Syntheses of dinuclear and trinuclear hydridoplatinum complexes with bridging phosphido ligands [Pt(2)H(2)(μ-PR(2))(2) (PEt3)2] (R = tBu, Ph) and [Pt(3)H(2)(μ-PPh(2))(4) (PEt3)2]. Characterization of

Article abstract of DOI:10.1021/om034131v

The reaction of Ph₂PH with Pt(PEt₃)₃ in 2:1 molar ratio produces the linear triplatinum complex [Pt₃H₂(μ-PPh₂)₄ (PEt₃)₂] (1). X-ray crystallography of 1 sho

Full text of DOI:10.1021/om034131v

1610
Organometallics 2004, 23, 1610-1621
Syn th eses of Din u clea r a n d Tr in u clea r Hyd r id op la tin u m
Com p lexes w ith Br id gin g P h osp h id o Liga n d s
t
[P t2H2(µ-P R2)2(P Et3)2] (R ) Bu , P h ) a n d
[P t3H2(µ-P P h 2)4(P Et3)2]. Ch a r a cter iza tion of th e
Tr ia n gu la r In ter m ed ia te [P t3H(µ-P P h 2)3(P Et3)3] a n d Its
Ch em ica l P r op er ties
Masumi Itazaki, Yasushi Nishihara, and Kohtaro Osakada*
Chemical Resources Laboratory, Tokyo Institute of Technology,
4259 Nagatsuta, Midori-ku, Yokohama 226-8503, J apan
Received August 26, 2003
The reaction of Ph2PH with Pt(PEt3)3 in 2:1 molar ratio produces the linear triplatinum
complex [Pt3H2(µ-PPh2)4(PEt3)2] (1). X-ray crystallography of 1 shows the structure of the
complex with two PEt3 ligands at anti positions, while it exists as a mixture of the isomers
with PEt3 at anti and syn positions. Pt(PEt3)3 reacts with equimolar Ph2PH to afford the
dinuclear complex [Pt2H2(µ-PPh2)2(PEt3)2] (2) and the cyclic trinuclear complex [Pt3H(µ-
PPh2)3(PEt3)3] (3) depending on the reaction conditions. A dinuclear platinum(II) complex
t
with a structure similar to 2, [Pt2H2(µ-PtBu2)2(PEt3)2] (4), is obtained by the reaction of -
Bu2PH with Pt(PEt3)3. Isolated complexes 2 and 3 cleanly react with Ph2PH to form 1,
indicating that the reaction of Ph2PH with Pt(PEt3)3, giving 1, involves these complexes as
the intermediates. Complex 3 contains a triangular Pt3 core with Pt-Pt bonds in the range
1
2.9784(4)-2.9983(3) Å, as shown by X-ray crystallography. The H NMR spectrum of 3
exhibits the hydrido signal at δ -7.98 accompanied by splitting due to H-P and H-Pt
coupling. Complex 3 reacts with Ph3SiH and Ph2SiH2 to give silylplatinum complexes
[Pt3(SiHn+1Ph4-n)(µ-PPh2)3(PEt3)2] (5, n ) 1; 6, n ) 2). Cationic triangular complexes [Pt3-
(µ-PPh2)3(PEt3)3]+I- (7) and [Pt3(µ-PPh2)3(PEt3)3]+[B4O4Ar4(OH)]- (8, Ar ) C6H4Me-4; 9, Ar
) C6H4F-4; 10, Ar ) C6H4CF3-4) are obtained from the reactions of complex 3 with MeI and
with ArB(OH)2, respectively.
In tr od u ction
plexes with bridging phosphido ligands have three
possible structures, shown in Scheme 1. The triangular
Bridging phosphido (µ-PR2) ligands form a number
of multimetallic complexes1 of transition metals because
of the stable coordination bond between the three-
electron donor and the two metal centers. The M-P-M
angles of the complexes vary ranging from 70° to 140°,
depending on the presence or absence of the metal-
metal bond between the metal centers and on the type
of metal centers.2 The flexible coordination of the
phosphido ligand enables the binding of two transition
metals of various homo-3 and heterobimetallic4 di-
nuclear complexes and cyclic trinuclear complexes of
transition metals. There have been many reports of
dinulclear and cyclic trinuclear platinum complexes
with bridging phosphido ligands.5-8 Triplatinum com-
(4) Zr (Hf)-Ni: (a) Baker, R. T.; Fultz, W. C.; Marder, T. B.;
Williams, I. D. Organometallics 1990, 9, 2357. Pt-Mn (W): (b)
Braunstein, P.; De J esus, E.; Dedieu, A.; Lanfranchi, M.; Tiripicchio,
A. Inorg. Chem. 1992, 31, 399. Pd-Pt: (c) Falvello, L. R.; Fornie´s, J .;
Fortun˜o, C.; Mart´ınez, F. Inorg. Chem. 1994, 33, 6242. Pt-Rh (Ir):
(d) Falvello, L. R.; Fornie´s, J .; Mart´ın, A.; Gomez, J .; Lalinde, E.;
Moreno, M. T.; Sacristan, J . Inorg. Chem. 1999, 38, 3116. Au-Ag: (e)
Blanco, M. C.; Fernandez, E. J .; Lopez-De-Luzuriaga, J . M.; Olmos,
M. E.; Crespo, O.; Gimeno, M. C.; Laguna, A.; J ones, P. G. Chem. Eur.
J . 2000, 6, 4116. Pt-Cu: (f) Archambault, C.; Bender, R.; Braunstein,
P.; Dusausoy, Y. Dalton Trans. 2002, 4084.
(5) µ-PPh2: (a) Carty, A. J .; Hartstock, F.; Taylor, N. J . Inorg. Chem.
1982, 21, 1349. (b) Van Leeuwen, P. W. N. M.; Roobeek, C. F.; Frijns,
J . H. G.; Orpen, A. G. Organometallics 1990, 9, 1211. (c) Alonso, E.;
Casas, J . M.; Cotton, F. A.; Feng, X.; Fornie´s, J .; Fortun˜o, C.; Toma´s,
M. Inorg. Chem. 1999, 38, 5034. (d) Bender, R.; Bouaoud, S.-E.;
Braunstein, P.; Dusausoy, Y.; Merabet, N.; Raya, J .; Rouag, D. J . Chem.
Soc., Dalton Trans. 1999, 735. (e) Falvello, L. R.; Fornie´s, J .; Gomez,
J .; Lalinde, E.; Mart´ın, A.; Moreno, M. T.; Sacristan, J . Chem. Eur. J .
1999, 5, 474.
* Corresponding author. E-mail: kosakada@res.titech.ac.jp.
(1) (a) Bender, R.; Braunstein, P.; Dedieu, A.; Dusausoy, Y. Angew.
Chem. 1989, 101, 931. (b) Schuh, W.; Wachtler, H.; Laschober, G.;
Kopacka, H.; Wurst, K.; Peringer, P. Chem. Commun. 2000, 1181. (c)
Leoni, P, Marchetti, F.; Marchetti, L.; Pasquali, M.; Quaglierini, S.
Angew. Chem., Int. Ed. 2001, 40, 3617.
(2) (a) Rosenberg, S.; Geoffroy, G. L.; Rheingold, A. L. Organome-
tallics 1985, 4, 1184. (b) Brauer, D. J .; Hessler, G.; Knuppel, P. C.;
Stelzer, O. Inorg. Chem. 1990, 29, 2370.
(3) Pd-Pd: (a) Hayter, R. G. J . Am. Chem. Soc. 1962, 84, 3046. (b)
Alonso, E.; Fornie´s, J .; Fortun˜o, C.; Mart´ın, A.; Rosair, G. M.; Welch,
A. J . Inorg. Chem. 1997, 36, 4426. Ru-Ru: (c) Omori, H.; Suzuki, H.;
Take, Y.; Moro-oka, Y. Organometallics 1989, 8, 2270.
(6) µ-PtBu2: (a) Leoni, P.; Pasquali, M.; Beringhelli, T.; D’Alfonso,
G.; Minoja, A. P. J . Organomet. Chem. 1995, 488, 39. (b) Leoni, P.;
Manetti, S.; Pasquali, M. Inorg. Chem. 1995, 34, 749, and references
therein. (c) Leoni, P.; Pasquali, M.; Fortunelli, A.; Germano, G.;
Albinati, A. J . Am. Chem. Soc. 1998, 120, 9564. (d) Leoni, P.; Pasquali,
M.; Cittadini, V.; Fortunelli, A.; Selmi, M. Inorg. Chem. 1999, 38, 5257.
(e) Leoni, P.; Chiaradonna, G.; Pasquali, M.; Marchetti, F. Inorg. Chem.
1999, 38, 253. (f) Cristofani, S.; Leoni, P.; Pasquali, M.; Eisentraeger,
F.; Albinati, A. Organometallics 2000, 19, 4589. (g) Crementieri, S.;
Leoni, P.; Marchetti, F.; Marchetti, L.; Pasquali, M. Organometallics
2002, 21, 2575.
10.1021/om034131v CCC: $27.50 © 2004 American Chemical Society
Publication on Web 03/03/2004

