Unsymmetrical platinum(II) phosphido derivatives: Oxidation and reductive coupling processes involving platinum(III) complexes as intermediates

Article abstract of DOI:10.1021/ic8011124

Reaction of the trinuclear [NBu₄]₂[(R _F)₂Pt(μ-PPh₂)₂Pt(μ-PPh ₂)₂Pt(R_F)₂] (1, R_F = C₆F₅) with HCl results in the formation of the unusual anionic hexanuclear derivative [NBu₄]₂[{(R _F)₂Pt(μ-PPh₂)₂Pt(μ-PPh ₂)₂Pt(μ-Cl)}₂] (4, 96 e^- skeleton) through the cleavage of two Pt-C₆F₅ bonds. The reaction of 4 with Tl(acac) yields the trinuclear [NBu₄][(R _F)₂Pt(μ-PPh₂)₂Pt(μ-PPh ₂)₂Pt(acac)] (5, 48 e^- skeleton), which is oxidized by Ag⁺ to form the trinuclear compound [(R_F) ₂Pt(μ-PPh₂)₂Pt(μ-PPh₂) ₂Pt(acac)][ClO₄] (6, 46 e^- skeleton) in mixed oxidation state Pt(III)-Pt(III)-Pt(II), which displays a Pt-Pt bond. The reduction of 6 by [NBu₄][BH₄] gives back 5. The treatment of 6 with Br^- (1:1 molar ratio) at room temperature gives a mixture of the isomers [(PPh₂R_F)(R_F)Pt(μ-PPh ₂)(μ-Br)Pt(μ-PPh₂)₂Pt(acac)], having Br trans to R_F (7a) or Br cis to R_F (7b), which are the result of PPh₂/C₆F₅ reductive coupling. The treatment of 5 with I₂ (1:1 molar ratio) yields the hexanuclear [{(PPh₂R_F)(R_F)Pt(μ-PPh₂)(μ-I) Pt(μ-PPh₂)₂Pt(μ-I)}₂] (8.96 e^- skeleton), which is easily transformed into the trinuclear compound [(PPh ₂R_F)(R_F)Pt(μ-PPh₂)(μ-I) Pt(μ-PPh₂)₂Pt(I)(PPh₃)] (9, 48 e^- skeleton). Reaction of [(R_F)₂Pt(μ-PPh ₂)₂Pt(μ-PPh₂)₂Pt(NCMe) ₂] (10) with I₂ at 213 K for short reaction times gives the trinuclear platinum derivative [(R_F)₂Pt(μ-PPh ₂)₂Pt(μ-PPh₂)₂Pt(I)₂] (11, 46e skeleton) in mixed oxidation state Pt(III)-Pt(III)-Pt(II) and with a Pt-Pt bond, while the reaction at room temperature and longer reactions times gives 8. The structures of the complexes have been established by multinuclear NMR spectroscopy. In particular, the ¹⁹⁵Pt NMR analysis, carried out also by ¹⁹F-¹⁹⁵Pt heteronuclear multiple-quantum coherence, revealed an unprecedented shielding of the ¹⁹⁵Pt nuclei upon passing from Pt(II) to Pt(III). The X-ray diffraction structures of complexes 4, 5, 6, 9, and 11 have been studied. A detailed study of the relationship between the complexes has been carried out.

Full text of DOI:10.1021/ic8011124

Inorg. Chem. 2008, 47, 9069-9080
Unsymmetrical Platinum(II) Phosphido Derivatives: Oxidation and
Reductive Coupling Processes Involving Platinum(III) Complexes as
†
Intermediates
‡
Irene Ara, Juan Forni e´ s,* Consuelo Fortu n˜ o,* Susana Ib a´ n˜ ez, Antonio Mart ´ı n,
,‡
,‡
‡
‡
§
Piero Mastrorilli, and Vito Gallo
§
Departamento de Qu ´ı mica Inorg a´ nica and Instituto de Ciencia de Materiales de Arag o´ n,
UniVersidad de Zaragoza, CSIC, 50009 Zaragoza, Spain, and Dipartimento di Ingegneria delle
Acque e di Chimica del Politecnico di Bari, Via Orabona 4, I-70125 Bari, Italy
Received June 16, 2008
Reaction of the trinuclear [NBu
of the unusual anionic hexanuclear derivative [NBu
through the cleavage of two Pt-C
4
]
2
[(R
F
)
2
Pt(µ-PPh
2
)
2
Pt(µ-PPh
2
)
2
Pt(R
F
)
2
] (1, R
F
) C
6
F
5
) with HCl results in the formation
-
4 2
] [{(R
F
)
2
Pt(µ-PPh
2 2
) Pt(µ-PPh
2
2
) Pt(µ-Cl)}
2
] (4, 96 e skeleton)
6
F
5
bonds. The reaction of 4 with Tl(acac) yields the trinuclear [NBu
4 F 2
][(R ) Pt-
-
+
(
µ-PPh
2
)
2
Pt(µ-PPh
2
)
2
Pt(acac)] (5, 48 e skeleton), which is oxidized by Ag to form the trinuclear compound
-
[(R Pt(µ-PPh
)
F 2
2 2
) Pt(µ-PPh
2 2
)
Pt(acac)][ClO
4
] (6, 46 e skeleton) in mixed oxidation state Pt(III)-Pt(III)-Pt(II), which
-
displays a Pt-Pt bond. The reduction of 6 by [NBu
ratio) at room temperature gives a mixture of the isomers [(PPh
Br trans to R (7a) or Br cis to R (7b), which are the result of PPh
with I (1:1 molar ratio) yields the hexanuclear [{(PPh )(R )Pt(µ-PPh
4
][BH
4
] gives back 5. The treatment of 6 with Br (1:1 molar
R
2 F
)(R
F
)Pt(µ-PPh
2
2 2
)(µ-Br)Pt(µ-PPh ) Pt(acac)], having
F
F
2 6
/C F
5
reductive coupling. The treatment of 5
-
2
2
R
F
F
2
)(µ-I)Pt(µ-PPh
)(R )Pt(µ-PPh )(µ-I)Pt(µ-PPh
] (10) with I at 213 K for short reaction times
Pt(I) ] (11, 46e skeleton) in mixed oxidation
2 2
) Pt(µ-I)}
2
] (8, 96 e skeleton),
which is easily transformed into the trinuclear compound [(PPh
-
2
R
F
F
2
2 2 3
) Pt(I)(PPh )] (9,
4
8 e skeleton). Reaction of [(R
F
)
2
Pt(µ-PPh
2
)
2
Pt(µ-PPh
Pt(µ-PPh
)
2 2
Pt(NCMe)
2
2
gives the trinuclear platinum derivative [(R
F
)
2
2 2
) Pt(µ-PPh
2
)
2
2
state Pt(III)-Pt(III)-Pt(II) and with a Pt-Pt bond, while the reaction at room temperature and longer reactions
times gives 8. The structures of the complexes have been established by multinuclear NMR spectroscopy. In
particular, the 195Pt NMR analysis, carried out also by F- Pt heteronuclear multiple-quantum coherence, revealed
an unprecedented shielding of the 1 Pt nuclei upon passing from Pt(II) to Pt(III). The X-ray diffraction structures
of complexes 4, 5, 6, 9, and 11 have been studied. A detailed study of the relationship between the complexes has
been carried out.
19
195
95
2
Introduction
(acac)}
2
] derivatives, which show a Pt(III)-Pt(III) bond or
donor/acceptor Pt(II)-Ag(I) bonds, respectively. The re-
placement of an acac chelate ligand for two terminal
pentafluorophenyl groups generates important differences in
their reactivity. We have reported that the symmetric tri-
The binuclear platinate(II) derivatives with diphenylphos-
n-
phido groups as bridging ligands [(R
) C ; L ) R , n ) 2; L
F 2
AgClO , affording the binuclear platinum(III) [(R )
F 2 2 2 2
) Pt(µ-PPh ) PtL ]
(
R
F
6
F
5
F
2
) acac, n ) 1) react with
Pt(µ-
F 2
(R ) -
4
1
nuclear platinate(II) derivative [NBu
PPh Pt(R ] (1), with only pentafluorophenyl groups as
terminal ligands, is oxidized to the neutral derivative
4 2 F 2 2 2
] [(R ) Pt(µ-PPh ) Pt(µ-
PPh
2
)
2
Pt(R
F
)
2
] or the hexanuclear [{AgPt
2
(µ-PPh
)
2 2
2
)
2
F 2
)
*
Authors to whom correspondence should be addressed. Fax: +349767-
6
(
1187 (J.F.). E-mail: juan.fornies@unizar.es (J.F.); cfortuno@unizar.es
3
[(R
F
)
2
Pt(µ-PPh
2
)
2
2 2 F 2
Pt(µ-PPh ) Pt(R ) ] (2), with formally two
C.F.)
†
Polynuclear Homo- or Heterometallic Palladium(II)-Platinum(II) Penta-
fluorophenyl Complexes Containing Bridging Diphenylphosphido Ligands.
2
5. For part 24, see ref 58.
(1) Alonso, E.; Casas, J. M.; Cotton, F. A.; Feng, X. J.; Forni e´ s, J.; Fortu n˜ o,
C.; Tom a´ s, M. Inorg. Chem. 1999, 38, 5034–5040.
(2) Alonso, E.; Forni e´ s, J.; Fortu n˜ o, C.; Mart ´ı n, A.; Orpen, A. G.
Organometallics 2003, 22, 5011–5019.
§
Dipartimento di Ingegneria delle Acque e di Chimica del Politecnico
di Bari.
‡
Universidad de Zaragoza.
1
0.1021/ic8011124 CCC: $40.75  2008 American Chemical Society
Inorganic Chemistry, Vol. 47, No. 19, 2008 9069
Published on Web 09/10/2008

Ara et al.
Scheme 1
platinum(III) centers, and which evolves to the platinum(II)
Results and Discussion
Synthesis of [NBu ][(R
4
derivative [(PPh
Scheme 1).
2 F F 2 2 2 F
R )(R )Pt(µ-PPh )Pt(µ-PPh ) Pt(R )
2
] (3,
4
F
)
2
Pt(µ-PPh
2
)
2
Pt(µ-PPh
2 2
) Pt-
(acac)]. The Oxidation with Ag(I). Some of the complexes
With the aim of obtaining information on the influence of
terminal ligands on the behavior of the metal centers within
these phosphido derivatives, we have now studied the
used in this study as starting materials had not been prepared
before, and their syntheses is described first (4, 5, and 10).
Their structural characterization was carried out by usual
methods (infrared (IR), nuclear magnetic resonance (NMR),
and X-ray diffraction (XRD), in some cases). A schematic
representation of their structures is given in Scheme 1, and
for the sake of clarity, the structural parameters are com-
mented on all together.
reactivity of the unsymmetrical platinum(II) derivatives
n-
[(R
F
)
2
Pt(µ-PPh
2
)
2
2 2 2
Pt(µ-PPh ) PtL ] . In this type of complex,
the three different metal centers are potential Lewis bases,
able to establish donor-acceptor Pt-Ag bonds. The oxida-
tion of the platinum complexes, that is, the formation of a
derivative with a Pt(III)-Pt(III) bond, which can be estab-
lished between the central platinum atom and one of the two
terminal metallic centers, cannot be discarded. In this paper,
The reaction of acetone solutions of the trinuclear complex
3
4 2 F 2 2 2
[NBu ] [(R ) Pt(µ-PPh ) Pt(µ-PPh
2 2 F
) Pt(R )
2
] (1) with HCl(aq)
(
1:2 molar ratio) was the procedure used for the preparation
[{(R Pt(µ-PPh Pt-
] (4). In this process, two Pt-C bonds
at the same metal center are broken with the formation of
two C H molecules. The intermediate [(R Pt(µ-PPh Pt(µ-
PPh
of the hexanuclear derivative [NBu
µ-PPh Pt(µ-Cl)}
4
]
2
F
)
2
2 2
)
we describe the synthetic strategy used to isolate the new
(
)
2 2
2
6 5
F
n-
unsymmetrical [(R
acac, n ) 1; L ) CH
behavior toward Ag(I) and I
F
)
2
Pt(µ-PPh
3
2
)
2
2 2 2 2
Pt(µ-PPh ) PtL )] (L )
CN, n ) 0) complexes and their
6
F
PtCl
5
F
)
2
2 2
)
2
.
2-
2
)
2
2
]
does not crystallize from the solution, but the
-
elimination of a Cl group and dimerization of the unsatur-
ated trinuclear fragment yields the hexanuclear [{(R
F
)
2
Pt(µ-
(4) instead. The XRD structure
of this peculiar hexanuclear anionic complex is discussed
below. The “Pt(µ-Cl) Pt” bridging system is expected to be
(
3) Alonso, E.; Casas, J. M.; Forni e´ s, J.; Fortu n˜ o, C.; Mart ´ı n, A.; Orpen,
A. G.; Tsipis, C. A.; Tsipis, A. C. Organometallics 2001, 20, 5571–
582.
4) Forni e´ s, J.; Fortu n˜ o, C.; Ib a´ n˜ ez, S.; Mart ´ı n, A. Inorg. Chem. 2006,
5, 4850–4858.
2
-
2 2 2 2 2
PPh ) Pt(µ-PPh ) PtCl} ]
5
(
4
2
9070 Inorganic Chemistry, Vol. 47, No. 19, 2008

