Synthesis and structural characterization of luminescent trinuclear gold(I) complexes with dithiocarbamates

Article abstract of DOI:10.1021/ic9914342

We have synthesized a series of trinuclear gold(I) complexes, namely, [Au₃(μ-dpmp)(S₂CNR₂)(n)Cl(3-n)] (n = 0-3; R = Me, CH₂Ph), [Au₃(μ-dpmp)(μ-S₂CNR₂)Cl](CF₃SO₃

Full text of DOI:10.1021/ic9914342

3560
Inorg. Chem. 2000, 39, 3560-3566
Synthesis and Structural Characterization of Luminescent Trinuclear Gold(I) Complexes
with Dithiocarbamates
Manuel Bardaj´ı and Antonio Laguna*
Departamento de Qu´ımica Inorga´nica, Instituto de Ciencia de Materiales de Arago´n,
Universidad de Zaragoza-CSIC, E-50009 Zaragoza, Spain
Peter G. Jones
Institut fu¨r Anorganische und Analytische Chemie der Technischen Universita¨t, Postfach 3329,
D-38023 Braunschweig, Germany
Axel K. Fischer
Institut fu¨r Chemie der Universita¨t Magdeburg, Universita¨tsplatz 2, D-37106 Magdeburg, Germany
ReceiVed December 15, 1999
We have synthesized a series of trinuclear gold(I) complexes, namely, [Au3(µ-dpmp)(S2CNR2)nCl3-n] (n ) 0-3;
R ) Me, CH2Ph), [Au3(µ-dpmp)(µ-S2CNR2)Cl](CF3SO3) (R ) Me, CH2Ph), and [Au3(µ-dpmp)(µ-S2CNMe2)-
(C6F5)]X (X ) Cl, CF3SO3), containing the triphosphine dpmp [bis(diphenylphosphinomethyl)phenylphosphine]
and varying amounts of dithiocarbamate. NMR experiments show fluxional behavior in solution for most of
these derivatives because several arrangements of the ligands are possible. The crystal structure of [(µ-dpmp)-
(AuCl)3] has been determined by X-ray diffraction studies; the molecule displays mirror symmetry and involves
an angular arrangement of the gold atoms [Au-Au-Au 119.603(14)°, Au-Au 3.3709(4) Å]. We have studied
the optical properties of these derivatives in the solid state, finding a red shift as a function of the dithiocarbamate
number and, for some derivatives, wavelength-dependent emission spectra at low temperature.
Introduction
ligands could thus be a promising method of enhancing this
phenomenon.
The synthesis and photophysical properties of closed shell
gold(I) complexes have attracted considerable attention during
recent years because of the intriguing short gold-gold distances,
which have been attributed to relativistic and correlation
effects.1,2 Photoluminescence studies have shown that most
derivatives involving such weak gold-gold interactions display
luminescence in the visible region; it has been suggested that
this arises from metal-centered electronic excited states that are
modified by metal-metal interaction.3-6 The use of polyphos-
phines promotes both the gold-gold contacts and the lumines-
cence.7
Furthermore, some mononuclear phosphine-thiolate-gold-
(I) and dinuclear diphosphine-thiolate-gold(I) derivatives have
been described that are luminescent because of sulfur to gold
charge transfer modified by the presence of gold-gold con-
tacts.8-10 The combination of both polyphosphines and S-donor
In this paper we report the synthesis and spectroscopic
characterization of a series of trinuclear gold(I) complexes
[Au3(µ-dpmp)(S2CNR2)nCl3-n] (n ) 0-3; R ) Me, CH2Ph),
[Au3(µ-dpmp)(µ-S2CNR2)Cl](CF3SO3) (R ) Me, CH2Ph), and
[Au3(µ-dpmp)(µ-S2CNMe2)(C6F5)]X (X ) Cl, CF3SO3), where
dpmp is the triphosphine bis(diphenylphosphinomethyl)phen-
ylphosphine. We have studied the luminescence properties of
these derivatives in the solid state at room temperature and at
77 K. The crystal structure of [(µ-dpmp)(AuCl)3] has been
determined by X-ray diffraction studies, showing an angular
arrangement of the gold atoms.
Experimental Section
General. All reactions were carried out under an argon atmosphere
at room temperature. IR spectra were recorded on a Perkin-Elmer 883
spectrophotometer, over the range 4000-200 cm-1, using Nujol mulls
between polyethylene sheets. 1H, 1H{31P}, 19F, and 31P{1H} NMR
spectra were recorded on a Varian UNITY 300, Bruker ARX‚300, or
GEMINI 2000 apparatus in CDCl3 solutions (if no other solvent is
(1) Pyykko¨, P. Chem. ReV. 1997, 97, 597 and references therein.
(2) Schmidbaur, H. Chem. Soc. ReV. 1995, 391 and references therein.
(3) Roundhill, D. M.; Fackler, J. P., Jr. Optoelectronic Properties of
Inorganic Compounds; Plenum Press; New York and London, 1998;
pp 195-231 and references therein.
1
stated); chemical shifts are quoted relative to SiMe4 (external, H),
CFCl3 (external, 19F), and 85% H3PO4 (external, 31P). C, H, N, and S
(4) Forward, J. M.; Assefa, Z.; Fackler, J. P., Jr. J. Am. Chem. Soc. 1995,
117, 9103.
(5) Feng, D.; Tang, S. S.; Liu, C. W.; Lin, I. J. B.; Wen, Y.; Liou, L.
Organometallics 1997, 16, 901.
(6) Mansour, M. A.; Connick, W. B.; Lachicotte, R. J.; Gysling, H. J.;
Eisenberg, R. J. Am. Chem. Soc. 1998, 120, 1329.
(7) Balch, A. L. Progress in Inorganic Chemistry; Lippard, S. J., Ed.;
Wiley: New York, 1994; Vol. 41, p 239 and references therein.
(8) Forward, J. M.; Bohmann, D.; Fackler, J. P., Jr.; Staples, R. J. Inorg.
Chem. 1995, 34, 6330.
(9) 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.
(10) Tang, S. S.; Chang, C.; Lin, I. J. B.; Liou, L.; Wang, J. Inorg. Chem.
1997, 36, 2294.
10.1021/ic9914342 CCC: $19.00 © 2000 American Chemical Society
Published on Web 07/12/2000

Gold(I) Complexes
Inorganic Chemistry, Vol. 39, No. 16, 2000 3561
analyses were performed with a Perkin-Elmer 2400 microanalyzer.
