Gold(I) Phosphido Complexes: Synthesis, Structure, and Reactivity

Article abstract of DOI:10.1021/ic035006e

Deprotonation of the phosphine complexes Au(PHR₂)Cl with aqueous ammonia gave the gold(I) phosphido complexes [Au(PR₂)] _n (PR₂ = PMes₂ (1), PCy₂ (2), P(t-Bu)₂ (3), PIs₂

Full text of DOI:10.1021/ic035006e

Inorg. Chem. 2003, 42, 8891−8901
Gold(I) Phosphido Complexes: Synthesis, Structure, and Reactivity
,†
Diana M. Stefanescu,† Holming F. Yuen,† David S. Glueck,* James A. Golen,‡,§ Lev N. Zakharov,‡
Christopher D. Incarvito,‡ and Arnold L. Rheingold‡
6128 Burke Laboratory, Department of Chemistry and Dartmouth Molecular Materials Group,
Dartmouth College, HanoVer, New Hampshire 03755, and Department of Chemistry and
Biochemistry, UniVersity of California San Diego, 9500 Gilman DriVe, La Jolla, California 92093
Received August 26, 2003
Deprotonation of the phosphine complexes Au(PHR )Cl with aqueous ammonia gave the gold(I) phosphido complexes
2
[Au(PR )]n (PR ) PMes2 (1), PCy2 (2), P(t-Bu)2 (3), PIs2 (4), PPhMes (5), PHMes* (6); Mes ) 2,4,6-Me3C H , Is
2
2
6 2
) 2,4,6-(i-Pr)3C H , Mes* ) 2,4,6-(t-Bu)3C H , Cy ) cyclo-C H ). 31P NMR spectroscopy showed that these
6
2
6
2
6 11
complexes exist in solution as mixtures, presumably oligomeric rings of different sizes. X-ray crystallographic structure
determinations on single oligomers of 1−4 revealed rings of varying size (n ) 4, 6, 6, and 3, respectively) and
+
conformation. Reactions of 1−3 and 5 with PPN[AuCl2] gave PPN[(AuCl)2(µ-PR )] (9−12, PPN ) (PPh3)2N ).
2
Treatment of 3 with the reagents HI, I2, ArSH, LiP(t-Bu)2, and [PH (t-Bu)2]BF gave respectively Au(PH(t-Bu)2)(I)
2
4
(14), Au(PI(t-Bu)2)(I) (15), Au(PH(t-Bu)2)(SAr) (16, Ar ) p-t-BuC H ), Li[Au(P(t-Bu)2)2] (17), and [Au(PH(t-Bu)2)2]-
6
4
BF (19).
4
Chart 1. Proposed Structures for Gold(I) Phosphido Complexes
Introduction
Because gold(I) thiolate complexes [Au(SR)]n have im-
portant applications in decoration of glass and ceramics and
in medicine, their chemistry has been studied in detail.1 In
contrast, the isoelectronic phosphido complexes [Au(PR2)]n
have been less well investigated since their discovery in
1976.2 Several groups have reported that [Au(PPh2)]n is
insoluble; its color depended on the base used in its
preparation from Au(PHPh2)(Cl) or related precursors.3
Parish et al. prepared several related complexes [Au(PR2)]n
(R ) Et, n-octyl, p-MeC6H4, p-(t-Bu)C6H4), which could be
obtained in soluble and insoluble forms, proposed to be cyclic
and linear chain polymers, respectively (Chart 1).3d
present in solution.3d The solid-state 31P NMR chemical shifts
for the soluble (ca. 90 ppm) and insoluble (ca. 40 ppm) forms
of [Au(PPh2)]n were consistent with different structures.
Mossbauer spectra indicated the expected linear coordination
with two phosphido ligands binding a given gold center, but
structural details were not available.3d,f
We report here that using bulkier R groups4 enables the
synthesis of the soluble gold phosphido complexes [Au-
(PR2)]n (PR2 ) PMes2 (1, Mes ) 2,4,6-Me3C6H2), PCy2 (2,
Cy ) cyclo-C6H11), P(t-Bu)2 (3), PIs2 (4, Is ) 2,4,6-(i-
Pr)3C6H2), PPhMes (5), and P(H)(Mes*) (6, Mes* ) 2,4,6-
(t-Bu)3C6H2)). Their solubility enabled the determination of
NMR studies of these materials, although made difficult
by precipitate formation, suggested that several species were
* To whom correspondence should be addressed. E-mail: glueck@
dartmouth.edu.
† Dartmouth College.
‡ University of California San Diego. Previous address: Department of
Chemistry, University of Delaware, Newark, DE 19716.
§ Permanent address: Department of Chemistry and Biochemistry,
University of Massachusetts Dartmouth, North Dartmouth, Massachusetts,
02747.
(3) (a) Vicente, J.; Chicote, M. T.; Jones, P. G. Inorg. Chem. 1993, 32,
4960-4964. (b) Vicente, J.; Chicote, M. T.; Saura-Llamas, I.; Lagunas,
M. C. J. Chem. Soc., Chem. Commun. 1992, 915-916. (c) Annan, T.
A.; Kumar, R.; Tuck, D. J. J. Chem. Soc., Dalton Trans. 1991, 18,
11-18. (d) Dyson, D. B.; Parish, R. V.; McAuliffe, C. A.; Pritchard,
R. G.; Fields, R.; Beagley, B. J. Chem. Soc., Dalton Trans. 1989, 18,
907-914. (e) Annan, T. A.; Kumar, R.; Tuck, D. J. J. Chem. Soc.,
Chem. Commun. 1988, 8, 446-448. (f) Dyson, D. B.; Parish, R. V.;
McAuliffe, C. A.; Fields, R. Hyperfine Interact. 1988, 40, 327-330.
(4) Dance, I. G.; Fitzpatrick, L. J.; Craig, D. C.; Scudder, M. L. Inorg.
Chem. 1989, 28, 1853-1861.
(1) (a) Landgraf, G. In Gold. Progress in Chemistry, Biochemistry and
Technology; Schmidbaur, H., Ed.; John Wiley and Sons: Chichester,
U.K., 1999; pp 143-171. (b) Shaw, C. F. Chem. ReV. 1999, 99, 2589-
2600. (c) Fackler, J. P., Jr.; van Zyl, W. E.; Prihoda, B. A. In Gold.
AdVances in Chemistry, Biochemistry, and Technology; Schmidbaur,
H., Ed.; John Wiley and Sons: Chichester, U.K., 1999; pp 795-839.
(2) Puddephatt, J.; Thompson, P. J. J. Organomet. Chem. 1976, 117, 395-
403.
10.1021/ic035006e CCC: $25.00 © 2003 American Chemical Society
Published on Web 11/20/2003
Inorganic Chemistry, Vol. 42, No. 26, 2003 8891

Stefanescu et al.
Table 1. Crystallographic Data for the Complexes [Au(PH(Ph)(Mes))(Cl)]2 (8), [PPN][(AuCl)2(µ-PCy2)] (10), Au(PI(t-Bu)2)(I) (14), Au(PH(t-Bu)2)(I)
(15), and [Au(PH(t-Bu)2)]BF4 (19)a
param
formula
8
10
14
15
19
C30H34Au2Cl2P2
921.35
C48H52Au2Cl2NP3
1199.2
C8H18AuI2P
595.96
C8H19AuIP
470.07
C16H36AuBF4P2
574.16
fw
temp, K
cryst size, mm3
cryst system
space group
a, Å
223(2)
219(2)
100(2)
100(2)
218(2)
0.20 × 0.20 × 0.10
monoclinic
C2/c
16.58(2)
8.681(11)
22.72(3)
90
105.51(2)
90
3152(7)
4
0.30 × 0.20 × 0.20
monoclinic
P21/c
9.4506(11)
18.557(2)
25.781(3)
90
93.412(3)
90
4513.2(9)
4
0.20 × 0.16 × 0.10
0.38 × 0.25 × 0.10
monoclinic
C2/c
23.4212(13)
7.8968(4)
15.4542(8)
90
121.4690(10)
90
2437.9(2)
8
0.25 × 0.25 × 0.15
monoclinic
C2/c
23.5726(12)
8.3679(4)
12.7000(6)
90
112.2540(10)
90
2318.5(2)
4
triclinic
P1h
8.4964(5)
11.4786(9)
15.7440(9)
71.0170(10)
78.5190(10)
78.0960(10)
1406.21(14)
4
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
Z
D(calc), g/cm3
µ(Mo KR), mm-1
R(F), %b
R(wF2), %b
1.942
9.587
4.47
15.18
1.721
6.716
3.07
6.74
2.815
14.926
2.29
4.89
2.561
14.683
2.80
7.24
1.645
6.511
2.48
6.69
a Data acquired with a Siemens P4 CCD diffractometer using Mo KR radiation (0.710 73 Å). b Quantity minimized ) R(wF2) ) ∑[w(Fo - Fc )2]/
2
2
2
2
2
∑[(wFo )2]1/2; R ) ∑∆/∑(Fo), ∆ ) |(Fo -Fc)|, w ) 1/[σ2(Fo ) + (aP)2 + bP], P ) [2Fc + max(Fo,0)]/3.
Scheme 1. Synthesis of Au(PHR2)(Cl) Complexes
the novel cyclic structures of 1-4 by X-ray crystallography5
and a survey of their reactivity.6
Results and Discussion
Synthesis and Structure. Vicente et al. reported that
[Au(PPh2)]n was conveniently prepared by treatment of
Au(PHPh2)(Cl) with aqueous ammonia.3a Related secondary
and primary phosphine complex precursors and the new
compounds Au(PHIs2)Cl (7) and Au(PH(Ph)(Mes))(Cl) (8)7
were prepared by a modification of the literature method,
using Au(THT)(Cl)8 (THT ) tetrahydrothiophene) instead
of Au(CO)(Cl) (Scheme 1).9
Figure 1. ORTEP diagram of [Au(PH(Ph)(Mes))Cl]2 (8). The hydrogen
atoms have been removed for clarity, except for the P-H bond. The AuCl
fragments are disordered; the major (80%) component is shown. Selected
bond lengths (Å) and angles (deg): for major, Au-P 2.197(3), Au-Au
3.108(4), Au-Cl 2.277(3), P-Au-Cl 176.06(10); for minor, Au-P
2.098(3), Au-Au 3.313(5), Au-Cl 2.313(12), P-Au-Cl 172.7(4).
