.7 (10H, m,
1
Ph). 31P{1H} NMR (CD3COCD3): δ 15.4 (s, J Pt-P ) 3136 Hz).
(P h 2P C2H4NEt2-κ1P )(tBu NC)MeP t {µ-η2,η2-C(O)C2(CO2-
Me)2}MoCp (µ-CO)(CO) (10). To a solution of 5 (55.5 mg,
0.0629 mmol) in acetone was added tBuNC (10 µL, 0.088 mmol)
at -30 °C, and the solution was stirred for a few hours. The
solution was evaporated under reduced pressure and recrys-
1
spectroscopically. Yield: 96%. H NMR (C6D6): δ 0.86 (3H, t,
3
3J H-H ) 6.8 Hz, Me (NEt)), 0.95 (3H, t, J H-H ) 7.0 Hz, Me

52 Organometallics, Vol. 23, No. 1, 2004
Tsutsuminai et al.
Ta ble 4. Cr ysta llogr a p h ic P a r a m eter s for 5, 8, a n d
10
(NEt)), 1.2-1.6 (4H, m, CH2CH2 (NC4H8)), 1.7-2.4 (4H, m,
CH2CH2), 2.6-2.9 (2H, m, CH2 (NEt)), 2.89 (3H, s, OMe), 3.1-
3.6 (5H, m, CH2 (NEt) and CH2 (NC4H8)), 3.53 (3H, s, OMe),
3.95 (1H, m, CH2 (NC4H8)), 5.34 (5H, s, Cp), 7.0-7.4 (6H, m,
m- and p-Ph), 7.8-8.0 (4H, m, o-Ph). 31P{1H} NMR (C6D6): δ
5
8
10
empirical
formula
formula wt
cryst syst
space group
a (Å)
C
33H38MoN- C32H38MoN-
O7PPt O6PPt
854.66
orthorhombic
C38H47MoN2-
O7PPt
965.80
1
38.6 (s, J Pt-P ) 4365 Hz).
882.67
monoclinic
P21/n (No. 14) P212121 (No. 19) P1h (No. 2)
12.235(6)
20.712(5)
14.634(3)
Hyd r ogen olysis of 13 a n d 14. Treatment of 13 (5.4 mg,
0.0057 mmol) with hydrogen gas (1 atm) at ambient temper-
ature for 2 days in C6D6 gave MeO2CCH2CH(CONEt2)CO2Me
(86%), which was confirmed by direct comparison with an
authentic sample prepared independently from MeO2CCH2-
CONEt2 (1.0971 g, 6.3339 mmol), potassium carbonate (842.8
mg, 6.098 mmol), tetra-n-butylammonium bromide (38.4 mg,
0.119 mmol), and methyl bromoacetate (520 µL, 5.49 mmol)
in benzene (12%). MS: m/z 245 (M+), 214 (M+ - OMe), 186
triclinic
15.239(2)
15.717(3)
12.894(2)
13.12(2)
15.35(1)
11.31(1)
93.55(9)
116.29(10)
76.2(1)
1980(4)
2
b (Å)
c (Å)
R (deg)
â(deg)
109.53(2)
γ(deg)
V (Å3)
3494(2)
4
1.677
1736.00
44.31
3088.3(8)
4
1.838
1680.00
50.09
Z
1
(M+ - CO2Me), 145 (M+ - CONEt2). H NMR (C6D6): δ 0.92
Dcalcd (g/cm3)
F000
1.619
960.00
39.17
(3H, t, 3J H-H ) 6.6 Hz, CH3), 0.94 (3H, t, 3J H-H ) 6.9 Hz, CH3),
3
µ(Mo KR) (cm-1
radiation
)
2.9-3.2 (6H, CH2), 4.01 (1H, t, J H-H ) 6.9 Hz, CH).
Mo KR (λ) 0.710 69 Å),
graphite monochromated
Treatment of 14, prepared in situ from 5 and pyrrolidine,
with hydrogen gas (1 atm) at ambient temperature in C6D6
gave MeO2CCH2CH(CONC4H8)CO2Me, which was character-
scan type
2θmax (deg)
ω-2θ
54.9
ω-2θ
55.0
ω-2θ
55.1
ized by GC-MS: m/z 243 (M+), 212 (M+ - OMe), 184 (M+
CO2Me), 145 (M+ - CONC4H8).
-
no. of rflns measd
total
unique
8440
7842
3973
3948
9398
9058
K+[(P h 2P C2H4NEt2-κ1P )Me{µ-MeO2C(P h O2C)CdCCO2-
Me}P t-MoCp (µ-CO)(CO)]- (15). A solution of KOPh (222
mg, 0.167 mmol) in THF was added dropwise to a THF solution
of 6 (51.3 mg, 0.0581 mmol) at -30 °C, and the resulting
mixture was stirred for 3 h at -30 °C. The mixture was further
stirred for 30 min at ambient temperature; the reaction
mixture was then evaporated to dryness, and the resulting
solid was extracted with benzene. After concentration of the
extract, a small amount of hexane was added and the mixture
was cooled to -30 °C to give complex 15 as dark red crystals.
structure soln
no. of observns
(I > 3.00σ(I))
direct methods (SIR92)
4237
362
3417
7209
no. of variables
379
451
b
residuals: R;a Rw 0.064; 0.121
goodness of fit
indicator
0.027; 0.038
1.08
0.060; 0.083
1.08
1.29
a
b
2 1/2
R ) ∑||Fo| - |Fc||/∑|Fo|. Rw ) [∑w(|Fo| - |Fc|)2/∑wFo
] .