Melting points were measured on a Bu¨chi apparatus and are uncorrected.
Conductivities were measured in acetone solution with a Philips PW
9509 apparatus. Mass spectra were recorded on a VG Autospec using
LSIMS technique (with Cs gun) and 3-nitrobenzyl alcohol as matrix.
UV-visible absorption spectra, either in solid or in dichloromethane
solution, were recorded at 300 K on a HITACHI U-3400. Emission
and excitation spectra were measured at room temperature and 77 K
with a Perkin-Elmer LS-50B spectrofluorometer.
Au3ClF3NO3P3S3: C, 37.1; H, 2.8; N, 0.9; S, 6.2. Found: C, 36.7; H,
2.5; N, 0.85; S, 5.85. Λ: 102 ohm-1 cm2 mol-1
.
c. [Au3(µ-dpmp)(S2CNR2)2Cl], R ) Me (5), CH2Ph (6). To a
dichloromethane suspension (20 mL) of [(µ-dpmp)(AuCl)3] (0.12 g,
0.1 mmol) was added NaS2CNR2 (0.2 mmol; R ) Me, 29 mg; R )
CH2Ph, 59 mg). The solid dissolved rapidly, and the resulting yellow
solution was stirred for about 2 h, then filtered through Celite and
concentrated to ca. 2 mL. Addition of hexane (20 mL) afforded
complexes 5 and 6 as yellow solids, which were washed with hexane
1
(2 × 5 mL). Yield of 5, 95%; mp, 160 °C (decomp). H NMR: δ
Preparation of Compounds. a. [Au3(µ-dpmp)(µ-S2CNR2)Cl2], R
) Me (1), CH2Ph (2). To a dichloromethane suspension (20 mL) of
[(µ-dpmp)(AuCl)3]11 (0.12 g, 0.1 mmol) was added NaS2CNR2 (0.1
mmol; R ) Me, 14 mg; R ) CH2Ph, 30 mg). The solid dissolved
rapidly, and the resulting yellow solution was stirred for about 2 h and
then filtered through Celite and concentrated to ca. 2 mL. Addition of
hexane (20 mL) afforded complexes 1 and 2 as yellow solids, which
were washed with hexane (2 × 5 mL). Yield of 1, 95%; mp, 195 °C
8.1-6.9 (m, 25H, Ph), 4.68 (m, 2H, P-CH2-P), 3.95 (m, 2H, P-CH2-
1
P), 3.58 (s, 12H, Me). H{31P} NMR: δ 8.1-6.9 (m, 25H, Ph), 4.68
(d, 2H, 2J(HH) ) 14.7 Hz, P-CH2-P), 3.95 (d, 2H, P-CH2-P), 3.58
(s, 12H, Me). 31P{1H} NMR: δ 33.6 (br). 1H NMR (-55 °C): δ 8.2-
6.9 (m, 25H, Ph), 4.64 (m, 2H, P-CH2-P), 3.89 (m, 2H, P-CH2-P),
3.62 (s, 12H, Me). 31P{1H} NMR (-55 °C): δ 34.5, 32.0. AB2 spin
2
system with J(AB) ) 72.8 Hz. Anal. Calcd for C38H41Au3ClN2P3S4:
1
C, 33.25; H, 3.0; N, 2.05; S, 9.35. Found: C, 33.1; H, 2.85; N, 2.0; S,
9.35. Λ: 47 ohm-1 cm2 mol-1. Yield of 6: 84%, mp 130 °C (decomp).
1H NMR: δ 8.2-6.9 (m, 45H, Ph), 5.04 (s, 8H, CH2Ph), 4.73 (“q”,
2H, N ) 12.1 Hz, P-CH2-P), 4.0 (“q”, 2H, N ) 9.2 Hz, P-CH2-P).
1H{31P} NMR: δ 8.1-7.0 (m, 45H, Ph), 5.02 (s, 8H, CH2Ph), 4.66 (d,
2H, 2J(HH) ) 14.7 Hz, P-CH2-P), 3.92 (d, 2H, P-CH2-P). 31P{1H}
NMR: δ 35.2, 33.3. AB2 spin system with 2J(AB) ) 68.6 Hz. 1H NMR
(-55 °C): δ 8.2-6.9 (m, 45H, Ph), 4.81 (s, 8H, CH2Ph), 4.70 (br,
2H, P-CH2-P), 3.80 (br, 2H, P-CH2-P). 31P{1H} NMR (-55 °C):
δ 35.9, 32.4. AB2 spin system with 2J(AB) ) 76.4 Hz. Anal. Calcd for
C62H57Au3ClN2P3S4: C, 44.4; H, 3.4; N, 1.65; S, 7.65. Found: C, 44.0;
(decomp). H NMR: δ 8.2-7.0 (m, 25H, Ph), 4.70 (“q”, 2H, N )
12.0 Hz, P-CH2-P), 4.02 (brs, 2H, P-CH2-P), 3.66 (s, 6H, Me).
2
1H{31P} NMR: δ 8.2-7.0 (m, 25H, Ph), 4.70 (d, 2H, J(HH) ) 14.8
Hz, P-CH2-P), 4.02 (brs, 2H, P-CH2-P), 3.65 (s, 6H, Me). 31P{1H}
NMR: δ 35.7 (m), 32.9 (m) with ca. the same intensity. 1H NMR (-55
°C): δ 8.2-6.8 (m, 25H, Ph), 5.2-5.0 (m, 3H, P-CH2-P), 3.68 (s,
3H, Me), 3.51 (s, 3H, Me), 2.46 (br, 1H, P-CH2-P). 31P{1H} NMR
2
(-55 °C): δ 36.5, 33.5, 27.4. ABX spin system with J(AB) ) 67.8
2
4
Hz, J(AX) ) 65.2 Hz, and J(BX) ) 0 Hz. Anal. Calcd for C35H35-
Au3Cl2NP3S2: C, 32.65; H, 2.75; N, 1.1; S, 5.0. Found: C, 32.5; H,
2.65; N, 1.0; S, 4.7. Λ: 46 ohm-1 cm2 mol-1. Yield of 2, 93%; mp,
H, 3.4; N, 1.55; S, 7.4. Λ: 45 ohm-1 cm2 mol-1
.