Scheme 2. Synthesis of Au(I) Phosphido Complexes
An X-ray crystallographic structure determination (Figure
1; Table 1) showed that 8 is a dimer in the solid state with
Au-Au interactions, as in Au(PH(o-MeC6H4)2)(Cl).9a With
two chiral phosphines, several diastereomers of 8 are
possible. The structure is complicated by an enantiomeric
disorder in which the AuCl fragments occupy two different
positions; each averaged site in the racemic, centrosymmetric
structure is composed of ca. 80% of either RR or SS and ca.
20% of either SS or RR (Supporting Information, Figure S1).
The compositional disorder is also manifest in the reduced
precision obtained for the unit-cell parameters.
(5) For related structures of Au(I) chalcogenolates and of an amide, see:
(a) Schroter, I.; Strahle, J. Chem. Ber. 1991, 124, 2161-2164. (b)
Bonasia, P. J.; Gindelberger, D. E.; Arnold, J. Inorg. Chem. 1993,
32, 5126-5131. (c) Wojnowski, W.; Becker, B.; Sassmanhausen, J.;
Peters, E.-M.; Peters, K.; von Schnering, H. G. Z. Anorg. Allg. Chem.
1994, 620, 1417-1421. (d) Wiseman, M. R.; Marsh, P. A.; Bishop,
P. T.; Brisdon, B. J.; Mahon, M. F. J. Am. Chem. Soc. 2000, 122,
12598-12599. (e) LeBlanc, D. J.; Lock, C. J. L. Acta Crystallogr.
1997, C53, 1765-1768. (f) Bunge, S. D.; Just, O.; Rees, W. S. Angew.
Chem., Int. Ed. 2000, 39, 3082-3083.
(6) For a preliminary communication of some of these results, see:
Stefanescu, D. M.; Yuen, H. F.; Glueck, D. S.; Golen, J. A.; Rheingold,
A. L. Angew. Chem., Int. Ed. 2003, 42, 1046-1048. Details of the
X-ray crystal structure determinations for complexes 1-4 are contained
in the Supporting Information for this paper.
(7) For related complexes with unsymmetrical secondary phosphines,
see: Angermaier, A.; Sladek, A.; Schmidbaur, H. Z. Naturforsch., B
1996, 51, 1671-1674.
(8) Uson, R.; Laguna, A.; Laguna, M. Inorg. Synth. 1989, 26, 85-91.
(9) (a) Schmidbaur, H.; Weidenhiller, G.; Aly, A. A. M.; Steigelmann,
O.; Mueller, G. Z. Naturforsch., B 1989, 44, 1503-1508. (b)
Schmidbaur, H.; Weidenhiller, G.; Steigelmann, O.; Mueller, G. Chem.
Ber. 1990, 123, 285-287.
Treatment of the precursors Au(PHR2)(Cl) with aqueous
ammonia in THF or CH2Cl2 caused precipitation of the white,
toluene-soluble, air-stable phosphido complexes [Au(PR2)]n
(1-6) (Scheme 2).
31P NMR spectra of these crude products showed the
presence of several species (for 1 or 2, 4; for 3, 5 or 10,
depending on reaction time; for 4, only 1, for 5 or 6, 2; Table
2).
The similarity of the chemical shifts for these species and
the observation of their interconversion on cooling or heating
an NMR sample of 1 in toluene suggests that they are a
8892 Inorganic Chemistry, Vol. 42, No. 26, 2003

Gold(I) Phosphido Complexes
Figure 2. ORTEP diagrams of [Au(PMes2)]4 (1), [Au(PCy2)]6‚2C7H8 (2‚2C7H8), [Au(P(t-Bu)2)]6‚C7H8 (3‚C7H8), and [Au(PIs2)]3 (4). Hydrogen atoms,
solvent molecules, and disorder in the isopropyl groups of 4 are not shown.
Table 2. 31P{1H} NMR Data for Phosphido Complexes 1-6a
could not be reproducibly separated, but on one occasion
crystals of one of these (δ 54.2) were isolated. Recrystalli-
zation of 3 from toluene yielded a mixture of two com-
pounds; the less soluble one was isolated after another
recrystallization. Recrystallization of 5 from benzene enabled
the separation of one compound, but in the case of 6, no
single product isolation was possible. Complexes 1-6 were
further characterized by elemental analyses, multinuclear
NMR, IR, and MALDI mass spectroscopy (molecular ions
were observed for 1-4, and mass spectral peaks were
consistent with a tetrameric structure for 5).
compd
31P NMR chem shift (ppm)
[Au(PMes2)]n (1)
[Au(PCy2)]n (2)b
[Au(P(t-Bu)2)]n (3)c
[Au(PIs2)]n (4)
[Au(P(Ph)(Mes))]n (5)
[Au(PHMes*)]n (6)
-17.0, -18.8, -23.4, -36.1
65.2, 62.4, 51.3, 42.9
115.3, 114.2, 107.4, 104.9, 89.9
-78.9
-12.1, -21.6
-40.9, -42.6
a Solvent ) C6D6 for 3-6, toluene-d8 for 1, and toluene for 2. The
chemical shift in bold font corresponds to the compound isolated (see the
text). b This compound could not be obtained as a single isomer reproduc-
ibly; see the text for details. c On shorter reaction time, more peaks were
observed: 31P{1H} NMR (THF): δ 115.3, 115.18, 115.12, 115.0, 114.31,
114.08, 113.68, 105.2, 104.3, 89.9.
The crystal structures of cyclic [Au(PMes2)]4 (1), [Au-
(PCy2)]6‚2C7H8 (2‚2C7H8), [Au(P(t-Bu)2)]6‚C7H8 (3‚C7H8),
and [Au(PIs2)]3 (4) are shown in Figure 2. In 2‚2C7H8 and
3‚C7H8 toluene is included in the channels between the rings,
which stack to yield an extended structure (Supporting
Information, Figure S2). Increasing the size of the P
substituents leads to a decreased ring size, presumably to
reduce unfavorable steric interactions.
mixture of compounds having the formula [Au(PR2)]n,
consistent with the observations of Parish and co-workers.3d
The chemical shifts of diarylphosphido complexes 1 and 5
are significantly different from that of their soluble
[Au(PPh2)]n (90 ppm), which may be due to different
structures or simply to the effects of the different aryl groups.
Heating 1 in toluene caused partial conversion to a major
product, which then crystallized out preferentially. Recrys-
tallization of 2 from toluene gave a mixture of two
compounds (31P{1H} NMR (C6D6): δ 54.2 and 48.1) that
As expected, the P-Au-P angles are close to linear, and
the phosphorus atoms are approximately tetrahedral (Table
3). The Au-P bond lengths are similar in all four complexes,
Inorganic Chemistry, Vol. 42, No. 26, 2003 8893

Stefanescu et al.
Table 3. Selected Bond Lengths (Å) and Angles (deg) in Au(I)
Phosphido Complexes 1, 2‚2C7H8, 3‚C7H8, and 4
param
1
2‚2C7H8
3‚C7H8
4
Au-P(av)
2.315(6)
167.0(2)
114.6(7)
94.2(2)
2.3155(13)
172.44(4)
108.18(18)
117.51(5)
105.8(2)
2.3309(12)
176.61(4)
106.93(17)
115.76(5)
113.5(2)
2.324(2)
156.93(8)
115.2(3)
83.06(7)
110.9(4)
P-Au-P(av)
Au-P-C(av)
Au-P-Au(av)
C-P-C(av)
105.4(9)
and the average Au-P bond length in 3‚C7H8 (2.3309(12)
Å) is slightly larger than that in the precursor Au(PH(t-Bu)2)-
(Cl) (2.230(2) Å).9a Aurophilic interactions10 are clearly
present in the Au3 triangle of 4, with Au-Au distances
ranging from 3.0661(4) to 3.0970(5) Å, and may also be
important in 1, with Au-Au distances of 3.3414 and 3.445
Å. In contrast, the shortest Au-Au separations in 2‚2C7H8
and 3‚C7H8 are 3.899 and 3.918 Å, respectively.
Although the ring in 2‚2C7H8 is almost planar (mean
deviation from the plane is 0.1116 Å) and that in 4 is planar
(mean deviation 0.0075 Å), 3‚C7H8 and 1 adopt puckered
structures (Supporting Information, Figure S3). The structure
of 1 may be described as a butterfly, with an angle between
the planes of 125.24(9)°, or as a plane of gold atoms with P
atoms alternating above and below the plane. In twisted 3‚
C7H8, two intersecting planes of P atoms (P1, P2, P3, P1a
and P1, P2a, P3a, P1a) are separated by an angle of
34.15(2)°.
Figure 3. ORTEP diagram of [PPN][(AuCl)2(µ-PCy2)] (10). Hydrogen
atoms and the PPN cation are not shown. Selected bond lengths (Å) and
angles (deg): Au(1)-P(1) 2.2481(13), Au(1)-Cl(1) 2.3027(14), Au(2)-
P(1) 2.2440(13), Au(2)-Cl(2) 2.3083(13), P(1)-Au(1)-Cl(1) 177.20(4),
P(1)-Au(2)-Cl(2) 177.94(4), C(7)-P(1)-Au(1) 110.69(17), C(1)-P(1)-
Au(1) 108.73(18), Au(2)-P(1)-Au(1) 111.82(4), C(7)-P(1)-C(1)
105.33(19), C(7)-P(1)-Au(2) 109.16(18), C(1)-P(1)-Au(2) 110.92(16).