Syntheses of Hydridoplatinum Complexes
Organometallics, Vol. 23, No. 7, 2004 1611
Sch em e 1
complexes with three Pt centers and three bridging
phosphido ligands are most common among the three
structures,9,10 while the complexes with bent11 and
linear12 structures were reported in a limited number
of cases. The linear trinuclear platinum complexes with
aryl and bridging phosphido ligands were prepared from
mono- and dinuclear Pt complexes and from mono- and
tetranuclear Pt complexes.12
In this paper, we report the preparation of a new
linear triplatinum complex with hydrido and bridging
phosphido ligands from the reaction of Ph2PH with
Pt(PEt3)3. The pathway of the reaction that involves an
intermediate cyclic triplatinum complex and its reac-
tions with organosilanes and arylboronic acids are also
described.
F igu r e 1. ORTEP drawing of anti-1‚Me2CO with 50%
thermal ellipsoidal plots. Atoms with asterisks are crys-
tallographically equivalent to those having the same
number without asterisks. Hydrido ligands were not lo-
cated. Hydrogen atoms and Me2CO were omitted for
simplicity. Selected bond distances (Å) and angles (deg):
Pt(1)-P(1) ) 2.277(4), Pt(1)-P(2) ) 2.352(3), Pt(1)-P(3)
) 2.336(4), Pt(2)-P(2) ) 2.353(3), Pt(2)-P(3) ) 2.357(3),
Pt(1)‚‚‚Pt(2) ) 3.572(1), P(2)‚‚‚P(3) ) 2.865(5); P(1)-Pt(1)-
P(2) ) 178.0(2), P(1)-Pt(1)-P(3) ) 105.3(1), P(2)-Pt(1)-
P(3) ) 75.3(1), P(2)-Pt(2)-P(3) ) 74.9(1), Pt(1)-P(2)-Pt(2)
) 98.8(1), Pt(1)-P(3)-Pt(2) ) 99.1(1), P(2)-Pt(2)-P(2*) )
180.0, P(3)-Pt(2)-P(3*) ) 180.0.
Resu lts a n d Discu ssion
The reaction of Ph2PH with Pt(PEt3)3 in 2:1 molar
ratio in benzene for 12 h and then in hexane for 96 h at
room temperature gave the linear triplatinum(II) com-
plex [Pt3H2(µ-PPh2)4(PEt3)2] (1) in 80% yield (eq 1).
terminal Pt centers are bonded with a PEt3 and two
bridging PPh2 ligands. The molecule has the PEt3
ligands at the opposite side of the linear Pt-Pt-Pt
alignment (anti position). The hydrido ligands are
considered to occupy the vacant coordination sites of the
square-planar Pt centers, although the positions of the
hydrido ligands were not determined in the final D-map.
The coordination planes around the terminal Pt atoms
and that around the central Pt atom form an angle of
147.0°. The Pt‚‚‚Pt distance of 3.572(1) Å strongly
suggests the absence of an intermetallic bond. The Pt2P2
four-membered ring contains larger Pt-P-Pt bond
angles (Pt(1)-P(2)-Pt(2) ) 98.8(1)°, Pt(1)-P(3)-Pt(2)
) 99.1(1)°) than the P-Pt-P bond angles (P(2)-Pt(1)-
P(3) ) 75.3(1)°, P(2)-Pt(2)-P(3) ) 74.9(1)°).
Figure 1 depicts the molecular structure of 1‚Me2CO by
X-ray crystallography. It consists of three square-planar
Pt(II) centers, bridged by four µ-PPh2 ligands. The two
The 1H NMR spectrum of 1 shows the hydrido signals
at δ -5.83 (2J (H-P) ) 10, 22, 142 Hz, 1J (H-Pt) ) 1032
(7) µ-PCy2: Mastrorilli, P.; Nobile, C. F.; Cosimo, F.; Fanizzi, P.;
Latronico, M.; Hu, C.; Englert, U. Eur. J . Inorg. Chem. 2002, 1210.
(8) µ-PPhH: Parkin, I. P.; Slawin, A. M. Z.; Williams, D. J .; Woollins,
J . D. Inorg. Chim. Acta 1990, 172, 159.
1
Hz) and δ -6.10 (2J (H-P) ) 11, 23, 142 Hz, J (H-Pt)
) 1036 Hz) in 78:22 peak area ratio. The two signals
are attributed to the isomers having the hydrido ligands
at anti or syn positions. We assigned the former signal
to the structure with anti hydrides, which was charac-
terized by X-ray crystallography. The signal at δ -6.10
with coupling constants similar to that at δ -5.83 is
attributed to the isomer with syn structure. The reaction
of Ph2PD with Pt(PEt3)3 gives complex 1-d2, which
(9) µ-PPh2: (a) Taylor, N. J .; Chieh, P. C.; Carty, A. J . J . Chem.
Soc., Chem. Commun. 1975, 448. (b) Bellon, P. L.; Ceriotti, A.;
Demartin, F.; Longoni, G.; Heaton, B. T. J . Chem. Soc., Dalton Trans.
1982, 1671. (c) Bender, R.; Braunstein, P.; Tiripicchio, A.; Camellini,
M. T. Angew. Chem., Int. Ed. Engl. 1985, 24, 861. (d) Hadj-Bagheri,
N.; Browning, J .; Dehghan, K.; Dixon, K. R.; Meanwell, N. J .; Vefghi,
R. J . Organomet. Chem. 1990, 396, C47. (e) Bender, R.; Braunstein,
P.; Dedieu, A.; Ellis, P. D.; Huggins, B.; Harvey, P. D.; Sappa, E.;
Tiripicchio, A. Inorg. Chem. 1996, 35, 1223. (f) Bender, R.; Braunstein,
P.; Bouaoud, S.-E.; Merabet, N.; Rouag, D.; Zanello, P.; Fontani, M.
New J . Chem. 1999, 23, 1045. (g) Archambault, C.; Bender, R.;
Braunstein, P.; Bouaoud, S.-E.; Rouag, D.; Golhen, S.; Ouahab, L.
Chem. Commun. 2001, 849. (h) Fortunelli, A.; Leoni, P.; Marchetti,
L.; Pasquali, M.; Sbrana, F.; Selmi, M. Inorg. Chem. 2001, 40, 3055.
(10) µ-PCy2: Leoni, P.; Marchetti, F.; Pasquali, M.; Marchetti, L.;
Albinati, A. Organometallics 2002, 21, 2176.
(11) (a) Alonso, E.; Fornie´s, J .; Fortun˜o, C.; Mart´ın, A.; Orpen, A.
G. Chem. Commun. 1996, 231. (b) Alonso, E.; Fornie´s, J .; Fortun˜o, C.;
Mart´ın, A.; Orpen, A. G. Organometallics 2000, 19, 2690. (c) Alonso,
E.; Fornie´s, J .; Fortun˜o, C.; Mart´ın, A.; Orpen, A. G. Organometallics
2001, 20, 850. (d) Brunner, H.; Dormeier, S.; Grau, I.; Zabel, M. Eur.
J . Inorg. Chem. 2002, 2603. (e) Alonso, E.; Fornie´s, J .; Fortun˜o, C.;
Mart´ın, A.; Orpen, A. G. Organometallics 2003, 22, 2723.
2
shows broad H NMR signals at δ -5.8 and -6.1 and
1
no H NMR signals in this region, indicating that the
hydrido of the complex is derived from the P-H (or
P-D) hydrogen of diphenylphosphine.
The 31P{1H} NMR spectrum of 1 contains the signals
due to the major isomer with anti structure. The signals
(12) (a) Alonso, E.; Fornie´s, J .; Fortun˜o, C.; Tomas, M. J . Chem. Soc.,
Dalton Trans. 1995, 3777. (b) Alonso, E.; Casas, J . M.; Fornie´s, J .;
Fortun˜o, C.; Mart´ın, A.; Orpen, A. G.; Tsipis, C. A.; Tsipis, A. C.
Organometallics 2001, 20, 5571.

1612 Organometallics, Vol. 23, No. 7, 2004
Itazaki et al.
Sch em e 2
of PEt3 of the bridging PPh2 ligands are observed at δ
1
18.6 (2J (P-P) ) 308 Hz, J (P-Pt) ) 2294 Hz) and δ
-105.9 and -118.6, respectively. The peak positions of
the PPh2 ligands are out of the range of the PPh2 ligand
which is bonded to the two metals, having a metal-
metal bond (δ > 50).3b,4a,12a,13 The signal pattern was
complicated due to the presence of the isotopomers of
the Pt centers and was characterized by comparison of
the spectrum with that simulated based on an AA′BB′M-
M′XX′X′′ spin system, where AA′, BB′, MM′, and XX′X′′
denote 31P nuclei of the PPh2 ligands trans to PEt3 and
those cis to PEt3, PEt3 ligands, and 195Pt nuclei, respec-
tively. The smaller signals of the syn isomer are severely
overlapped with those of the anti isomer, and the precise
peak positions and coupling constants were not deter-
mined.
F igu r e 2. (a) ORTEP drawing (top view) of 3‚Ph2PH with
50% thermal ellipsoidal plots. Hydrogen atoms except for
Pt-H and Ph2PH were omitted for simplicity. (b) Side view
of 3‚Ph2PH. Only Pt and P atoms and hydrido are shown.
complex. Thus, complex 3 is a 46e-trinuclear platinum
complex, containing two Pt(I) and one Pt(II) center.
Braunstein found two crystallographic structures of
the 44e complex with two Pt(I) and one Pt(II) centers,
[Pt3(Ph)(µ-PPh2)3(PPh3)2].9e The structures with “an
open form” had two shorter Pt-Pt bonds (2.758(3) Å)
than the other (3.586(2) Å), whereas “a closed form” with
three similar Pt-Pt bond lengths (2.956(3) and 3.074-
(4) Å) was observed as the crystal structures of the same
complex from different solvents. The geometry of 3 is
comparable with the latter structure with three similar
Pt-Pt distances.
The IR peak of 3 due to Pt-H stretching is observed
at 2035 cm-1, which suggests the nonbridging coordina-
tion of the hydride to a Pt center. The 1H NMR spectrum
of 3 shows the hydrido signal at δ -7.98 as a doublet
(2J (H-P) ) 26 Hz) of triplets (2J (H-P) ) 66 Hz) with
195Pt satellites (1J (H-Pt) ) 899 Hz), indicating that the
hydrido ligand is bonded to one of the three Pt centers
in solution. The coupling constant between the hy-
drido and the P nucleus of PEt3 (26 Hz) is in the range
of PtH(PEt3)Ln complexes17 with H and PEt3 ligands at
cis positions (2J (H-P) ) 14-30 Hz) and much smaller
than those of the complexes with the two ligands at
trans positions (150-162 Hz). The actual H-Pt-PEt3
bond angle in the solid state was determined as 117-
(4)° by X-ray crystallography. Figure 3 shows the
Equimolar reactions of Ph2PH with Pt(PEt3)3 at room
temperature produce the dinuclear platinum(II) complex
[Pt2H2(µ-PPh2)2(PEt3)2] (2) in 67% yield after 15 min and
the triangular complex [Pt3H(µ-PPh2)3(PEt3)3] (3) in 87%
yield after 24 h, respectively, as shown in Scheme 2.
1
The H NMR data of 2 indicate the presence of anti and
syn isomers in 82:18 ratio, similarly to the previously
reported authentic sample.14
An ORTEP view of complex 3 projected onto the plane
of the Pt3 triangle is shown in Figure 2, while selected
bond lengths and angles are listed in Table 2. The three
Pt centers form an equilateral triangle with the Pt-Pt
bond distances Pt(1)-Pt(2) ) 2.9929(4) Å, Pt(1)-Pt(3)
) 2.9784(4) Å, and Pt(2)-Pt(3) ) 2.9983(3) Å. These
distances are longer than those observed in platinum
metal (2.774 Å)9b,15 and in the range reported for
triangular platinum complexes with Pt-Pt bonds.9a,c,e,16
All three edges of the triangle are bridged by µ-PPh2
ligands with bond distances of Pt-P ) 2.242(2)-
2.244(2) Å and bond angles of Pt-P-Pt ) 82.25(6)-
82.73(6)°. The six P atoms of the PEt3 and PPh2 ligands
are included in the Pt3 plane with a deviation smaller
than 0.19 Å from the plane. The hydrido ligand is
located at a distance of 1.4(1) Å from the Pt center. The
distances and angles of the Pt-P bonds around this Pt
center are similar to the other bond parameters of the
(15) (a) Teatum, E. T.; Gschneider, K. A., J r.; Waber, J . T. 1968
Compilation of Calculated Data Useful in Predicting Metallurgical
Behavior of the Elements in Binary Alloy Systems; USAEC Report
LA-4003, 1968 (supersedes Report LA-2345, 1960). (b) Bender, R.;
Braunstein, P.; J ud, J . M.; Dusausoy, Y. Inorg. Chem. 1984, 23, 4489.
(16) (a) Green, M.; Howard, J . A. K.; Murray, M.; Spencer, J . L.;
Stone, F. G. A. J . Chem. Soc., Dalton Trans. 1977, 1509. (b) Evans, D.
G.; Hughes, G. R.; Mingos, D. M. P.; Basset, J .-M.; Welch, A. J . J .
Chem. Soc., Chem. Commun. 1980, 1255. (c) Farrugia, L. J . Howard,
J . A. K.; Mitrprachachon, P.; Stone, F. G. A.; Woodward, P. J . Chem.
Soc., Dalton Trans. 1981, 1134. (d) Scherer, O. J .; Konrad, R.; Guggolz,
E.; Ziegler, M. L. Chem. Ber. 1985, 118, 1. (e) Ferguson, G.; Lloyd, B.
R.; Puddephatt, R. J . Organometallics 1986, 5, 344. (f) Bott, S. G.;
Hallam, M. F.; Ezomo, O. J .; Mingos, D. M. P.; Williams, I. D. J . Chem.
Soc., Dalton Trans. 1988, 1461.
(13) (a) Fornie´s, J .; Fortun˜o, C.; Navarro, R.; Mart´ınez, F.; Welch,
A. J . J . Organomet. Chem. 1990, 394, 643. (b) Falvello, L. R.; Fornie´s,
J .; Fortun˜o, C.; Mart´ın, A.; Mart´ınez-Sarin˜ena, A. P. Organometallics
1997, 16, 5849.
(14) (a) Chatt, J .; Davidson, J . M. J . Chem. Soc. 1964, 2433. (b)
Eaborn, C.; Odell, K. J .; Pidcock, A. J . Organomet. Chem. 1979, 170,
105.