1
175 °C (decomp). H NMR: δ 8.2-7.0 (m, 35H, Ph), 5.27 (s, 4H,
d. [Au3(µ-dpmp)(µ-S2CNMe2)(C6F5)Cl] (7). To a dichloromethane
solution (20 mL) of [Au3(µ-dpmp)(µ-S2CNMe2)2Cl] (0.137 g, 0.1 mmol)
was added [Au(C6F5)(tht)]12 (0.045 g, 0.1 mmol). The mixture was
stirred for about 2 h. A yellow solid ([Au2(µ-S2CNMe2)2] by infrared
spectrum) was filtered off, and the clear solution was concentrated to
ca. 2 mL. Addition of hexane (20 mL) afforded 7 as a yellow solid,
which was washed with hexane (2 × 5 mL). Yield, 92%; mp, 160 °C
CH2Ph), 4.73 (“q”, 2H, N ) 12.3 Hz, P-CH2-P), 4.02 (brs, 2H,
P-CH2-P). 31P{1H} NMR: δ 36.2 (m), 32.6 (m) with ca. the same
intensity. 1H NMR (-55 °C): δ 8.2-7.0 (m, Ph), 5.8-2.5 (m, CH2Ph
and P-CH2-P). 31P{1H} NMR (-55 °C): δ 37.6, 33.7, 28.0. ABX
spin system with 2J(AB) ) 67.0 Hz, 2J(AX) ) 64.7 Hz, and 4J(BX) )
0 Hz. Anal. Calcd for C47H43Au3Cl2NP3S2: C, 39.2; H, 3.0; N, 0.95;
S, 4.45. Found: C, 38.8; H, 3.05; N, 0.9; S, 4.1. Λ: 24 ohm-1 cm2
1
(decomp). H NMR: δ 8.1-6.9 (m, 25H, Ph), 5.15 (“q”, 1H, N )
mol-1
.
14.0 Hz, P-CH2-P), 4.55 (m, 2H, P-CH2-P), 3.47 (m, 7H, Me +
b. [Au3(µ-dpmp)(µ-S2CNR2)Cl]CF3SO3, R ) Me (3), CH2Ph (4).
To a dichloromethane solution (20 mL) of [Au3(µ-dpmp)(µ-S2CNR2)-
Cl2] (0.05 mmol; R ) Me, 64 mg; R ) CH2Ph, 72 mg) was added
AgCF3SO3 (13 mg, 0.05 mmol). The mixture was stirred for about 2 h
protected from light, then filtered through Celite and concentrated to
ca. 2 mL. Addition of diethyl ether (20 mL) afforded 3 and 4 as yellow
solids, which were washed with diethyl ether (2 × 5 mL). Yield of 3,
85%; mp, 195 °C (decomp). 1H NMR: δ 7.8-6.9 (m, 25H, Ph), 4.24
(“q”, 2H, N ) 11.6 Hz, P-CH2-P), 3.65 (s, 6H, Me), 3.40 (brs, 2H,
1
P-CH2-P). H{31P} NMR: δ 8.1-6.9 (m, 25H, Ph), 5.15 (d, 1H,
2J(HH) ) 15.0 Hz, P-CH2-P), 4.55 (s, 2H, P-CH2-P), 3.46 (m, 7H,
Me + P-CH2-P). 19F NMR: δ -115.6 (m, 2F, Fo), -160.1 (t, 1F,
Fp), -163.6 (m, 2F, Fm). 31P{1H} NMR: δ 35.0, 33.8, 32.6. ABC spin
system with calculated 2J(AB) ) 67.9 Hz, 4J(AC) ) 4.8 Hz, 2J(BC) )
1
70.7 Hz. H NMR (-55 °C): δ 8.1-6.9 (m, 25H, Ph), 5.41 (br, 1H,
P-CH2-P), 4.72 (br, 1H, P-CH2-P), 3.93 (br, 1H, P-CH2-P), 3.41
(s, 3H, Me), 3.32 (s, 3H, Me), 2.74 (br, 1H, P-CH2-P). 31P{1H} NMR
(-55 °C): δ 34.1, 33.7, 30.8. ABC spin system with calculated 2J(AB)
) 69.5 Hz, 4J(AC) ) 1.3 Hz, 2J(BC) ) 68.8 Hz. Anal. Calcd for C41H35-
Au3ClF5NP3S2: C, 34.7; H, 2.5; N, 1.0; S, 4.5. Found: C, 34.4; H,
1
P-CH2-P). 31P{1H} NMR: δ 35.1 (m, 2P), 29.3 (m, 1P). H NMR
(-55 °C): δ 7.9-6.8 (m, 25H, Ph), 4.7-3.4 (m, 4H, P-CH2-P), 3.68
(s, 3H, Me), 3.51 (s, 3H, Me). 31P{1H} NMR (-55 °C): δ 35.0, 33.3,
2.45; N, 1.15; S, 4.8. Λ: 49 ohm-1 cm2 mol-1
.
2
2
27.9. ABX spin system with J(AB) ) 67.5 Hz, J(AX) ) 67.1 Hz,
and 4J(BX) ) 0 Hz. Anal. Calcd for C36H35Au3ClF3NO3P3S3: C, 30.85;
H, 2.5; N, 1.1; S, 6.85. Found: C, 30.5; H, 2.3; N, 1.15; S, 7.05. Λ:
e. [Au3(µ-dpmp)(µ-S2CNMe2)(C6F5)]CF3SO3 (8). To a dichlo-
romethane solution (20 mL) of [Au3(µ-dpmp)(µ-S2CNMe2)(C6F5)Cl]
(71 mg, 0.05 mmol) was added AgCF3SO3 (13 mg, 0.05 mmol). The
mixture was stirred for about 2 h, protected from light. The solid AgCl
was filtered off, and the clear solution was concentrated to ca. 2 mL.
