Self-association in gold chemistry: A tetragold(I) complex linked by both aurophilic and hydrogen bonding

Article abstract of DOI:10.1021/ic991497k

Hydrolysis of the complex [1,3-C₆H₄(OPPh₂AuSPh)₂] gives the emissive, neutral tetragold(I) complex [{Au₂-(μ-SPh)(PPh₂O)(PPh₂OH)}₂], which is associated through pairs of gold···gold interactions and P-O-H···O-P hydrogen bonds.

Full text of DOI:10.1021/ic991497k

Inorg. Chem. 2000, 39, 2699-2702
2699
Chart 1
Self-Association in Gold Chemistry: A
Tetragold(I) Complex Linked by Both Aurophilic
and Hydrogen Bonding
William J. Hunks, Michael C. Jennings, and
Richard J. Puddephatt*
Department of Chemistry, University of Western Ontario,
London, Ontario, N6A 5B7, Canada
ReceiVed December 29, 1999
Introduction
The supramolecular chemistry of gold(I) complexes has
become an intriguing subject, because many d10 gold(I) com-
pounds display interesting photochemistry that may be depend-
ent on the state of aggregation and that has potential applications
in electronic, optical, or sensing devices.1 Self-assembly of gold-
(I) compounds may be aided by the existence of Au‚‚‚Au
aurophilic attractions, which may have a strength comparable
to hydrogen bonding (7-11 kcal/mol).2 These interactions have
a profound influence on the properties, structures and conforma-
tions of gold complexes.3,4 Theory suggests that these Au‚‚‚Au
attractions arise from relativistic London forces, with relative
strength predicted to increase with the softness of the ligands,5
and this is supported by the observation that, in the series of
complexes Me2PhPAuX, the Au‚‚‚Au distances decrease in the
order (X ) Cl > Br > I).6 Some developments that are relevant
to the present work are described below.
forces of Au‚‚‚Au and hydrogen bonding have resulted in the
assembly of dimers, tetramers, chains, and two-dimensional
networks such as C - E.10,11 Several gold(I) complexes of the
P-donor ligands phosphinite, R2(O)P-, and phosphite, (RO)2(O)P-,
have been synthesized by fortuitous oxidation or hydrolysis of
precursor molecules.12 Complexes containing the S-Au-P
group have been used in gold drugs for the treatment of
rheumatoid arthritis, so water-stable complexes of this kind have
added interest.13 Many gold(I) drugs used in chrysotherapy are
thought to be oligomers with sulfur atoms in bridging posi-
tions,1,14 and so there is increasing interest in analogous gold
Several complexes of the form [{RS(AuL)2}2]2+, with L )
a tertiary phosphine ligand, assemble into centrosymmetric six-
membered dicationic rings through short Au‚‚‚Au contacts with
thiolate ligands bridging opposite edges above and below the
molecular plane, forming a V/ inverted-V configuration (A,
Chart 1).7 Furthermore, difunctional alkylthiols have been used
to link analogous cationic six-membered rings together to
generate extended structures,8 and eight-membered rings, with
S4Au4 cores B, were constructed using the dithiols 3,4-
dimercaptotoluene and benzene-1,2-dithiol.9 The complementary
* Author to whom all correspondence should be addressed.
(1) Forward, J. M.; Fackler, J. P., Jr.; Assefa, Z. in Optoelectronic
Properties of Inorganic Compounds; Roundhill, D. M., Fackler, J. P.,
Jr. Eds.; Plenum Press: New York, 1999; pp 195-239.
(2) For reviews see (a) Schmidbaur, H., Ed. Gold: Progress in Chemistry,
Biochemistry and Technology; Wiley: New York, 1999. (b) Pud-
dephatt, R. J. In ComprehensiVe Coordination Chemistry; Wilkinson,
G., Gillard, R. D., McCleverty, J. A., Eds.; Pergamon Press: Oxford,
1987, Vol. 5, pp 861-923. (c) Schmidbaur, H. Gold Bull. 1990, 23,
11.
(3) (a) Pathaneni, S. S.; Desiraju, G. R. J. Chem. Soc., Dalton Trans.