Syntheses of Hydridoplatinum Complexes
Organometallics, Vol. 23, No. 7, 2004 1613
Ta ble 1. An a lytica l Resu lts of Com p lexesa
complex
C (%)
H (%)
[Pt3H2(µ-PPh2)4(PEt3)2] (1)
46.37
43.59
36.39
48.44
46.52
39.85
49.91
46.50
44.77
(46.70)
(43.35)
(36.60)
(48.44)
(46.18)
(39.98)
(49.64)
(46.84)
(44.42)
4.86
4.88
7.22
4.41
4.65
4.40
5.41
4.68
4.22
(4.73)
(5.12)
(7.46)
(4.62)
(4.59)
(4.66)
(5.28)
(4.64)
(4.37)
[Pt3H(µ-PPh2)3(PEt3)3] (3)
[Pt2H2(µ-PtBu2)2(PEt3)2] (4)
[Pt3(SiPh3)(µ-PPh2)3(PEt3)2] (5)
[Pt3(SiHPh2)(µ-PPh2)3(PEt3)2] (6)
[Pt3(µ-PPh2)3(PEt3)3]+I- (7)b
[Pt3(µ-PPh2)3(PEt3)3]+[B4O4(C6H4Me-4)4(OH)]- (8)
[Pt3(µ-PPh2)3(PEt3)3]+[B4O4(C6H4F-4)4(OH)]- (9)
[Pt3(µ-PPh2)3(PEt3)3]+[B4O4(C6H4CF3-4)4(OH)]- (10)
a
b
Calculated values are shown in parentheses. I; 8.05 (7.82).
Ta ble 2. Selected Bon d Dista n ces (Å) a n d An gles (d eg) of Com p lexes 3 a n d 5-8
3
5
6
7
8
(neutral, 46e)
(neutral, 44e)
(neutral, 44e)
(cationic, 44e)
(cationic, 44e)
Pt(1)-Pt(2)
2.9929(4)
2.9784(4)
2.9983(3)
2.242(2)
2.244(2)
2.244(2)
60.281(9)
59.621(9)
60.099(9)
82.25(6)
82.32(6)
82.73(6)
3.0680(2)
3.0413(3)
3.0035(2)
2.314(2)
2.239(1)
2.244(2)
58.892(5)
60.109(5)
60.999(5)
85.31(6)
83.45(3)
82.84(5)
2.9709(3)
3.0090(2)
3.0992(3)
2.313(1)
2.237(1)
2.286(1)
62.430(6)
59.387(6)
58.183(6)
81.54(4)
82.82(4)
86.02(4)
3.0085(4)
3.0140(3)
3.0001(5)
2.249(1)
2.242(2)
2.242(2)
59.755(9)
60.215(9)
60.030(9)
82.54(7)
82.83(7)
82.39(5)
3.0149(3)
3.0309(3)
3.0053(5)
2.258(2)
2.254(2)
2.247(2)
59.613(8)
60.459(8)
59.928(8)
82.99(6)
83.33(7)
82.55(5)
Pt(1)-Pt(3)
Pt(2)-Pt(3)
Pt(1)-P(1) or Si(1)
Pt(2)-P(2)
Pt(3)-P(3)
Pt(2)-Pt(1)-Pt(3)
Pt(1)-Pt(2)-Pt(3)
Pt(1)-Pt(3)-Pt(2)
Pt(1)-P(4)-Pt(2)
Pt(1)-P(6)-Pt(3)
Pt(2)-P(5)-Pt(3)
t
31P{1H} NMR spectrum of 3 and a simulated spectrum
based on the structure. Two signals assigned to the
µ-PPh2 ligands were observed at δ -24.68 (2J (P-P) )
147, 210 Hz, 1J (P-Pt) ) 1960, 2239 Hz) and 161.50
Pt(PEt3)3 reacts with Bu2PH in benzene at 70 °C to
produce the dinuclear platinum(II) complex [Pt2H2(µ-
PtBu2)2(PEt3)2] (4) in 72% isolated yield (eq 2). Figure
1
(2J (P-P) ) 15, 210 Hz, J (P-Pt) ) 2700 Hz) in a 2:1
peak area ratio. High magnetic field shift of the latter
signal is attributed to the µ-PPh2 ligand between the
two Pt(I) centers bonded to each other.9c,e-h,10,18 The two
signals due to the PEt3 ligands are observed at δ 13.64
(2J (P-P) ) 147 Hz, 1J (P-Pt) ) 2403 Hz) and 15.38
(2J (P-P) ) 15 Hz, 3J (P-P) ) -160 Hz, 1J (P-Pt) ) 2942
Hz, 2J (P-Pt) ) 502 Hz, 3J (P-Pt) ) 48 Hz) in ap-
proximately 1:2 peak area ratio. All the NMR results
indicate that complex 3 has one Pt(II) and two Pt(I)
centers and a certain Pt-Pt bond between the Pt(I)
centers.
4 depicts the molecular structure of 4 established by
X-ray crystallography. The two Pt centers are bridged
by the µ-PtBu2 ligands and are bonded with the terminal
PEt3 ligands. Positions of the terminal hydrido ligands
are not determined by X-ray diffraction. Between the
two possible isomers of 4 which have the PEt3 ligands
at the same side or the opposite side of the Pt-Pt
alignment, only the latter isomer was found in the
crystallographic structures (anti).19 Complex 4 shows a
Pt(1)‚‚‚Pt(1*) distance (3.646(1) Å) longer than that of
the Pt-Pt bond of 1. The bond angles P(2)-Pt(1)-P(2*)
) 79.93(11)° and Pt(1)-P(2)-Pt(1*) ) 100.07(11)° are
slightly out of the range of the structural parameters
of the reported phosphido-bridged platinum(II) dimers
without a metal-metal bond (P-Pt-P 74.6-77.2°;
Pt-P-Pt 102.8-105.4°).5a,d,12 The Pt-PPh2 bond trans
(17) (a) Barker, G. K.; Green, M.; Stone, F. G. A.; Welch, A. J .; Onak,
T. P.; Siwapanyoyos, G. J . Chem. Soc., Dalton Trans. 1979, 1687. (b)
Barker, G. K.; Green, M.; Stone, F. G. A.; Welch, A. J .; Wolsey, W. C.
J . Chem. Soc., Chem. Commun. 1980, 627. (c) Almeida, J . F.; Dixon,
K. R.; Eaborn, C.; Hitchcock, P. B.; Pidcock, A.; Vinaixa, J . J . Chem.
Soc., Chem. Commun. 1982, 1315. (d) Barker, G. K.; Green, M.; Stone,
F. G. A.; Wolsey, W. C.; Welch, A. J . J . Chem. Soc., Dalton Trans. 1983,
2063. (e) Cowan, R. L.; Trogler, W. C. J . Am. Chem. Soc. 1989, 111,
4750. (f) Litz, K. E.; Henderson, K.; Gourley, R. W.; Banaszak Holl,
M. M. Organometallics 1995, 14, 5008. (g) Ara, I.; Berenguer, J . R.;
Fornies, J .; Lalinde, E.; Moreno, M. T. Organometallics 1996, 15, 1820.
(h) Han, L.-B.; Choi, N.; Tanaka, M. Organometallics 1996, 15, 3259.
(i) Bender, J . E., IV; Litz, K. E.; Giarikos, D.; Wells, N. J .; Banaszak
Holl, M. M.; Kampf, J . W. Chem. Eur. J . 1997, 3, 1793. (j) Koizumi,
T.; Osakada, K.; Yamamoto, T. Organometallics 1997, 16, 6014. (k)
Batten, S. A.; J effery, J . C.; J ones, P. L.; Mullica, D. F.; Rudd, M. D.;
Sappenfield, E. L.; Stone, F. G. A.; Wolf, A. Inorg. Chem. 1997, 36,
2570. (l) Edelbach, B. L.; Lachicotte, R. J .; J ones, W. D. J . Am. Chem.
Soc. 1998, 120, 2843. (m) Edelbach, B. L.; Vicic, D. A.; Lachicotte, R.
J .; J ones, W. D. Organometallics 1998, 17, 4784. (n) Goodwin, A. A.;
Bu, X.; Deming, T. J . J . Organomet. Chem. 1999, 589, 111.
(18) Brandon, J . B.; Dixon, K. R. Can. J . Chem. 1981, 59, 1188.
(19) The other isomer, syn, for [Pt2H2(PCy3H)2(µ-PCy2)2] was re-
ported.7