Unsymmetrical Platinum(II) Phosphido DeriWatiWes
Figure 2. Molecular structure of the anion of complex [NBu4][(RF)2Pt(µ-
PPh2)2Pt(µ-PPh2)2Pt(acac)]·2Me2CO (5·2Me2CO).
Figure 1. Molecular structure of the anion of complex [NBu4]2[{(RF)2Pt(µ-
PPh2)2Pt(µ-PPh2)2Pt(µ-Cl)}2]·5.5Me2CO (4·5.5Me2CO).
easily split, and thus this hexanuclear complex, 4, represents
an excellent starting material for the synthesis of unsym-
metrical trinuclear phosphido-bridged derivatives. Complex
4
reacts with Tl(acac) (1:2 molar ratio), and after the
elimination of TlCl, the trinuclear complex [NBu ][(R Pt(µ-
PPh Pt(µ-PPh Pt(acac)] (5) is crystallized (Scheme 1).
4
F 2
)
2
)
2
2 2
)
This reaction is reversible, and the addition of HCl solutions
to 5 (1:1 molar ratio) yields back the hexanuclear complex
4
.
The addition of AgClO
4
to 5 (2:1 molar ratio) results in
the precipitation of Ag and the formation of the cationic
complex [(R Pt(µ-PPh Pt(µ-PPh Pt(acac)][ClO ] (6; Pt(I-
0
Figure 3. Molecular structure of the complex in [(RF)2Pt(µ-PPh2)2Pt(µ-
PPh2)2Pt(acac)][ClO4]·3CH2Cl2 (6·3CH2Cl2).
F
)
2
2
)
2
2
)
2
4
II), Pt(III), Pt(II), Scheme 1), which is isolated from the
Table 1. Selected Bond Distances (Å) and Angles (deg) for
solution. The reaction of 5 (48 valence electron count) with
[
(
NBu4]2[{(RF)2Pt(µ-PPh2)2Pt(µ-PPh2)2Pt(µ-Cl)}2]·5.5Me2CO
+
Ag results in an oxidation process which affords the
a
4·5.5Me2CO)
trinuclear complex 6, of 46 valence electrons, with formally
two platinum(III) metal centers joined by a metal-metal
Pt(1)-C(7)
2.070(10)
2.292(2)
2.318(2)
2.336(2)
2.237(2)
2.418(2)
90.1(3)
Pt(1)-C(1)
2.072(8)
2.311(2)
2.331(2)
2.356(2)
2.248(2)
2.421(2)
95.0(2)
169.0(3)
75.19(7)
74.36(7)
177.02(8)
108.17(7)
97.98(8)
178.01(8)
83.49(8)
97.15(8)
99.91(8)
Pt(1)-P(2)
Pt(1)-P(1)
Pt(2)-P(4)
Pt(2)-P(2)
bond located in the fragment “(R
F
)
2
Pt(µ-PPh
2
)
2
Pt”. It is
Pt(µ-
Pt(acac)] reactswithAg ,yieldingstableplatinum(II)-
Pt(2)-P(3)
Pt(2)-P(1)
noteworthy that the binuclear acac derivative [(R )
F 2
Pt(3)-P(4)
Pt(3)-P(3)
-
+
PPh )
2 2
Pt(3)-Cl′
Pt(3)-Cl
C(7)-Pt(1)-C(1)
C(1)-Pt(1)-P(2)
C(1)-Pt(1)-P(1)
P(4)-Pt(2)-P(2)
P(2)-Pt(2)-P(3)
P(2)-Pt(2)-P(1)
P(4)-Pt(3)-P(3)
P(3)-Pt(3)-Cl′
P(3)-Pt(3)-Cl
Pt(3′)-Cl-Pt(3)
Pt(1)-P(2)-Pt(2)
Pt(3)-P(4)-Pt(2)
a
C(7)-Pt(1)-P(2)
C(7)-Pt(1)-P(1)
P(2)-Pt(1)-P(1)
P(4)-Pt(2)-P(3)
P(4)-Pt(2)-P(1)
P(3)-Pt(2)-P(1)
P(4)-Pt(3)-Cl′
P(4)-Pt(3)-Cl
Cl′-Pt(3)-Cl
Pt(1)-P(1)-Pt(2)
Pt(3)-P(3)-Pt(2)
silver(I) bonds, while from the similar trinuclear acac
174.9(2)
99.7(2)
derivative 5, the platinum(II)-silver(I) adduct evolves with
2
electron transfer, yielding 6. This oxidation process is
103.73(8)
176.20(7)
73.64(7)
77.68(8)
175.45(8)
100.83(8)
96.51(8)
98.41(8)
100.80(8)
reversible, and the addition of NBu
4 4
BH to solutions of 6
gives back the platinum(II) complex 5.
Structural Characterization of Complexes 4, 5, and
6
. X-Ray Studies. The crystal structures of complexes 4, 5,
and 6 have been determined by single-crystal X-ray diffrac-
tion. The structures of the anions are shown in Figures 1, 2,
and 3, respectively. Tables 1, 2, and 3 collect some relevant
bond distances and angles. In the case of 4, the structural
determination confirms its hexanuclear nature, with the six
Pt atoms disposed in an almost linear array. The anion has
an inversion center, and thus both halves of the molecule
are equivalent. The terminal Pt(1) has two pentafluorophenyl
Symmetry transformation used to generate equivalent primed atoms:
x, -y, -z.
-
joined with its symmetry equivalent, Pt(3′), by two bridging
chloro ligands. The Pt · · · Pt distances are large (range from
3.500(1) Å to 3.610(1) Å) and clearly indicate the absence
of any metal-metal interaction, as expected for a saturated
species with a 96 valence electron count (VEC). The
environments of the Pt atoms are square-planar, with the
P-Pt-P and Pt-P-Pt angles typically found in these kinds
2
terminal ligands and two PPh groups, which are acting as
a bridge with Pt(2). Also, this Pt(2) center is joined to Pt(3)
through two diphenylphosphido bridging ligands. Pt(3) is
Inorganic Chemistry, Vol. 47, No. 19, 2008 9071