Addition of diethyl ether (20 mL) afforded 8 as a yellow solid, which
was washed with diethyl ether (2 × 5 mL). Yield: 90%, mp 155 °C
1
100 ohm-1 cm2 mol-1. Yield of 4, 80%; mp, 160 °C (decomp). H
NMR: δ 7.9-6.9 (m, 35H, Ph), 5.27 (m, 4H, CH2Ph), 4.23 (“q”, 1H,
N ) 13.6 Hz, P-CH2-P), 4.19 (“q”, 1H, N ) 13.6 Hz, P-CH2-P),
3.58 (“q”, 1H, N ) 12.4 Hz, P-CH2-P), 3.23 (“q”, 1H, N ) 13.5 Hz,
1
P-CH2-P). H{31P} NMR: δ 7.9-6.9 (m, 35H, Ph), 5.25 (m, 4H,
1
(decomp). H NMR: δ 8.0-7.0 (m, 25H, Ph), 4.54 (“q”, 1H, N )
2
CH2Ph), 4.23 (d, 1H, J(HH) ) 13.6 Hz, P-CH2-P), 4.19 (d, 1H,
13.5 Hz, P-CH2-P), 4.18 (“q”, 1H, N ) 12.5 Hz, P-CH2-P), 3.75
(“q”, 1H, N ) 12.6 Hz, P-CH2-P), 3.57 (s, 3H, Me), 3.42 (s, 3H,
Me), 3.06 (“q”, 1H, N ) 12.6 Hz, P-CH2-P). 1H{31P} NMR: δ 7.9-
2J(HH) ) 12.5 Hz, P-CH2-P), 3.58 (d, 1H, 2J(HH) ) 12.5 Hz,
P-CH2-P), 3.23 (d, 1H, 2J(HH) ) 13.6 Hz, P-CH2-P). 31P{1H}
2
NMR: δ 35.5, 34.6, 28.9. ABX spin system with J(AB) ) 67.0 Hz,
2
7.0 (m, 25H, Ph), 4.48 (d, 1H, J(HH) ) 14.7 Hz, P-CH2-P), 4.16
2J(AX) ) 62.0 Hz, and 4J(BX) ) 6.7 Hz. 1H NMR (-55 °C): δ 7.8-
2
(d, 1H,2J(HH) ) 14.5 Hz, P-CH2-P), 3.72 (d, 1H, J(HH) ) 14.7
2
6.9 (m, 35H, Ph), 5.55 (d, 1H, J(HH) ) 15.7 Hz, CH2Ph), 5.37 (d,
Hz, P-CH2-P), 3.55 (s, 3H, Me), 3.39 (s, 3H, Me), 3.08 (d, 1H, 2J(HH)
) 14.5 Hz, P-CH2-P). 19F NMR: δ -78.9 (s, 3F, CF3), -115.6 (m,
2F, Fo), -159.8 (t, 1F, Fp), -163.4 (m, 2F, Fm). 31P{1H} NMR: δ
34.4, 33.2, 32.4. ABC spin system with calculated 2J(AB) ) 68.1 Hz,
4J(AC) ) 2.2 Hz, and 2J(BC) ) 72.4 Hz. 1H NMR (-55 °C): δ 8.0-
1H, CH2Ph), 4.94 (d, 1H, CH2Ph), 4.92 (d, 1H, CH2Ph), 4.27 (“q”,
2H, N ) 13.7 Hz, P-CH2-P), 3.61 (m, 2H, P-CH2-P). 31P{1H} NMR
2
(-55 °C): δ 35.9, 33.1, 27.8. ABX spin system with J(AB) ) 70.0
2
4
Hz, J(AX) ) 67.3 Hz, and J(BX) ) 0 Hz. Anal. Calcd for C48H43-
(11) Bardaj´ı, M.; Laguna, A.; Orera, V. M.; Villacampa, M. D. Inorg. Chem.
1998, 37, 5125.
(12) Uso´n, R.; Laguna, A.; Vicente, J. J. Chem. Soc., Chem. Commun.
1976, 353.

3562 Inorganic Chemistry, Vol. 39, No. 16, 2000
Bardaj´ı et al.
Table 1. Crystal Data and Structure Refinement (Additional Values
Can Be Found in the Text)
radiation (λ ) 0.710 73 Å) on a Siemens Smart diffractometer; 4212
unique reflections (Rint ) 0.0519) were used for all calculations.
Absorption corrections were based on multiple scans (program SAD-
ABS); transmission factors are 0.509-0.999. The structure was refined
on F2 using the program SHELXL-97.13 H atoms were included using
a riding model. Special feature of refinement: The phenyl rings C21-
26 and C31-36 are disordered over two positions; the disorder
components were refined with idealized geometry. The structure could
also be refined without disorder in P21, but the temperature factors of
the corresponding rings were unsatisfactory. It is unlikely that the
alternative models could be distinguished on the basis of X-ray
measurements alone.
empirical formula
fw
temp (K)
cryst syst
space group
a (Å)
C32H29Au3Cl3P3
1203.71
173
monoclinic
P21/m
a ) 7.2032(10)
b ) 20.7396(10)
c ) 11.6983(10)
90
106.672(10)
90
1674.2(3)
2
2.388
13.52
1108
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
vol (Å3)
Z
Results and Discussion
density (calcd) (Mg/m3)
Synthesis and Spectroscopic Characterization. The starting
material, which allows us to introduce the S-donor ligands, is
the trinuclear gold(I) derivative recently described by us,11
namely, [(µ-dpmp)(AuCl)3] (dpmp ) bis(diphenylphosphinom-
ethyl)phenylphosphine), and whose X-ray crystal structure and
optical properties will be described later in this paper. The
reaction of this insoluble complex with sodium dithiocarbamate
salts in the appropriate molar ratio proceeds with dissolution
of the starting material to give a yellow solution from which
the corresponding product containing one, two, or three dithio-
carbamate ligands can be isolated (see Scheme 1). Chloride
anion can be replaced by triflate, a noncoordinating counterion
for gold, in complexes 1 and 2 by reaction with silver(I) triflate.
Complex 5 reacts with AuXtht (tht ) tetrahydrothiophene; X
) Cl, C6F5) to afford not the expected tetranuclear derivatives
but the trinuclear derivatives, by exchanging a dithiocarbamate
for X (Cl (1) or C6F5 (7)) and the insoluble polymeric gold(I)
derivative [AuS2CNMe2]n. Again, chloride can be substituted
by triflate to give complex 8 (see Scheme 1).
These derivatives are air- and moisture-stable yellow solids
at room temperature. Their IR spectra show absorptions due to
ν(Au-Cl)14 at 334 and 326 (1), 331 (2), 322 (3), 335, and 324
(4) cm-1, at 1257, 1223, and 638 cm-1 from triflate anions15
(3, 4, 8), and at 955 and 791 cm-1 from the pentafluorophenyl
groups16 (7, 8). Acetone solutions behave as 1:1 electrolytes
for complexes 3, 4, and 8 and as nonconducting for the others,
although showing some conductivity if chloride is the counte-
rion; this implies some equilibrium between neutral species,
arising from chloride coordination to gold(I), and 1:1 electro-
lytes, as will be described for the NMR experiments.