1614 Organometallics, Vol. 23, No. 7, 2004
Itazaki et al.
F igu r e 5. (a) Observed (C6D6, rt) and (b) calculated
31P{1H} NMR spectra (121.5 MHz) of 4.
F igu r e 3. (a) Observed (CD2Cl2, rt) and (b) simulated 31P-
{1H} NMR spectra (202.4 MHz) of 3.
F igu r e 6. Profile of the amounts of Pt contained in the
complexes during the reaction of Ph2PH with Pt(PEt3)3 in
an NMR tube scaled at 25 °C. [Pt(PEt3)3] ) 160 mM at
t ) 0.
(2J (P-P) ) -15, 40, 285 Hz, 1J (P-Pt) ) 1496, 2016 Hz).
The high-field signal at δ -83.6 is typical for the
bridging phosphido ligand involved in the complexes
without a Pt-Pt bond. All these NMR results indicate
a symmetrical dimeric structure, in which two platinum
atoms bearing a PEt3 ligand are bridged by two PtBu2
ligands.
Mech a n ism of F or m a tion of 1. Complex 1 is formed
also from the reaction of Ph2PH with a mixture of 2 and
Pt(PEt3)3 in 70% yield (eq 3). This reaction is enhanced
F igu r e 4. ORTEP drawing of 4 with 50% thermal el-
lipsoidal plots. Atoms with asterisks are crystallographi-
cally equivalent to those having the same number without
asterisks. Hydrido ligands were not located. Hydrogen
atoms were omitted for simplicity. Selected bond distances
(Å) and angles (deg): Pt(1)-P(1) ) 2.277(3), Pt(1)-P(2) )
2.345(3), Pt(1)-P(2*) ) 2.412(3), Pt(1)‚‚‚Pt(1*) ) 3.646(1),
P(2)‚‚‚P(2*) ) 3.056(6); P(1)-Pt(1)-P(2) ) 166.01(12),
P(1)-Pt(1)-P(2*) ) 114.05(11), P(2)-Pt(1)-P(2*) ) 79.93-
(11), Pt(1)-P(2)-Pt(1*) ) 100.07(11).
to PEt3 (2.345(3) Å) is shorter than the bond trans to
the hydrido ligand (2.412(3) Å), suggesting that the
hydrido ligand has stronger trans influence than PEt3.
Complex 4 exhibits the IR band due to Pt-H stretch-
ing at 2022 cm-1. The 1H NMR signal of the hydrido
ligand at δ -7.33 exhibits splitting due to H-P coupling.
The coupling constant (151 Hz) being much larger than
the other two coupling constants is assigned to that
between the hydrido and µ-PtBu2 ligand at trans posi-
tions. The coupling constant, 1J (H-Pt), of 903 Hz is
within those of the terminal hydrido ligand of diplati-
num complexes (800-1400 Hz).20 Figure 5 compares the
observed and calculated 31P{1H} NMR spectra which
contain resonances at δ 22.0 (2J (P-P) ) -20, -15, 285
by removal of a free PEt3 ligand under vacuum, which
renders the replacement of the PEt3 ligand by Ph2PH
facile. Figure 6 depicts a change of the amount of the
1
3
Hz, J (P-Pt) ) 1972 Hz, J (P-Pt) ) 74 Hz) and -83.6

Syntheses of Hydridoplatinum Complexes
Organometallics, Vol. 23, No. 7, 2004 1615
dimerization of [PtH(PtBu2)(PEt3)2] into 4 and prevents
formation of the linear trinuclear complex [Pt3H2-
(µ-PtBu2)4(PEt3)2] with bridging di(tert-butyl)phosphido
ligands. Complex 2 reacts further with Pt(PEt3)3 in the
presence of Ph2PH and/or with [PtH(PPh2)(PEt3)2] to
form the triangular intermediate 3. Evolution of H2,
which was detected by GC during reaction 1, takes place
at this stage. Complex 3 reacts with Ph2PH to form the
linear complex 1 accompanied by liberation of PEt3.
Scheme 4 summarizes a mechanism of the reaction
involving skeletal rearrangement of the Pt3 unit. Re-
placement of a PEt3 ligand of 3 with added Ph2PH is
followed by transfer of the P-H hydrogen of the ligand
to the Pt(I) center bonded to the PEt3 ligand. A cyclic
intermediate A, formed by the reaction, undergoes
bridging coordination of this PPh2 ligand and rear-
rangement to the linear complex 1, while another
possible intermediate B undergoes bridging coordination
of the two PPh2 ligands to give 1. Oxidative addition of
Ph2PH to the two Pt(I) centers of 3 is less plausible for
the formation of these intermediates than reactions in
Scheme 4 because formation of 1 in the reactions 1, 3,
and 4 is accelerated by removal of PEt3 from the solution
under vacuum.
Rea ction s of 3 w ith Or ga n osila n es a n d Ar ylbo-
r on ic Acid s. Complex 3 has a neutral and 46-electron
structure composed of two Pt(I) and one Pt(II) center.
The hydrido ligand of the triangular platinum com-
plexes is much rarer9b,h,10,22 than mono- and dinuclear
hydridoplatinum complexes.6b We conducted the reac-
tions of several organic molecules with 3, expecting the
formation of new triangular Pt complexes via the
reaction of the Pt-H bond. The reactions of Ph3SiH and
of Ph2SiH2 with 3 afford [Pt3(SiPh3)(µ-PPh2)3(PEt3)2] (5)
and [Pt3(SiHPh2)(µ-PPh2)3(PEt3)2] (6) in 75% and 82%
yields, respectively (eq 5). The molecular structures of
Sch em e 3
complexes monitored by the 1H NMR spectra of the
reaction mixture of Ph2PH and Pt(PEt3)3 (2:1) at room
temperature. The 1H NMR spectrum after 20 min
showed characteristic signals assigned to the hydrido
ligands of 2 (δ -5.32) and 3 (δ -7.52), indicating the
formation of the complexes in 55% and 18% yields,
respectively. The 31P{1H} NMR spectrum of the reaction
mixture measured at -70 °C and ESI-MS spectrum (m/z
997, calculated for [Pt2H(µ-PPh2)2(PEt3)2]+; m/z 1494,
calculated for [Pt3(µ-PPh2)3(PEt3)3]+) also support the
formation of 2 and 3 at this stage. Complex 3 increases
concomitantly with a decrease of 2, indicating conver-
sion of 2 into 3 during the reaction. The initially formed
2 is consumed completely after 168 h, along with
formation of 1. In this reaction, removal of a free PEt3
ligand under reduced pressure accelerates conversion
of 3 into 1. The 1:2 reaction of isolated complex 3 with
Ph2PH also produces 1 in 75% yield (eq 4). These results
indicate that complexes 2 and 3 are formed as the in-
termediate of reaction 1.
A plausible reaction pathway for formation of di-
nuclear complexes 2 and 4 and trinuclear complexes 1
and 3 is shown in Scheme 3. Oxidative addition of
R2PH (R ) Ph, tBu) to Pt(PEt3)3 produces an intermedi-
ate Pt(II) complex, [PtH(PPh2)(PEt3)2], via cleavage of
the P-H bond,21 although this complex was not ob-
served in the reaction mixture. Dimerization of the
complex accompanied by elimination of PEt3 leads to
the dinuclear intermediate complex 2. The reaction of
tBu2PH with Pt(PEt3)3 produces 4 under more severe
conditions (24 h at 70 °C) than that of Ph2PH (15 min
at room temperature) and does not give any trinuclear
complexes. The sterically bulky tBu substituent retards
5 and 6 determined by X-ray crystallography are
depicted in Figures7 and 8. The Pt-Pt bond distances
of 5 are similar to those of [Pt3{Si(OSiMe3)3}(µ-PPh2)3-
(PPh3)2], in which the Pt(I)-Pt(I) bond opposite the silyl
ligand (3.0035(2) Å) is the shortest among the three
Pt-Pt bond distances. Complex 6, however, has a
Pt(I)-Pt(I) bond (3.0992(3) Å) that is slightly longer
than the Pt(I)-Pt(II) bond (2.9709(3) and 3.0090(2) Å).
Steric repulsion between the phenyl rings of the µ-PPh2
and of the SiPh3 ligands renders the angle of Pt(2)-
Pt(1)-Pt(3) smaller (58.892(5)°) than the corresponding
bond angle of 6, with the less bulky SiHPh2 ligand

1616 Organometallics, Vol. 23, No. 7, 2004
Itazaki et al.
Sch em e 4
the chemically inequivalent phosphido ligands (5, δ
79.05 and 92.49; 6, δ 79.96 and 91.73) in a 1:2 peak area
ratio. All these signals are flanked by satellites due
to a coupling with 195Pt. Their formation could be
explained by oxidative addition of the hydrosilanes to
3, followed by reductive elimination of H2 or, alterna-
tively, by σ-bond metathesis. The latter mechanism
would have the advantage of avoiding formal oxidation
of the Pt(II) center in the mixed-valence complex 3.
MeI was also employed to abstract the hydrido ligand
of 3.24 An orange benzene solution of 3 quickly turned
red upon addition of an equimolar amount of MeI. After
the solution was stirred for 5 h at room temperature,
[Pt3(µ-PPh2)3(PEt3)3]+I- (7) was isolated as a dark red
solid (eq 6). A perspective view of the molecular struc-
F igu r e 7. ORTEP drawing of 5 with 50% thermal el-
lipsoidal plots. Hydrogen atoms were omitted for simplicity.
ture of 7 is shown in Figure 9, while the bond distances
and angles are listed in Table 2. The cation has three
Pt atoms arranged in an almost regular triangle, with
Pt-Pt bond distances of Pt(1)-Pt(2) ) 3.0085(4) Å,
Pt(1)-Pt(3) ) 3.0140(3) Å, and Pt(2)-Pt(3) ) 3.0001-
F igu r e 8. ORTEP drawing of 6 with 50% thermal el-
lipsoidal plots. Hydrogen atoms were omitted for simplicity.
(62.430(6)°). The Pt-P bond distances lie in the usual
range, and the Pt-Si bonds (2.314(2) Å in 5 and 2.313-
(1) Å in 6) are comparable to the single bond of the
reported silylplatinum complexes.23
(20) (a) Brown, M. P.; Puddephatt, R. J .; Rashidi, M.; Seddon, K. R.
J . Chem. Soc., Dalton Trans. 1978, 516. (b) Bracher, G.; Grove, D. M.
Venanzi, L. M.; Bachechi, F.; Mura, P.; Zambonelli, L. Angew. Chem.,
Int. Ed. Engl. 1978, 17, 778. (c) Morris, R. H.; Foley, H. C.; Targos, T.
S.; Geoffroy, G. L. J . Am. Chem. Soc. 1981, 103, 7337. (d) Venanzi, L.
M. Coord. Chem. Rev. 1982, 43, 251. (e) Moore, D. S.; Robinson, S. D.
Chem. Soc. Rev. 1983, 12, 415. (f) Paonessa, R. S.; Troger, W. C. J .
Am. Chem. Soc. 1982, 104, 3529. (g) Paonessa, R. S.; Trogler, W. C.
Inorg. Chem. 1983, 22, 1038. (h) Bachechi, F.; Bracher, G.; Grove, D.
M.; Kellenberger, B.; Pregosin, P. S.; Venanzi, L. M.; Zambonelli, L.
Inorg, Chem. 1983, 22, 1031. (i) McLennan, A. J .; Puddephatt, R. J .
Organometallics 1986, 5, 811.
1
The H NMR spectrum of 6 shows the signal of the
3
Si-H hydrogen at δ 5.74 (3J (H-P) ) 10 Hz, J (H-Pt)
) 65 Hz, 2J (H-Pt) ) 170 Hz). The 31P{1H} NMR spectra
of 5 and 6 contain three signals, corresponding to the
terminal PEt3 ligands (5, δ -7.68; 6, δ -4.43) and to