Ara et al.
Table 2. Selected Bond Distances (Å) and Angles (deg) for
NBu4][(RF)2Pt(µ-PPh2)2Pt(µ-PPh2)2Pt(acac)]·2Me2CO (5·2Me2CO)
Å) or the Pt(2) · · · Pt(3) distance in 6, 3.612(1) Å, where no
Pt-Pt bonds are present. The existence of the Pt(1)-Pt(2)
bond in 6 also becomes apparent in the values of the P-Pt-P
and Pt-P-Pt angles. Thus, the former ones take broad values
(P(1)-Pt(1)-P(2) ) 107.6(1)°, P(1)-Pt(2)-P(2) ) 104.1(1)°;
cf. 75.2(1)° and 73.2(1)°, respectively, in 5), while the latter
ones are more acute (Pt(1)-P(1)-Pt(2) ) 74.0(4)°, Pt(1)-
P(2)-Pt(2) ) 74.3(4)°; cf. 101.2(1)° and 100.0(1)°, respec-
tively, in 5). The analogous angles in 6 involving Pt(2), Pt(3),
[
Pt(1)-C(7)
2.057(8)
2.2796(18) Pt(1)-P(2)
2.328(2) Pt(2)-P(3)
2.3428(19) Pt(2)-P(2)
2.068(5) Pt(3)-O(2)
Pt(1)-C(1)
2.062(7)
2.3086(19)
2.333(2)
2.3529(19)
2.102(5)
2.237(2)
Pt(1)-P(1)
Pt(2)-P(4)
Pt(2)-P(1)
Pt(3)-O(1)
Pt(3)-P(4)
2.2258(19) Pt(3)-P(3)
C(7)-Pt(1)-C(1)
C(1)-Pt(1)-P(1)
C(1)-Pt(1)-P(2)
P(4)-Pt(2)-P(3)
P(3)-Pt(2)-P(1)
P(3)-Pt(2)-P(2)
O(1)-Pt(3)-O(2)
92.5(3)
C(7)-Pt(1)-P(1) 173.4(2)
93.54(19)
167.86(19)
73.62(7)
107.43(7)
179.26(8)
88.36(19)
C(7)-Pt(1)-P(2)
P(1)-Pt(1)-P(2)
P(4)-Pt(2)-P(1)
P(4)-Pt(2)-P(2)
P(1)-Pt(2)-P(2)
O(1)-Pt(3)-P(4)
99.0(2)
75.16(7)
173.11(7)
105.74(7)
73.15(7)
94.90(14)
2 2
P(3), and P(4) are typical for a “Pt(µ-PPh ) Pt” bridging
system with no Pt-Pt bond and are very similar to the
analogous values found in the precursor 5.
O(2)-Pt(3)-P(4) 173.09(15)
O(2)-Pt(3)-P(3) 99.41(15)
O(1)-Pt(3)-P(3) 172.18(14)
P(4)-Pt(3)-P(3) 77.48(7)
Another structural difference between complexes 5 and 6
is their overall shape, since while in 5 the environment of
the Pt centers is not coplanar, the existence of the Pt(1)-Pt(2)
bond in 6 causes its core to be nearly planar. Thus, the
dihedral angle between the Pt(1) and Pt(2) square planes is
only 3.5(1)°, while the dihedral angle between the Pt(2) and
Pt(3) planes is 14.0(1)° (compare with 28.8(1)° and 24.2(1)°
for 5). A common feature for 5 and 6 is that the acac ligand
is planar, and almost coplanar with the Pt(3) plane, the
corresponding dihedral angle being 13.1(1)° in 5 and 5.1(1)°
in 6.
Pt(1)-P(1)-Pt(2) 101.16(7)
Pt(3)-P(3)-Pt(2) 101.88(8)
Pt(1)-P(2)-Pt(2) 100.00(7)
Pt(3)-P(4)-Pt(2) 102.40(7)
Table 3. Selected Bond Distances (Å) and Angles (deg) for
(RF)2Pt(µ-PPh2)2Pt(µ-PPh2)2Pt(acac)][ClO4]·3CH2Cl2 (6·3CH2Cl2)
[
Pt(1)-C(1)
2.064(4)
2.2655(13) Pt(1)-P(2)
2.7633(3) Pt(2)-P(2)
2.3247(13) Pt(2)-P(3)
2.3934(12) Pt(3)-O(2)
Pt(1)-C(7)
2.090(4)
Pt(1)-P(1)
2.2664(12)
2.3108(13)
2.3678(12)
2.064(3)
Pt(1)-Pt(2)
Pt(2)-P(1)
Pt(2)-P(4)
Pt(3)-O(1)
2.066(3)
2.2226(13)
84.79(17)
166.33(13)
83.07(12)
104.14(4)
94.15(4)
165.65(4)
90.01(13)
96.02(10)
Pt(3)-P(3)
2.2129(13)
Pt(3)-P(4)
C(1)-Pt(1)-C(7)
C(7)-Pt(1)-P(1)
C(7)-Pt(1)-P(2)
P(2)-Pt(2)-P(1)
P(1)-Pt(2)-P(3)
P(1)-Pt(2)-P(4)
O(2)-Pt(3)-O(1)
O(1)-Pt(3)-P(3)
C(1)-Pt(1)-P(1)
C(1)-Pt(1)-P(2) 165.05(13)
85.83(13)
Spectroscopic Studies. The IR spectra of 4-6 show two
P(1)-Pt(1)-P(2)
P(2)-Pt(2)-P(3)
P(2)-Pt(2)-P(4)
P(3)-Pt(2)-P(4)
107.57(4)
160.64(4)
89.89(4)
72.29(4)
-
1
absorptions in the 800 cm region, in agreement with the
5
,6
maintenance of the cis-“Pt(C
6
6
F
5
)
2
” fragment, and for 5 and
-1
two absorptions in the 1600-1500 cm due to the
O(2)-Pt(3)-P(3) 173.48(10)
-
1
presence of the acac ligand. The absorption in the 950 cm
groups appears at 965 cm in 6,
while in the precursor 5, it appears at 949 cm . The
O(2)-Pt(3)-P(4)
P(3)-Pt(3)-P(4)
Pt(1)-P(2)-Pt(2)
95.45(10)
78.56(5)
74.27(4)
-
1
O(1)-Pt(3)-P(4) 174.45(10)
Pt(1)-P(1)-Pt(2) 74.01(4)
Pt(3)-P(3)-Pt(2) 104.02(5)
region due to the C
F
6 5
-1
Pt(3)-P(4)-Pt(2) 102.89(5)
displacement toward higher frequencies of this absorption
of bridging systems with no metal-metal bonds. The Pt
square planes are not coplanar but establish a sort of zigzag
setup (see Figure 1b). Thus, the Pt(1) plane and the Pt(2)
plane form a dihedral angle of 36.5(1)°, while the Pt(2) and
Pt(3) planes establish a dihedral angle of 26.9(5)°. The Pt(3)
and Pt(3′) planes are coplanar in accordance with the
molecular symmetry constraints. The topology of the cation
of 4 is very remarkable, the total length of the anion being
around 25.6 Å.
has been largely related with the increase in the oxidation
1,3,6,7
state of the metal bonded to the C
F
6 5
groups,
and this
is also in agreement with the formal oxidation states of the
Pt centers bonded to C in 5 and 6.
6 5
F
1
The H NMR spectra of 4-6 in solution show signals due
the phenyl H atoms and for 4 and 5 those expected for the
+
NBu
4
counterion. Complexes 5 and 6 show two singlets at
ca. 5.0 and 1.5 ppm (1:6 intensity ratio) due to the acac
ligand.
The structure of 5 (Figure 2) confirms that it is a trinuclear
unsymmetrical complex resulting from the cleavage of the
chloro bridging system in 4 and the replacement of these
The 19F NMR spectra of 4 and 5 show three signals due
to the o-F, m-F, and p-F. This pattern is in agreement with
the equivalence of the C F groups in the complexes and
6 5
ligands by acac. The “(R
F 2
)
Pt(µ-PPh
2
)
2 2 2
Pt(µ-PPh ) Pt” frag-
the equivalence of the two o-F atoms, as well as the two
m-F atoms, within each ring. The P atoms in 4 and 5 appear
ment is very similar to the analogous one in the precursor 4,
with the Pt atoms in square-planar environments and no
Pt · · · Pt interactions (Pt(1) · · · Pt(2) ) 3.571(1) Å and
Pt(2) · · · Pt(3) ) 3.549(1) Å). The environments of the Pt
centers are not coplanar, the dihedral angles between the Pt(1)
plane and the Pt(2) plane being 28.8(1)°, and 24.2(1)°
between the Pt(2) plane and the Pt(3) plane. The acac ligand
is planar and almost coplanar with the Pt(3) coordination
plane (dihedral angle 13.1(1)°).
The crystal structure of complex 6 (Figure 3) shows a very
short Pt(1)-Pt(2) distance, 2.763(1) Å, indicative of the
existence of a metal-metal bond, as expected for a 46 VEC
complex. This short distance can be compared with the
separation of the analogous atoms in its precursor 5 (3.571(1)
31
1
as an AA′XX′ spin system in the P{ H} NMR spectra of
195
the isotopologues not having Pt. The high-field chemical
shifts at δ -113.0 and -132.5 are in agreement with the
presence of “Pt(µ-PPh
platinum-platinum distances.
2 2
) Pt” fragments with non bonding
3,8-12
The AA′ part (δ -113.0)
(
5) Maslowsky, E. J. Vibrational Spectra of Organometallic Compounds;
Wiley: New York, 1997.
(
(
6) Us o´ n, R.; Forni e´ s, J. AdV. Organomet. Chem. 1988, 28, 219–297.
7) Alonso, E.; Forni e´ s, J.; Fortu n˜ o, C.; Mart ´ı n, A.; Orpen, A. G.
Organometallics 2001, 20, 850–859.
(
8) Carty, A. J.; MacLaughlin, S. A.; Nucciarone, D. Phosphorus-31 NMR
Spectroscopy in Stereochemical Analysis; VCH: New York, 1987.
9) Ara, I.; Chaouche, N.; Forn ´ı es, J.; Fort u˜ no, C.; Kribii, A.; Mart ´ı n, A.
Eur. J. Inorg. Chem. 2005, 389, 4–3901.
(
9072 Inorganic Chemistry, Vol. 47, No. 19, 2008

Unsymmetrical Platinum(II) Phosphido DeriWatiWes
respect to the anionic starting material 5 (δ -113.0), in
agreement with the shorter intermetallic distances between
1
2
8,13
195
1
Pt (III) and Pt (III).
The Pt{ H} NMR signals (Figure
3
S9, Supporting Information) of the Pt atoms (i.e., the ones
remaining in the formal oxidation state +2) are almost
unchanged (δ -3159 in 5 and δ -3087 in 6), whereas those
of the other Pt atoms become more shielded passing from
to 6. In particular, the triplet of triplets attributable to Pt
1or2
2
5
is shifted by ca. 900 ppm to higher fields passing from δ
1
-
3894 in 5 to δ -4809 in 6, while the Pt multiplet results
are high-field-shifted by almost 1500 ppm (δ -3793 in 5
1
95
and δ -5279 in 6). The strong shielding found for Pt
Figure 4. 19F- P HMQC spectrum of 5 (acetone-d6, 295 K).
31
nuclei upon increasing the oxidation state deserves a com-
1
4-16
ment. In fact, it has been reported
that the oxidation
is broader than its XX′ counterpart (δ -132.5), suggesting
that A and A′ are to be assigned to the P atoms trans to the
groups. This was validated by the F- P heteronuclear
multiple-quantum coherence (HMQC) spectrum showing the
correlation between the o-F and the P nuclei at δ -113.0
Figure 4 and Figure S3, Supporting Information).
All P features of 4 and 5 (see Experimental Section) were
determined by computer simulation of the AA′XX′ (29.0%),
AA′XX′M (14.8% for each of the three isotopomers), and
AA′XX′MM′ (7.6% for each of the three isotopomers) spin
systems (A and X ) P; M ) Pt), using as starting
chemical shifts and coupling constants those extractable
directly from the experimental P{ H} and P{ H} cor-
relation spectroscopy (COSY) NMR spectra (Figure 5,
Figures S1 and S5, Supporting Information). In particular,
the tilts of the cross-peaks in the P{ H} COSY spectra
allowed us to unequivocally determine the J or JP,Pt values
that were not directly extractable from 1D spectra due to
195
from Pt(II) to Pt(III) causes a deshielding of the Pt nuclei
(Table 4) ranging from 903 to 2182 ppm.
19
31
C F
6 5
However, in the literature examples shown in Table 4, the
change of oxidation state occurs with a change of complex
geometry (from square-planar to octahedral), which is known
3
1
1
7
(
195
to affect the Pt chemical shift. Thus, in order to confirm
the effect on δPt of the +2 f +3 oxidation for square-planar
complexes not undergoing a geometry change upon removal
31
195
1
of the electrons, we recorded the Pt{ H} NMR spectra of
III
III
complexes [(R
F 2
)
Pt (µ-PPh
2 2 F 2
) Pt (R ) ] and 2 (Scheme 1)
3
1
195
and compared the obtained δPt values with those of their
II
II
2-
Pt(II) precursors [(R
F 2
)
Pt (µ-PPh
2
)
2
Pt (R
F
)
2
]
and 1, re-
3
1
1
31
1
spectively. The values shown in Table 4 indicate that for
square-planar Pt(III) complexes the increase of oxidation state
195
results, in all cases, in a strong shielding of the Pt nuclei.
3
1
1
Although it is premature to draw conclusions on the basis
of only those few examples, it seems that the geometry
around the Pt atoms (in particular, the presence of the Pt P
2 2
ring endowed with a Pt-Pt bond) plays a role in its chemical
shift. Further studies are warranted to gain insights on this
topic.
The few platinum(III) or palladium(III) binuclear phos-
phido derivatives that we have prepared behave as intermedi-
ates for platinum(II) or palladium(II) complexes through
1
2
1
95
overlapping of the Pt satellites.
1
95
1
The Pt{ H} NMR spectra of 4 and 5 (Figures S2 and
S6, Supporting Information) show three signals: a triplet (δ
3357 for 4 and δ -3159 for 5) assigned to the Pt atoms
bound to Cl and acac, respectively), a triplet of triplets (δ
3857 for 4 and δ -894 for 5) arising from the “(µ-
Pt (µ-PPh ) ” fragment, and a multiplet (δ -3795 for
2 2
and δ -3793 for 5) assigned to the Pt (bearing the C
groups). The broadness of the latter signals is mainly due to
the scalar coupling between
F- Pt HMQC spectrum of 5 (Figure 6) shows that Pt is
scalarly coupled with the o-F ( JF,Pt ) 330 Hz) as well as
with the m-F (ca. 2 Hz).
The increase in the formal oxidation state of Pt and Pt
atoms passing from 5 [Pt (II)-Pt (II)-Pt (II)] to 6
3
-
(
-
PPh
2
2
)
2
reductive coupling processes with the formation of P-C or
1
4
6
F
5
4,18-20
P-P bonds.
Aiming to study the stability of the
19
31
1
platinum(III) complex 6, we recorded the F and P{ H}
NMR spectra of a deuterochloroform solution of 6 after 24,
1
95
19
Pt and F atoms. The
1
9
195
1
4
8, and 72 h at room temperature. These spectra showed a
3
great number of signals, indicating the disappearance of 6
and the presence of mixtures of complexes that we have not
been able to identify, although signals due to the presence
1
2
1
2
3
1
2
3
[
Pt (III)-Pt (III)-Pt (II)] is accompanied by significant
(
(
(
(
(
13) Falvello, L. R.; Forni e´ s, J.; Fortu n˜ o, C.; Mart ´ı nez, F. Inorg. Chem.
1994, 33, 6242–6246.
3
1
195
31
1
changes of the P and Pt NMR features. The P{ H}
NMR spectrum of 6 contains signals centered at δ 268.6
and δ -137.2 (Figures S7 and S8, Supporting Information).
The chemical shift of P atoms of the “Pt (µ-PPh
fragment is strongly low-field-shifted in 6 (δ 268.6) with
14) King, C.; Roundhill, D. M.; Dickson, M. K.; Fronczek, F. R. J. Chem.
Soc., Dalton Trans. 1987, 2769–2780.
15) O’Halloran, T. V.; Roberts, M. M.; Lippard, S. J. Inorg. Chem. 1986,
1
2
2
5, 957–964.
2 2
) Pt ”
16) Whitfield, S. R.; Sanford, M. S. Organometallics 2008, 27, 1683–
689.
17) Pregosin, P. S. Coord. Chem. ReV. 1982, 44, 247–291.
1
(
(
(
10) Alonso, E.; Forni e´ s, J.; Fortu n˜ o, C.; Tom a´ s, M. J. Chem. Soc., Dalton
(18) Chaouche, N.; Forni e´ s, J.; Fortu n˜ o, C.; Kribii, A.; Mart ´ı n, A.; Karipidis,
P.; Tsipis, A. C.; Tsipis, C. A. Organometallics 2004, 23, 1797–1810.
(19) Ara, I.; Chaouche, N.; Forni e´ s, J.; Fortu n˜ o, C.; Kribii, A.; Tsipis, A. C.
Organometallics 2006, 25, 1084–1091.
(20) Forni e´ s, J.; Fortu n˜ o, C.; Ib a´ n˜ ez, S.; Mart ´ı n, A.; Tsipis, A. C.; Tsipis,
C. A. Angew. Chem., Int. Ed. 2005, 44, 2407–2410.
Trans. 1995, 3777–3784.
11) Forni e´ s, J.; Fortu n˜ o, C.; Gil, R.; Mart ´ı n, A. Inorg. Chem. 2005, 44,
9
534–9541.
12) Falvello, L. R.; Forni e´ s, J.; Fortu n˜ o, C.; Dur a´ n, F.; Mart ´ı n, A.
Organometallics 2002, 21, 2226–2234.
Inorganic Chemistry, Vol. 47, No. 19, 2008 9073