Fluxional behavior is observed in most of the 31P{1H} NMR
spectra at room temperature but can be stopped at low
temperature. This behavior could be produced in some cases
for the equilibria shown in Scheme 2; the dithiocarbamate can
bridge two gold centers associated with P1 and P2 phosphorus
(type I), the mirror image of type I (type II), or the dithiocar-
bamate bridging the terminal phosphine phosphorus P1 and P3
(type III), although the last one is less probable because the
phosphorus atoms could be far away. Another fact to consider
is the presence of chloride anion, which can coordinate to the
gold(I) centers. In Table 2 are summarized the chemical shifts
at room temperature and -55 °C, the numbering scheme P1,
P2, and P3 being as shown in Scheme 2. The phosphorus spectra
of 1-4 at low temperature show an ABX spin system as
expected for a type I (or type II) structure. For complexes 1
abs coeff (mm-1
F(000)
)
θ range for data
collection (deg)
index range
1.82-28.21
-8 e h e 9,
-21 e k e 27,
-15 e l e 14
refinement method
full-matrix least-squares on F2
4212/17/141
data/restraint/parameter
goodness-of-fit on F2
final R indices [I > 2σ(I)]
R indices (all data)
0.982
R1 a ) 0.0381, wR2 b ) 0.0839
R1 a ) 0.0518, wR2 b ) 0.0885
2.409 and -2.836
largest diffraction
peak and hole (e Å-3
)
2
a R1(F) ) ∑||Fo| - |Fc||/∑|Fo|. b wR2(F2) ) [∑{w(Fo - Fc2)2}/
2
2
∑∑{w(Fo )2}]0.5; w-1 ) σ2(Fo ) + (aP)2 + bP, where P ) [Fo2 + 2Fc2]/
3 and a and b are constants adjusted by the program.
6.9 (m, 25H, Ph), 4.57 (br, 1H, P-CH2-P), 3.77 (br, 2H, P-CH2-P),
3.51 (s, 3H, Me), 3.44 (s, 3H, Me), 2.64 (br, 1H, P-CH2-P). 19F NMR
(-55 °C): δ -78.7 (s, 3F, CF3), -115.0 (m, 2F, Fo), -158.1 (t, 1F,
Fp), -161.9 (m, 2F, Fm). 31P{1H} NMR (-55 °C): δ 33.1, 32.8, 30.8.
2
2
ABC spin system with calculated J(AB) ) 71 Hz, J(BC) ) 68 Hz,
4
and J(AC) ) 1 Hz. Anal. Calcd for C42H35Au3F8NO3P3S3: C, 32.9;
H, 2.3; N, 0.9; S, 6.25. Found: C, 32.65; H, 2.1; N, 0.9; S, 6.25. Λ:
101 ohm-1 cm2 mol-1
.
f. [Au3(µ-dpmp)(S2CNR2)3], R ) Me (9), CH2Ph (10). To a
dichloromethane suspension (20 mL) of [(µ-dpmp)(AuCl)3] (0.12 g,
0.1 mmol) was added NaS2CNR2 (0.3 mmol; R ) Me, 43 mg; R )
CH2Ph, 89 mg). The solid dissolved rapidly, and the resulting yellow
solution was stirred for about 2 h, then filtered through Celite and
concentrated to ca. 2 mL. Addition of diethyl ether (20 mL) afforded
complexes 9 and 10 as yellow solids, which were washed with diethyl
ether (2 × 5 mL). A second fraction was obtained by concentration
and precipitation with hexane. Yield of 9, 95%; mp, 125 °C (decomp).
1H NMR: δ 7.9-6.9 (m, 25H, Ph), 3.98 (br, 2H, P-CH2-P), 3.52
(br, 2H, P-CH2-P), 3.50 (s, 18H, Me). 31P{1H} NMR: δ 26.5 (m,
2P), 23.2 (m, 1P). 1H NMR (-55 °C): δ 7.8-6.8 (m, 25H, Ph), 3.8-
3.2 (m, 4H, P-CH2-P), 3.52 (s, 18H, Me). 31P{1H} NMR (-55 °C):
δ 25.7 (2P), 20.7 (1P). Anal. Calcd for C41H47Au3N3P3S6: C, 33.75;
H, 3.25; N, 2.9; S, 13.2. Found: C, 33.5; H, 3.6; N: 2.9; S: 13.05. Λ:
1
19 ohm-1 cm2 mol-1. Yield of 10, 88%; mp, 110 °C (decomp). H
NMR: δ 7.9-6.9 (m, 55H, Ph), 5.09 (s, 12H, CH2Ph), 3.84 (br, 2H,
P-CH2-P), 3.53 (br, 2H, P-CH2-P). 31P{1H} NMR: δ 26.1 (m, 2P),
1
22.6 (m, 1P). H NMR (-55 °C): δ 7.9-6.6 (m, 55H, Ph), 5.02 (s,
12H, CH2Ph), 4.92 (s, P-CH2-P), 3.50 (s, P-CH2-P), 2.90 (s,
P-CH2-P). 31P{1H} NMR (-55 °C): δ 25.9 (2P), 21.0 (1P). A2B
spin system with 2J(AB) ) 63.3 Hz. Anal. Calcd for C77H71-
Au3N3P3S6: C, 48.3; H, 3.75; N, 2.2; S, 10.05. Found: C, 48.1; H,
3.6; N, 2.25; S, 9.85. Λ: 18 ohm-1 cm2 mol-1
.
(13) Sheldrick, G. M. SHELXL 97: A Program for Crystal Structure
Refinement; University of Go¨ttingen: Go¨ttingen, Germany, 1997.
(14) Uso´n, R.; Laguna, A.; Laguna, M.; Fraile, M. N.; Jones, P. G.;
Sheldrick, G. M. J. Chem. Soc., Dalton Trans. 1986, 291.
(15) Stang, P. J.; Huang, Y.; Arif, A. M. Organometallics 1992, 11, 231.
(16) Uso´n, R.; Laguna, A.; Garc´ıa, J.; Laguna, M. Inorg. Chim. Acta 1979,
37, 201.