1993, 319. (b) Schmidbaur, H.; Graf, W.; Mu¨ller, G. Angew. Chem.,
Int. Ed. Engl. 1988, 27, 417. (c) Payne, N. C.; Ramachandran, R.;
Puddephatt, R. J. Can. J. Chem. 1995, 73, 6. (d) Schmidbaur, H.;
Reber, G.; Schier, A.; Wagner, F. E.; Mu¨ller, G. Inorg. Chim. Acta
1988, 147, 143.
(8) (a) Lo´pez-de-Luzuriaga, J.; Sladek, A.; Schneider, W.; Schmidbaur,
H. Chem. Ber. 1997, 130, 641. (b) Sladek, A.; Schmidbaur, H. Inorg.
Chem. 1996, 35, 3268.
(9) (a) Da´vila, R. M.; Elduque, A.; Grant, T.; Staples, R. J.; Fackler, J.
P., Jr. Inorg. Chem. 1993, 32, 1749. (b) Nakamoto, M.; Schier, A.;
Schmidbaur, H. J. Chem. Soc., Dalton Trans. 1993, 1347.
(10) (a) Schneider, W.; Bauer, A.; Schmidbaur, H. Organometallics 1996,
15, 5445; J. Chem. Soc., Dalton Trans. 1997, 415. (b) Mingos, D. M.
P.; Yau, J.; Menzer, S.; Williams, D. J. J. Chem. Soc., Dalton Trans.
1995, 319. (c) Vicente, J.; Chicote, M. T.; Abrisqueta, M. D.; Guerrero,
R.; Jones, P. G. Angew. Chem., Int. Ed. Engl. 1997, 36, 1203. (d)
Shi, J. C.; Kang, B. S.; Mak, T. C. W. J. Chem. Soc., Dalton Trans.
1997, 2171. (e) Hollatz, C.; Schier, A.; Schmidbaur, H. Z. Naturforsch.
1999, 54b, 30. (f) Hollatz, C.; Schier, A.; Schmidbaur, H. Inorg. Chem.
Commun. 1998, 1, 115. (g) Tzeng, B.-C.; Schier, A.; Schmidbaur, H.
Inorg. Chem. 1999, 38, 3978. (h) Jones, P. G.; Ahrens, B. New J.
Chem. 1998, 1041.
(11) (a) Hollatz, C.; Schier, A.; Riede, J.; Schmidbaur, H. J. Chem. Soc.,
Dalton Trans. 1999, 111. (b) Hollatz, C.; Schier, A.; Schmidbaur, H.
J. Am. Chem. Soc. 1997, 119, 8115.
(12) (a) Hollatz, C.; Schier, A.; Schmidbaur, H. Chem. Ber. 1997, 130,
1333. (b) Vicente, J.; Chicote, M. T.; Jones, P. G. Inorg. Chem. 1993,
32, 4960. (c) Schmidbaur, H.; Aly, A. M. Angew. Chem., Int. Ed.
Engl. 1980, 19, 71. (d) Schmidbaur, H.; Aly, A. M.; Schubert, U.
Angew. Chem., Int. Ed. Engl. 1978, 17, 846.
(4) (a) Schmidbaur, H. Chem. Soc. ReV. 1995, 24, 391. (b) Mingos, D.
M. P. J. Chem. Soc., Dalton Trans. 1996, 561.
(5) (a) Pyykko¨, P.; Li, J.; Runeberg, N. Chem. Phys. Lett. 1994, 218, 133.
(b) Li, J.; Pyykko¨, P. Chem. Phys. Lett. 1992, 197, 586.
(6) Toronto, D. V.; Weissbart, B.; Tinti, D. S.; Balch, A. L. Inorg. Chem.
1996, 35, 2484.
(7) (a) Sladek, A.; Schneider, W.; Angermaier, K.; Bauer, A.; Schmidbaur,
H. Z. Naturforsch. 1996, 51b, 765. (b) Sladek, A.; Angermaier, K.;
Schmidbaur, H. J. Chem. Soc., Chem. Commun. 1996, 1959. (c)
Sladek, A.; Schmidbaur, H. Chem. Ber. 1995, 128, 907. (d) Wang,
S.; Fackler, J. P., Jr. Inorg. Chem. 1990, 29, 4404.