Ara et al.
Figure 5. 31P{ H} COSY spectra of 5 (acetone-d6, 295 K).
1
18,19,21
31
1
the Experimental Section).
The P{ H} NMR spectra
of 7a and 7b are conclusive in ascertaining their structures,
and all data extracted from the spectra are given in the
Experimental Section (see Scheme 1 for atom numbering).
The signals due to the P4 (doublet of doublets) and the P3
(
doublet) atoms appear at high field (from -132.9 to -146.5
ppm), in the range expected for two PPh groups bonding
to two metal centers not joined by a metal-metal
2
3
,4,8–11,22
bond.
doublets (7a) or as a doublet (7b) at -31.3 or -37.9,
respectively, in the range expected for this “Pt(µ-PPh )(µ-
Finally,
the signal due to P2 appears as a doublet or as a singlet.
Oxidation Processes with I . In order to determine the
influence of the oxidizing agent on the oxidation of 5, we
have studied the addition of I to CH Cl solutions of 5 (1:1
molar ratio). After workup, the hexanuclear Pt(II) complex
{(PPh )(R )Pt(µ-PPh )(µ-I)Pt(µ-PPh Pt(µ-I)} ] (8) is
obtained (Scheme 1). The IR spectrum of 8 shows the
The signal due to P1 appears as a doublet of
2
10,11,18,19,23,24
Br)Pt” fragment in a saturated complex.
Figure 6. 19F-195Pt HMQC spectrum of 5 (acetone-d6, 295 K).
2
2 F
of the PPh R ligand were identified. It is worth noting that
2
2
2
complex 6 is related to complex 2 since both derivatives
show a linear arrangement of the three metal centers, a 46
valence electron count, and a Pt(III)-Pt(III) bond in the
[
R
2 F
F
2
)
2 2
2
analogous “(R
F
)
2
2 2
Pt(µ-PPh ) Pt” fragment. Complex 2 is
characteristic absorptions due to the PPh
2
R
F
ligand (1519,
stable at room temperature, but upon heating, it evolves
toward the Pt(II) derivative 3, with the formation of a P-C
bond. Complex 2 reacts with bromide to produce a binuclear
-
1
19,21
-1
9
82 cm )
and only one signal in the 800 cm region
5
,6
(X-sensitive, C F ), while the absorptions due to the acac
6 5
1
9
31
1
ligand are absent. The F NMR and P{ H} NMR spectra
2 F
Pt(II) bromo derivative with PPh R through a reductive P-C
4
of 8 in deuteroacetone show the same pattern as for complex
coupling. Because of that, we have studied the behavior of
7
a, and all data extracted from the spectra are given in the
trinuclear complex 6 toward bromide.
Experimental Section. Unfortunately, we have not been able
to obtain suitable crystals of 8 for X-ray studies in order to
establish unequivocally the hexanuclear nature of 8, but the
Reaction of Complex 6 with NBu
the orange complex 6 with Br (1:1 molar ratio) at room
temperature yields a yellow solid identified as a mixture of
4
Br. The reaction of
-
reaction of 8 with PPh
)Pt(µ-PPh )(µ-I)Pt(µ-PPh
expected cleavage process of the Pt(µ-I)
Complex 9 has been fully characterized by IR, F NMR,
3
(1:2 molar ratio) yields [(PPh
PtI(PPh )], 9, through the
Pt bridging system.
2 F
R )-
isomers of stoichiometry [(PPh
PPh Pt(acac)] (7a,b, Scheme 1), which are the result of
the coupling between a C group bonded to a Pt(III) center
and a bridging PPh ligand. Although we have not been able
2 F
R
)(R
F
)Pt(µ-PPh )(µ-Br)Pt(µ-
2
(R
F
2
)
2 2
3
2 2
)
2
6 5
F
1
9
2
3
1
1
195
1
P{ H} NMR, and Pt{ H} NMR spectroscopy (see the
to separate the isomers, two fractions of the yellow solid
with different 7a/7b ratios were obtained, and we have
identified each isomer by spectroscopic means (see the
Experimental Section) and single-crystal X-ray diffraction.
The structure of 9 is shown in Figure 7. Selected bond
distances and angles are listed in Table 5. As can be seen, 9
is a trinuclear complex in which the three Pt atoms are held
1
9
Experimental Section). Both the F NMR spectra of 7a and
b show six signals in a 2:2.1:2:1:2 intensity ratio (see the
7
Experimental Section), in agreement with the presence of
two kinds of pentafluorophenyl groups and the equivalence
of the two o-F atoms, as well as the m-F atoms, within each
(21) Falvello, L. R.; Forni e´ s, J.; Fortu n˜ o, C.; Mart ´ı n, A.; Mart ´ı nez-Sari n˜ ena,
A. P. Organometallics 1997, 16, 5849–5856.
(
22) Forni e´ s, J.; Fortu n˜ o, C.; Navarro, R.; Mart ´ı nez, F.; Welch, A. J. J.
Organomet. Chem. 1990, 394, 643–658.
ring. The different chemical shifts of the F atoms of C
6
F
5
(23) Ara, I.; Chaouche, N.; Forni e´ s, J.; Fortu n˜ o, C.; Kribii, A.; Tsipis, A. C.;
Tsipis, C. A. Inorg. Chim. Acta 2005, 358, 1377–1385.
24) Alonso, E.; Forni e´ s, J.; Fortu n˜ o, C.; Mart ´ı n, A.; Rosair, G. M.; Welch,
groups bonded to the platinum center or to the phosphorus
atom allow the unequivocal assignment of these signals (see
(
A. J. Inorg. Chem. 1997, 36, 4426–4431.
9074 Inorganic Chemistry, Vol. 47, No. 19, 2008

Unsymmetrical Platinum(II) Phosphido DeriWatiWes
Table 4. Values of Chemical Shifts (ppm) of 195Pt in Pt(II), Octahedral Pt(III), and Square-Planar Pt(III) Complexes
together through PPh
establish any kind of metal-metal interaction (48 valence
electron count) as is evidenced by the Pt· · ·Pt separations
2
and I bridges. The Pt centers do not
P(2)-Pt(2)-P(3) and I(1)-Pt(2)-P(4) “external” angles
(106.3(1)° and 98.2(1)°, respectively) and acute P(2)-Pt-
(2)-I(1) and P(3)-Pt(2)-P(4) “internal” angles (78.8(1)°
and 76.7(1)°, respectively), as expected for a system with
no Pt-Pt bonds. The square plane of Pt(1) forms a dihedral
angle of 41.5(1)° with the Pt(2) coordination plane. Again,
Pt(3) shows an essentially square-planar environment, with
terminal iodo and triphenylphosphine ligands, the “internal”
P(3)-Pt(3)-P(4) angle being more acute, 76.4(1)°, as
expected. The dihedral angle between the best square-planar
environments of Pt(2) and Pt(3) is 16.6(1)°.
(
Pt(1) · · ·Pt(2) 3.566(1) Å, Pt(1) · · ·Pt(2) 3.576(1) Å). The
platinum atoms lie in the centers of square-planar environ-
ments that are not coplanar. The environment of Pt(1) is
formed by a terminal pentafluorophenyl ligand, a PPh
ligand originated by a P-C coupling process of PPh
ligands in the precursor 8, a PPh bridging ligand, and
an iodo bridging ligand trans to the C group. The central
Pt(2) has a more distorted environment, with obtuse
2 6 5
(C F )
2
and
C
6
F
5
2
6 5
F
Inorganic Chemistry, Vol. 47, No. 19, 2008 9075