Crystal Structure Determination of [(µ-dpmp)(AuCl)3]. Crystal
data and details of data collection and structure refinement of [(µ-dpmp)-
(AuCl)3] are given in Table 1. Crystals of [(µ-dpmp)(AuCl)3] were
grown from dimethyl sulfoxide. A colorless plate ca. 0.70 mm × 0.26
mm × 0.04 mm was mounted in an inert oil on a glass fiber. A total
of 11 050 intensities were registered using monochromated Mo KR

Gold(I) Complexes
Inorganic Chemistry, Vol. 39, No. 16, 2000 3563
Scheme 1a
a (i) +NaS2CNMe2 - NaCl; (ii) +AgCF3SO3 - AgCl; (iii) +2NaS2CNMe2 - 2NaCl; (iv) +AuCltht - (1/n)[AuS2CNMe2]n; (v) +Au(C6F5)tht
- (1/n)[AuS2CNMe2]n; (vi) +AgCF3SO3 - AgCl; (vii) +3NaS2CNMe2 - 3NaCl.
Scheme 2
Table 2. 31P{1H} NMR Data in CDCl3 Solutiona
different from those of 3 and 4. Consequently, such a structure
is unlikely. P2 becomes chiral, and therefore, these complexes
should be racemic mixtures. It is also clear that chloride is not
an innocent counterion because P2 is shifted by ca. 1.6 ppm (in
1 and 2 compared to 3 and 4) even at -55 °C. This chloride
coordination to gold is observed in the crystal structure of the
related derivative [Au3(µ-dpmp)2Cl2]Cl.17 At room temperature
two broad signals are observed for 1 and 2, while for 3 two
broad signals 3.5 ppm farther apart are found, and for 4 an ABX
spin system is already observed, showing the effect of changing
the counterion, chloride versus triflate, on the equilibria. In the
31P{1H} NMR spectrum of 5 only a broad signal is observed
whereas at low temperature an AB2 spin system is found; for 6
the AB2 spin system is already observed at room temperature,
which indicates (by comparison of 3 vs 4) that the greater steric
requirements of benzyl (CH2Ph) versus methyl can, at least
partially, hinder the fluxionality. These spectra and the non-
complex
δ (18°C) P1, P2, P3
δ (-55°C) P1, P2, P3
1
2
3
4
5
6
7
8
9
35.7, 32.9b
33.5, 36.5, 27.4
33.7, 37.6, 28.0
33.3, 35.0, 27.9
33.1, 35.9, 27.8
32.0, 34.5, 32.0
32.4, 35.9, 32.4
33.7, 34.1, 30.8
33.1, 32.8, 30.8
25.7, 20.7, 25.7
25.9, 21.0, 25.9
36.2, 32.6b
35.1, 29.3b
35.5, 34.6, 28.9
33.6b
33.3, 35.2, 33.3
35.0, 33.8, 32.6
34.4, 33.2, 32.4
26.5, 23.2, 26.5
26.1, 22.6, 26.1
10
a P1, P2, P3 assigned as in Scheme 2. Coupling constants and spin
system are described in Experimental Section. b There are only broad
signals, so the corresponding values are given, but it is not possible to
assign to P1, P2, P3.
and 2 a structure with a monodentate dithiocarbamate bound to
P1 and two P-Au-Cl units could be produced. However, for
this triphosphine, δ for the P-Au-Cl unit should occur near
23 ppm11 and the 31P NMR spectra would be considerably
(17) Xiao, H.; Weng, Y.; Wong, W.; Mak, T. C. W.; Che, C. J. Chem.
Soc., Dalton Trans. 1997, 221.

3564 Inorganic Chemistry, Vol. 39, No. 16, 2000
Bardaj´ı et al.
conducting behavior in acetone solution do not permit the
assignment of a unique reasonable structure, and we have been
unable to grow single crystals. The 31P{1H} NMR spectra of 7
and 8 show ABC spin systems at room temperature and at low
temperature, which can be explained with a type I arrangement
(as for complexes 1 and 2 a structure with a monodentate
dithiocarbamate and two gold-chloride units can be discarded),
and indicate again the importance of the steric requirements
around the gold center. As observed previously, chloride shifts
P2 1.3 ppm at low temperature and 0.6 ppm at room temperature
(8 versus 7) while P1 is shifted 0.6 ppm at both temperatures.
Again, these complexes should be racemic mixtures after P2
becomes chiral. Finally the 31P{1H} NMR spectra of 9 and 10
show two broad signals with an integration area ratio of 2:1;
only for 10 at low temperature can the typical A2B spin system
characteristic of [(µ-dpmp)(AuL)3] complexes be observed.11
The 19F NMR spectra of 7 and 8 show the presence of one
1
pentafluorophenyl group as expected. The H NMR spectra at
Figure 1. Molecular structure of complex [(µ-dpmp)(AuCl)3]. Atom
room temperature usually involve two multiplets or two broad
signals due to the four diastereotopic methylene protons of the
triphosphine (see Experimental Section). For complexes 4 and
8 four signals are observed, which are pseudoquartets by
coupling with the two neighboring phosphorus and the vicinal
radii are arbitrary.
Table 3. Selected Bond Lengths [Å] and Angles [deg]a
Au(1)-P(1)
Au(1)-Cl(1)
Au(1)-Au(2)
2.248(2)
2.308(2)
3.3709(4)
Au(2)-P(2)
Au(2)-Cl(2)
2.2411(17)
2.3036(18)
1
proton. Therefore, in a H{31P} NMR experiment for these
complexes, pseudoquartets became doublets by coupling with
the vicinal proton. For complex 7, three signals (integral 1:2:1)
are observed and a 1H{31P} NMR experiment confirms that two
methylene protons have the same chemical shift as already
observed in [Au4(µ-dpmp)2Cl2](CF3SO3)2 (here, the four protons
have the same chemical shift at room temperature).11 In the 1H
NMR spectra the number of signals for the dithiocarbamate
substituents is also important. Complexes 1-3, 5-7, and 9 and
10 show only one resonance at room temperature, while 4 shows
a multiplet (for CH2Ph) and 8 two resonances (for Me), as
expected because their 31P{1H} NMR spectra show asymmetric
environments for these. At low temperature, the 1H NMR spectra
of complexes 1, 3, 7, and 8 show two resonances for Me and
the spectra of 2 and 4 multiplets for CH2Ph while for 5, 6 and
9, 10 only singlets are observed, which cannot always be
interpreted as three coordination of gold(I), as has been shown
in other cases.18
P(1)-Au(1)-Cl(1)
P(1)-Au(1)-Au(2)
Cl(1)-Au(1)-Au(2) 108.75(3) P(2)-Au(2)-Au(1)
P(1)-Au(1)-Au(2)#1 73.88(3) Cl(2)-Au(2)-Au(1)
Cl(1)-Au(1)-Au(2)#1 108.75(3)
173.78(8) Au(2)-Au(1)-Au(2)#1 119.603(14)
73.88(3) P(2)-Au(2)-Cl(2)
176.20(7)
73.62(4)
104.67(5)
a Symmetry transformation used to generate equivalent atoms: (#1)
1
x, -y + /2, z.