Syntheses of Hydridoplatinum Complexes
Organometallics, Vol. 23, No. 7, 2004 1617
(5) Å. The Pt-Pt bonds are bridged by the phosphido
ligands, with the P atoms lying approximately on the
plane defined by the Pt atoms. Although a certain
number of 44e- cationic triangular platinum species
such as [Pt3(µ-X)(µ-PPh2)2(PPh3)3]+ (X ) Cl, Br, SR,
PPh2) are known,9d complex 7, to the best of our
knowledge, is the first cationic Pt triangular derivative
represented by the general formula [Pt3(µ-L)3(L′)3]+ (L
) phosphido, L′ ) phosphines) characterized by X-ray
crystallography. The 31P{1H} NMR spectrum of 7 ex-
hibits two signals at δ -2.65 (m, 2J (P-P) ) 63 Hz,
1J (P-Pt) ) 118, 4173 Hz) and δ 81.47 (m, J (P-P) )
2
-211 Hz, 1J (P-Pt) ) -103, 2246 Hz), indicating
equivalency of all PEt3 and µ-PPh2 ligands.
F igu r e 9. ORTEP drawing of 7‚CH2Cl2 with 50% thermal
ellipsoidal plots. Hydrogen atoms and CH2Cl2 were omitted
for simplicity.
One of the other synthetic protocols to obtain a
cationic trinuclear platinum complex is protonation by
a Brønsted acid. Leoni et al. reported that the neutral
[Pt3(µ-PtBu2)3(H)(CO)2] protonated with TfOH generated
the cationic [Pt3(µ-PtBu2)(µ-H)(PtBu2H)(CO)2]OTf, along
with migration of the µ-PtBu2 ligand into one of the
Pt-H bonds.9h We have been engaged in studies of the
reaction of weakly acidic arylboronic acid with Rh
complexes to form novel Rh complexes with B-contain-
ing counteranions.25 The reactions of 4 times molar
arylboronic acids with 3 afforded the cationic platinum
complexes [Pt3(µ-PPh2)3(PEt3)3][B4O4(OH)Ar4] (8, Ar )
4-methylphenyl; 9, Ar ) 4-fluorophenyl; 10, Ar )
4-trifluoromethylphenyl) (eq 7). Complexes 8-10 were
F igu r e 10. ORTEP drawing of 8 with 50% thermal
ellipsoidal plots. Hydrogen atoms were omitted for sim-
plicity. Selected bond distances (Å) and angles (deg):
O(1)-B(1) ) 1.45(1), O(1)-B(2) ) 1.33(1), O(2)-B(2) )
1.393(8), O(2)-B(3) ) 1.38(1), O(3)-B(1) ) 1.513(8), O(3)-
B(3) ) 1.34(1), O(4)-B(1) ) 1.48(1), O(4)-B(4) ) 1.433(1),
O(5)-B(4) ) 1.37(1), C(55)-B(1) ) 1.64(2); O(1)-B(1)-O(3)
) 111.0(7), O(1)-B(1)-O(4) ) 108.0(7), O(3)-B(1)-O(4) )
108.8(7), O(1)-B(2)-O(2) ) 121.6(8), O(2)-B(3)-O(3) )
121.9(6), O(4)-B(4)-O(5) ) 123.4(7), O(1)-B(1)-C(55) )
109.3(7), O(3)-B(1)-C(55) ) 110.2(7), O(4)-B(1)-C(55) )
109.4(7).
of the cationic part of 8 is similar to that of 7, while the
anion part is composed of a novel tetraborate anion,
[B4O4(C6H4Me-4)4(OH)]-, bearing a six-membered borox-
ine ring. The boroxine ring is almost flat due to pπ-pπ
conjugation between filled p orbitals of oxygen and
vacant p orbitals of boron.26 The presence of a tetraco-
ordinate boron atom of the B3O3 ring is observed; the
B-O bonds of tetracoordinate boron (1.45(1)-1.513(8)
Å) are longer than those observed in tricoordinate boron
atoms (1.33(1)-1.393(8) Å). The two aryl planes are
situated in parallel to a boroxine plane by the delocal-
ization of the pπ orbitals of the boroxine and aryl rings.
The 11B NMR spectrum of 8 contains the two signals
which are assigned to the tetracoordinate boron (δ 4.10)
and tricoordinate boron (δ 28.12) nuclei in ca. 1:3 ratio.
characterized by comparison of the NMR signals with
those of 7 (1H, 13C{1H}, and 31P{1H}), elemental analy-
ses, and X-ray diffraction of 8. An ORTEP drawing of 8
by X-ray diffraction is shown in Figure 10. The structure
(21) (a) Pringle, P. G.; Smith, M. B. J . Chem. Soc., Chem. Commun.
1990, 1701. (b) Hogarth, G.; Lavender, M. H. J . Chem. Soc., Dalton
Trans. 1992, 2759. (c) Baker, R. T.; Calabrese, J . C.; Harlow, R. L.;
Williams, I. D. Organometallics 1993, 12, 830. (d) Han, L.-B.; Tanaka,
M. J . Am. Chem. Soc. 1996, 118, 1571. (e) Wicht, D. K.; Kourkine, I.
V.; Lew, B. M.; Nthenge, J . M.; Glueck, D. S. J . Am. Chem. Soc. 1997,
119, 5039. (f) Bourumeau, K.; Gaumont, A.-C.; Denis, J .-M. J . Orga-
nomet. Chem. 1997, 529, 205. (g) Costa, E.; Pringle, P. G.; Worboys,
K. Chem. Commun. 1998, 49. (h) Field, L. D.; J ones, N. G.; Turner, P.
J . Organomet. Chem. 1998, 571, 195. (i) Dorn, H.; J aska, C. A.; Singh,
R. A.; Lough, A. J .; Manners, I. Chem. Commun. 2000, 1041. (j) King,
J . D.; Mays, M. J .; Mo, C.-Y.; Solan, G. A.; Conole, G.; McPartlin, M.
J . Organomet. Chem. 2002, 642, 227.
1
The H, 11B, and 31P{1H} NMR spectra of 9 and 10 are
similar to those of 8. An inorganic borate with a similar
framework, [B4O4(OH)5]-, was detected as a product of
the gas phase analysis of H3BO3 by negative CI mass
spectra.27 The anion of 8 is the first fully characterized
anion with the [B4O4(OH)X4]- framework.
Mech a n ism for F or m a tion of 8-10. Scheme 5
depicts the plausible pathway for the formation of 8-10.
An arylboronic acid reacts with 3 to produce the cationic
triplatinum complex and the arylboronate anion ac-
(22) Pt-H (terminal): Leoni, P.; Mannetti, S.; F.; Pasquali, M.;
Albinati, A. Inorg. Chem. 1996, 35, 6045.
(23) (a) Ebsworth, E. A. V.; Marganian, V. M.; Reed F. J . S.; Gould,
R. O. J . Chem. Soc., Dalton Trans. 1978, 1167. (b) Tilley, T. D. In
Transition-Metal Silyl Derivatives; Patai, S., Rappoport, Z., Eds.;
Wiley: New York, 1991; p 245. (c) Braunstein, P.; Knorr, M.; Hirle,
B.; Reinhard G.; Schubert, U. Angew. Chem., Int. Ed. Engl. 1992, 31,
1583.

1618 Organometallics, Vol. 23, No. 7, 2004
Itazaki et al.
Sch em e 5
Å). The IR spectra were recorded on a Shimadzu FTIR-8100A
spectrometer in KBr.
companied by liberation of H2. Transfer of the borate
to the electrophilic boron centers of arylboronic acid
accompanied by cyclocondensation with two other aryl-
boronic acid molecules or direct B-O bond formation
between the borate and boroxine,26a,b,d which is equili-
brated with the arylboronic acid via cyclocondensation,
leads to the formation of [B4O4(Ar)4(OH)]-. An equimo-
lar reaction of 4-methylphenylboronic acid with 3 pro-
duces 8 in 24% yield (by NMR) and unreacted 3,
indicating that the Pt-complex-promoted activation of
the O-H bond in the added arylboronic acid is slower
than the condensation of arylboronic acids toward
arylboroxine or arylboronates.
In conclusion, this paper presents new di- or tri-
nuclear phosphido-bridged platinum complexes with
hydrido ligands and mechanistic implication of forma-
tion of the linear triplatinum complex, complex 3, an
intermediate of the formation of the linear trinuclear
complex 1 upon addition of Ph2PH. The Pt-H bond of
3 reacts with the Si-H bond of neutral Ph3SiH and
Ph2SiH2, the C-I bond of electrophilic MeI, and the
O-H bond of weakly acidic arylboronic acid to produce
the products with the respective new structures.
P r ep a r a t ion of [P t3H 2(µ-P P h 2)4(P E t3)2] (1) (eq 1). To
a benzene (15 mL) solution of Pt(PEt3)3 (560 mg, 1.0 mmol)
was added Ph2PH (348 µL, 2.0 mmol) at room temperature.
The color of the solution turned from orange to red with
stirring. After 12 h the volatiles were removed under reduced
pressure. Addition of hexane (10 mL) to the resulting dark
red oily materials and stirring for 96 h led to the formation of
a yellow powder, which was filtered, washed with acetone (5
mL, 2 times), and dried in vacuo to give 1 as a yellow solid
(426 mg, 0.27 mmol, 80% based on Pt, anti:syn ) 78:22).
Complex 1 crystallized from acetone at room temperature as
yellow crystals. 1H NMR (500 MHz, CD2Cl2, rt): δ -6.10 (ddd
(syn) 2J (H-P) ) 11, 23, 142 Hz, 1J (H-Pt) ) 1036 Hz, 2H,
Pt-H), -5.83 (ddd, (anti) 2J (H-P) ) 10, 22, 142 Hz,
1J (H-Pt) ) 1032 Hz, 2H, Pt-H), 0.84 (dt, (anti) 3J (H-H) ) 7
Hz, 3J (H-P) ) 17.0 Hz, 18H, PCH2CH3, overlapped syn), 1.24
(dq, (anti) 3J (H-H) ) 8 Hz, 2J (H-P) ) 8 Hz, 12H, PCH2CH3),
1.34 (dq, (syn), 3J (H-H) ) 8 Hz, 2J (H-P) ) 8 Hz, 12H, PCH2-
CH3), 6.79-7.30 (m, (anti) 40H, Ph, overlapped with syn).
31P{1H} NMR (202 MHz, CD2Cl2, rt): δ -118.6 ((anti),
2J (P-P) ) -19, 108, 200 Hz, 1J (P-Pt) ) 1232, 1273 Hz,
3J (P-Pt) ) 248 Hz, overlapped with syn), -105.9 ((anti),
2J (P-P) ) -19, 108, 300 Hz, 1J (P-Pt) ) 1807, 1935 Hz
,
3J (P-Pt) ) 13 Hz, overlapped with syn), 18.6 ((anti),
2J (P-P) ) 308 Hz, 1J (P-Pt) ) 2294 Hz, overlapped with syn).
Exp er im en ta l Section
IR (KBr): 1989 cm-1 (νPtH).
Gen er a l P r oced u r es. All manipulations were carried out
under a nitrogen or an argon atmosphere using standard
Schlenk techniques. Pt(PEt3)3,28 Ph2PH,29 and Ph2PD29 were
prepared according to literature methods. NMR spectra (1H,
13C{1H}, and 31P{1H}) were recorded on J EOL GX-500, J EOL
EX-400, and Varian Mercury 300 spectrometers. Residual
peaks of solvent were used as the reference for 1H NMR (δ
5.32 dichloromethane-d2, δ 7.15 benzene-d6) and for 13C{1H}
NMR (δ 53.8 dichloromethane-d2, δ 128.0 benzene-d6). 31P{1H}
and 11B NMR signals were referenced with external 85%
H3PO4 (δ 0) and BF3‚OEt2 (δ 0), respectively. 19F{1H} NMR
signals were referenced with internal CFCl3 (δ 0). Elemental
analyses were carried out with a Yanaco MT-5 CHN auto-
corder. The evolution of H2 gas was analyzed by on-line gas
chromatography (Shimadzu, GC-8A, TCD, molecular sieve 5
P r ep a r a t ion of [P t2H 2(µ-P P h 2)2(P E t3)2] (2) (Sch em e
1).14 To a hexane (5 mL) solution of Pt(PEt3)3 (1.1 g, 2.0 mmol)
was added Ph2PH (360 µL, 2.0 mmol) at room temperature.
The color of the solution turned from orange to red with
stirring. The resulting red solution led to the formation of an
orange solid with stirring for 15 min. After the sample was
cooled at -20 °C, the resulting orange solid was filtered off
and dried in vacuo to give 2 as an orange solid (668 mg, 67%,
anti:syn ) 82:18). 1H NMR (500 MHz, toluene-d8, rt): δ -6.13
2
1
(br, J (H-P) ) 198 Hz, J (H-Pt) ) 1034 Hz, 2H, PtH (syn)),
-5.69 (ddd, 2J (H-P) ) 47, 61, 198 Hz, 1J (H-Pt) ) 1046
3
3
Hz, 2H, PtH (anti)), 0.88 (dt, J (H-H) ) 8 Hz, J (H-P) ) 16
Hz, 18H, PCH2CH3, (anti) overlapped with syn), 1.20 (m,
3J (H-H) ) 8 Hz, 12H, PCH2CH3 (anti)), 1.32 (br, 12H, PCH2-
CH3 (syn)), 6.94-7.10 (m, 12H, Ph (anti) overlapped with syn),