(13) Shaw. C. F., III; Isab, A. A.; Hoeschele, J. D.; Starich, M.; Locke, J.;
Schulteis, P.; Xiao, J. J. Am. Chem. Soc. 1994, 116, 2254.
10.1021/ic991497k CCC: $19.00 © 2000 American Chemical Society
Published on Web 05/20/2000

2700 Inorganic Chemistry, Vol. 39, No. 12, 2000
Notes
Table 1. Crystal Data for Complexes 2 and 4
complex 2
Scheme 1
complex 4
empirical formula
fw
temp
C30H24Au2Cl2O2P2
943.27
150(2) K
C90H78Au6O6P6S3
2719.32
200(2) K
wavelength
cryst syst, space group Triclinic, P1h
unit cell dimensions
0.71073 Å
0.71073 Å
monoclinic, P21/c
a ) 18.5609(3) Å
b ) 21.4281(3) Å
c ) 21.2130(4) Å
R ) 90°
a ) 10.262(2) Å
b ) 11.308(2) Å
c ) 13.882(3) Å
R ) 69.51(3)°
â ) 77.52(3)°
γ ) 74.99(3)°
1443.4(5) Å3
2
â ) 90.6420(10)°
γ ) 90°
volume
Z
D (calcd)
abs coeff
F(000)
8436.4(2) Å3
4
2.170 mg/m3
10.476 mm-1
884
2.141 mg/m3
10.637 mm-1
5112
independent reflns
5859 [R(int) ) 0.1080] 18517 [R(int) )
0.0980]
data/restraints/param
goodness of fit on F2
R [I > 2σ(I)]
5859/0/343
1.046
R1 ) 0.0569,
wR2 ) 0.1585
18517/0/1003
1.069
R1 ) 0.0530,
wR2 ) 0.1306
2
4
R1 ) ∑||Fo| - |Fc||/∑|Fo|. wR2 ) {∑[w(Fo - Fc2)2/∑Fo }1/2
complexes that include functional groups that are capable of
hydrogen bonding.7,10,12
This article describes the synthesis of a tetranuclear gold(I)
metallacycle containing bridging thiolate ligands, with Au‚‚Au
bonding analogous to that in A. However, a phosphinous acid/
phosphinite ligand combination is also present and gives
additional bridging through strong hydrogen bonding between
these groups. This combination gives the first neutral complex
of type A (Chart 1).
Results and Discussion
Reaction of two equivalents of chlorodiphenylphosphine with
resorcinol in the presence of triethylamine as base gave the
ligand 1,3-bis(diphenylphosphinito)benzene, 1, as a pale-yellow
oil, as expected by analogy with similar syntheses.15,16 The 31
P
NMR spectrum of 1 gave a singlet resonance at δ ) 111.8, in
agreement with the literature values for similar arylphosphinite
derivatives,17 and the mass spectrum gave a parent ion at
478.124 amu, consistent with the expected structure.
The bis(phosphinite) ligand, 1, reacted with [AuCl(SMe2)],
with displacement of dimethyl sulfide, to form the binuclear
gold phosphinite complex, 2, as illustrated in Scheme 1.
Complex 2 was obtained as a colorless crystalline solid, and
was characterized by its NMR spectra [δ(31P) ) 116.7] and by
an X-ray structure determination (Table 1). The structure of 2
is shown in Figure 1, and selected bond distances and angles
are presented in Table 2.
Figure 1. A view of the molecular structure of [1,3-C6H4(OPPh2-
AuCl)2], 2, showing the weakly associated dimers. Hydrogen atoms
are omitted for clarity.