phenylarsine (3.131(1), 3.138(1) Å),20 and [(µ-TP)(AuCl)3] (TP
) bis[2-(diphenylphosphino)phenylene]phenylphosphine (2.9671-
(4), 2.9250(4) Å)),21 but it is of the same order as in [(µ-dppm)-
(AuCl)2] (dppm ) bis(diphenylphosphino)methane (3.351(2)
Å)).22 The intergold angle is greater than in the tetranuclear
[Au4(µ-dpmp)2Cl2](CF3SO3)2 (112.25 (3)°) or in [(µ-dpma)-
(AuCl)3] (110.9°) but smaller than in [(µ-TP)(AuCl)3] (126.88-
(2)°), in [Au3(µ-dpmp)2Cl2]Cl (149.56(9)°(1)), or in [Au3(µ-
dpmp)2][SCN]3 (167.21(2)°).
The P-Au-Cl units are almost linear (173.78(8)° and
176.20(7)°, respectively). Au-Cl bond distances (2.308(2) and
2.3036(18) Å) are as expected and compare well with those
found in the related polynuclear complexes mentioned
above.11,20-22 Au-P bond lengths (2.248(2) and 2.2411(17) Å)
are similar to those found in [(µ-dpma)(AuCl)3] (2.234(4),
2.227(4) Å), in [(µ-TP)(AuCl)3] (2.228(2)-2.243(2) Å), and or
in [(µ-dppm)(AuCl)2] (2.238(5) Å) but shorter than that found
in [Au4(µ-dpmp)2Cl2](CF3SO3)2 (2.326(4) Å trans to P; 2.264-
(4) Å trans to Cl), in [Au3(µ-dpmp)2Cl2]Cl (2.32(1)-2.35(1)
Å), and in [Au3(µ-dpmp)2][SCN]3 (2.295(3)-2.312(3) Å) prob-
ably as a consequence of the lesser trans influence of Cl.
Photophysical Characterization. The optical absorption
spectra in dichloromethane were measured for all the complexes.
The spectra of complexes 1, 3, 5, and 8 are plotted in Figure 2.
The main features are the following: (a) an intense absorption
at 230 nm due to phenyl phosphine rings;23 (b) an absorption
at 270 nm (for methyl dithiocarbamate derivatives 1, 3, 5, 7-9)
The LSIMS mass spectra show the peak corresponding to
[M-X]+ at m/z (complex, % abundance, X): 1252 (1, 100, Cl;
3, 100, CF3SO3), 1404 (2, 40, Cl; 4, 100, CF3SO3), 1337 (5,
25, Cl; 9, 20, S2CNMe2), 1641 (6, 100, Cl; 10, 100, S2CN-
(CH2Ph)2), and 1384 (7, 25, Cl; 8, 100, CF3SO3).
Crystal Structure of [(µ-dpmp)(AuCl)3]. The geometry of
this trinuclear derivative was confirmed by an X-ray diffraction
study, although the phenyl rings C21-26 and C31-36 are
disordered. The molecular structure is shown in Figure 1, with
selected bonds and angles in Table 3. The molecule possesses
mirror symmetry, with Au1, Cl1, P1, and the ring C11-16
lying in the mirror plane. The gold atoms display aurophilic
contacts with a gold-gold distance Au1‚‚‚Au2 of 3.3709(4) Å
and an angular geometry (Au2‚‚‚Au1‚‚‚Au2′ 119.603(14)°) This
distance is longer than in the related tetranuclear derivative
[Au4(µ-dpmp)2Cl2](CF3SO3)2 (3.1025(11), 3.1059 (14) Å)11 or
in the trinuclear derivatives [Au3(µ-dpmp)2Cl2]Cl (2.946(3),
2.963(3) Å)17 [Au3(µ-dpmp)2][SCN]3 (3.0137(8), 3.0049(8) Å),19
[(µ-dpma)(AuCl)3] (dpma ) bis[(diphenylphosphino)methyl]-
(20) Balch, A. L.; Fung, E. Y.; Olmstead, M. M. J. Am. Chem. Soc. 1990,
112, 5181.
(18) Bardaj´ı, M.; Blasco, A.; Jime´nez, J.; Jones, P. G.; Laguna, A.; Laguna,
M.; Mercha´n, F. Inorg. Chim. Acta 1994, 223, 55.
(19) Li, D.; Che, C.; Peng, S.; Liu, S.; Zhou, Z.; Mak, T. C. W. J. Chem.
Soc., Dalton Trans. 1993, 189.
(21) Zank, J.; Schier, A.; Schmidbaur, H. J. Chem. Soc., Dalton Trans.
1998, 323.
(22) Schmidbaur, H.; Wohlleben, A.; Wagner, F.; Orama, O.; Huttner, G.
Chem. Ber. 1977, 110, 1748.

Gold(I) Complexes
Inorganic Chemistry, Vol. 39, No. 16, 2000 3565
ature, the maxima being located in the range 525-560 nm.
Complexes 3 and 4 are strongly luminescent, whereas 5 and 6
are less intense, and finally, 9 and 10 do not emit. Excitation
maxima are observed from 430 to 470 nm.
At low temperature all the complexes except 9 are lumines-
cent and in all cases luminesce much more intensely than at
room temperature, as expected because of the decrease of
nonradiative thermal activated processes. Even complex [(µ-
dpmp)(AuCl)3], which was reported by us as nonemitting at
room temperature, becomes strongly luminescent at 77 K, the
excitation and emission frequencies (350 and 465 nm, respec-
tively) being very different from those of the other complexes,
probably because of the different nature of the electronic
transition involved. In this case, ligand base transitions could
be involved as described in [{AuXPPhMe2}n] (X ) Cl, Br, I;
n ) 2, 3)25 or in AuX(ER3) (X ) Cl, Br; E ) P, As)
complexes.26 The emissions have the maximum in the range
520-580 nm, the frequency growing gradually with the number
of dithiocarbamate ligands: 520-540 nm for derivatives
containing one (slightly blue-shifted versus room temperature
except 8), 565 nm for derivatives with two (slightly red-shifted
versus room temperature), and 580 nm with three of these
ligands. Maxima in the excitation spectra are also different,
depending on the number of dithiocarbamate: 415-425 nm for
derivatives with one dithiocarbamate (1-4, 7-8), 440-460 nm
with two (5 and 6), and 455 nm with three (10); all of them are
blue-shifted versus room temperature. The intensity follows the
same order as at room temperature; the most intense are 3, 4,
then 1, 2, 5, 7, 8, and [(µ-dpmp)(AuCl)3], followed by 6 and
finally 10 (9 does not emit).