Scheme 3. Synthesis of Phosphido-Bridged Dinuclear Complexes
Hexameric 2‚2C7H8 and 3‚C7H8 have the same nuclearity
as [Au(S(2,4,6-(i-Pr)3C6H2))]6, in which the Au6S6 ring adopts
a chair conformation.5a,e However, 2‚2C7H8 is almost planar
and the twisted ring in 3‚C7H8 is closer to a boat conforma-
tion. The copper analogue of 3 is tetrameric [Cu(P(t-Bu)2)]4
with a centrosymmetric, planar Cu4P4 core and a Cu-P
average bond length of 2.209(5) Å, smaller than in the
corresponding gold complex [2.3309(12) Å].11 The structure
of cyclic tetramer 1 may be compared to that of [Au-
(N(SiMe3)2)]4,5f which contains a planar Au4N4 core. The
shorter Au-N bond length [2.082(3) Å] is accompanied by
reduced Au-Au distances [3.0100(3) and 3.0355(3) Å].5f
In contrast, the Au4S4 core in [Au(S(SiO(t-Bu)3))]4 is folded
as in 1 with an angle of 157.3° with respect to the S-S
diagonal,5c but [Au(SC(SiMe3)3)]4 is planar and [Au(TeC-
(SiMe3)3)]4 adopts a butterfly structure with a dihedral angle
of 144.98(6)°.5b
Several planar complexes with a Au3 triangle supported
by bridging ligands are known, but these include two-atom
bridges and nine-membered rings.12 In contrast, the shorter
bridges in 4 lead to unusually bent P-Au-P angles (average
156.93(8)°). We are not aware of other simple [AuX]n
complexes with trinuclear structures, but recently Scheer et
al. published the structure of [(CpCr)6Au3P3], a Au(I)
complex with a planar Au3P3 framework and bridging Cr.13
Another precedent is the Au-Nb raft cluster [Au(Cp′2-
NbH2)]3 (Cp′ ) η5-C5H4SiMe3), which also features bridging
hydrides.14 These comparisons suggest that ring size and
conformation in these classes of homoleptic compounds
depend strongly on the substituents and the possibility of
Au-Au interactions.
Reactivity. In the only previous report on the reactivity
of gold phosphido complexes, treatment of insoluble [AuPPh2]n
with PPN[AuX2] gave the phosphido-bridged complexes
PPN[(AuX)2(µ-PPh2)] (PPN ) (PPh3)2N+, X ) Cl, Br, I). 3a
Similarly, complexes 1-3 and 5 reacted quickly with PPN-
[AuCl2] to give the dinuclear complexes 9-12 (Scheme 3).
The crystal structures of PCy2 and P(t-Bu)2 derivatives
10 and 11 (Figure 3 and Supporting Information Figure S4;
Table 1), with almost linear Cl-Au-PR2 angles, tetrahedral
phosphorus, and nonbonding Au-Au distances (Table 4),
are very similar to that of the sole previous example of a
structurally characterized gold phosphido complex, [NBu4]-
[(AuBr)2(µ-PPh2)] (13).15
Other reactions of di-tert-butylphosphido complex 3 are
summarized in Scheme 4.
Treatment of 3 with I2 and HI gave the air-stable gold(I)
phosphine complexes Au(PI(t-Bu)2)(I) (14) and Au(PH-
(t-Bu)2)(I) (15), respectively, the results of formal addition
(10) (a) Schmidbaur, H. Gold Bull. 2000, 33, 3-10. (b) Schmidbaur, H.
Chem. Soc. ReV. 1995, 24, 391-400.
(14) (a) Antinolo, A.; Burdett, J. K.; Chaudret, B.; Eisenstein, O.; Fajardo,
M.; Jalon, F.; Lahoz, F.; Lopez, J. A.; Otero, A. J. Chem. Soc., Chem.
Commun. 1990, 17-19. (b) Antinolo, A.; Jalon, F. A.; Otero, A.;
Fajardo, M.; Chaudret, B.; Lahoz, F.; Lopez, J. A. J. Chem. Soc.,
Dalton Trans. 1991, 1861-1866.
(15) Pritchard, R. G.; Dyson, D. B.; Parish, R. V.; McAuliffe, C. A.;
Beagley, B. J. Chem. Soc., Chem. Commun. 1987, 371-372.
(11) Cowley, A. H.; Giolando, D. M.; Jones, R. A.; Nunn, C. M.; Power,
J. M. J. Chem. Soc., Chem. Commun. 1988, 208-209.
(12) Balch, A. L.; Olmstead, M. M.; Vickery, J. C. Inorg. Chem. 1999,
38, 3494-3499 and references therein.
(13) Vogel, U.; Sekar, P.; Ahlrichs, R.; Huniar, U.; Scheer, M. Eur. J.
Inorg. Chem 2003, 1518-1522.
8894 Inorganic Chemistry, Vol. 42, No. 26, 2003

Gold(I) Phosphido Complexes
Table 4. Selected Bond Lengths (Å) and Angles (deg) for the Anions
[(AuX)2(µ-PR2)]- a
atom(s)
13b
10
11
X
R
Br
Ph
Cl
Cy
Cl
t-Bu
Au-X(av)
Au-P(av)
Au-Au
X-Au-P(av)
Au-P-Au
Au-P-C(av)
C-P-C
2.401(2)
2.243(3)
3.722
176.6(1)
112.1(2)
108.1(5)
102.4(8)
2.3055(14)
2.2460(13)
3.720
177.57(4)
111.82(4)
109.88(18)
105.33(19)
2.3140(11)
2.2568(10)
3.616
175.21(4)
106.49(4)
109.40(19)
112.58(19)
a Cation ) PPN for 10 and 11, NBu4 for 13; see: Pritchard, R. G.; Dyson,
D. B.; Parish, R. V.; McAuliffe, C. A.; Beagley, B. J. Chem. Soc., Chem.
Commun. 1987, 371-372. b The two halves of 13 are symmetry-related,
so only one set of bond lengths and angles is included.
Scheme 4. Reactivity of [Au(P(t-Bu)2)] (3)
across the Au-P bond. In contrast, MeI did not react with
3. Compound 14 is a rare example of a dialkylhalophosphine
complex; the analogous [Au(PCl(t-Bu)2)(Cl)] was synthe-
sized previously by Schmidbaur and Aly from P(Cl)(t-Bu)2
and Au(Cl)(CO).16 Similar reactions of Fe and Os phosphido
complexes with iodine to form P-I bonds were reported by
Dobbie and Mason17 and Bohle and Roper.18 Complex 15
was also synthesized independently from Au(PH(t-Bu)2)(Cl)9a
and excess NaI.
The crystal structures of 14 and 15 (Figures 4 and 5; Table
1) showed that the I-Au-P angle is close to 180° (as
expected), and the Au-P bond length is the same for both
compounds (Table 5). The slightly larger Au-I bond length
in 15 suggests a higher trans-influence of the PH(t-Bu)2 group
in comparison to PI(t-Bu)2. One of the two independent
molecules of 14 forms a centrosymmetric dimer with
intermolecular Au-I distances of 3.729 Å (Figure 4), longer
than the normal Au-I bond for the same compound (2.5551-
(4) Å). Long-range interactions at a Au-I distance of 3.876-
(1) Å in (Me3S)2[AuI4][I3] have been discussed previously.19
Heating 3 for several days at 70 °C with p-(t-Bu)C6H4SH
gave the phosphine thiolate complex Au(S(p-(t-Bu)C6H4))-
(PH(t-Bu)2) (16), which was prepared more conveniently in
a fast reaction at room temperature from the known
Figure 4. ORTEP diagrams of Au(PI(t-Bu)2)(I) (14). One of the two
independent molecules is shown, along with the centrosymmetric dimeric
unit (hydrogens omitted) formed by the other molecule. Selected average
bond lengths (Å) and angles (deg): Au(1)-P(1) 2.2532(12), Au(1)-I(2)
2.5521(4), I(1)-P(1) 2.4407(12), P(1)-Au(1)-I(2) 176.74(3), C(5)-P(1)-
C(1) 115.5(2), C(5)-P(1)-Au(1) 111.19(15), C(1)-P(1)-Au(1)
111.85(17), C(5)-P(1)-I(1) 103.11(15), C(1)-P(1)-I(1) 105.24(15).
similar reaction with 3 gave Li[Au(P(t-Bu)2)2] (17) as a white
solid, characterized by 1H and 31P NMR spectroscopy.
However, this compound decomposed readily in solution and
could not be obtained in pure form. Similarly, the reaction
of 3 with BuLi gave a single product (31P NMR (THF): δ
62.8), presumably the anion Li[Au(P(t-Bu)2)(n-Bu)] (18) in
analogy to the chemistry of [Cu(P(t-Bu)2)]4, but it decom-
posed on attempted isolation.21
Treatment of 3 with the phosphonium salt [PH2(t-Bu)2]-
BF4 gave the linear two-coordinate phosphine complex
[Au(PH(t-Bu)2)2]BF4 (19).22 The limited solubility of 3 and
of the salt made this reaction inconvenient; it was very slow
in CH2Cl2 at room temperature. Although reaction was faster
in bromobenzene at 85 °C over 2 d, an unidentified byproduct
was also formed in these reactions. Therefore, 19 was
20
[AuS(p-(t-Bu)C6H4))]n and HP(t-Bu)2. Complex 16 was
stable in the solid state but decomposed in solution to form
[AuP(t-Bu)2]n.
Jones et al. reported that treatment of [Cu(P(t-Bu)2)]4 with
LiP(t-Bu)2 gave the anionic complex Li[Cu(P(t-Bu2)2)].11
A
(16) Schmidbaur, H.; Aly, A. A. M. Z. Naturforsch., B 1979, 34, 23-26.