Table 2. Selected Interatomic Distances (Å) and Angles (deg) for
Compound 2
Au(1)-P(1)
Au(1)-Cl(1)
P(1)-O(1)
O(1)-C(1)
2.217(3)
2.284(3)
1.622(8)
1.37(1)
Au(2)-P(2)
Au(2)-Cl(2)
P(2)-O(2)
O(2)-C(5)
2.213(3)
2.295(3)
1.618(8)
1.40(1)
P(1)-Au(1)-Cl(1)
O(1)-P(1)-Au(1)
C(1)-O(1)-P(1)
173.5(1)
113.6(3)
123.9(6)
P(2)-Au(2)-Cl(2)
O(2)-P(2)-Au(2)
C(5)-O(2)-P(2)
173.6(1)
115.6(3)
122.1(7)
Molecules of 2 contain two roughly linear gold(I) centers
with angles P-Au-Cl ) 173.5(1) and 173.6(1)°, and the Au-P
[2.217(3) and 2.213(3) Å] and Au-Cl [2.284(3) and 2.295(3)
Å] bond lengths are typical of such groupings.2 The P-O
distances of 1.622(8) and 1.618(8) Å are typical for a single
bond to oxygen.18 The molecules form loosely associated
dimers, although the shortest gold-gold contact between
(14) Fricker, S. P. Gold Bull. 1996, 29, 53.
(15) Xu, W.; Rourke, P.; Vittal, J. J.; Puddephatt, R. J. Inorg. Chem. 1995,
34, 323.
(16) (a) Gerrard, W. J. Chem. Soc. 1940, 1464. (b) Verkade, J. G., Coskran,
K. J. In Organophosphorus Compounds; Kosolapoff, G., Maier, L.,
Eds.; Wiley-Interscience: New York, 1972, Vol. 2, pp 1-187. (c)
Hamilton, L. A. Landis, P. S. In Organophosphorus Compounds;
Kosolapoff, G., Maier, L.,Eds.; Wiley-Interscience: New York, 1972;
Vol. 4, pp 463-531.
(17) Verstuyft, A. W.; Redfield, D. A.; Cary, L. W.; Nelson, J. H. Inorg.
Chem. 1977, 16, 2776.
(18) Bondi, A. J. Phys. Chem. 1964, 68, 441.

Notes
Inorganic Chemistry, Vol. 39, No. 12, 2000 2701
Table 3. Selected Interatomic Distances (Å) and Angles (deg) for
Compound 4a
Au(3)-P(3)
Au(4)-P(4)
Au(3)-Au(5)
Au(5)-P(5)
Au(6)-P(6)
P(3)-O(3)
2.266(2)
2.272(2)
3.0733(5)
2.272(2)
2.263(2)
1.563(7)
1.545(6)
Au(3)-S(9)
Au(4)-S(9)
Au(4)-Au(6)
Au(5)-S(8)
Au(6)-S(8)
P(4)-O(4)
2.348(2)
2.346(2)
3.0756(5)
2.338(2)
2.335(2)
1.545(6)
1.557(7)
P(5)-O(5)
P(6)-O(6)
S(9)-Au(3)-Au(5)
P(4)-Au(4)-Au(6)
79.73(5) P(4)-Au(4)-S(9)
85.84(6) S(9)-Au(4)-Au(6)
176.80(8)
91.91(5)
113.4(3)
174.87(8)
89.23(5)
Au(6)-S(8)-Au(5) 102.52(8) O(3)-P(3)-Au(3)
O(4)-P(4)-Au(4)
P(5)-Au(5)-Au(3)
P(6)-Au(6)-S(8)
S(8)-Au(6)-Au(4)
C(8)-S(8)-Au(5)
O(5)-P(5)-Au(5)
116.0(3)
P(5)-Au(5)-S(8)
85.71(6) S(8)-Au(5)-Au(3)
175.25(8) P(6)-Au(6)-Au(4) 100.07(6)
76.69(5) Au(4)-S(9)-Au(3)
97.85(7)
107.4(3)
112.4(3)
110.3(3)
115.4(3)
C(8)-S(8)-Au(6)
O(6)-P(6)-Au(6)
a There are two independent tetragold molecules in the unit cell. Data
are given for only one of them. The second is very similar.
[3.0733(5) and 3.0756(5) Å] are considerably shorter and
indicate a much stronger aurophilic attraction between these
atoms. Overall, the four gold atoms are arranged in a distorted
square, and the Au4S2 core gives a six-membered ring in the
chair conformation. The P-O bond lengths are all equivalent
within experimental error [1.544(6) to 1.558(7) Å], which
indicates P-O-‚‚‚H-O-P bonding such that the P-O bond
lengths are intermediate between those in diphenylphosphinite
complexes [1.499(4) - 1.52(1) Å]10,12 and the single P-O bonds
[1.62(1) Å] found in complex 2, and considerably longer than
a PdO bond [1.49(1) Å].20 Thus, the tetranuclear gold(I)
complex bears two neutral diphenylphosphinous acid groups,
Ph2POH, and two anionic diphenylphosphinite ligands, Ph2PO-,
each bound to a gold(I) center through the phosphorus atom.