Syntheses of Hydridoplatinum Complexes
Organometallics, Vol. 23, No. 7, 2004 1619
7.89 (m, 8H, Ph (anti) overlapped with syn). IR (KBr): 2004
cm-1 (νPtH).
were removed under reduced pressure. Addition of hexane (10
mL) to the resulting dark red oily materials led to the
formation of a yellow powder with stirring at 96 h, which was
filtered and washed with 5 mL of acetone (2 times), collected
by filtration, and dried in vacuo to give 3 as a yellow solid
(176 mg, 0.11 mmol, 75%).
Rea ction of P h 2P H w ith P t(P Et3)3 on th e NMR Sca le
(F igu r e 6). To a solution of Pt(PEt3)3 (55 mg, 0.1 mmol) in
toluene-d8 (0.6 mL) was added Ph2PH (35 µL, 0.2 mmol) at
room temperature. The 1H NMR spectra were recorded over
168 h. The yields of complexes 1-3 were determined by 1H
NMR based on Pt using diphenylmethane (17 µL, 0.1 mmol)
as an internal standard.
P r ep a r a tion of [P t3H(µ-P P h 2)3(P Et3)3] (3) (Sch em e 1).
To a hexane (3 mL) solution of Pt(PEt3)3 (560 mg, 1.0 mmol)
was added Ph2PH (180 µL, 1.0 mmol) at room temperature.
The color of the solution turned from orange to red with
stirring. The resulting red solution led to the formation of an
orange solid with stirring for 24 h. The solid product was
collected by filtration and dried in vacuo to give 3 as an orange
solid (440 mg, 87%). Dark red single crystals of 3 were obtained
from the reaction mixture of Ph2PH with Pt(PEt3)3 in 2:1 ratio
in toluene-d8. 1H NMR (500 MHz, CD2Cl2, rt): δ -7.98 (dt,
2J (H-P) ) 26, 66 Hz, 1J (H-Pt) ) 899 Hz, 1H, Pt-H), 0.56
(dt, 3J (H-H) ) 8 Hz, 3J (H-P) ) 16 Hz, 18H, PCH2CH3), 1.03
P r ep a r a tion of [P t3(SiP h 3)(µ-P P h 2)3(P Et3)2] (5) a n d
[P t3(SiHP h 2)(µ-P P h 2)3(P Et3)2] (6). To a benzene (3 mL)
solution of 3 (150 mg, 0.1 mmol) was added Ph3SiH (26.0 mg,
0.1 mmol) at room temperature. The color of the solution
turned immediately from orange to red with stirring. After 12
h, the solvent was removed under reduced pressure. Addition
of hexane (2 mL) to the resulting red residue at -78 °C led to
the formation of an orange solid, which was washed with
hexane (2 mL, 2 times), collected by filtration, and dried in
vacuo to give 5 as an orange solid (123.5 mg, 0.075 mmol, 75%).
Complex 5 crystallized from CH2Cl2-hexane at room temper-
ature as dark red crystals suitable for X-ray analysis. 1H NMR
3
3
(dt, J (H-H) ) 8 Hz, J (H-P) ) 16 Hz, 9H, PCH2CH3), 1.16
3
2
(dq, J (H-H) ) 8 Hz, J (H-P) ) 4 Hz, 12H, PCH2CH3), 1.40
3
2
(dq, J (H-H) ) 8 Hz, J (H-P) ) 8 Hz, 6H, PCH2CH3), 6.95-
6.96 (m, 12H, Ph), 7.28-7.33 (m, 6H, Ph), 7.54-7.55 (m, 8H,
Ph), 7.78 (m, 4H, Ph). 13C{1H} NMR (126 MHz, CD2Cl2, rt): δ
3
3
8.21 (s, J (C-Pt) ) 20 Hz, PCH2CH3), 9.15 (s, J (C-Pt) ) 26
1
2
Hz, PCH2CH3), 19.38 (m, J (C-P) ) 2, 10 Hz, J (C-Pt) ) 45
Hz, PCH2CH3), 20.23 (d, 1J (C-P) ) 29 Hz, 2J (C-Pt) ) 36 Hz,
PCH2CH3), 126.12 (s, Ph-para), 126.43 (d, 3J (C-P) ) 8 Hz,
Ph-meta), 127.73 (d, 3J (C-P) ) 10 Hz, Ph-meta), 127.79 (s,
Ph-para), 133.14 (d, 2J (C-P) ) 13 Hz, 3J (C-Pt) ) 16 Hz,
Ph-ortho), 135.82 (d, 2J (C-P) ) 12 Hz, 3J (C-Pt) ) 32 Hz,
Ph-ortho), 141.65 (d, 1J (C-P) ) 19 Hz, 2J (C-Pt) ) 35 Hz,
3
3
(500 MHz, CD2Cl2, rt): δ 0.38 (dt, J (H-H) ) 8 Hz, J (H-P)
) 16 Hz, 18H, PCH2CH3), 1.51 (dq, 3J (H-H) ) 8 Hz, 3J (H-P)
) 8 Hz, 12H, PCH2CH3), 6.72 (t, J (H-H) ) 8 Hz, 6H,
Si-Ph), 6.87-6.90 (m, 9H, Si-Ph), 6.94 (t, J (H-H) ) 8 Hz,
8H, µ-PPh), 7.05-7.13 (m, 12H, µ-PPh), 7.23 (m, 2H, µ-PPh),
7.29 (m, 4H, µ-PPh), 7.75 (m, 4H, µ-PPh). 13C{1H} NMR (126
MHz, CD2Cl2, rt): δ 7.91 (s, PCH2CH3), 18.70 (dd, PCH2CH3),
126.05 (s), 127.21 (m), 127.32 (br), 127.93 (m), 133.74 (dt, J )
13, 2 Hz), 133.94 (dt, J ) 7, 2 Hz), 137.18 (s, J (C-Pt) ) 23
Hz), 139.69 (dt, J ) 18, 2 Hz), 140.24 (dt, J ) 31, 2 Hz), 146.68
(s, J (C-Pt) ) 66 Hz, Ph-ipso). 31P{1H} NMR (202 MHz,
CD2Cl2, rt): δ -7.68 (m, 1J (P-Pt) ) 4133, 2J (P-Pt) ) 191 Hz,
J (P-P) ) 108 Hz, PEt3), 79.05 (m, 1J (P-Pt) ) 2330, 2J (P-Pt)
1
Ph-ipso), 147.94 (d, J (C-P) ) 18 Hz, Ph-ipso). 31P{1H} NMR
2
(202 MHz, CD2Cl2, rt): δ -24.68 (br, J (P-P) ) 147, 210 Hz,
1J (P-Pt) ) 1960, 2239 Hz, µ-PPh), 13.64 (t, 2J (P-P) ) 147
Hz, 1J (P-Pt) ) 2403 Hz, PEt3), 15.38 (m, 3J (P-P) ) -160 Hz,
2J (P-P) ) 15 Hz, 3J (P-Pt) ) 48 Hz, 2J (P-Pt) ) 502 Hz,
2
1J (P-Pt) ) 2942 Hz, PEt3), 161.50 (tt, J (P-P) ) 15, 210 Hz,
1J (P-Pt) ) 2700 Hz, µ-PPh). IR (KBr): 2035 cm-1 (νPtH).
P r ep a r a tion of [P t2H2(µ-P tBu 2)2(P Et3)2] (4) (eq 2). To a
benzene (10 mL) solution of Pt(PEt3)3 (550 mg, 1.0 mmol) was
t
added Bu2PH (407 µL, 2.2 mmol) at room temperature. The
resulting mixture was heated at 70 °C for 24 h, and the color
of the solution turned from pale orange to orange with stirring.
The volatiles were removed under reduced pressure. Addition
of hexane (2 mL) to the resulting orange oily materials at -78
°C led to the formation of a pale yellow powder, which was
washed with 2 mL of hexane (2 times) at -78 °C, collected by
filtration, and dried in vacuo to give 4 as a pale yellow solid
(331 mg, 0.36 mmol, 72%/based on Pt). Complex 4 crystallized
from hexane at -20 °C as yellow crystals. 1H NMR (500 MHz,
2
1
) -70 Hz, J (P-P) ) 195 Hz, µ-PPh2), 92.49 (m, J (P-Pt) )
2283, 2195 Hz, 2J (P-Pt) ) 147 Hz, 2J (P-P) ) 248, 195 Hz,
µ-PPh2).
[Pt3(SiHPh2)(µ-PPh2)3(PEt3)2] (6) was prepared analogously
to 5 from the reaction of Ph2SiH2 (18.6 µL, 0.1 mmol) with 3
(150 mg, 0.1 mmol) for 3 h at room temperature (128.0 mg,
0.082 mmol, 82%). Complex 6 crystallized from CH2Cl2-
hexane at room temperature as dark red crystals. 1H NMR
2
1
3
3
C6D6, rt): δ -7.33 (ddd, J (H-P) ) 19, 23, 151 Hz, J (H-Pt)
(500 MHz, CD2Cl2, rt): δ 0.44 (dt, J (H-H) ) 8 Hz, J (H-P)
) 16 Hz, 18H, PCH2CH3), 1.61 (dt, 3J (H-H) ) 8 Hz, 3J (H-P)
) 16 Hz, 12H, PCH2CH3), 5.74 (t, 3J (H-P) ) 10 Hz, 3J (H-Pt)
) 65 Hz, 2J (H-Pt) ) 170 Hz, 1H), 6.77 (t, J (H-H) ) 8 Hz,
4H, Ph), 6.89-6.92 (m, 6H, Ph), 7.06 (t, J (H-H) ) 8 Hz, 8H,
Ph), 7.13 (m, 4H, Ph), 7.23 (m, 2H, Ph), 7.29 (m, 4H, Ph), 7.37-
7.42 (m, 8H, Ph), 7.71-7.74 (m, 4H, Ph). 13C{1H} NMR (126
MHz, CD2Cl2, rt): δ 8.01 (s, PCH2CH3), 19.25 (t, 2J (C-P) )
16 Hz, 3J (C-Pt) ) 64 Hz, PCH2CH3), 126.12 (s, Ph-para),
126.43 (d, 3J (C-P) ) 8 Hz, Ph-meta), 127.73 (d, 3J (C-P) ) 10
Hz, Ph-meta), 127.79 (s, Ph-para), 133.14 (d, 2J (C-P) ) 13
Hz, 3J (C-Pt) ) 16 Hz, Ph-ortho), 135.82 (d, 2J (C-P) ) 12 Hz,
3J (C-Pt) ) 32 Hz, Ph-ortho), 141.65 (d, 1J (C-P) ) 19 Hz,
2J (C-Pt) ) 35 Hz, Ph-ipso), 147.94 (d, 1J (C-P) ) 18 Hz,
Ph-ipso). 31P{1H} NMR (202 MHz, CD2Cl2, rt): δ -4.43 (m,
1J (P-Pt) ) 4191 Hz, 2J (P-Pt) ) 188 Hz, PEt3), 79.96 (m,
3
) 903 Hz, PtH), 1.01 (dt, J (H-P) ) 8, 16 Hz, CH3), 1.68 (d,
4J (H-H) ) 12 Hz, PEt3), 1.71 (dq, J (H-P) ) 8, 8 Hz, CH2).
2
31P{1H} NMR (122 MHz, C6D6, rt): δ -83.6 (2J (P-P) )
-15, 40, 285 Hz, 1J (P-Pt) ) 1496, 2016 Hz, µ-PtBu2), 22.0
(2J (P-P) ) -20, -15, 285 Hz, 1J (P-Pt) ) 74, 1972 Hz, PEt3).
13C{1H} NMR (126 MHz, C6D6, rt): δ 9.32 (J (C-Pt) ) 23 Hz),
22.43 (d, 1J (C-P) ) 25 Hz, 2J (C-Pt) ) 58 Hz), 33.83 (d, 2J (C-
P) ) 6 Hz), 34.01 (d, J (C-P) ) 39 Hz). IR (KBr): 2022 cm-1
1
(νPtH).
Rea ction of P h 2P H w ith 2 a n d P t(P Et3)3 (eq 3). To a
benzene (5 mL) solution of Pt(PEt3)3 (110 mg, 0.2 mmol) were
added [Pt2H2(µ-PPh2)2(PEt3)2] (2) (200 mg, 0.2 mmol) and
Ph2PH (86 µL, 0.5 mmol) at room temperature. The color of
the solution turned from orange to red with stirring. After 12
h the volatiles were removed under reduced pressure. Addition
of hexane (10 mL) to the resulting dark red oily materials led
to the formation of a yellow powder with stirring at 96 h, which
was filtered and washed with 5 mL of acetone (2 times),
collected by filtration, and dried in vacuo to give 3 as a yellow
solid (219 mg, 0.14 mmol, 70%).
2
2
1J (P-Pt) ) 2379 Hz, J (P-Pt) ) -76 Hz, J (P-P) ) 199 Hz,
µ-PPh2), 91.73 (m, 1J (P-Pt) ) 2203, 2216 Hz, 2J (P-Pt) ) 132
Hz, J (P-P) ) 240 Hz, µ-PPh2).
2
P r ep a r a tion of [P t3(µ-P P h 2)3(P Et3)3]+I- (7). To a benzene
(2 mL) solution of 3 (150 mg, 0.1 mmol) was added MeI (6.25
µL, 0.1 mmol) at room temperature. The color of the solution
turned immediately from orange to red with stirring. Stirring
of the resulting red solution for 5 h led to separation of a brown
solid, which was collected by filtration, washed with hexane
Rea ction of P h 2P H w ith 2 (eq 4). To a benzene (5 mL)
solution of 3 (225 mg, 0.15 mmol) was added Ph2PH (27 µL,
0.3 mmol) at room temperature. The color of the solution
turned from orange to red with stirring. After 12 h the volatiles