(17) Dobbie, R. C.; Mason, P. R. J. Chem. Soc., Dalton Trans. 1974, 2439-
2442.
(18) Bohle, D. S.; Roper, W. R. J. Organomet. Chem. 1984, 273, C4-C6.
(19) Svensson, P. H.; Rosdahl, J.; Kloo, L. Chem.sEur. J. 1999, 5, 305-
311.
(21) Martin, S. F.; Fishpaugh, J. R.; Power, J. M.; Giolando, D. M.; Jones,
R. A.; Nunn, C. M.; Cowley, A. H. J. Am. Chem. Soc. 1988, 110,
7226-7228.
(22) This phosphonium salt was reported previously with a different anion
(SO3F-). See: Krech, F.; Zschunke, A. Z. Anorg. Allg. Chem. 1978,
440, 45-51.
(20) Al-Sa’ady, A. K.; Moss, K.; McAuliffe, C. A.; Parish, R. V. J. Chem.
Soc., Dalton Trans. 1984, 8, 1609-1616.
Inorganic Chemistry, Vol. 42, No. 26, 2003 8895

Stefanescu et al.
Figure 6. ORTEP diagram of [Au(PH(t-Bu)2)]BF4 (19). Hydrogen atoms
and the distorted anion are not shown. Selected bond lengths (Å) and angles
(deg): Au(1)-P(1) 2.3119(8), Au(1)-P(1A) 2.3119(8), P(1A)1-Au(1)-
P(1) 180.0, C(4)-P(1)-C(8) 119.3(2), C(4)-P(1)-Au(1) 110.89(11),
C(8)-P(1)-Au(1) 111.30(13).
Figure 5. ORTEP diagram of Au(PH(t-Bu)2)(I) (15). Hydrogen atoms,
except for the P-H, are not shown. Selected bond lengths (Å) and angles
(deg): Au(1)-P(1) 2.2581(12), Au(1)-I(1) 2.5731(4), P(1)-H(1) 1.31-
(5), P(1)-Au(1)-I(1) 168.75(3), C(5)-P(1)-C(1) 117.2(2), C(5)-P(1)-
Au(1) 112.25(15), C(1)-P(1)-Au(1) 115.03(15), C(5)-P(1)-H(1) 100(2),
C(1)-P(1)-H(1) 99(2).
[Cu(bipy)(PPh2)]n,29 while treatment of CuCl or AgCl with
silylphosphines PR2SiMe3 in the presence of tertiary phos-
phines PR′3 yields the phosphine phosphido complexes
[M(PR2)(PR′3)x]n.30
However, Puddephatt and Thompson’s original synthesis
of [AuPPh2]n from HPPh2 and [AuMe(PMe2Ph)] with dis-
sociation of the tertiary phosphine suggests that gold phos-
phido complexes might not readily undergo such reactions
with donor ligands.2 Treatment of [Au(P(t-Bu)2)]n (3) with
the multidentate phosphines triphos [MeC(CH2PPh2)3] and
tetraphos [P(CH2CH2PPh2)3] or addition of bipy to [AuPMes2]n
(1) did not result in reaction even on heating. Similarly, [Au-
(P(t-Bu)2)]n (3) did not react at room temperature with PPh3,
PEt3, or PH(t-Bu)2. However, on heating of samples to 60-
90 °C, mixtures of unidentified products, presumably
[Au(PR3)x(P(t-Bu)2)y]n in analogy to the known copper and
Table 5. Selected Bond Lengths (Å) and Angles (deg) for
Au(PI(t-Bu)2)(I) (14, Averages) and Au(PH(t-Bu)2)(I) (15)
complex
Au-I (Å)
Au-P (Å)
I-Au-P (deg)
Au(PI(t-Bu)2)(I) (14)
Au(PH(t-Bu)2)(I) (15)
2.5521(4)
2.5731(4)
2.2532(12)
2.2581(12)
176.74(3)
168.75(3)
prepared more readily by addition of di-tert-butylphosphine
1
to [Au(NCPh)2]BF4.23 The H and 31P NMR spectra of this
compound in CD2Cl2 (Figure S5, Supporting Information)
showed the expected [AMX18]2 spin system.24 In the 1H NMR
spectrum, the tert-butyl protons gave rise to a multiplet at
1.5 ppm, and the P-H part of the spectrum was a multiplet
centered at 5.2 ppm. Analysis of the spectra25 and simulation
silver chemistry, were formed. Surprisingly, peaks in the 31
P
1
using gNMR26 yielded the coupling constants JPH ) 363,
NMR spectra of these mixtures showed no P-P coupling.
However, Stelzer et al. reported that reaction of [CuPPh2]n
with PMe3 gave [Cu4(PPh2)4(PMe3)4], whose 31P NMR
spectrum showed broad resonances and no P-P coupling.31
In contrast, Caulton et al. reported a large JPP as evidence
for monomeric Cu(PPh2)(PPh3).28 For similar Ag phosphido
phosphine complexes, no 31P NMR data were reported.30
The reaction of 3 with the secondary phosphine might
initially make the phosphine-phosphide complex [Au(P-
(t-Bu)2)(PH(t-Bu)2)], which could react further to form a
mixture of compounds. However, attempts to synthesize this
complex independently by deprotonation (KO(t-Bu)) of the
bis(phosphine) cation [Au(PH(t-Bu)2)]BF4 (19) or by pro-
tonation (HBF4) of the anion Li[Au(P(t-Bu)2)2] (17) gave
mixtures of unknown compounds.
3
3
2JPP ) 278, JPH′ ) 2, JP-H(t-Bu) ) 18, and JHH′ ) 0 Hz.
The trans JPP value is similar in magnitude to that observed
in two other examples of linear Au(I) complexes containing
mutually trans phosphines.27 The Au-P bond length (Figure
6; Table 1) was 2.3119(8) Å, smaller than in the correspond-
ing oligomer, [AuP(t-Bu)2]n (3) (2.3309(12) Å) but larger
than in the phosphido-bridged complex, [PPN][(AuCl)2(µ-
P(t-Bu)2] (11) (2.2568(10) Å).
The chalcogenolate complexes [Au(ER)]n (E ) Te, Se,
S) can be readily cleaved by tertiary phosphines to give
compounds such as Au(PPh3)(ER).5b,20 Similarly, polymeric
[Cu(PPh2)]n reacts with PHPh2 to give [Cu(PPh2)(PHPh2)]n
and with chelating dinitrogen ligands, like bipy, to give
28
(23) For the synthesis of [Au(NCPh)2]BF4 and similar bis(phosphine)
complexes, see: Yau, J.; Mingos, D. M. P. J. Chem. Soc., Dalton
Trans. 1997, 1103-1111.
Because treatment of the phosphido complexes with donor
ligands did not readily yield monomeric two-coordinate
(24) Leoni, P. Organometallics 1993, 12, 2432-2434.
(25) Harris, R. K. Can. J. Chem. 1964, 42, 2275-2281.
(26) Budzelaar, P. gNMR, V3.6.5; Cherwell Scientific Publishing Limited:
Oxford, U.K., 1996.
(27) (a) Bayler, A.; Schier, A.; Schmidbaur, H. Inorg. Chem. 1998, 37,
4353-4359. (b) Bhargava, S. K.; Mohr, F.; Bennett, M. A.; Welling,
L. L.; Willis, A. C. Inorg. Chem. 2001, 40, 4271-4275. We thank a
reviewer for calling these papers to our attention.
(29) Meyer, C.; Grutzmacher, H.; Pritzkow, H. Angew. Chem., Int. Ed.
Engl. 1997, 36, 2471-2473.
(30) (a) Eisenmann, J.; Fenske, D.; Simon, F. Z. Anorg. Allg. Chem. 1995,
621, 1681-1688. (b) Eichhofer, A.; Fenske, D.; Holstein, W. Angew.
Chem., Int. Ed. Engl. 1993, 32, 242-245. (c) Eichhofer, A.; Eisen-
mann, J.; Fenske, D.; Simon, F. Z. Anorg. Allg. Chem. 1993, 619,
1360-1368.
(28) Lemmen, T. H.; Goeden, G. V.; Huffman, J. C.; Geerst, R. L.; Caulton,
K. G. Inorg. Chem. 1990, 29, 3680-3685.
(31) Brauer, D. J.; Hessler, G.; Knueppel, P. C.; Stelzer, O. Inorg. Chem.
1990, 29, 2370-2375.
8896 Inorganic Chemistry, Vol. 42, No. 26, 2003

Gold(I) Phosphido Complexes
Scheme 5. Reactions of Au(PPh3)[N(SiMe3)2] with Secondary
Phosphines
Davidson observed that Pt-PR2 bridges resisted cleavage
even in boiling P(n-Pr)3.33
Experimental Section
General Details. Manipulations and reactions of secondary
phosphines were performed in dry glassware under a nitrogen
atmosphere at 20 °C in a drybox or using standard Schlenk
techniques. NMR spectra were recorded (at 21 °C unless otherwise
noted) with Varian 300 or 500 MHz spectrometers. 1H or 13C NMR
chemical shifts are reported vs Me4Si and were determined by
reference to the residual 1H or 13C solvent peaks. 31P NMR chemical
shifts are reported vs H3PO4 (85%) used as an external reference.