Ara et al.
Figure 7. Molecular structure of the complex in [(PPh2RF)(RF)Pt(µ-PPh2)(µ-
I)Pt(µ-PPh2)2PtI(PPh3)] · 0.25CH2Cl2 · 0.5n-C6H14 (9 · 0.25CH2Cl2 · 0.5n-
C6H14).
Table 5. Selected Bond Distances (Å) and Angles (deg) for
Figure 8. Molecular structure of the complex in [(RF)2Pt(µ-PPh2)2Pt(µ-
PPh2)2PtI2]·2CH2Cl2 ·3H2O (11·2CH2Cl2 ·3H2O).
[
(PPh2RF)(RF)Pt(µ-PPh2)(µ-I)Pt(µ-PPh2)2PtI(PPh3)]·0.25CH2Cl2 ·
0
.5n-C6H14 (9·0.25CH2Cl2 ·0.5n-C6H14)
Table 6. Selected Bond Distances (Å) and Angles (deg) for
Pt(1)-C(1)
2.002(9)
2.313(3)
2.259(3)
2.361(3)
2.272(2)
2.336(2)
92.0(3)
171.33(10)
94.36(7)
76.65(8)
176.86(9)
98.23(6)
76.38(8)
173.79(9)
91.42(6)
83.32(2)
Pt(1)-P(1)
2.293(3)
2.6779(7)
2.319(3)
2.6872(7)
2.320(2)
2.6436(7)
94.6(3)
a
[
(RF)2Pt(µ-PPh2)2Pt(µ-PPh2)2PtI2]·2CH2Cl2 ·3H2O (11·2CH2Cl2 ·3H2O)
Pt(1)-P(2)
Pt(1)-I(1)
Pt(1)-C(1)
2.119(17)
2.7778(13)
2.380(4)
2.6466(15)
86.7(10)
84.9(5)
104.7(2)
97.3(2)
78.7(2)
Pt(1)-P(1)
Pt(2)-P(1)
Pt(3)-P(2)
2.281(5)
2.298(4)
2.229(5)
Pt(2)-P(3)
Pt(2)-P(4)
Pt(1)-Pt(2)
Pt(2)-P(2)
Pt(2)-I(1)
Pt(2)-P(2)
Pt(3)-I
Pt(3)-P(4)
Pt(3)-P(3)
Pt(3)-P(5)
Pt(3)-I(2)
C(1)-Pt(1)-C(1′)
C(1)-Pt(1)-P(1)
P(1)-Pt(2)-P(1′)
P(1)-Pt(2)-P(2)
P(2)-Pt(3)-P(2′)
P(2)-Pt(3)-I
Pt(1)-P(1)-Pt(2)
a
C(1)-Pt(1)-P(1′)
P(1′)-Pt(1)-P(1)
P(1)-Pt(2)-P(2′)
P(2′)-Pt(2)-P(2)
P(2)-Pt(3)-I′
I′-Pt(3)-I
Pt(3)-P(2)-Pt(2)
164.8(5)
C(1)-Pt(1)-P(1)
P(1)-Pt(1)-P(2)
P(1)-Pt(1)-I(1)
P(3)-Pt(2)-P(4)
P(4)-Pt(2)-P(2)
P(4)-Pt(2)-I(1)
P(4)-Pt(3)-P(3)
P(3)-Pt(3)-P(5)
P(3)-Pt(3)-I(2)
Pt(1)-I(1)-Pt(2)
C(1)-Pt(1)-P(2)
C(1)-Pt(1)-I(1)
P(2)-Pt(1)-I(1)
P(3)-Pt(2)-P(2)
P(3)-Pt(2)-I(1)
P(2)-Pt(2)-I(1)
P(4)-Pt(3)-P(5)
P(4)-Pt(3)-I(2)
P(5)-Pt(3)-I(2)
105.9(2)
148.89(15)
72.9(2)
94.12(12)
93.03(8)
104.2(2)
170.4(3)
79.78(6)
106.28(9)
173.73(6)
78.77(6)
103.08(9)
167.45(6)
89.37(7)
172.85(12)
74.70(14)
Symmetry transformation used to generate equivalent primed atoms:
x, y, -z + 3/2.
molar ratio) proceeds with different results, depending on
the reaction conditions. Thus, when the reaction is carried
out at 213 K and with a very short reaction time (10 min),
the trinuclear platinum complex, in mixed oxidation state
The formation of 8 can be envisaged as the result of the
oxidation of 5 probably with the formation of the intermedi-
ate 6 and two I anions. The presence of I- favors the
-
reductive coupling of PPh
ligand). Surprisingly, one I replaces the chelating acac
ligand, and the dimerization of the trinuclear unsaturated
2
and R
F
(formation of the PPh
2
R
F
Pt(III)-Pt(III)-Pt(II), [(R
F
)
2 2 2 2 2 2
Pt(µ-PPh ) Pt(µ-PPh ) PtI ] 11
-
is obtained. This 46 VEC complex has to display a Pt-Pt
bond, which can be located at two different positions, and
because of that, an XRD study has been carried out. This,
which will be discussed in detail later, reveals that the Pt-Pt
bond is located between the central Pt atom and the one
2
fragments through the formation of the Pt(µ-I) Pt system
2
5
produces the hexanuclear complex 8.
Finally, we have prepared the neutral unsymmetrical
trinuclear complex [(R Pt(µ-PPh Pt(µ-PPh Pt(NCMe)
10) and studied its behavior toward I in order to prepare a
Pt(III) iodo derivative (considering the lability of the CH CN
)
F 2
)
2 2
)
2 2
2
]
6 5
containing the C F groups. This is an important fact, which
(
2
allows for explanation of the evolution of 11 at room
temperature. The formation of 11 is not surprising and seems
to be the result of the oxidation of 10 to form a mixed
Pt(III)-Pt(III)-Pt(II) complex and substitution of the labile
3
ligands) and study its evolution by raising the temperature.
The synthesis of 10 has been carried out by protonation
with HClO
4
of the acac ligand in 5 in the presence of
-
acetonitrile by the formed I . We have observed, previously,
1
9
acetonitrile (Scheme 1). All data extracted from the IR and
NMR spectra of 10 are in agreement with the proposed
formula and are collected in the Experimental Section. The
similar behavior with other similar binuclear derivatives.
On the other hand, when a CH
treated with a CH Cl solution of I
2
Cl
2
solution of 10 is
2
2
2
(1:1 molar ratio) and
3
1
1
P{ H} NMR signals in DMF (295 K) fall at -119.2 and
the mixture is stirred at room temperature for 24 h, a
yellow solid identified as 8 (Scheme 1) is obtained.
Obviously, the formation of 8 is again a consequence of
the transformation of 11, which at room temperature
1
95
1
1
2
-
127.7, while the Pt{ H} NMR signals for Pt , Pt , and
3
Pt fall at δ -3773, δ -3881, and δ -3461, respectively.
The reaction of complex 10 with I in CH Cl /MeCN (1:1
2
2
2
results in a PPh
already-known process which takes place in pentafluo-
rophenyl binuclear platinum complexes.
The crystal structure of complex 11 has been determined by
single-crystal X-ray diffraction. (Figure 8, Table 6). Complex
11 is a trinuclear complex in which, and in accordance with
2 6 5
/C F reductive coupling. This is an
(
25) According to reviewer’s suggestion, we have studied the room
temperature reaction of I- with 6 in CH2Cl2. To a suspension of 75
mg of 6 in 10 mL of CH2Cl2 was added NBu4I (46 mg). The solution
was stirred for 30 h at room temperature and passed through a silica
1
9
i
gel column. The yellow solution was evaporated to ca. 1 mL and PrOH
was added. A yellow solid crystallized, which was identified (IR and
1
9
F NMR) as complex 8.
9076 Inorganic Chemistry, Vol. 47, No. 19, 2008

Unsymmetrical Platinum(II) Phosphido DeriWatiWes
the crystallographic symmetry on the molecule, the three Pt
atoms form a straight line. The phosphido ligands bridge the
Pt centers, the coordination of the external platinum atoms being
completed by two terminal pentafluorophenyl groups, attached
to Pt(1), and two terminal iodo ligands bonded to Pt(3). The
Pt(1)-Pt(2) distance is short, 2.778(1) Å, indicating the
existence of a Pt-Pt bond, while no interaction is present
between Pt(2) and Pt(3) (distance 3.636(1) Å). In accordance
with the existence of the Pt(1)-Pt(2) bond, the P(1)-Pt(1,2)-
P(1′) angles are broad and the Pt(1)-P(1,1′)-Pt(2) angles are
Concluding Remarks
The oxidative addition of X
2
(X ) halogen) to square-
8
planar d platinum(II) centers usually affords Pt(IV) com-
27-30
plexes,
and the addition to binuclear derivatives is an
entry to binuclear Pt(III) derivatives. The metal centers in
the binuclear Pt(III) complexes usually display an octahedral
31-35
environment.
2
The addition of I to our polynuclear
phosphido derivatives of platinum(II) is carried out with two-
electron oxidation on a Pt (II) unit, giving a Pt (III) unit.
Nevertheless, in our phosphido Pt (III) fragments, the two
2
2
2
26
narrow (see Table 6). The continuous shape measures obtained
for Pt(1), S(SP-4) ) 2.037, and Pt(3), S(SP-4) ) 1.172, indicate
that these atoms lie in the centers of square-planar environments.
Nevertheless, Pt(2) shows a significant deviation from the SP-4
geometry, as is evident in the value of the continuous shape
measure: S(SP-4) ) 6.490. Thus, the planes formed by the
Pt(2), P(1), and P(1′) atoms and the Pt(2), P(2), and P(2′) atoms
are rotated one with respect to the other and form a dihedral
angle of 39.1(1)°. Thus, the core of complex 11 can be regarded
metal centers display nearly coplanar square-planar coordina-
tion environments. The complexes are not stable enough,
and they evolve to new polynuclear Pt(II) derivatives.
The oxidative addition-reductive coupling (with or without
3
6-41
elimination) sequences,
involving M(0)/M(II)/M(0) or
26
M(II)/M(IV)/M(II) (M ) palladium or platinum), have been
proposed in a great number of reaction processes. In our case,
these sequences involve Pt (II)/Pt (III)/Pt (II) fragments, the
2
2
2
Pt(III) intermediates being isolated.
2 2
as formed by two planes “C Pt(1)(µ-P) Pt(2)” and “Pt(2)(µ-
The activation of a P-C bond of a tertiary phosphine is
P) Pt(3)I ” rotated one with respect to the other, with the Pt(2)
center as a pivot point.
2
2
an easy entry into phosphido complexes of transition
42-50
metals.
The reverse M-P and M-C cleavage and P-C
The 19F NMR spectrum of 11 registered at room temper-
ature shows the expected pattern for the proposed structure:
three signals in a 2:1:2 intensity ratio. Moreover, some
signals of very low intensity assigned to the hexanuclear
bond formation in phosphido derivatives is unusual, but it
4
,18,19,21,51-53
has been observed in some cases.
coupling is even more remarkable taking into consideration
the strength of the Pt-C and Pt-PPh bonds in the
This P-C
F
6 5
2
3
1
1
complex 8 are also observed. The P{ H} NMR spectrum
of 11 at 183 K shows only two signals at δ 261.9 and
(
(
(
27) Yahav, A.; Goldberg, I.; Vigalok, A. Organometallics 2005, 24, 5654–
5
659.
-
157.1, in agreement with the presence of two “Pt(µ-
PPh Pt” fragments with and without a metal-metal bond,
respectively, as expected for 11. The signals are broad, and
28) Gracia, C.; Marco, G.; Navarro, R.; Romero, P.; Soler, T.; Urriolabeitia,
E. P. Organometallics 2003, 22, 4910–4921.
29) Forni e´ s, J.; Fortu n˜ o, C.; G o´ mez, M. A.; Menj o´ n, B. Organometallics
2 2
)
1
993, 12, 4368–4375.
195
(30) Ruiz, J.; L o´ pez, J. F. J.; Rodr ´ı guez, V.; P e´ rez, J.; Ram ´ı rez de Arellano,
from the spectrum, only the coupling constants with the Pt
atoms can be extracted. When the same spectrum is recorded
at room temperature, the signals indicate now the existence
in solution of a mixture made up of the hexanuclear complex
M. C.; L o´ pez, G. J. Chem. Soc., Dalton Trans. 2001, 268, 3–2689.
31) Bennett, M. A.; Bhargava, S. k. M. B. A.; Edwards, A. J.; Guo, S.-
(
X.; Priv e´ r, S. H.; Rae, A. D.; Willis, A. C. Inorg. Chem. 2004, 43,
7
752–7763.
(
32) Matsumoto, K.; Ochiai, M. Coord. Chem. ReV. 2002, 231, 229–238.
8
as the main component and a very small amount of the
(33) Rendina, L. M.; Hambley, T. W. In ComprehensiVe Coordination
Chemistry II; McCleverty, J. A., Meyer, T. J. Eds.; Elsevier Inc.: San
Diego, 2004; Vol. 6.
trinuclear complex 11. These results indicate that 11 is
unstable in solution at room temperature and evolves toward
(34) Lippert, B. Coord. Chem. ReV. 1999, 263–295.
(
35) Muller, J.; Freisinger, E.; Sanz-Miguel, P. J.; Lippert, B. Inorg. Chem.
8
2 6 5
through the coupling of the PPh and C F groups bonded
2
003, 42, 5117–5125.
to a Pt(III) center. The evolution of 11 to 8 can be compared
with the evolution of the binuclear platinum(III) complex
(36) van Belzen, R.; Elsevier, C. J.; Dedieu, A.; Veldman, N.; Spek, A. L.
Organometallics 2003, 22, 722–736.
37) Christmann, U.; Vilar, R. Angew. Chem., Int. Ed. 2005, 44, 366–374.
(
[
(R
num(II) [{(R
ous that the reductive coupling process, which transforms
1 into 8, takes place between ligands bonded to metal
centers in a formal +3 oxidation state.
F
)
2
Pt(µ-PPh
2
)
2
PtI
2
], which renders the tetranuclear plati-
(38) Leca, F.; Sauthier, M.; Deborde, V.; Toupet, L.; R e´ au, R. Chem.sEur.
J. 2003, 9, 3785–3795.
F
)Pt(µ-PPh
2
)(µ-I)Pt(PPh )(µ-I)} ]. It is obvi-
R
2 F
2
(
39) Moncarz, J. R.; Brunker, T. J.; Glueck, D. S.; Sommer, R. D.;
Rheingold, A. L. J. Am. Chem. Soc. 2003, 125, 1180–1181.
40) Hristov, I. H.; Ziegler, T. Organometallics 2003, 22, 3513–3525.
41) Espinet, P.; Echavarren, A. M. Angew. Chem., Int. Ed. 2004, 42, 4704–
4734.
(
(
1
(42) Zhuravel, M. A.; Moncarz, J. R.; Glueck, D. S.; Lam, K.-C.; Rheingold,
A. L. Organometallics 2000, 19, 3447–3454.
(
26) For the definition and use of the continuous shape measure, S, as a
parameter quantifying the reliability with which a real coordination
entity can be described by means of a given regular geometric
polyhedron, see: (a) Pinsky, M.; Avnir, D. Inorg. Chem. 1998, 37,
(43) Shulman, P. M.; Burkhardt, E. D.; Lundquist, E.; Pilato, R. S.;
Geoffroy, G. L.; Rheingold, A. L. Organometallics 1987, 6, 101–
109.
(44) Mizuta, T.; Onishi, M.; Nakazono, T.; Nakazawa, H.; Miyoshi, K.
Organometallics 2002, 21, 717–726.
5
575. (b) Casanova, D.; Llunell, M.; Alemany, P.; Alvarez, S.
Chem.sEur. J. 2005, 11, 1479. (c) Cirera, J.; Alemany, P.; Alvarez,
S. Chem.sEur. J. 2004, 10, 190. (d) Casanova, D.; Alemany, P.; Bofill,
J. M.; Alvarez, S. Chem.sEur. J. 2003, 9, 281. (e) Alvarez, S.; Avnir,
D.; Llunell, M.; Pinsky, M. New J. Chem. 2002, 996. (f) Alvarez, S.;
Llunell, M. J. Chem. Soc., Dalton Trans. 2000, 3288. The smaller the
value of S, the better the agreement between the real molecule and
the suggested model, S ) 0 being for perfect coincidence.
(45) Bender, R.; Braunstein, P.; Dedieu, A.; Ellis, P. D.; Huggins, B.;
Harvey, P. D.; Sappa, E.; Tiripicchio, A. Inorg. Chem. 1996, 35, 1223–
1234.
(46) Shiu, K. B.; Jean, S. W.; Wang, S. L.; Liao, F. L.; Wang, J. C.; Liou,
L. S. Organometallics 1997, 16, 114–119.
(47) Garc ´ı a, G.; Garc ´ı a, M. E.; Mel o´ n, S.; Riera, V.; Ruiz, M. A.; Villafa n˜ e,
F. Organometallics 1997, 16, 624–631.
Inorganic Chemistry, Vol. 47, No. 19, 2008 9077