These groups combine intermolecularly by P-O‚‚‚H-O-P
bonding, thus forming two peripheral seven-membered rings
(Figure 2). The distances between oxygen atoms O(5)-O(3)
and O(6)-O(4) [2.40(1) and 2.42(1) Å, respectively] are in the
middle of the range of O-O separations [2.2-2.5 Å] that is
considered diagnostic of a strong hydrogen bond.21 The
hydrogen atoms were tentatively located in the structure
determination, but it should be noted that the formulation is
based on the presence of the neutral tetranuclear complex, which
requires the presence of only two Ph2PO- ligands. It is this
combination of intermolecular Au‚‚Au and OH‚‚O secondary
bonding effects that gives the neutral gold(I) complex 4 its
unique character when compared to the cationic complexes
studied previously.7,8 It is noted that the structure of 4 contains
two independent dimers and that they have very similar
structures and bond parameters, indicating that the structure
observed is rather rigid and not much influenced by crystal
packing forces.
Figure 2. A view of the molecular structure of [{Au2(µ-SPh)-
(PPh2O)(PPh2OH)}2], 4. Dashed lines indicate the Au‚‚Au and OH‚‚O
secondary bonds.
adjacent molecules, d(Au1A‚‚Au2B) ) 3.695(1) Å, is slightly
longer than the sum of the van der Waals radii (3.6 Å and so is
on the edge of the range considered for Au‚‚‚Au intermolecular
bonding.18 There are also relatively short Au‚‚Cl contacts, Cl1A‚
‚Au2B ) 3.407(2) Å and Cl1A.‚‚Au1B ) 3.616(2) Å, as
indicated in Figure 1.
Treatment of 2 with benzenethiol in the presence of triethy-
lamine gave complex 3 as a pale-yellow crystalline powder, as
shown in Scheme 1. Complex 3 was characterized by its
spectroscopic properties [δ(31P) ) 124.6] and by microanalysis.
Reaction of 3 with a stoichiometric amount of water in acetone
solution led to hydrolysis of the P-O bonds to yield ben-
zenethiol, resorcinol, and the gold(I) complex derivative [{Au2-
(µ-SPh)(PPh2O)(PPh2OH)}2], 4, as depicted in Scheme 1. It was
isolated as colorless prisms, which were stable to air and
moisture. Complex 4 was sparingly soluble in nitrobenzene/
CH2Cl2 solution but insoluble in other common organic solvents
and in water. The complex gives δ(31P) ) 82.4, in the expected
region for a phosphinite gold(I) derivative with PdO‚‚‚H-O-P
bonding.11 The IR spectrum of 4 shows the presence of a strong
absorption band characteristic of the ν(PdO) stretching vibration
at 1025 cm-1, which is absent in the IR spectra of 2 and 3.
Complex 4 was also characterized by an X-ray structure
determination (Table 1).