Coupling constants are reported in Hz, as absolute values unless
noted otherwise. Unless indicated, peaks in NMR spectra are
singlets. Infrared spectra were recorded using KBr pellets on a
products Au(L)(PR2), we attempted to prepare such terminal
phosphido complexes by a different route. Arnold et al.
reported that reaction of Au(PPh3)[N(SiMe3)2] with bulky
thiols and selenols gave HN(SiMe3)2 and Au(PPh3)(ER).5b
Scheme 5 shows that similar reactions with secondary
phosphines quickly gave PPh3 and [Au(PR2)]n (1-3 and 5)
as a mixture of the presumed isomers; we assume that HN-
(SiMe3)2 is also formed. The bulkier PHIs2 gave instead,
initially, PPh3 and a yellow complex formulated as PPh3-
Au(µ-PIs2)Au(PIs2) (20) on the basis of its 31P NMR
spectrum (toluene; δ 44.0 (d, J ) 267, PPh3), -15.4 (dd, J
) 267, 148, µ-PIs2), -54.3 (d, J ) 148, PIs2); this
intermediate decomposed over 2 d to yield PPh3 and
[Au(PIs2)]3 (4). Yellow 20 was generated independently,
along with PPh3, by treatment of Au(PPh3)Cl with AgOTf
and PHIs2, followed by addition of NaOt-Bu.
Perkin-Elmer 1600 series FTIR machine and are reported in cm-1
.
Elemental analyses were provided by Schwarzkopf Microanalytical
Laboratory. MALDI-TOF mass spectroscopy was performed at the
University of Illinois using an Applied Biosystems Voyager-DE
STR. The spectra were obtained in linear mode, with accuracy of
0.05-0.1%. Thus, an error of 1 or 2 amu at 2000 amu is expected.
In the assignment of the mass spectra of 1-6, the observed peaks
match the calculated ones within this experimental error; in addition,
protonating complexes 1-6 to make cations could also cause small
changes in their observed mass spectra.
Unless otherwise noted, reagents were from commercial suppli-
ers. The complexes Au(PHR2)(Cl) (R ) Mes, Cy, t-Bu) and
Au(PH2Mes*)(Cl) were prepared by a modification of the literature
method: Au(THT)(Cl)8 was used instead of Au(CO)Cl.9 PHIs2,34
PH(Ph)(Mes),35 PHMes2,36 PH2Mes*,37 [AuSC6H4(p-(t-Bu))]n,20
[Au(NCPh)2]BF4,23 Au(PPh3)[N(SiMe3)2],38 and PPN[AuCl2]3a were
prepared by literature procedures.
These observations suggest that the phosphido group has
a strong tendency to bridge in these Au(I) complexes and
are also consistent with its expected large trans influence;32
this ligand thus behaves differently from the isoelectronic
chalcogenolates.
[Au(PMes2)]n (1). About 5 mL of aqueous ammonia (29.6%,
78 mmol) was added to a solution of [Au(PHMes2)(Cl)] (340 mg,
0.68 mmol) in 10 mL of THF; a white precipitate formed. After
the mixture was stirred for 30 min, the solvent was pumped off,
and the resulting white solid was washed with 30 mL of water to
give 220 mg of 1, 69%.
Conclusions
31P{1H} NMR (toluene-d8): δ -17.0 (major), -18.8 (minor),
-23.4 (minor), -36.1 (minor). This material was dissolved in
toluene by heating to 70 °C. Slow evaporation of toluene at room
temperature yielded a single product, shown to be a cyclic tetramer
by X-ray crystallography. Typical yield of this pure compound from
the mixture was about 42%.
Anal. Calcd for C72H88Au4P4: C, 46.36, H, 4.76. Found: C,
46.20; H, 4.58. 31P{1H} NMR (C6D6): δ -36.1. 1H NMR (C6D6):
δ 6.70 (16H), 2.65 (48H), 2.07 (24H). IR: 3015, 2954, 2915, 1715,
1592, 1546, 1454, 1392, 1292, 1246, 1015, 838, 700, 615, 554,
423. MALDI TOF-MS (cyano-4-hydroxycinnamic acid): m/z 2800
((AuPMes2)6), 2530 (Au6(PMes2)5), 2333 ((AuPMes2)5), 2202, 2153,
2108, 2064 (Au5(PMes2)4), 1884, 1867 ((AuPMes2)4), 1783, 1717,
1641, 1597 (Au4(PMes2)3), 1417, 1317, 1237, 1175, 951.
X-ray crystallographic studies of Au(I) phosphido com-
plexes have for the first time established the structures of
this class of compounds as cyclic oligomers. 31P NMR
spectroscopy showed that several species, presumably rings
of different sizes, exist in solution and that they can
interconvert in some cases. A brief reactivity survey showed
that the reagents HI, I2, ArSH, [PH2(t-Bu)2]BF4, and PPN-
[AuCl2] led to the products of addition across the Au-P
bond. The anions LiP(t-Bu)2 and n-BuLi also appeared to
cleave the oligomeric structure of 3, although the products
could not be obtained in pure form.
Although similar oligomeric Cu and Ag phosphides or Au
chalcogenolates are cleaved readily by donor ligands such
as phosphines or bipy, it is more difficult to break up the
oligomeric structure of the gold phosphido oligomers or to
prepare terminal phosphido complexes Au(L)PR2 directly.
This is consistent with a particularly strong Au-P bond and
a preference for µ2-bridging coordination, as observed for
platinum phosphido complexes; for example, Chatt and
(33) Chatt, J.; Davidson, J. M. J. Chem. Soc. 1964, 2433-2445.
(34) Brauer, D. J.; Bitterer, F.; Dorrenbach, F.; Hessler, G.; Stelzer, O.;
Kruger, C.; Lutz, F. Z. Naturforsch. 1996, 51B, 1183-1196.
(35) Kovacik, I.; Wicht, D. K.; Grewal, N. S.; Glueck, D. S.; Incarvito, C.
D.; Guzei, I. A.; Rheingold, A. L. Organometallics 2000, 19, 950-
953.
(36) Bartlett, R. A.; Olmstead, M. M.; Power, P. P.; Sigel, G. A. Inorg.
Chem. 1987, 26, 1941-1946.
(37) Cowley, A. H.; Norman, N. C.; Pakulski, M. Inorg. Synth. 1990, 27,
235-240.
(32) (a) Appleton, T. G.; Clark, H. C.; Manzer, L. E. Coord. Chem. ReV.
1973, 10, 335-422. (b) Wicht, D. K.; Paisner, S. N.; Lew, B. M.;
Glueck, D. S.; Yap, G. P. A.; Liable-Sands, L. M.; Rheingold, A. L.;
Haar, C. M.; Nolan, S. P. Organometallics 1998, 17, 652-660.
(38) (a) Schmidbaur, H.; Shiotani, A. J. Am. Chem. Soc. 1970, 92, 7003-
7004. (b) Wegner, G. L.; Jockisch, A.; Schier, A.; Schmidbaur, H. Z.
Naturforsch. 2000, 55b, 347-351.
Inorganic Chemistry, Vol. 42, No. 26, 2003 8897

Stefanescu et al.
[Au(PCy2)]n (2). Aqueous ammonia (5 mL, 29.6%, 78 mmol)
was added to a solution of [Au(PHCy2)(Cl)] (815 mg, 1.9 mmol)
in 5 mL of THF, forming a white precipitate. The mixture was
stirred for 15 min, and the white solid was filtered off to give 2
(720 mg, 96%) as a mixture. 31P{1H} NMR (toluene): δ 65.2, 62.4,
51.3, 42.9 (ratios varied depending on the experiment). Recrystal-
lization from toluene/acetonitrile (or simply heating in toluene) gave
a mixture of two species in ca. 1:1 ratio. 31P{1H} NMR (C6D6): δ
54.2, 48.2. 1H NMR (C6D6): δ 2.61-2.54 (m, 2H), 2.33-2.25 (m,
4H), 1.89-1.66 (m, 10H), 1.35-1.21 (m, 6H). [This material was
a toluene solvate, but recrystallization from CH2Cl2 gave a solvent-
free sample for elemental analysis: Anal. Calcd for C12H22PAu:
C, 36.56; H, 5.62. Found: C, 36.77; H, 5.42.] These compounds
could not be separated reproducibly, but on one occasion, slow
evaporation from toluene gave crystals shown to be a single
compound by X-ray crystallography and NMR.
31P{1H} NMR (C6D6): δ 54.2. IR: 3144, 2911, 2844, 1628, 1444,
1400, 1339, 1261, 1172, 1100, 994, 883, 840, 728, 700. MALDI
TOF-MS (cyano-4-hydroxycinnamic acid): m/z 2805, 2761 ((AuP-
Cy2)7), 2608, 2564, 2384, 2366 ((AuPCy2)6), 2284, 2212, 2171 (Au5-
(PCy2)6), 2085, 2016, 1972 ((AuPCy2)5), 1818, 1776 (Au4(PCy2)5),
1623, 1578 ((AuPCy2)4), 1398, 1382 (Au3(PCy2)4), 1200, 1093,
1004, 988. In addition to the molecular ion peaks, MALDI mass
spectra for this compound and for 1-4 also showed signals at higher
m/z ratios. These peaks may be due to higher mass oligomers of
the Au complexes and/or to formation of multimers, which is
commonly observed in MALDI-MS.39
[Au(P(t-Bu)2)]n (3). Under N2, aqueous ammonia (5 mL, 29.6%,
78 mmol) was added to a solution of [Au(PH(t-Bu)2)(Cl)] (450
mg, 1.19 mmol) in 5 mL of THF; a white precipitate formed. The
mixture was stirred for 2 h and then filtered in air. The white solid
was washed with 30 mL of water and 20 mL of acetone. 31P{1H}
NMR (C6D6): δ 115.3, 114.2, 107.4 (major), 104.9 (major), 89.9.