Ara et al.
i
precursors, and with no doubt the +3 oxidation state of the
Pt center, in a nonoctahedral environment, plays a key role
in this process.
washed with PrOH (2 × 0.5 mL), and vacuum-dried (0.534 g, 73%
yield). Anal. found (calcd for C81 Pt ): C, 48.56 (48.53);
H, 3.47 (4.18); N, 0.55 (0.70). IR (cm ): 778, 769 (X-sensitive
F
10
H
83NO
P
2 4
3
-
1
-1
2
C
mol
6
F
5
-
); 1562, 1515 (ν(CdC), ν(CdO) acac). Λ
M
) 51 ohm cm
From the spectroscopic point of view, Pt atoms in the +3
oxidation state and in a nonoctahedral environment exhibit
1
19
3
.
F NMR (acetone-d
6
, 295 K): δ -113.1 (o-F, d, JF,F ) 30
3
3
Hz, JF,Pt(1) ) 329 Hz), -167.6 (m-F, br m), -168.9 (p-F, t, JF,F
195
strong shielding of their Pt nuclei with respect to their Pt(II)
1
)
J
)
4
20 Hz). 31P{ H} NMR (acetone-d
6
2
, 295 K): δ -113.0 [P(1/2),
1
95
1
19
195
precursors, as ascertained by Pt{ H} and F- Pt HMQC
experiments. The fact that
2
2
1
P(1),P(2) ) 150 Hz, JP(1),P(3) ) 7 Hz, JP(1),P(4) ) 298 Hz, JP(1),Pt(1)
1
95
Pt(III) nuclei in octahedral
1
3
1769 Hz, JP(1),Pt(2) ) 1626 Hz, JP(1),Pt(3) ) 77 Hz], -132.5 [P(3/
environments experience a deshielding with respect to their
Pt(II) precursors suggests that the presence of three-membered
), 2JP(3),P(1) ) 7 Hz, JP(3),P(2) ) 298 Hz, JP(3),P(4) ) 117 Hz, JP(3),Pt(2)
2
2
1
1
JP(3),Pt(3) ) 2590 Hz]. 195Pt{
1
) 1730 Hz,
H} NMR (acetone-d6,
1
2
Pt P rings may play a role for such effects.
295 K): δ -3159 [Pt(3), t, J
P(1),Pt(1) ) 1769 Hz], -3894 [Pt(2), tt, JPt(2),P(1) ) 1626 Hz,
Pt(2),P(3) )1730 Hz].
) 2590 Hz], -3793 [Pt(1), m,
Pt(3),P(3)
1
1
J
Experimental Section
1
J
General Comments. Literature methods were used to prepare
3
4 2 F 2 2 2 2 2 F 2
the starting material [NBu ] [(R ) Pt(µ-PPh ) Pt(µ-PPh ) Pt(R ) ].
C, H, and N analysis and IR spectra procurement were performed
1
9
as described elsewhere. NMR spectra were recorded on Bruker
ARX 300, Varian UNITY 300, and Bruker Avance 400 spectrom-
1
19
eters; frequencies are referenced to SiMe
4
( H), CFCl
3
( F), 85%
31
195
H PO ( P), and H PtCl ( Pt). NMR simulations were performed
3 4 2 6
4 F 2 2 2 2 2
Reaction of [NBu ][(R ) Pt(µ-PPh ) Pt(µ-PPh ) Pt(acac)], 5,
with HCl. To a yellow solution of 5 (0.150 g, 0.075 mmol) in
acetone (10 mL) was added 0.32 mL (0.075 mmol) of HCl (HCl/
using the program WINDAISY 4.05. Signal attributions and
coupling constant assessments were made on the basis of a
19
31
19
195
multinuclear NMR analysis that included F- P HMQC, F- Pt
2
H O, 0.24 M). The solution was stirred for 24 h and evaporated to
3
1
1
HMQC, and P{ H} COSY experiments. Coupling constants not
i
ca. 1 mL, and PrOH (10 mL) was added. Complex 4 crystallizes
directly extractable from the 1D spectra were obtained and attributed
i
upon stirring, which was filtered off and washed with PrOH (2 ×
54
on the basis of the tilts of the multiplets due to the “passive” nuclei
in the aforementioned 2D spectra.
1
mL) and vacuum-dried (0.072 g, 50% yield).
Synthesis of [(R
. To a yellow solution of 5 (0.270 g, 0.135 mmol) in CH
(0.060 g, 0.289 mmol). The mixture was
F
)
2
Pt(µ-PPh
2
)
2
Pt(µ-PPh
2
)
2
Pt(acac)][ClO
4
],
Caution! Perchlorate salts of metal complexes with organic
ligands are potentially explosiVe. Only small amounts of materials
should be prepared, and these should be handled with great caution.
6
2
2
Cl (20
mL) was added AgClO
4
stirred in the dark for 7 h and filtered through celite. The orange
Synthesis of [NBu
. To a yellow solution of 1 (2.000 g, 0.800 mmol) in acetone (30
mL) was added HCl (1.600 mmol, HCl/H O solution, 0.24 M). The
solution was stirred for 20 h and evaporated to ca. 2 mL. PrOH
20 mL) was added, and the mixture was stirred for 5 h. The yellow
4 2
] [{(R
F
)
2
Pt(µ-PPh
2
)
2
Pt(µ-PPh
2
)
2
Pt(µ-Cl)}
2
],
i
solution was evaporated to ca. 2 mL, and PrOH (3 mL) was added.
4
The solution was evaporated until an orange solid crystallized, 6,
2
i
which was filtered off, washed with cold PrOH (2 × 0.5 mL), and
i
vacuum-dried (0.142 g, 57% yield). Anal. found (calcd for
(
-1
C
7
Λ
(
2
2
1
65ClF10H
47
O
6
P
4
Pt
3
): C, 41.63 (41.98); H, 1.99 (2.54). IR (cm ):
i
solid 4 was filtered off, washed with PrOH (3 × 1 mL), and
94, 784 (X-sensitive C F ); 1561, 1522 (ν(CdC), ν(CdO) acac).
6 5
vacuum-dried (1.330 g, 85% yield). Anal. found (calcd for
-1
2
-1 19
M
3
) 86 ohm cm mol . F NMR (CDCl , 295 K): δ -119.5
C
152Cl
2
F
20
H
152
N
2
1
P
8
Pt
6
): C, 46.97 (47.07); H, 3.82 (3.92); N, 0.60
o-F, d, JF,F ) 23 Hz, 3JF,Pt(1) ) 280 Hz), -156.2 (p-F, t, JF,F
3
3
)
-
-1
(
0.72). IR (cm ): 779, 771 (X-sensitive C
6
F
5
). Λ
M
) 84 ohm
31
1
0 Hz), -160.7 (m-F, br m). P{ H} NMR (CDCl
3
, 295 K): δ
2
-1 19
3
cm mol
.
3
F NMR (acetone-d
6
, 295 K): δ -113.8 (o-F, d, JF,F
2
2
2
68.6 [P(1/2), JP(1),P(2) ) 40.1 Hz, JP(1),P(3) ) 24 Hz, JP(1),P(4)
)
)
30 Hz, JF,Pt(1) ) 324 Hz), -167.6 (m-F, br m), -168.9 (p-F, t,
F,F ) 20 Hz). P{ H} NMR (acetone-d
1
1
3
14 Hz, JP(1),Pt(1) ) 1305 Hz, JP(1),Pt(2) ) 1065 Hz, JP(1),Pt(3) ) 50
3
31
1
J
6
, 295 K): δ -111.6 [P(1/
Hz], -137 [P(3/4), JP(3),P(1) ) 24 Hz, 2JP(3),P(2) ) 114 Hz, JP(3),P(4)
2
2
2
2
2
2
J
), m, JP(1),P(2) ) 125 Hz, JP(1),P(3) ) 13 Hz, JP(1),P(4) ) 293 Hz,
107 Hz, JP(3),Pt(1) ) 80 Hz, 1JP(3),Pt(2) ) 1939 Hz, 1JP(3),Pt(3)
)
)
1
1
P(1),Pt(1) ) 1771 Hz, JP(1),Pt(2) ) 1624 Hz], -128.4 [P(3/4), m,
195
1
2
967 Hz]. Pt{ H} NMR (CDCl
3
, 295K): δ -3087 [Pt(3), t,
2JP(3),P(1) ) 13 Hz, JP(3),P(2) ) 293 Hz, JP(3),P(4) ) 163 Hz, JP(3),Pt(2)
2
2
1
1
1
J
Pt(3),P(3) ) 2967 Hz], -3793 [Pt(1), m, JP(1),Pt(1) ) 1305 Hz,
1
195
1
)
1714 Hz, JP(3),Pt(3) ) 2552 Hz]. Pt{ H} NMR (acetone-d6,
1JPt(1),Pt(2) ) 434 Hz], -3894 [Pt(2), tt, JPt(2),P(1) ) 1065 Hz, JPt(2),P(3)
1
1
1
2
J
95 K): δ -3337 [Pt(3), t, JPt(3),P(3) ) 2552 Hz], -3795 [Pt(1), m,
1939 Hz, 1JPt(2),Pt(1) ) 434 Hz].
)
1
1
P(1),Pt(1) ) 1771 Hz], -3857 [Pt(2), tt, JPt(2),P(1) ) 1624 Hz,
1JPt(2),P(3) )1714 Hz].
Reaction of [(R
NBu BH . To an orange solution of 6 (0.100 g, 0.054 mmol) in
CH Cl (10 mL) was added NBu BH (0.030 g, 0116 mmol) solved
F 2 2 2 2 2 4
) Pt(µ-PPh ) Pt(µ-PPh ) Pt(acac)][ClO ] with
4
4
Synthesis of [NBu
4
][(R
F
)
2
Pt(µ-PPh
2
)
2
Pt(µ-PPh
2
)
2
Pt(acac)],
2
2
4
4
5
. To a yellow solution of 4 (0.704 g, 0.181 mmol) in acetone (30
in methanol (2 mL). The yellow solution was evaporated to ca. 1 mL;
PrOH (10 mL) was added, and 5 crystallized (0.042 g, 41% yield).
i
mL) was added Tlacac (0.116 g, 0.381 mmol). The mixture was
stirred in the dark for 20 h and filtered through celite. The solution
was evaporated to ca. 2 mL; PrOH (20 mL) was added, and the
Reaction of [(R
NBu Br. To an orange solution of 6 (0.350 g, 0.188 mmol) in
CH Cl (20 mL) was added NBu Br (0.061 g, 0.189 mmol). The
F 2 2 2 2 2 4
) Pt(µ-PPh ) Pt(µ-PPh ) Pt(acac)][ClO ] with
i
4
mixture was stirred for 3 h. The yellow solid 5 was filtered off,
2
2
4
9078 Inorganic Chemistry, Vol. 47, No. 19, 2008