The structure of 4 is shown in Figure 2, and selected bond
distances and angles are presented in Table 3. The hydrolysis
product 4 can be considered to comprise two Au2(µ-SPh)-
(PPh2O)(PPh2OH) units linked by both Au‚‚Au and OH‚‚O
secondary bonds. Within each unit, the P-Au-S angles range
from 177.37(8) to 175.38(8)°, only a little distorted from
linearity. The Au-S [2.335(2) - 2.348(2) Å] and Au-P [2.263-
(2) - 2.272(2) Å] bond lengths are unremarkable.19 The angles
AuSAu ) 97.85(7) and 102.52(8)° are somewhat less than the
tetrahedral angle, and the corresponding intramolecular Au‚‚‚
Au distances [3.538(1) and 3.645(1) Å, respectively] suggest a
weak aurophilic attraction. The intermolecular Au‚‚‚Au distances
The photophysical properties of complexes 3 and 4 are
summarized in Table 4. Complex 3 is brightly luminescent at
room temperature in dichloromethane solution, with a peak
maximum at 413 nm, in contrast to 2, which gives only a very
weak, broad emission at 367 nm. The emission for 3 is red-
shifted to 445 nm as a solid in KBr matrix, and is asymmetric,
broad, and featureless. Finely ground single crystals of 4 in a
KBr matrix display a broad and featureless luminescence
spectrum at room temperature, having a full width at half-
(19) (a) Ahmed, L. S.; Clegg, W.; Davies, D. A.; Dilworth, J. R.; Elsegood,
M. R. J.; Griffiths, D. V.; Horsburgh, L.; Miller, J. R.; Wheatley, N.
Polyhedron 1999, 18, 593. (b) Nakamoto, M.; Hiller, W.; Schmidbaur,
H. Chem. Ber. 1993, 126, 605.
(20) Allen, F. H.; Kennard, O.; Watson, D. G.; Brammer, L.; Orpen, A.
G.; Taylor, R. J. Chem. Soc., Perkin Trans. 2 1987, S1.
(21) Jeffrey, G. A. An Introduction to Hydrogen Bonding; Oxford University
Press: New York, 1997.

2702 Inorganic Chemistry, Vol. 39, No. 12, 2000
Table 4. Luminescence Data for 3 and 4a
Notes
[1,3-C6H4(OPPh2AuCl)2], 2. To a solution of [AuCl(SMe2)] (0.184
g, 0.62 mmol) in THF (5 mL) was added a solution of 1 (0.150 g, 0.31
mmol) in THF (5 mL). The colorless solution was stirred for 1 h, and
the solvent was removed under vacuum. The residue was washed with
ether and pentane. A white crystalline solid was obtained. Yield: 0.217
g, 74%. NMR (acetone-d6): δ(1H) ) 7.10-7.20 [m, 3H, H2, H4, H6 of
Ar]; 7.40 [t, 1H, H5 of Ar]; 7.8-8.0 [m, 20H, Ph]. δ(31P) ) 116.74
[s]. Anal. Calcd for C30H24Au2Cl2O2P2: C, 38.20; H, 2.56. Found: C,
37.36; H, 2.63%.
complex
medium
emission max, nm
3
3
4
CH2Cl2
solid
solid
413
445
420
a λexcitation ) 270 nm; spectra of solids were obtained in a KBr
matrix.
[1,3-C6H4(OPPh2AuSPh)2], 3. To a solution of 2 (0.200 g, 0.21
mmol) in THF (20 mL) at 0 °C under nitrogen was added triethylamine
(59 µL, 0.42 mmol) and benzenethiol (44 µL, 0.42 mmol). A white
precipitate slowly formed. The mixture was stirred for 3 h and filtered
through a sintered glass funnel, and the solvent was removed under
vacuum. The residue was washed with ether and pentane. A pale-yellow
crystalline solid was obtained. Yield: 0.125 g, 54%. NMR (acetone-
d6): δ(1H) ) 6.70-7.00 [m, 4H, Ar]; 7.40-8.00 [m, 30H, Ph]. δ(31P)
) 124.62 [s]. Anal. Calcd for C42H34Au2O2P2S2: C, 46.25; H, 3.14; S,
5.88. Found: C, 46.20; H, 3.52; S, 5.58%.
[{Au2(µ-SPh)(PPh2O)(PPh2OH)}2], 4. A solution of 3 (20 mg) was
dissolved in wet acetone (1 mL). Colorless prisms were grown by slow
diffusion of pentane. NMR (CD2Cl2/nitrobenzene-d5): δ(1H) ) 7.1-
7.8 [m, Ph]. δ(31P) ) 82.43 (s). Anal. Calcd for C60H52Au4O4P4S2: C,
39.75; H, 2.89. Found: C, 39.30; H, 2.46%.
maximum of 100 nm. The peak maximum occurs at 420 nm.