[When the mixture was stirred for only 15 min, different speciation
was observed by 31P{1H} NMR (THF): δ 115.3, 115.18, 115.12,
115.0, 114.31, 114.08, 113.68, 105.2, 104.3, 89.9, with major peaks
the ones around 114-115 ppm.] The solid was dissolved in toluene
at ca. 50 °C and then cooled to room temperature. Acetonitrile (10
mL) was added, and overnight cooling to 0 °C gave 350 mg (86%)
of 3 as a mixture of two species with 31P NMR shifts of 107.4 and
104.9 (ca. 2:1). IR: 2978, 2933, 2889, 2856, 1461, 1383, 1357,
1172, 1011, 933, 811, 728, 694, 603, 581, 475 cm-1. MALDI TOF-
MS (cyano-4-hydroxycinnamic acid): m/z 2515, 2172, 2078, 2055
((AuP(t-Bu)2)6), 1999, 1911 (Au6(P(t-Bu)2)5), 1855 (Au5(P(t-Bu)2)6),
1830, 1796, 1713 ((AuP(t-Bu)2)5), 1664, 1652, 1595, 1568 (Au5-
(P(t-Bu)2)4), 1540, 1491, 1488, 1370 ((AuP(t-Bu)2)4), 1279, 1226
(Au4(P(t-Bu)2)3), 1162, 1147, 1105, 1046, 1030, 958, 927, 898, 894,
867.
resulting pale pink solution was stirred under nitrogen for 20 min
and then evaporated to dryness in vacuo. The crude product
[Au(PHIs2)(Cl)] (7) was washed with 25 mL of hexane twice to
give 696 mg of white solid. The hexane solution was evaporated
to dryness giving a sticky yellow solid, which was washed with 5
mL of hexane to yield 125 mg more product (total yield 821 mg
(71%)).
A sample for elemental analysis was obtained as follows. After
the reaction mixture was stirred for 20 min, the white-pink product
was precipitated with methanol at -60 °C. It was redissolved in
CH2Cl2 and filtered to remove some pink undissolved solid. The
solvent was pumped off from the clear filtrate to give an off-white
solid.
Anal. Calcd for C30H47ClPAu: C, 53.69; H, 7.06. Found: C,
53.50; H, 7.10. 31P NMR (C6D6): δ -56.4 (JP-H ) 400). 1H NMR
(C6D6): δ 7.0 (d, J ) 4, 4H, Ar), 6.95 (d, P-H, JP-H ) 400), 3.67
(m, 4H, o-CH), 2.64 (septet, J ) 7, 2H, p-CH), 1.09 (d, J ) 7,
12H, Me), 1.04 (d, J ) 7, 12H, Me), 0.96 (d, J ) 7, 12H, Me). IR:
2950, 2925, 2866, 2410 (w, P-H), 1601, 1551, 1460, 1419, 1381,
1361, 1316, 1258, 1238, 1190, 1166, 1135, 1101, 1060, 1043, 940,
906, 879, 848, 810, 749, 701, 650, 574, 523, 492, 427.
Aqueous ammonia (3 mL, 29.6%, 47 mmol) was added under
N2 to a solution of [Au(PHIs2)(Cl)] (335 mg, 0.5 mmol) in 5 mL
of THF. The solution turned yellow. After the mixture was stirred
for 30 min, the solution became turbid. The solvent was evaporated,
giving a white solid that was washed with 20 mL of water to give
243 mg (77%) of [Au(PIs2)]3 (4). Crystals suitable for X-ray
crystallography were obtained by slow evaporation of hexane at 0
°C. Recrystallization from benzene/methanol at 0 °C gave a sample
for elemental analysis.
Anal. Calcd for C30H46AuP: C, 56.78; H, 7.31. Found: C, 56.75;
H, 7.59. 31P{1H} NMR (C6D6): δ -78.9. 1H NMR (C6D6): δ 7.17
(6H), 7.01 (6H), 5.56-5.52 (m, 6H), 3.82-3.78 (m, CH, 6H),
2.80-2.70 (m, CH, 6H), 1.56 (d, J ) 7, 18H), 1.37 (d, J ) 7,
18H), 1.21-1.18 (m, 36 H), 1.09 (d, J ) 7, 18H), 0.70 (d, J ) 7,
18H). IR: 2959, 2867, 1601, 1556, 1460, 1417, 1383, 1361, 1306,
1100, 878. MALDI TOF-MS (cyano-4-hydroxycinnamic acid):
2976, 2774, 2687, 2571, 2539 ((AuPIs2)4), 2336, 2287, 2217, 2145
(Au2(PIs2)4), 2101 (Au4(PIs2)3), 2090, 1904 ((AuPIs2)3), 1890, 1724,
1708, 1694, 1505, 1456, 1315, 1270 ((AuPIs2)2), 1088, 1074
(Au(PIs2)2).
[Au(P(Ph)(Mes))]n (5). Under N2, a solution of 0.457 g (2 mmol)
of PH(Ph)(Mes) in 2 mL of CH2Cl2 was added to 0.640 g (2 mmol)
of solid Au(THT)Cl to give a turbid solution which became clear
after addition of 5 mL of CH2Cl2. The solution was stirred for 15
min, and then 10 mL of pentane was added and a white precipitate
formed. Two recrystallizations from THF/pentane gave pure
Au(PH(Ph)(Mes))Cl (8) (350 mg, 38%). X-ray-quality crystals
were obtained by slow evaporation of methylene chloride at room
temperature.
The mixture of two compounds was dissolved in toluene at 55
°C and then the solution slowly cooled to room temperature,
affording small off-white crystals, which were collected by filtration
and shown to be a single product which contained cocrystallized
toluene by X-ray crystallography and NMR. Anal. Calcd for (C8H18-
PAu)6‚toluene: C, 30.80; H, 5.45. Found: C, 30.99; H, 5.37. 31P-
Anal. Calcd for C15H17AuClP: C, 39.11; H, 3.72. Found: C,
39.01; H 3.50. 31P NMR (CD2Cl2): δ -31.8 (d, J ) 403). 1H NMR
(CD2Cl2): δ 7.68-7.64 (m, 2H, Ar), 7.57-7.55 (m, 1H, Ar), 7.49-
7.46 (m, 2H, Ar), 7.30 (d, 1H, JPH ) 403), 7.05 (m, 2H, Ar), 2.51
(6H, o-Me), 2.37 (3H, p-Me). 13C{1H} NMR (CD2Cl2): δ 142.8
(d, J ) 2.5), 142.0 (d, J ) 9), 134.3 (d, J ) 14), 132.25 (d, J ) 9),
130.6 (d, J ) 2.5), 129.5 (d, J ) 13), 124.9 (d, J ) 63), 120.0 (d,
J ) 66), 23.2 (d, J ) 11, o-Me), 21.2 (d, J ) 1, p-Me).
Aqueous ammonia (10 mL, 29.6%, 86 mmol) was added to a
solution of Au(PH(Ph)(Mes))Cl (1.4 g, 3 mmol) in 15 mL of THF,
and the mixture was stirred for 30 min. The resulting white-yellow
precipitate was filtered off and washed with 50 mL of H2O.
1
{1H} NMR (C6D6): δ 107.3. H NMR (C6D6): δ 1.57. The 31P
NMR spectrum of the filtrate showed the presence of 3 and the
other compound, in ca. 1:2 ratio. Typical yield of pure 3 from the
mixture was 60%.
[Au(PIs2)]3 (4). To a solution of [Au(THT)(Cl)] (552 mg, 1.72
mmol) in 10 mL of dry, degassed CH2Cl2 was added a solution of
PHIs2 (765 mg, 1.74 mmol) in 4 mL of dry, degassed CH2Cl2. The
(39) Karas, M.; Hillenkamp, F. Anal. Chem. 1988, 60, 2299-2301.
8898 Inorganic Chemistry, Vol. 42, No. 26, 2003

Gold(I) Phosphido Complexes
Recrystallization from THF gave a white solid (1.1 g, 85%) which
was a mixture of two isomers.
mixture was almost clear. It was filtered, and the solvent was
evaporated from the filtrate yielding a white-yellowish powder,
which was recrystallized twice from CH2Cl2 and ether to give a
material containing both these solvents as shown by NMR integra-
tion and elemental analysis. Yield ) 170 mg, 37%. Crystals suitable
for X-ray crystallography were obtained by slow diffusion of ether
into a CH2Cl2 solution.
Anal. Calcd for C48H52Au2Cl2NP3(CH2Cl2)0.17[Et2O]0.06: C, 47.68;
H, 4.38; N, 1.15. Found: C, 47.38; H, 4.14; N, 1.20. 31P{1H} NMR
(CD2Cl2): δ 34.8 (PCy2), 22.2 (PPN). 1H NMR (CD2Cl2): δ 7.76-
7.72 (m, 6H, Ph), 7.60-7.52 (m, 24H, Ph), 2.12-1.99 (m, 6H,
Cy), 1.80-1.78 (m, 4H, Cy), 1.67 (m, 2H, Cy), 1.47-1.27 (m,
10H, Cy). 13C{1H} NMR (CD2Cl2): δ 134.0, 132.5-132.3 (m),
129.9-129.6 (m), 128.0, 126.6, 35.5 (d, J ) 29), 34.3 (d, J ) 2),
27.2 (d, J ) 13), 26.6.
[PPN][(AuCl)2(µ-P(t-Bu)2)] (11). To a slurry of 100 mg (0.3
mmol) of [AuP(t-Bu)2]n in 20 mL of CH2Cl2 was added 311 mg
(0.386 mmol) of [PPN][AuCl2]. After being stirred for 3 h, the
reaction mixture was clear and pale red. The reaction mixture was
filtered to give a clear solution, from which the solvent was
evaporated to yield a white solid, which was recrystallized twice
from CH2Cl2/ether. Yield ) 238 mg, 69%. Crystals suitable for
X-ray crystallography were obtained by slow diffusion of ether into
a CH2Cl2 solution.
Anal. Calcd for AuPC15H16: C, 42.47; H, 3.80. Found: C, 42.10;
H, 3.78. 31P{1H} NMR (C6D6): δ -12.1 (minor), -21.6 (major).
1H NMR (C6D6): δ 7.80-7.49 (m, 2H), 6.92-6.86 (m, 2H), 6.82-
6.70 (m, 3H), 2.90-2.83 (m, 6H, o-Me), 2.08-2.03 (m, 3H, p-Me).