Unsymmetrical Platinum(II) Phosphido DeriWatiWes
solution was stirred for 68 h and evaporated to dryness. Et
2
O (20
) was
filtered off. The solution was evaporated to ca. 2 mL, and hexane
20 mL) was added. A yellow solid crystallized that was filtered,
washed with hexane (2 × 0.5 mL), and vacuum-dried (0.149 g,
7% yield, 7a/7b ratio ca. 3.5:1). The solution was left in the freezer
H, 2.13 (2.52). IR (cm-1): 1519, 982 (PPh
2
C
6
F
5
); 798 (X-sensitive
, 293 K): δ -117.6 (2 o-F, JPt,F ) 432
), -149.1 (1 p-F, PPh ), -161.0
1
9
mL) was added to the residue, and a white solid (NBu
4
ClO
4
C
6
F
5
). F NMR (CD
Hz), -124.2 (2 o-F, PPh
(2 m-F, PPh ), -165.0 (1 p-F), -165.3 (2 m-F). P{ H} NMR
2 2
Cl
2
C
F
6 5
2 6 5
C F
3
1
1
(
2 6 5
C F
2
1
(CD
2
Cl
2
, 293 K): δ 20.0 [P5, d, JP(5),P(3) ) 392 Hz, JP(5),Pt(3)
)
2154 Hz], 12.9 [P1, d, JP(1),P(2) ) 329 Hz, 1JP(1),Pt(1) ) 2283 Hz],
2
5
-40.8 [P2, dd, JP(2),P(1) ) 329 Hz, 2JP(2),P(4) ) 304 Hz, JP2,Pt(1)
)
2
1
for 3 days, and a second fraction of yellow solid crystallized that
was filtered, washed with cold hexane (2 × 0.5 mL), and vacuum-
dried (0.031 g, 9% yield, 7a/7b ratio ca. 1:2.9). Anal. found (calcd
1
2
1677 Hz, JP2,Pt(2) ) 1854 Hz], -148.7 [P3,dd, JP(3),P(4) ) 190 Hz,
2
P(3),P(5) ) 392 Hz, 1JP3,Pt(2) ) 2863, JP3,Pt(3) ) 1846 Hz], -162.2
1
J
[P4, dd, JP(4),P(2) ) 304 Hz, 2JP(4),P(3) ) 190 Hz, 1JP(4),Pt(2) ) 1561
2
for BrC65
F
10
H
47
O
2
P
4
Pt
3
): C, 42.33 (42.45); H, 2.73 (2.57). IR
); 802 7a, 784 7b (X-sensitive C );
, 293 K) for
-
1
1
195
1
(
cm ): 1520, 983 (PPh
2
C
6
F
5
6
F
5
2 2
Hz, JP(4),Pt(3) ) 2509 Hz]. Pt{ H} NMR (CD Cl , 295 K): δ
1
1
1
1
7
575, 1520 (ν(CdC), ν(CdO) acac). H NMR (CDCl
a and 7b: δ 5.2 (CH, acac), 1.7 (CH , acac), 1.6 (CH
, 293 K) for 7a: δ -117.7 (2 o-F, JF,Pt(1) ) 449 Hz),
124.5 (2 o-F, PPh ), -148.7 (1 p-F, PPh ), -160.7 (2
m-F, PPh ), -164.5 (1 p-F), -165.5 (2 m-F). For 7b: δ -119.2
2 o-F, JF,Pt(1) ) 221 Hz), -122.1 (2 o-F, PPh ), -147.7 (1
p-F, PPh ), -160.4 (2 m-F, PPh ), -161.8 (1 p-F), -163.7
, 293 K) for 7a: δ 15.3 [P2, d,
3
-3959 [Pt(2), ddd, JPt(2),P(2) ) 1854 Hz, JPt(2),P(3) ) 2863 Hz,
1
9
1
1
1
1
3
3
, acac).
F
J
J
J
Pt(2),P(4) ) 1561 Hz], -4416 [Pt(3), ddd, JPt(3),P(3) ) 1846 Hz,
Pt(3),P(4) ) 2509 Hz, JPt(3),P(5) ) 2154 Hz], -4525 [Pt(1), dd,
Pt(1),P(1) ) 2283 Hz, JPt(1),P(2) )1677 Hz].
3
1
NMR (CDCl
-
3
1
2
C
6
F
5
2
C
6
F
5
2 6 5
C F
3
(
2 6 5
C F
2
C
6
1
F
5
1
2 6 5
C F
3
(
2
2 m-F). P{ H} NMR (CDCl
3
J
1
2
P(1),P(2) ) 333 Hz, JP(2),Pt(1) ) 2307 Hz], -31.3 [P1, dd, JP(1),P(2)
2
1
)
333 Hz, JP(1),P(4) ) 306 Hz, JP(1), Pt ) 1965, 1764 Hz], -134.0
2
1
[
P3, d, JP(3),P(4) ) 170 Hz, JP(3),Pt ) 3001, 3265 Hz], -146.0 [P4,
Synthesis of [(R
a yellow solution of 5 (1.000 g, 0.499 mmol) in MeCN (15 mL)
was added HClO (0.499 mmol, 2.85 mL of a HClO /MeOH
F 2 2 2 2 2 2
) Pt(µ-PPh ) Pt(µ-PPh ) Pt(NCMe) ], 10. To
2
2
1
dd, JP(1),P(4) ) 306 Hz, JP(3),P(4) ) 170 Hz, JP(4),Pt(2) ) 1770 Hz,
1
1
J
P(4),Pt(3) ) 2015 Hz]. For 7b: δ -5.0 [P2, s, JP(2),Pt(1) ) 4861
4
4
2
1
1
Hz], -37.9 [P1, d, JP(1),P(4) ) 295 Hz, JP(1),Pt(1) ≈ JP(1),Pt(2) ≈ 1600
solution at 0.175 M). Instantaneously, a pale yellow solid crystal-
lized, 10, which was stirred for 30 min, filtered, washed with cold
MeCN (2 × 0.5 mL), and vacuum-dried (0.761 g, 87% yield). Anal.
2
1
Hz], -132.9 [P3, d, JP(3),P(4) ) 173 Hz, JP(3),Pt ) 2964, 3390 Hz],
2
2
1
-
)
146.5 [P4, dd, JP(1),P(4) ) 295 Hz, JP(3),P(4) ) 173 Hz, JP(4),Pt(2)
1720 Hz, JP(4),Pt(3) ) 2656 Hz].
1
10 46 2 4 3
found (calcd for C64F H N P Pt ): C, 43.88 (44.09); H, 2.43 (2.64);
Reaction of [NBu
. To a solution of 5 (0.200 g, 0.100 mmol) in CH
was dripped a CH Cl solution (10 mL) of I (0.026 g, 0.100 mmol).
4
][(R
F 2
) Pt(µ-PPh
)
2 2
Pt(µ-PPh
)
2 2
Pt(acac)] with
N, 1.64 (1.60). IR (cm-1): 2323, 2316 (ν(CtN)); 782, 770 (X-
sensitive C F ). 19F NMR (DMF, 295 K): δ -113.5 (o-F, d,
JF,F
JF,Pt(1) ) 317 Hz), -166.7 (m-F, br m), -167.4 (p-F, t,
I
2
2
Cl (15 mL)
2
3
6
5
3
2
2
2
) 30 Hz,
The solution was stirred for 30 h and evaporated to ca. 2 mL, and
3
JF,F ) 20 Hz). 31P{
1
H} NMR (DMF, 315 K): δ -118.8 [P(1/2),
i
1J
1
1
1
PrOH (10 mL) was added. A yellow solid, 8, crystallized, which
) 150 Hz, J
) 3 Hz, J
) 1670 Hz], -128.8 [P(3/4), J
) 298 Hz, J
P(1),P(2)
P(1),P(3)
P(1),P(4)
P(1),Pt(1)
i
1
1
was filtered, washed with PrOH (2 × 0.5 mL), and vacuum-dried
) 1740 Hz, J
Hz,
1
) 3
P(1),Pt(2)
P(3),P(1)
(
3
8
(
0.085 g, 44% yield). Anal. found (calcd for C120
F
20
H
80
I
4
P
8
Pt
6
): C,
);
, 293 K): δ -116.4
), -150.0 (1
2 6 5
C F ), -164.8 (1 p-F), -165.1
1
JP(3),P(2) ) 298 Hz,
JP(3),Pt(3) ) 2690 Hz]. Pt{ H} NMR (dmf, 295 K): δ -3461
1
J
) 120 Hz, JP(3),Pt(2) ) 1700 Hz,
1
P(3),P(4)
195 1
-1
7.60 (37.62); H, 1.90 (2.09). IR (cm ): 1519, 982 (PPh
01 (X-sensitive C
). 19F NMR (acetone-d
2
C
6
F
5
F
5
6
[Pt(3), t, J
1
) 2690 Hz], -3773 [Pt(1), m, J
1
) 1740
6
Pt(3),P(3)
P(1),Pt(1)
3
1
1
2 o-F, JF,Pt(1) ) 440 Hz), -124.0 (2 o-F, PPh
2
C
6
F
5
Hz], -3881 [Pt(2), tt, J
) 1670 Hz, J
)1700 Hz].
Pt(2),P(1)
Pt(2),P(3)
p-F, PPh ), -161.8 (2 m-F, PPh
(
2
3
C
6
F
5
1
1
2
2 m-F). P{ H} NMR (acetone-d
332 Hz, JP1,Pt(1) ) 2303 Hz], -44.6 [P2, dd, JP(1),P(2) ) 332
6
, 293 K): δ 12.9 [P1, d, JP(1),P(2)
1
2
)
Hz, JP(2),P(4) ) 303 Hz, 1JP(2),Pt(1) ≈ JP(2),Pt(1) ≈ 1870 Hz], -142.6
2
1
2
1
[
P3, d, JP(3),P(4) ) 175 Hz, JP(3),Pt ) 3154, 2806 Hz], -152.6 [P4,
2
2
1
dd, JP(2),P(4) ) 303 Hz, JP(3),P(4) ) 175 Hz, JP(4),Pt can not be
measured unambiguously].
F 2 2 2 2 2 2
Reaction of [(R ) Pt(µ-PPh ) Pt(µ-PPh ) Pt(NCMe) ] with
2
I . To a pale yellow suspension of 10 (0.150 g, 0.086 mmol) in
Reaction of [{(PPh
I)} ] with PPh . To a yellow suspension of 8 (0.114 g, 0.029 mmol)
in acetone (20 mL) was added PPh (0.016 g, 0.060 mmol), and
this was stirred for 24 h. The mixture was filtered trough celite,
and the solution was evaporated to ca. 0.5 mL. CHCl (2 mL) was
added, and a yellow solid, 9, crystallized, which was filtered, washed
with cold CHCl
(2 × 0.5 mL), and vacuum-dried (0.025 g, 19%
yield). Anal. found (calcd for C78 Pt ): C, 42.96 (43.02);
2 F F 2 2 2
R )(R )Pt(µ-PPh )(µ-I)Pt(µ-PPh ) Pt(µ-
CH
2
Cl
2
/MeCN (20/5 mL) was dropped I
2
(0.022 g, 0.086 mmol)
2
3
in CH
2
Cl (5 mL). The mixture was stirred for 24 h at room
2
3
temperature, and the solution was evaporated to ca. 1 mL. A yellow
solid crystallized, 8, which was filtered and vacuum-dried (0.084
g, 51% yield).
3
To a pale yellow suspension of 10 (0.150 g, 0.086 mmol) in CH
MeCN (20/5 mL) at 213 K was dropped I (0.022 g, 0.086 mmol) in
CH Cl (5 mL). The mixture was stirred at 213 K for 10 min, and a
2 2
Cl /
3
F
10
H
55
I
2
P
5
3
2
2
2
small amount of yellow solid was filtered off. The dark red solution
was evaporated to ca. 1 mL, and hexane (20 mL) was added. The
brown-red solid, 11, was filtered, washed with hexane (2 × 1 mL),
and vacuum-dried (0.113 g, 66% yield). Anal. found (calcd for
(
(
48) Fahey, D. R.; Mahan, J. E. J. Am. Chem. Soc. 1976, 98, 4499–4503.
49) Ang, H. G.; Kwik, W. L.; Leong, W. K.; Johnson, B. F. G.; Lewis,
J.; Raithby, P. R. J. Organomet. Chem. 1990, 396, C43.
50) Heyn, R. H.; Gorbitz, C. H. Organometallics 2002, 21, 2781–2784.
51) Archambault, C.; Bender, R.; Braunstein, P.; Decian, A.; Fischer, J.
Chem. Commun. 1996, 2729–2730.
(
(
-1
C
60
F
10
H
40
I
2
P
4
Pt
3
): C, 37.26 (37.63); H, 2.06 (2.09). IR (cm ): 794,
19
(
(
(
52) Cabeza, J. A.; del R ´ı o, I.; Riera, V.; Garc ´ı a-Granda, S.; Sanni, B.
782 (X-sensitive C F ). F NMR (CD Cl , 293 K): δ -118.3 (o-F,
6 5 2 2
Organometallics 1997, 16, 1743–1748.
3
31
1
J
F,Pt(1) ) 288 Hz), -157.0 (p-F), -161.4 (m-F). P{ H} NMR
2
53) Albinati, A.; Filippi, V.; Leoni, P.; Marchetti, L.; Pasquali, M.;
Passarelli, V. Chem. Commun. 2005, 2155–2157.
1
(CD
Cl
2
, 183 K): δ 261.9 (P atoms trans to C
6
F
5
, JP,Pt ) 1198, 1325
1
54) Carlton, L. Bruker Rep. 2000, 148, 28–29.
Hz), -157.1 (P atoms trans to I, JP,Pt ) 1664, 2709 Hz).
Inorganic Chemistry, Vol. 47, No. 19, 2008 9079