Because several gold(I) thiolates are known to give room-
temperature emission,22 whereas the diphosphinite complex
[Au(Ph2PO)2]- does not luminesce in solution or as a solid,11b
it seems clear that the thiolatogold(I) unit is responsible for the
observed emission in 3 and 4. In accord with precedent, the
emission is assigned to an excited state arising from a ligand-
to-metal charge transfer [from sulfur to gold(I)].22 The redshift
of ca. 30 nm in the emission spectrum of 3 going from solution
to the solid state suggests that gold‚‚‚gold interactions are present
in the solid state.22
Experimental Section
NMR spectra were recorded using a Varian Gemini 300 MHz
spectrometer, and chemical shifts are reported relative to TMS (1H) or
85% H3PO4 external standard (31P). Mass and IR spectra were recorded
using a Finnigan MAT 8320 and a Perkin-Elmer 2000 FTIR, respec-
tively. Emission spectra were recorded at room temperature on a
Fluorolog-3 spectrofluorometer using a 3-nm slit width and excitation
λmax ) 270 nm. All reactions were conducted under an inert nitrogen
atmosphere using standard Schlenk techniques. THF and ether were
dried and distilled immediately prior to use. Triethylamine was distilled
over KOH. [AuCl(SMe2)] was prepared according to a literature
method.23
1,3-C6H4(OPPh2)2, 1. A solution of resorcinol (0.500 g, 4.54 mmol)
in diethyl ether (20 mL) was cooled in an ice bath. Triethylamine (1.33
mL, 9.54 mmol) was added, followed by chlorodiphenylphosphine (1.63
mL, 9.08 mmol) to yield a white precipitate of Et3NHCl. The mixture
was stirred for 1 h and filtered through a sintered glass funnel, and the
solvent was removed under vacuum. The product was obtained as a
clear, yellow oil. Yield: 1.88 g, 86%. NMR (CDCl3): δ(1H) ) 6.90-
7.60 [m, Ph]; δ(31P) ) 111.77 [s]. EI-MS, m/z: 478.124; calcd for
C30H24O2P2: 478.125.
X-ray Structure Determinations. Crystals of 2 were grown by slow
diffusion of ether into an acetone solution. A yellow crystal was
mounted on a glass fiber. Data were collected at 150 K using a Nonius
Kappa CCD diffractometer using COLLECT software. Crystal cell
refinement and data reduction were carried out using the Nonius
DENZO package. The data were scaled using SCALEPACK (Nonius,
1998), and no other absorption corrections were applied. The reflection
data were consistent with a triclinic system, and the structure was solved
successfully in P1h. The SHELXTL 5.03 program package was used to
solve the structure by Patterson and successive difference Fouriers. All
non-hydrogen atoms were refined with anisotropic thermal parameters.
The hydrogen atoms were calculated geometrically and rode on their
respective carbon atoms. The largest residual electron density peak (2.24
e/Å3) was associated with a gold atom.
Crystals of 4 were grown by slow diffusion of pentane into an
acetone solution. A colorless prism was mounted on a glass fiber. Data
were collected at 200 K and treated as above. The reflection data and
systematic absences were consistent with a monoclinic system, P21/c.
Hydrogen bonding: [H1A‚‚‚O2 ) 1.70 Å; H4A‚‚‚O6 ) 1.70 Å; H5A‚
‚‚O3 1.61 Å]. The largest residual electron density peak (2.051 e/Å3)
was associated with one of the gold atoms.
(22) (a) Hanna, S. D.; Khan, S. I.; Zink, J. I. Inorg. Chem. 1996, 35, 5813.
(b) Hanna, S. D.; Zink, J. I. Inorg. Chem. 1996, 35, 297. (c) Jones,
W. B.; Yuan, J.; Narayanaswamy, R.; Young, M. A.; Elder, R. C.;
Bruce, A. E.; Bruce, M. R. M. Inorg. Chem. 1995, 34, 1996. (d)
Forward, J. M.; Bohmann, D.; Fackler, J. P., Jr.; Staples, R. J. Inorg.
Chem. 1995, 34, 6330. (e) Assefa, Z.; Staples, R. J.; Fackler, J. P., Jr.
Inorg. Chem. 1994, 33, 2790. (f) Yam, V. W. W.; Lo, K. K. W. Chem.
Soc. ReV. 1999, 28, 323.
Acknowledgment. We thank the NSERC (Canada) for
financial support.
Supporting Information Available: Tables of X-ray data for
complexes 2 and 4. This material is available free of charge via the
Internet at http://pubs.acs.org.
(23) Tamaki, A.; Kochi, J. K. J. Organomet. Chem. 1974, 64, 411.
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