1620 Organometallics, Vol. 23, No. 7, 2004
Ta ble 3. Cr ysta l Da ta a n d Deta ils of th e Str u ctu r e Refin em en t of 1 a n d 3-8
Itazaki et al.
1
3
4
formula
molecular weight
cryst syst
space group
a (Å)
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
C
60H72P6Pt3‚Me2CO
C54H76P6Pt3‚Ph2PH
1682.50
monoclinic
P21/c (No. 14)
12.866(2)
31.112(5)
18.060(3)
90
109.847(2)
90
6799.9(21)
4
C28H68P4Pt2
918.92
1622.42
triclinic
P1h (No. 2)
12.549(2)
13.145(2)
11.270(3)
94.12(1)
94.067(8)
115.04(1)
1669.3(6)
1
monoclinic
P21/c (No. 14)
10.732(2)
15.903(3)
11.707(2)
90
116.063(6)
90
1794.8(5)
2
Z
µ (mm-1
F(000)
)
6.425
788
1.614
6.333
3288
1.643
7.948
904
1.700
Dcalcd (g cm-3
)
cryst size (mm)
2θ range (deg)
no. of unique reflns
no. of used reflns
no. of variables
R
0.15 × 0.12 × 0.07
5.0-55.0
6258
4669
390
0.61 × 0.59 × 0.57
5.0-55.0
14 268
12 312
787
0.23 × 0.18 × 0.12
5.0-55.0
4047
3195
187
0.063
0.078
0.043
0.070
0.049
0.072
a
Rw
GOF
0.98
1.410
1.06
5
6
7
8
formula
C
66H75P5SiPt3
C
60H71P5SiPt3
C
54H75IP6Pt3‚CH2Cl2
C82H104B4O5P6Pt3
molecular weight
cryst syst
space group
a (Å)
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
1636.54
triclinic
P1h (No. 2)
13.874(2)
14.179(1)
19.134(2)
74.373(8)
75.470(7)
60.964(5)
3136.6(6)
2
1560.45
monoclinic
P21/n (No. 14)
15.325(2)
18.498(3)
20.097(3)
90
91.157(2)
90
5696.0(15)
4
1707.14
triclinic
P1h (No. 2)
14.035(2)
14.083(1)
18.915(3)
72.418(7)
85.439(9)
61.155(6)
3111.9(7)
2
1984.07
triclinic
P1h (No. 2)
16.302(2)
17.107(2)
19.010(3)
88.341(8)
66.841(6)
65.780(5)
4389.3(9)
2
Z
µ (mm-1
F(000)
)
6.832
1588
1.733
7.519
3016
1.819
7.469
1636
1.822
4.905
1960
1.501
Dcalcd (g cm-3
)
cryst size (mm)
2θ range (deg)
no. of unique reflns
no. of used reflns
no. of variables
R
0.53 × 0.35 × 0.22
5.0-50.0
13 221
11 545
751
0.50 × 0.40 × 0.20
5.0-55.0
13 396
11 028
696
0.70 × 0.40 × 0.25
5.0-55.0
13 201
11 916
681
0.72 × 0.56 × 0.25
5.0-55.0
18 602
15 597
1005
0.038
0.047
0.032
0.038
0.036
0.057
0.039
0.055
a
Rw
GOF
0.738
0.696
1.180
1.035
a
Weighting scheme [σ(Fo)2]-1
.
(2 mL, 2 times), and dried in vacuo to give 7 as a brown solid
(129.9 mg, 0.080 mmol, 80%). Complex 7 crystallizes from
CH2Cl2-hexane at room temperature as dark red crystals.
1H NMR (500 MHz, CD2Cl2, rt): δ 0.39 (dt, J (H-H) ) 8 Hz,
J (H-P) ) 17 Hz, 27H, PCH2CH3), 1.62 (m, J (H-H) ) 8 Hz,
18H, PCH2CH3), 7.31-7.34 (m, 18H, Ph), 7.67 (m, 12H, Ph).
13C{1H} NMR (126 MHz, CD2Cl2, rt): δ ) 7.87 (s, J (C-Pt) )
25 Hz, PCH2CH3), 18.7 (m, J (C-P) ) 15 Hz, J (C-Pt) ) 60
Hz, PCH2CH3), 128.55 (m, J (C-P) ) 5 Hz, Ph-meta), 129.31
(s, Ph-para), 133.47 (ddd, J (C-P) ) 2, 5, 9 Hz, Ph-ortho),
137.11 (ddd, J (C-P) ) 2, 13, 24 Hz, Ph-ipso). 31P{1H} NMR
(202 MHz, CD2Cl2, rt): δ -2.65 (m, J (P-P) ) 63 Hz, J (P-Pt)
) 118, 4173 Hz), 81.47 (m, J (P-P) ) -211 Hz, J (P-Pt) )
-103, 2246 Hz).
P r ep a r a tion of [P t3(µ-P P h 2)3(P Et3)3][B4O4(OH)Ar 4] (8,
Ar ) C6H4Me-4; 9, Ar ) C6H4F -4; 10, Ar ) C6H4CF 3-4). To
a benzene (3 mL) solution of 3 (150 mg, 0.1 mmol) was added
4-methylphenylboronic acid (54.4 mg, 0.4 mmol) at room
temperature. The color of the solution turned immediately
from orange to red with stirring. After 30 min the solvent was
removed under reduced pressure. Addition of hexane (5 mL)
to the red residue at -78 °C led to the formation of a red-
dish brown solid, which was washed with hexane (5 mL, 5
times), collected by filtration, and dried in vacuo to give 8 as
a reddish brown solid (182.5 mg, 0.092 mmol, 92%). Complex
8 crystallized from CH2Cl2-hexane at room temperature as
dark red crystals. 1H NMR (500 MHz, CD2Cl2, rt): δ 0.41
(dt, 3J (H-H) ) 8 Hz, 3J (H-P) ) 18 Hz, 27H, PCH2CH3),
3
3
1.63 (dq, J (H-H) ) 8 Hz, J (H-P) ) 8 Hz, 18H, PCH2CH3),
2.24 (s, 3H, Me), 2.35 (s, 3H, Me), 2.39 (s, 6H, Me), 6.95 (d,
3
3J (H-H) ) 8 Hz, 2H), 7.15 (d, J (H-H) ) 8 Hz, 2H), 7.21 (d,
3J (H-H) ) 8 Hz, 4H), 7.31-7.36 (m, 18H, Ph), 7. 51 (d,
3J (H-H) ) 8 Hz, 2H), 7.53 (s, 1H, OH), 7.67-7.71 (m, 12H),
3
3
7.88 (d, J (H-H) ) 8 Hz, 2H), 8.01 (d, J (H-H) ) 8 Hz, 4H).
11B NMR (161 MHz, CD2Cl2): δ 4.10 (br, 1B), 28.12 (br, 3B).
13C{1H} NMR (126 MHz, CD2Cl2, rt): δ 7.92 (s, J (C-Pt) ) 25
Hz, PCH2CH3), 18.78 (t, J (C-P) ) 16 Hz, J (C-Pt) ) 71 Hz,
PCH2CH3), 21.32 (s, Me), 21.68 (s, Me), 21.77 (s, 2C, Me),
127.62 (s), 128.09 (s), 128.32 (s), 128.60 (t, J (C-P) ) 5 Hz,
Ph-meta), 129.39 (s, Ph-para), 131.60 (s), 133.51 (ddd,
J (C-P) ) 2, 5, 9 Hz, Ph-ortho), 133.88 (s, Ph-ipso), 134.96 (s),
135.15 (s), 137.17 (ddd, J (C-P) ) 2, 13, 24 Hz, Ph-ipso), 138.82
(s, Ph-ipso), 139.80 (s, 2C, Ph-ipso). 31P{1H} NMR (202 MHz,
CD2Cl2, rt): δ -2.63 (m, J (P-P) ) 66 Hz, J (P-Pt) ) 116, 4168
Hz, PEt3), 81.56 (m, J (P-P) ) -208 Hz, J (P-Pt) ) -92, 2240
Hz, µ-PPh2).