IR: 3056, 3011, 2956, 1600, 1583, 1456, 1428, 1400, 1372, 1289,
1067, 1022, 844, 739, 689, 622, 556, 483, 456. MALDI TOF-MS
(cyano-4-hydroxycinnamic acid): m/z 3167 (Au8(PPhMes)7), 2922,
2743 (Au7(PPhMes)6), 2499, 2363, 2318 (Au6(PPhMes)5), 2122
(AuPPhMes)5, 2074, 1982, 1938, 1910, 1894 (Au5(PPhMes)4),
1834, 1742, 1714, 1697 (AuPPhMes)4, 1666 (Au5(PPhMes)3), 1590,
1514, 1470 Au4(PPhMes)3, 1381, 1274 (AuPPhMes)3, 1090, 1077.
Recrystallization from benzene gave a single compound (31P-
{1H} NMR (C6D6): δ -21.6; 43% recovery). 1H NMR (C6D6): δ
7.52 (2H), 7.42 (1H), 6.90 (2H), 6.79 (2H), 2.92 (6H, o-Me), 2.08
(3H, p-Me). The 31P{1H} NMR spectrum (C6D6) of the filtrate
showed two peaks at -12.1 and -21.6 ppm, in a ratio of ∼ 1:1.
[Au(PHMes*)]n (6). Under N2, aqueous ammonia (3 mL, 29.6%,
47 mmol) was added to a solution of Au(PH2Mes*)Cl (330 mg,
0.65 mmol) in 5 mL of THF; a white precipitate formed. The
mixture was stirred for 15 min, and then the solvent was evaporated.
The white-yellowish solid was washed with 30 mL of water. The
yield was 164 mg, 53%. The compound was recrystallized from
toluene and ethanol.
Anal. Calcd for C44H48Au2Cl2P3N: C, 46.01; H, 4.21; N, 1.22.
Found: C, 45.89; H, 4.08; N, 1.14. 31P{1H} NMR (CDCl3): δ 82.5
1H NMR (toluene-d8): δ 7.64-7.48 (m, 2H, Ar), 6.04 (broad,
1H, JP-H ) 230), 1.92-1.78 (m, 18H, o-t-Bu), 1.33-1.24 (m, 9H,
p-t-Bu). 31P{1H} NMR (toluene-d8): δ -40.9, -42.6 (ratio ca. 1:1).
IR: 2944, 2867, 2456 (P-H), 2378 (P-H), 1756, 1594, 1539, 1467,
1394, 1356, 1278, 1233, 1205, 1183, 1122, 1072, 1028, 922, 900,
872, 856, 744, 644. MALDI TOF-MS (cyano-4-hydroxycinnamic
acid): m/z 3075, 2798, 2601, 2569 (Au6(PHMes*)5), 2357, 2325,
2175 (Au4(PHMes*)5), 2084, 2079, 1947, 1854, 1717, 1701 (Au3-
(PHMes*)4), 1624, 1609, 1473, 1456, 1379, 1226 (Au2(PHMes*)3),
1152, 1136, 997, 987, 982, 906, 778, 752 (Au(PHMes*)2), 725,
664, 610. Anal. Calcd for C18H30AuP: C, 45.58; H, 6.37. Found:
C, 45.69; H, 6.34.
1
(P(t-Bu)2), 22.2 (PPN). H NMR (CDCl3): δ 7.74-7.69 (m, 6H,
Ph), 7.54-7.47 (m, 24H, Ph), 1.42 (d, 18H, J ) 15, CH3). 13C-
{1H} NMR (CDCl3): δ 134.2, 132.5-132.3 (m), 130.0-129.8 (m),
127.9, 126.5, 37.9 (d, J ) 22, CMe3), 34.2 (d, J ) 8, Me).
[PPN][(AuCl)2(µ-P(Ph)(Mes))] (12). To a slurry of 127 mg (0.3
mmol) of [AuPPhMes]n in 20 mL of CH2Cl2 was added 242 mg
(0.3 mmol) of [PPN][AuCl2], and this mixture was stirred for 30
min. The reaction mixture cleared almost immediately and turned
colorless. Upon the addition of ether a white precipitate formed.
Recrystallization from CH2Cl2/ether gave an ether solvate as
1
quantified by H NMR integration. Yield ) 128 mg, 35%.
1
At lower temperatures the H and 31P NMR peaks due to 6 in
Anal. Calcd for C51H46Au2Cl2NP3[Et2O]0.5: C, 50.21; H, 4.05;
toluene-d8 became broader. At temperatures above 25 °C, the 31P
NMR spectrum showed, instead of two broad peaks, multiple sharp
peaks in the same region, suggesting that additional species were
formed on heating. These changes were reversible.
N, 1.10. Found: C, 50.42; H, 3.64; N, 1.12. 31P{1H} NMR
1
(CDCl3): δ 21.6 (PPN), -25.6 (P(Ph)(Mes)). H NMR (CDCl3):
δ 7.68-7.65 (m, 6H, Ph), 7.52-7.46 (m, 26H, Ph), 7.08-7.06 (m,
3H, Ph), 6.82 (d, J ) 3.5, 2H, Mes), 2.78 (6H, o-Me), 2.24 (3H,
p-Me). 13C{1H} NMR (CDCl3): δ 142.6 (d, J ) 9), 139.7, 139.3,
138.4, 135.8, 134.4-134.3 (m), 134.1, 133.4 (d, J ) 14), 130.6
(d, J ) 8), 129.9-129.8 (m), 127.9 (d, J ) 11), 127.6, 126.7 (d, J
) 2), 27.2 (d, J ) 11, o-Me), 21.1 (p-Me).
Au(PI(t-Bu)2)(I) (14). To a slurry of 85 mg (0.25 mmol) of
[AuP(t-Bu)2]n in 40 mL of toluene was added 67 mg (0.26 mmol)
of I2 in 5 mL of toluene. After 15 min of stirring, the white slurry
turned into a reddish solution. After another 1 h of stirring, the
solvent was evaporated, yielding a yellow solid. The solid was
washed carefully with 5 mL of ethanol, since the product is slightly
soluble in this solvent. Yield ) 90 mg, 60%, of analytically pure
light yellow solid. White crystals suitable for X-ray crystallography
were obtained by slow evaporation of hexane from a solution of
Au(PI(t-Bu2))(I).
[PPN][(AuCl)2(µ-PMes2)] (9). To a slurry of 70 mg (0.15 mmol)
of [AuPMes2]n in 20 mL of CH2Cl2 was added 120 mg (0.15 mmol)
of [PPN][AuCl2]. After being stirred for 1 h, the solution darkened
from yellow to violet and became cloudy. The reaction mixture
was filtered to give a clear yellow solution, which was reduced in
volume to ca. 10 mL and then treated with ether to precipitate the
product as a white solid, which was recrystallized from CH2Cl2/
1
ether for elemental analysis. Integration of the H NMR spectrum
of this sample showed that it contained both solvents. Yield ) 102
mg, 53%.
Anal. Calcd for C54H52Au2Cl2NP3(CH2Cl2)0.5[Et2O]0.33: C, 50.05;
H, 4.24; N, 1.05. Found: C, 49.94; H, 4.05; N, 1.15. 31P{1H} NMR
(CDCl3): δ 22.3 (PPN), -53.6 (PMes2). 1H NMR (CDCl3): δ 7.71-
7.68 (m, 6H, Ph), 7.55-7.50 (m, 24H, Ph), 6.75 (d, J ) 3, 4H,
Mes), 2.60 (12H, o-CH3), 2.23 (6H, p-CH3). 13C{1H} NMR
(CDCl3): δ 140.9 (d, J ) 9), 137.0, 134.15, 132.5-132.3 (m), 130.4
(d, J ) 8), 130.0-129.8 (m), 127.9, 126.5, 25.8 (d, J ) 11, o-CH3),
21.0 (p-CH3).
Anal. Calcd for C8H18AuPI2: C, 16.12; H, 3.04. Found: C, 16.43;
1
H, 2.99. H NMR (C6D6): δ 0.90 (d, J ) 18). 31P NMR (C6D6):
δ 116.3 (m, JPH ) 18). 13C{1H} NMR (C6D6): δ 39.5 (d, J ) 3),
28.9 (d, J ) 8).
[PPN][(AuCl)2(µ-PCy2)] (10). To a slurry of 152 mg (0.386
mmol) of [AuPCy2]n in 35 mL of CH2Cl2 was added 311 mg (0.386
mmol) of [PPN][AuCl2]. After being stirred for 3 h, the reaction
Au(PH(t-Bu)2)(I) (15). To a slurry of 103 mg (0.3 mmol) of
[AuP(t-Bu)2]n in 40 mL of toluene was added 60 µL of a 55-58%
aqueous HI solution (58 mg, 0.45 mmol), which was then stirred
Inorganic Chemistry, Vol. 42, No. 26, 2003 8899

Stefanescu et al.
for 15 h under nitrogen atmosphere. Then the solvent was
evaporated yielding a white-yellow solid. Yield ) 88 mg, 62%.
The compound was recrystallized from THF/hexane to give white
crystals. White crystals suitable for X-ray crystallography were
obtained by slow diffusion of ether into a THF solution of
Au(PH(t-Bu)2)(I). 31P{1H} NMR (C6D6): δ 59.9.
This compound was also synthesized independently from
Au(PH(t-Bu)2)(Cl) and NaI and further characterized. To a solution
of 150 mg (0.44 mmol) of Au(PH(t-Bu)2)(Cl) in 5 mL of THF
was added an excess of NaI (130 mg, 0.87 mmol) in 5 mL of THF.
After NaI addition, the solution became turbid and the mixture was
stirred for 2 h. The turbid solution was filtered through Celite, giving
a clear filtrate to which 20 mL of hexane were added; a white
precipitate formed. Yield ) 148 mg, 72%. For elemental analysis,
the sample was dissolved in toluene and then filtered. The solvent
was evaporated from the filtrate under vacuum to give a white solid.