Ara et al.
Table 7. Crystal Data and Structure Refinement for Complexes [NBu4]2[{(RF)2Pt(µ-PPh2)2Pt(µ-PPh2)2Pt(µ-Cl)}2]·5.5Me2CO (4·5.5Me2CO),
[NBu4][(RF)2Pt(µ-PPh2)2Pt(µ-PPh2)2Pt(acac)]·2Me2CO (5·2Me2CO), [(RF)2Pt(µ-PPh2)2Pt(µ-PPh2)2Pt(acac)][ClO4]·3CH2Cl2 (6·3CH2Cl2),
[(PPh2RF)(RF)Pt(µ-PPh2)(µ-I)Pt(µ-PPh2)2PtI(PPh3)]·0.25CH2Cl2 ·0.5n-C6H14 (9·0.25CH2Cl2 ·0.5n-C6H14), and
[(RF)2Pt(µ-PPh2)2Pt(µ-PPh2)2PtI2]·2CH2Cl2 ·3H2O (11·2CH2Cl2 ·3H2O)
4
·5.5Me2CO
5·2Me2CO
6·3CH2Cl2
9·0.25CH2Cl2 ·0.5n-C6H14 11·2CH2Cl2 ·3H2O
formula
C152H146Cl2F20N2P8Pt6 ·
C81H82F10NO2P4Pt3 ·
2Me2CO
2117.79
223(1)
C65H47ClF10O6P4Pt3 ·
3CH2Cl2
2113.4
C78H55F10I2P5Pt3 ·
0.25CH2Cl2 ·0.5n-C6H14
2236.93
C60H40F10I2P4Pt3 ·
2CH2Cl2 ·3H2O
2137.77
100(1)
5
.5Me2CO
Mt [g mol-1]
T [K]
4189.34
100(1)
100(1)
100(1)
λ [Å]
0.71073
triclinic
P1j
0.71073
monoclinic
P21
11.8212(4)
20.0776(7)
17.6024(6)
90
95.251(1)
90
4160.2(2)
2
0.71073
monoclinic
P21/c
21.0543(9)
10.8851(5)
30.7207(14)
90
93.398(1)
90
7028.1(5)
4
0.71073
triclinic
P1j
0.71073
monoclinic
C2/c
18.8343(14)
26.2950(19)
15.6164(12)
90
110.635(1)
90
7237.8(9)
4
cryst syst
space group
a [Å]
13.042(2)
17.449(3)
8.659(3)
97.277(4)
96.305(3)
97.511(3)
4140.9(12)
1
18.7253(7)
20.8882(8)
22.7255(8)
90.644(1)
109.611(1)
97.570(1)
8285.6(5)
4
b [Å]
c [Å]
R [deg]
ꢀ
[deg]
γ [deg]
3
V [Å ]
Z
F [g cm 3]
µ [mm 1]
F(000)
-
1.680
5.234
2050
1.691
5.181
2080
1.997
6.392
4048
1.793
5.974
4240
1.962
6.940
4016
-
2
θ range [deg]
2.4-50.1
22969
3.4-52.9
35852
2.0-50.0
37609
3.3-52.6
67365
3.3-50.0
19544
no. of reflns collected
no. of unique reflns
14489
16574
12369
32989
6375
R(int)
0. 0302
0.0417
0.0313
0.0502
0.0806
a
final R indices [I > 2σ(I)]
R1
wR2
0.0455
0.1094
0.0339
0.0560
0.0262
0.0484
0.0431
0.0891
0.0697
0.1689
R indices (all data)
R1
wR2
0.0707
0.1218
1.014
0.0448
0.0580
0.817
0.0333
0.0503
1.036
0.0817
0.09495
0.995
2 2
0.1119
0.1823
1.052
2
b
goodness-of-fit on F
a
R1 ) ∑(|Fo| - |Fc|)/∑ |Fo|. wR2 ) [∑w (Fo2 - Fc ) /∑w(Fo ) ]1/2. Goodness-of-fit ) [∑w (Fo2 - Fc ) /(nobs - nparam)]1/2.
2 2
2 2
b
X-Ray Structure Determinations. Crystal data and other details
of the structure analysis are collected in Table 7. Suitable crystals
noted. All hydrogen atoms were constrained to idealized geometries
and assigned isotropic displacement parameters 1.2 times the Uiso
value of their attached carbon atoms (1.5 times for methyl hydrogen
of 4·5.5Me
14, and 11·2CH
of n-hexane into an acetone (4 and 5) or CH
2
CO, 5·2Me
2
CO, 6·3CH
O were obtained by the slow diffusion
Cl (6, 9 and 11)
2
Cl
2
, 9·0.25CH
2 2
Cl ·0.5n-
C
6
H
2
Cl ·3H
2
2
2 2
atoms). For 4·5.5Me CO, one of the Me CO solvent molecules
2
2
was found to be disordered over two positions that were refined
with 0.5 partial occupancy. The geometry in these disordered
moieties was restrained to acceptable values, and all of the atoms
were assigned a common set of anisotropic thermal parameters.
solution of the complex. Crystals were mounted at the end of a
glass fiber. In all cases, the diffraction data were collected with a
Bruker Smart Apex diffractometer. For 4·5.5Me
dimensions were determined from the positions of 941 reflections
from the main data set. For 5·2Me CO, unit cell dimensions were
determined from the positions of 9661 reflections from the main
data set. For 6·3CH Cl , unit cell dimensions were determined from
the positions of 6921 reflections from the main data set. For
·0.25CH Cl ·0.5n-C 14, unit cell dimensions were determined
from the positions of 8208 reflections from the main data set. For
1·2CH Cl ·3H O, unit cell dimensions were determined from the
2
CO, unit cell
For 9·0.25CH
2
Cl
2
6
·0.5n-C H14, two molecules of n-hexane and a
2
molecule of dichloromethane were found and refined at 0.5
occupancy each, and, in the case of n-hexane, with isotropic
displacement parameters. No H atoms were assigned to the solvent
molecules. Full-matrix least-squares refinement of these models
2
2
2
9
2
2
6
H
against F converged to final residual indices given in Table 7.
1
2
2
2
Acknowledgment. This work was supported by the Spanish
MCYT (DGI)/FEDER (Project CTQ2005-08606-C02-01) and
the Gobierno de Arag o´ n (Grupo de Excelencia: Qu ´ı mica
Inorg a´ nica y de los Compuestos Organomet a´ licos). S.I. ac-
knowledges the Ministerio de Ciencia y Tecnolog ´ı a for a grant.
positions of 2489 reflections from the main data set. For all of the
structures, the diffraction frames were integrated using the SAINT
5
5
56
package and corrected for absorption with SADABS. Lorentz
and polarization corrections were applied in all cases.
The structures were solved by Patterson and Fourier methods.
57
All refinements were carried out using the program SHELXL-97.
Supporting Information Available: Further details of the
structure determinations of 4·5.5Me CO, 5·2Me CO, 6·3CH Cl ,
All non-hydrogen atoms were assigned anisotropic displacement
parameters and refined without positional constraints except as
2
2
2
2
9·0.25CH Cl ·0.5n-C H , and 11·2CH Cl ·3H O including atomic
2
2
6
14
2
2
2
coordinates, bond distances and angles, and thermal parameters and
(
(
55) SAINT, version 5.0; Bruker Analytical X-ray Systems: Madison, WI.
56) Sheldrick, G. M. SADABS; University of Gottingen: Gottingen,
Germany, 1996.
19
F HMQC; experimental and calculated P{ H}, Pt{ H}, and
F- P HMQC; F- Pt HMQC; and P{ H}-COSY spectra.
31
1
195
1
19
31
19
195
31
1
This material is available free of charge via the Internet at
http://pubs.acs.org.
(
57) Sheldrick, G. M.; SHELXL-97; University of Gottingen: Gottingen,
Germany, 1997.
(
58) Forni e´ s, J.; Fortu n˜ o, C.; Ib a´ n˜ ez, S.; Mart ´ı n, A. Inorg. Chem. 2008,
4
7, 5978–5987.
IC8011124
9080 Inorganic Chemistry, Vol. 47, No. 19, 2008