Syntheses of Hydridoplatinum Complexes
Organometallics, Vol. 23, No. 7, 2004 1621
[Pt3(µ-PPh2)3(PEt3)3][B4O4(OH)(C6H4F-4)4] (9) was prepared
analogously from the reaction of 4-fluorophenylboronic acid
(56.0 mg, 0.4 mmol) with 3 (150 mg, 0.1 mmol) in benzene (3
mL) for 30 min at room temperature (186.5 mg, 0.093
mmol, 93%). Complex 9 crystallized from CH2Cl2-hexane at
room temperature as dark red crystals. 1H NMR (500 MHz,
CD2Cl2, rt): δ 0.40 (dt, 3J (H-H) ) 8 Hz, 3J (H-P) ) 17 Hz,
X-r a y Diffr a ction . Single crystals of 1 and 3-8 were grown
from acetone and CH2Cl2-hexane, respectively. Crystallo-
graphic data and details of refinement are summarized in
Table 3. The crystals were sealed in glass capillary tubes and
mounted on a Rigaku RAXIS imaging plate (1) and a Rigaku
Saturn CCD (3-8) area detector with graphite-monochro-
mated Mo KR radiation. An empirical absorption correction
was applied. The data were corrected for Lorentz and polariza-
tion effects. All calculations were performed using the Crys-
talStructure30 crystallographic software package. The struc-
ture was solved by direct methods31 and expanded using
Fourier techniques.32 All non-hydrogen atoms were refined
with anisotropic thermal parameters, whereas all hydrogen
atoms were located by assuming the ideal geometry and
included in the structure calculation without further refine-
ment of the parameters.33
3
3
27H, PCH2CH3), 1.62 (dq, J (H-H) ) 8 Hz, J (H-P) ) 8 Hz,
18H, PCH2CH3), 6.83 (t, 3J (H-H) ) 9 Hz, 2H), 6.99 (t,
3J (H-H) ) 9 Hz, 2H), 7.06 (m, 4H), 7.30-7.34 (m, 18H), 7.39
(s, 1H, OH), 7.60 (t, 3J (H-H) ) 8 Hz, 2H), 7.59-7.69 (m, 12H),
7.96 (t, 3J (H-H) ) 8 Hz, 2H), 8.10 (m, 4H). 11B NMR (161
MHz, CD2Cl2, rt): δ 3.95 (br, 1B), 27.67 (br, 3B). 13C{1H} NMR
(126 MHz, CD2Cl2, rt): δ 7.90 (s, J (C-Pt) ) 22, 11 Hz,
PCH2CH3), 18.76 (t, J (C-P) ) 18 Hz, J (C-Pt) ) 72 Hz, PCH2-
CH3), 113.28 (d, 2J (C-F) ) 19 Hz), 114.01 (d, 2J (C-F) ) 20
Hz), 114.31 (d, 2J (C-F) ) 20 Hz), 114.43 (d, 2J (C-F) ) 20
Hz), 128.60 (m, J (C-P) ) 5 Hz, Ph-meta), 129.37 (s, Ph-para),
132.91 (d, 3J (C-F) ) 6 Hz), 133.52 (dd, J (C-P) ) 5, 9 Hz,
Ph-ortho), 136.86 (d, 3J (C-F) ) 7 Hz), 137.14 (d, 3J (C-F) ) 7
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, Science, Sports, Technology
and Culture of J apan. We also thank Prof. Munetaka
Akita (Tokyo Institute of Technology) for X-ray crystal
analysis of 1 with the imaging plate.
3
Hz), 137.17 (dd, J ) 25,16 Hz, Ph-ipso), 137.27 (d, J (C-F) )
8 Hz), 161.91 (d, 1J (C-F) ) 239 Hz), 164.46 (d, 1J (C-F) )
1
1
245 Hz), 164.91 (d, J (C-F) ) 247 Hz), 164.94 (d, J (C-F) )
246 Hz). 19F{1H} NMR (282 MHz, CD2Cl2, rt): δ -112.23 (m,
1F), -112.36 (m, 1F), -113.66 (m, 1F), -120.40 (m, 1F). 31P-
{1H} NMR (202 MHz, CD2Cl2, rt): δ -2.65 (m, J (P-P) ) 2,
10, 66 Hz, J (P-Pt) ) 117, 4168 Hz, PEt3), 81.56 (m, J (P-P)
) -206 Hz, J (P-Pt) ) -99, 2234 Hz, µ-PPh2).
Su p p or tin g In for m a tion Ava ila ble: Table of crystal-
lographic data and complete tables of non-hydrogen and
selected hydrogen parameters, bond lengths and angles,
calculated hydrogen atom parameters, anisotropic thermal
parameters, and intermolecular contacts for 1 and 3-8. This
material is available free of charge via the Internet at
http://pubs.acs.org.
[Pt3(µ-PPh2)3(PEt3)3][B4O4(OH)(C6H4CF3-4)4] (10) was pre-
pared from the reaction of 4-trifluoromethylphenylboronic acid
(76.0 mg, 0.4 mmol) with 3 (150 mg, 0.1 mmol) in benzene (3
mL) for 30 min at room temperature (189 mg, 0.086 mmol,
86%). Complex 10 crystallized from CH2Cl2-hexane at
room temperature as dark red crystals. 1H NMR (500 MHz,
CD2Cl2, rt): δ 0.40 (dt, 3J (H-H) ) 8 Hz, 3J (H-P) ) 16 Hz,
OM034131V
(24) Paonessa, R. S.; Prignano, A. L.; Trogler, W. C. Organometallics
1985, 4, 647.
(25) Nishihara, Y.; Nara, K.; Osakada, K. Inorg. Chem. 2002, 41,
4090.
(26) (a) Yalpani, M.; Boese, R. Chem. Ber. 1983, 116, 3347. (b) Song,
Z. Z.; Zhou, Z. Y.; Mak, T. C. W.; Wong, H. N. C. Angew. Chem., Int.
Ed. Engl. 1993, 32, 432. (c) Beckett, M. A.; Strickland, G. C.; Varma,
K. S.; Hibbs, D. E.; Hursthouse, M. B.; Malik, K. M. A. J . Organomet.
Chem. 1997, 535, 33. (d) Beckett, M. A.; Brassington, D. S.; Owen, P.;
Hursthouse, M. B.; Light, M. E.; Malik, K. M. A.; Varma, K. S. J .
Organomet. Chem. 1999, 585, 7.
3
3
27H, PCH2CH3), 1.62 (dq, J (H-H) ) 8 Hz, J (H-P) ) 8 Hz,
18H, PCH2CH3), 7.30-7.33 (m, 19H, Ph overlapped OH), 7.42
(d, 3J (H-H) ) 8 Hz, 2H), 7.58 (d, 3J (H-H) ) 8 Hz, 2H),
7.66-7.68 (m, 16H), 7.81 (d, 3J (H-H) ) 8 Hz, 2H), 8.09 (d,
3J (H-H) ) 8 Hz, 2H),8.25 (d, 3J (H-H) ) 8 Hz, 4H). 11B
NMR (161 MHz, CD2Cl2, rt): δ 3.94 (br, 1B), 28.01 (br, 3B).
13C{1H} NMR (126 MHz, CD2Cl2, rt): δ 7.91 (s, J (C-Pt)
2
3
) 28 Hz, PCH2CH3), 18.82 (t, J (C-P) ) 16 Hz, J (C-Pt) )
(27) Attina, M.; Cacace, F.; Occhiucci, G.; Ricci, A. Inorg. Chem.
1992, 31, 3114.
71 Hz, PCH2CH3), 123.67 (q, 3J (C-F) ) 4 Hz), 124.00 (q, 3J (C-
F) ) 4 Hz), 124.32 (q, J (C-F) ) 4 Hz), 125.12 (q, J (C-F) )
272 Hz, 2C, CF3), 125.26 (q, J (C-F) ) 272 Hz, CF3), 125.77
3
1
(28) (a) Muetterties, E. L.; Gerlach, D. H.; Kane, A. R.; Parshall, G.
W.; J esson, J . P. J . Am. Chem. Soc. 1971, 93, 3543. (b) Yoshida, T.;
Matsuda, T.; Otsuka, S. Inorg. Synth. 1979, 19, 107.
(29) Aguiar, A. M.; Beisler, J .; Mills, A. J . Org. Chem. 1962, 27, 1001.
(30) Crystal Structure 3.10, Crystal Structure Analysis Package;
Rigaku and Rigaku/MSC, 2000-2002.
(31) SIR92: Altomare, A.; Cascarano, G.; Giacovazzo, C.; Guagliardi,
A.; Burla, M.; Polidori, G.; Camalli, M. J . Appl. Crystallogr. 1994, 27,
435.
(32) DIRDIF99: Beurskens, P. T.; Admiraal, G.; Beurskens, G.;
Bosman, W. P.; de Gelder, R.; Israel, R.; Smits, J . M. M. The DIRDIF-
99 Program System, Technical Report of the Crystallography Labora-
tory; University of Nijmegen: The Netherlands, 1999.
(33) International Tables for X-ray Crystallography; Kynoch: Bir-
mingham, England, 1974; Vol. 4.
1
(q, 1J (C-F) ) 271 Hz, CF3), 127.26 (q, 2J (C-F) ) 32 Hz),
128.62 (t, J (C-P) ) 5 Hz, Ph-meta), 129.40 (s, Ph-para), 130.98
(q, 2J (C-F) ) 32 Hz), 131.69 (s), 131.84 (q, 2J (C-F) ) 32 Hz),
133.56 (ddd, J ) 9, 5, 2 Hz, Ph-ortho), 135.09 (s), 135.33 (s),
137.22 (ddd, J (C-P) ) 24, 13, 2 Hz, 2J (C-Pt) ) 68 Hz,
Ph-ipso), 140.61 (m), 142.26 (m). 19F{1H} NMR (282 MHz,
CD2Cl2, rt): δ -62.00 (s, 3F), -62.65 (s, 3F), -62.78 (s, 6F).
31P{1H} NMR (202 MHz, CD2Cl2, rt): δ -2.67 (m, J (P-P) )
2, 10, 66 Hz, J (P-Pt) ) 117, 4168 Hz, PEt3), 81.60 (m,
J (P-P) ) -209 Hz, J (P-Pt) ) -99, 2247 Hz, µ-PPh2).