Yield: 89% (52.6 mg, 0.0518 mmol). Anal. Calcd for C39H43
-
s, Cp), 6.70 (1H, m, p-Ph (CO2Ph)), 7.0-7.3 (4H, m, o- and
m-Ph (CO2Ph)), 7.5-7.8 (10H, m, Ph (PPh)). 31P{1H} NMR
KMoNO8PPt: C, 46.16; H, 4.27; N, 1.38. Found: C, 46.29; H,
4.12; N, 1.35. Molar electrical conductivity Λ (THF, 20 °C):
1
(CD3COCD3): δ 43.1 (s, J Pt-P ) 4139 Hz).
1
3
0.77 S cm2 mol-1. H NMR (CD3COCD3): δ 0.25 (3H, d, J P-H
X-r a y Str u ctu r e An a lysis. A single crystal was selected
by using a microscope and sealed in a thin-glass capillary
(GLASS, 0.7 mm i.d.) under N2. Diffraction experiments were
performed on a Rigaku RASA-7R diffractometer with graphite-
monochromated Mo KR radiation (λ ) 0.710 69 Å) and a
rotating anode generator. The intensities of 3 representative
reflections were measured after every 150 reflections. No
intensity decay was observed for 8. For complexes 5 and 10, a
small intensity decay was observed, 6.2 and 9.1%, respectively,
and decay corrections were applied. These structures were
solved by direct methods16 expanded using Fourier tech-
niques,17 and refined by full-matrix least squares. For complex
5, all non-hydrogen atoms were refined with anisotropic
displacement parameters except for C19 and C21-C26, and
all hydrogen atoms were included in theoretical positions. For
8 and 10, all non-hydrogen atoms were refined anisotropically,
and the hydrogen atoms were included in theoretical positions.
For complex 15, single crystals were obtained from diethyl
ether, but the crystals rapidly degradated under vacuum.
Therefore, a single crystal was carefully mounted in a glass
capillary tube. However, sufficient diffraction data could not
be obtained due to extensive signal intensity decay (33.4%,
2θmax ) 40.0°), and only a brief structural feature was
2
)
8.2 Hz, J Pt-H
)
78.7 Hz, Pt-Me), 0.86 (6H, t,
3J H-H ) 7.2 Hz, Me (NEt)), 2.41 (4H, q, J H-H ) 7.2 Hz, CH2
(NEt)), 2.4-2.8 (4H, m, CH2CH2), 3.45 (3H, s, OMe), 3.55 (3H,
s, OMe), 4.93 (5H, s, Cp), 7.0-7.7 (15H, m, Ph). 31P{1H} NMR
3
(CD3COCD3): δ 19.9 (s, J Pt-P ) 3038 Hz). IR (KBr, cm-1):
1
1592 (s), 1661 (s), 1677 (s), 1710 (s), 1919 (s).
Rea ction of 15 w ith MeI. Complex 15 (8.2 mg, 0.0081
mmol) was placed in an NMR tube into which CD3COCD3 was
added by vacuum distillation. The NMR tube was capped with
a rubber septum under a nitrogen atmosphere, and then MeI
(1.0 µL, 0.016 mmol) was injected into the NMR tube by use
of a hypodermic syringe. (Ph2PC2H4NEt2-κ2N,P)Me2{µ-MeO2C-
(PhO2C)CdCCO2Me}Pt-MoCp(µ-CO)(CO) (16) was character-
1
ized spectroscopically. Yield: 95%. H NMR (CD3COCD3): δ
3
2
0.33 (3H, d, J P-H ) 7.5 Hz, J Pt-H ) 75.1 Hz, Pt-Me), 0.79
(3H, t, 3J H-H ) 7.5 Hz, Me (NEt)), 0.87 (3H, t, 3J H-H ) 7.1 Hz,
3
2
Me (NEt)), 0.99 (3H, d, J P-H ) 6.9 Hz, J Pt-H ) 67.9 Hz, Pt-
Me), 2.4-2.7 (2H, m, CH2CH2), 3.0-3.3 (6H, m, CH2 (NEt) and
CH2CH2), 3.64 (3H, s, OMe), 3.77 (3H, s, OMe), 5.37 (5H, s,
Cp), 7.2-7.8 (15H, m, Ph). 31P{1H} NMR (CD3COCD3): δ -2.4
(s, J Pt-P ) 2105 Hz). IR (KBr, cm-1): 1543 (s), 1703 (s), 1744
1
(s), 1925 (vs).