Filtration through Celite gave a yellow solution, but attempts to
crystallize and isolate this material were unsuccessful.
[PH2(t-Bu)2]BF4. To a solution of PH(t-Bu)2 (400 mg, 2.74
mmol) in 5 mL of ether was added HBF4‚Me2O (ca. 500 mg, 3.7
mmol). A white solid formed immediately, and the mixture became
hot and bubbled. After addition of 5 mL of ether, the white slurry
was stirred and then allowed to settle. The ether was decanted to
yield a sticky white solid, which was washed with about 10 mL
more ether and then dried under vacuum to give 604 mg of white
powder (94%).
Anal. Calcd for C8H20BF4P: C, 41.06; H, 8.61. Found: C, 40.72;
1
H, 8.62. 31P{1H} NMR (CD3CN): δ 24.4. H NMR (CD3CN): δ
5.91 (d, J ) 470, 2H), 1.51 (d, J ) 18, 18H). 13C{1H} NMR (CD3-
CN): δ 32.3 (d, J ) 35, CMe3), 27.7 (d, J ) 2, CMe3).
Formation of [Au(PH(t-Bu)2)2]BF4 (19) from [Au(P(t-Bu)2)]n
and [PH2(t-Bu)2]BF4. A white slurry of [Au(P(t-Bu)2)]n (10 mg,
0.044 mmol) and [PH2(t-Bu)2]BF4 (15 mg, 0.044 mmol) in 1 mL
of CH2Cl2 was prepared in an NMR tube, which was suspended in
an ultrasonic cleaning bath for 1 h and then allowed to stand.
Monitoring by 31P NMR showed slow formation of [Au(PH(t-
Bu)2)2]BF4 over several days. Another NMR tube reaction was
carried out on the same scale in bromobenzene. After the sample
was heated for 5 h at 85 °C, 31P NMR monitoring showed starting
materials, some of the desired product, and an unknown impurity
(multiplet patterns, δ 109.2, 66.6). On further heating, most of the
white solid dissolved; the major species present were cation 19
and the impurity (which was also observed in the CH2Cl2 experi-
ment above after 6 d).
[Au(PH(t-Bu)2)2]BF4 (19). A sample of [Au(NCPh)2]BF4 (48
mg, 0.1 mmol) was dissolved in 2 mL of acetonitrile. The turbid
solution was filtered through Celite. To the colorless filtrate was
added 29 mg (0.2 mmol) of HP(t-Bu)2 in 2 mL of acetonitrile, and
the mixture was stirred for 15 min. The solvent was pumped off
yielding a white-yellow solid, which was recrystallized from CH2-
Cl2/hexane to give 36 mg (63%) of analytically pure white solid.
White crystals suitable for X-ray crystallography were obtained by
slow evaporation of CH2Cl2 at -30 °C. NMR spectra were done
on a sample recrystallized from THF/hexane.
Anal. Calcd for C8H19AuPI: C, 20.44; H, 4.07. Found: C, 20.71,
H, 4.10. 1H NMR (C6D6): δ 3.94 (d, J ) 361, 1H, P-H), 0.80 (d,
J ) 17, 18H, t-Bu). 31P NMR (C6D6): δ 59.8 (dm, JPH ) 361,
JP-t-Bu ) 17). 13C{1H} NMR (C6D6): δ 33.7 (d, J ) 26), 29.9 (d,
J ) 6). IR: 2944, 2856, 2322 (P-H), 1633, 1467, 1389, 1362,
1179, 1029, 901, 826, 622, 594, 472.
Au(S(p-(t-Bu)C6H4)(PH(t-Bu)2) (16). To a solution of 150 mg
(0.414 mmol) of [Au(S(p-(t-Bu))C6H4)]n in 2 mL of toluene was
added 60 mg (0.414 mmol) of HP(t-Bu)2 in 3 mL of toluene. On
phosphine addition, the solution turned from yellow to colorless.
A small amount of solid was removed by filtration through Celite
and the solvent was evaporated, yielding a white solid, which was
washed with 10 mL of hexane and dried. Yield ) 109 mg, 52%.
Anal. Calcd for C18H32AuPS: C, 42.52; H, 6.34. Found: C,
1
42.62; H, 6.56. H NMR (C6D6): δ 8.00 (d, J ) 8, 2H), 7.2 (d, J
) 8, 2H), 3.84 (d, J ) 351, 1H), 1.24 (9H), 0.85 (d, J ) 16, 18H).
31P{1H} NMR (C6D6): δ 59.7. IR: 3065, 2953, 2863, 2340 (P-
H), 1591, 1490, 1466, 1394, 1366, 1267, 1183, 1119, 1080, 1026,
817.
The same compound was also synthesized from 68 mg (0.2
mmol) of [AuP(t-Bu)2]n and 34 mg (0.2 mmol) of p-(t-Bu)C6H4-
SH in 35 mL of toluene. The mixture was stirred under N2 for 48
h at room temperature and then heated for 24 h at 70 °C. The
solution was initially turbid, but turned clear at the end of the
reaction. The solvent was pumped off, yielding a white solid. The
solid was dissolved in toluene giving a turbid solution, which was
filtered through Celite. Addition of ethanol to the filtrate precipitated
some impurities, which were filtered off. Evaporation of the filtrate
gave a white solid. 31P NMR (C6D6): δ 59.9 (JP-H ) 357).
Anal. Calcd for C16H38AuP2BF4: C, 33.35; H, 6.65. Found: C,
1
33.62; H, 6.83. H NMR (CD2Cl2): δ 5.46-4.72 (m, 2H), 1.48-
1
1.44 (m, 36H). H{31P} NMR (CD2Cl2): δ 5.12 (m, 2H), 1.47
(36H). 31P NMR (CD2Cl2): δ 65.5 (m, JPP ) 278, JPH ) 363, JPH′
) 2, JPH(t-Bu) ) 18, JHH′ ) 0). 13C{1H} NMR (CD2Cl2): δ 35.0 (t,
J ) 13), 30.8 (t, J ) 3). 19F{1H} NMR (CD2Cl2): δ -153.1. IR:
2948, 2894, 2863, 2334 (P-H), 1625, 1467, 1394, 1366, 1301,
1181, 1083, 1037, 943, 902, 818, 792, 699.
Li[Au(P(t-Bu)2)2] (17). To a solution of 29 mg (0.2 mmol) of
HP(t-Bu)2 in 1 mL of THF was added 125 µL of n-BuLi (1.6 M
hexane solution, 0.2 mmol). The mixture turned instantly from
colorless to yellow. To the solution, 68 mg (0.2 mmol) of [AuP-
(t-Bu)2]n was added. The yellow slurry formed was filtered through
Celite, yielding a clear yellow filtrate. The solvent was pumped
off, leaving a yellow sticky solid behind. This solid was washed
with hexane, yielding a white solid. Yield ) 30 mg, 30%. The
compound decomposes readily in THF at 25 °C, and it could not
be obtained in analytically pure form. An attempt to stabilize the
anion by cation exchange with PPNCl caused rapid decomposition.
1H NMR (THF-d8): δ 1.35 (m). 31P{1H} NMR (THF-d8): δ 80.6.
Addition of BuLi to [Au(P(t-Bu)2)]n. To a solution of [Au(P(t-
Bu)2)]n (29 mg, 0.085 mmol) in 2 mL of THF was added BuLi
(125 µL of 1.6 M solution in hexanes (0.2 mmol)) in 2 mL of
THF. After the mixture was stirred for 15 min, the 31P NMR
spectrum (THF) of the yellow slurry showed a peak at 62.8 ppm.
Reaction of Au(PPh3)[N(SiMe3)2] with Secondary Phosphines.
Method 1. To a clear solution of Au(PPh3)[N(SiMe3)2] (18 mg,
0.029 mmol) in 1 mL of toluene in an NMR tube was added
dimesitylphosphine (8 mg, 0.03 mmol). The 31P NMR spectrum of
the solution after 5 min showed the formation of PPh3 and of [Au-
(PMes2)]n. Reactions with PHCy2, PH(t-Bu)2, and PH(Ph)(Mes)
were carried out similarly.
Method 2. To a clear solution of Au(PPh3)[N(SiMe3)2] (15 mg,
0.024 mmol) in 1 mL of toluene in an NMR tube was added
diisitylphosphine (11 mg, 0.025 mmol). The solution immediately
became yellow. 31P NMR after 15 min showed the formation of
PPh3 and of a new complex (20): δ 44.0 (d, J ) 267, PPh3), -15.4
(dd, J ) 267, 148, µ-PIs2), -54.3 (d, J ) 148, PIs2). When the
sample was left standing at room temperature over 2 d, the yellow
color slowly bleached and this species disappeared; [Au(PIs2)]3 and
PPh3 were observed. Intermediate 20 was generated independently,
along with PPh3, as follows. A solution of Au(PPh3)Cl (10 mg,
8900 Inorganic Chemistry, Vol. 42, No. 26, 2003

Gold(I) Phosphido Complexes
0.02 mmol) in 1 mL of THF was treated with AgOTf (5 mg, 0.02
mmol) to give a slurry that was filtered through Celite onto solid
PHIs2 (9 mg, 0.02 mmol). The resulting clear solution was filtered
and allowed to stand for 1 day before addition of NaOt-Bu (2 mg,
0.02 mmol), which caused immediate color change to yellow. The
31P NMR spectrum showed that 20, PPh3, and some PHIs2 were
present.
Foundation for partial support, including an NSF-REU
fellowship for H.F.Y.
Supporting Information Available: Figures S1-S5 (PDF) and
details of the X-ray crystallographic studies (CIF). This material is
available free of charge via the Internet at http://pubs.acs.org.
Acknowledgment. We thank the American Chemical
Society Petroleum Research Fund and the National Science
IC035006E
Inorganic Chemistry, Vol. 42, No. 26, 2003 8901