P r oton olysis of 15. Complex 15 (4.2 mg, 0.0042 mmol) was
placed in an NMR tube into which CD3COCD3 was added by
vacuum distillation. The NMR tube was capped with a rubber
septum under a nitrogen atmosphere, and then 1.7 M of HCl/
CH3COCH3 (2.6 µL, 0.0044 mmol) was injected into the NMR
tube by use of a hypodermic syringe. Methane was detected
in 106% yield. (Ph2PC2H4NEt2-κ2N,P){µ-MeO2C(PhO2C)CdC-
CO2Me}Pt-MoCp(µ-CO)(CO) (17) was characterized spectro-
discussed in the text. Crystal data for 15‚Et2O: C43H53
-
KMoNO9PPt, FW ) 1089.00, triclinic, P1h, a ) 16.430(6) Å,
b ) 16.882(4) Å, c ) 10.530(3) Å, R ) 101.34(2)°, â ) 106.64-
(3)°, γ ) 71.23(2)°, V ) 2631(1) Å3, Z ) 2, Dcalcd ) 1.374 g cm-3
,
µ(Mo KR) ) 30.36 cm-1, 2θmax ) 40.0°, 4950 reflections
(16) SIR92: Altomare, A.; Burla, M. C.; Camalli, M.; Cascarano, M.;
Giacovazzo, C.; Guagliardi, A.; Polidori, G. J . Appl. Crystallogr. 1994,
27, 435.
(17) DIRDIF94: Beurskens, P. T.; Admiraal, G.; Beurskens, G.;
Bosman, W. P.; de Gelder, R.; Israel, R.; Smits, J . M. M. 1994. The
DIRDIF-94 Program System; Technical Report of the Crystallography
Laboratory; University of Nijmegen, Nijmegen, The Netherlands.
1
scopically. Yield: 98%. H NMR (CD3COCD3): δ 0.88 (3H, t,
3
3J H-H ) 7.2 Hz, Me (NEt)), 1.31 (3H, t, J H-H ) 7.2 Hz, Me
(NEt)), 2.4-2.7 (2H, m, CH2CH2), 3.0-3.3 (6H, m, CH2 (NEt)
and CH2CH2), 3.01 (3H, s, OMe), 3.53 (3H, s, OMe), 5.22 (5H,

Heterodinuclear Methylplatinum-Molybdenum Complexes
Organometallics, Vol. 23, No. 1, 2004 53
measured (4718 unique), 3704 observations with I > 3.00σ(I),
R (Rw) ) 0.059 (0.091), GOF ) 1.01. Selected bond distances
(Å): Pt(1)-Mo(1) ) 2.792(2), Pt(1)-P(1) ) 2.272(5), Pt(1)-
C(1) ) 2.10(2), Pt(1)-C(2) ) 2.04(1), Pt(1)-C(33) ) 2.16(2),
Mo(1)-C(2) ) 2.14(2), Mo(1)-C(5) ) 2.32(2), Mo(1)-C(33) )
1.98(2) Å. Selected bond angles (deg): Mo(1)-Pt(1)-P(1) )
131.8(1), Mo(1)-Pt(1)-C(1) ) 141.0(5), Mo(1)-Pt(1)-C(2) )
49.6(4), Mo(1)-Pt(1)-C(33) ) 44.9(6), P(1)-Pt(1)-C(1) ) 87.1-
(5), P(1)-Pt(1)-C(2) ) 173.2(4), P(1)-Pt(1)-C(33) ) 91.4(6),
C(1)-Pt(1)-C(2) ) 91.5(7), C(1)-Pt(1)-C(33) ) 161.5(7),
C(2)-Pt(1)-C(33) ) 92.1(7), Pt(1)-C(33)-Mo(1) ) 84.6(8), Pt-
(1)-C(33)-O(7) ) 126(1), Mo(1)-C(33)-O(7) ) 148(1).
These data were processed using the teXsan crystal solution
package18 operating on a SGI O2 workstation. The crystal-
lographic data and details associated with data collection for
5, 8, and 10 are given in Table 4. Crystallographic thermal
parameters and bond distances and angles have been deposited
as Supporting Information.
Ack n ow led gm en t. This work was financially sup-
ported by a Grant-in-Aid for Scientific Research from
the Ministry of Education, Sports, Culture, Science and
Technology of J apan and the 21st Century COE (Center
of Excellence) program of “Future Nano-materials” at
the Tokyo University of Agriculture and Technology.
Su p p or tin g In for m a tion Ava ila ble: Tables of atomic
coordinates, anisotropic displacement parameters, and bond
distances and angles for 5, 8, 10, and 15. This material is
available free of charge via the Internet at http://pubs.acs.org.
(18) teXsan: Crystal Structure Analysis Package; Molecular Struc-
ture Corp., The Woodlands, TX, 1985 and 1999.
OM034162Q