The effect of exchanging the coordinating chloride for the
noncoordinating triflate at room and low temperature (1, 2, 7
versus 3, 4, 8, respectively) is a blue shift of the emission max-
ima (10-20 nm), while the effect of replacing chloride by pen-
tafluorophenyl (1, 3 versus 7, 8) is a shift from -5 to 10 nm.
It is also important to note that sodium dithiocarbamate salts
and the tris(phosphine) dpmp do not emit in the visible range.
In luminescent mononuclear or dinuclear phosphine-thiolate-
gold(I) complexes, these emissions have been assigned to LMCT
transitions that in some cases can be shifted by the gold-gold
interactions, the emission maxima being between 480 and 702
nm.8-10 On the other hand, the nature of luminescence in most
gold(I) complexes with a tris(phosphine) or a bis(phosphine)
has been described as related to metal-metal interactions, being
therefore MC transitions.17,19,27 In our case both kinds of
transitions are plausible; the emission is found to be wavelength-
dependent for derivatives 3, 4, 7, 8, and [(µ-dpmp)(AuCl)3] at
low temperature, with higher energy emission seen for higher
energy excitation (excitation spectra is also wavelength-depend-
ent for these derivatives). In Figure 3 we can observe the
emission spectrum of 4 where the emission maxima go from
500 to 540 nm with excitation frequency from 380 to 460 nm,
the maximum of intensity being at 520 nm. A wavelength-
dependent emission spectrum was recently described for the
dinuclear gold(I) derivative [Au(S2(CN(C5H11)2]2 and tentatively
explained by a distribution of aggregates in the glass (it was
measured at 77 K) with gold(I) chains of different length
absorbing and emitting at different wavelengths.6 We can also
propose a nonhomogeneous system arising from a multiple
Figure 2. Absorption spectra in dichloromethane solution of complexes
1, 3, 5, and 8.
Table 4. Emision and Excitation Maxima (in nm) Measured for
Complexes 1-10 and [(µ-dpmp)(AuCl)3] at 298 and 77K
excitation emission excitation
289 K 298 K 77 K
emission
77 K
complex
[(µ-dpmp)(AuCl)3]
350
465, 520 (sh)
1
455
455
540, 545 405 (sh), 535
415
2
3
4
545
405 (sh), 535
415
405 (sh), 520
415
405 (sh), 520
415
440 (sh), 530
455
440 (sh), 530
455
5
6
7
8
455
470
455
430
540, 555 440, 455 565
560
545
460
565
415, 425 540
490 (sh), 405 (sh), 480 (sh),
525 415 530
455 580
10
or 277 nm (for benzyl dithiocarbamate derivatives 2, 4, 6, 10),
which becomes more intense when the proportion of dithiocar-
bamate grows and has previously been assigned to these
ligands;10 (c) shoulders around 300-305 and 330 nm for
derivatives 1-4, 7 (in which the absorption at 330 nm is
relatively more intense), and 8 (in which the absorption at 300
nm is relatively more intense), while for complexes 5-6 and
9-10 these absorptions are not clearly seen probably because
they are weak and eclipsed by the more intense 270 or 277 nm
peak; there is absorption up to around 400 nm for all the
complexes. These shoulders can be assigned to LMCT (S f
Au) and/or to MC transitions as reported for other mononuclear
or dinuclear phosphine-thiolate-gold(I) derivatives10,24 and for
trinuclear tris(phosphine)gold(I) derivatives.11,17,19 Solid samples
in KBr pellets show similar, but very broad and ill-defined,
absorption bands.
The solid-state emission and excitation spectra at 298 and
77 K have been determined, and the results are summarized in
Table 4. Optimal excitation was observed at the low-energy side
of the absorption bands, due presumably to autoabsorption of
the emitting light. Complexes 1-8 luminesce at room temper-
(25) Weissbart, B.; Toronto, D. V.; Balch, A. L.; Tinti, D. S. Inorg. Chem.
1996, 35, 2490.
(26) Larson, L. J.; McCauley, E. M.; Weissbart, B.; Tinti, D. S. J. Phys.
Chem. 1995, 99, 7218.
(27) Field, J. S.; Grieve, J.; Haines, R. J.; May, N.; Zulu, M. M. Polyhedron
1998, 17, 3021.
(23) King, C.; Wang, J.-C.; Khan, M. N. I.; Fackler, J. P., Jr. Inorg. Chem.
1989, 28, 2145.
(24) Narayanaswamy, R.; Young, M. A.; Parkhurst, E.; Ouellette, M.; Kerr,
M. E.; Ho, D. M.; Elder, R. C.; Bruce, A. E.; Bruce, M. R. M. Inorg.
Chem. 1993, 32, 2506.

3566 Inorganic Chemistry, Vol. 39, No. 16, 2000
Bardaj´ı et al.
the fact that the tris(phosphine) is a flexible ligand and that
different interactions may be possible with several geometries
for the gold atoms.
The red shift at low temperature, related to the number of
dithiocarbamate ligands, can be explained in a similar way as
the reported red shift in mononuclear phosphine-thiolate-gold-
(I) derivatives, arising from gold(I)-gold(I) interactions that
perturb the orbital energies involved in the LMCT transition,8
mainly stabilizing the empty gold orbital and destabilizing the
filled sulfur orbital. In our case, raising the number of dithio-
carbamate ligands that can interact with the gold(I) centers to
give tricoordinated gold(I) leads to a splitting of orbitals and
consequently to a red shift of the emission maxima.
Acknowledgment. We thank the Direccio´n General de
Investigacio´n Cient´ıfica y Te´cnica (Project PB97-1010-C02-
01) and the Fonds der Chemischen Industrie for financial
support. We also thank Dr. V. Orera and Dr. J. Galba´n
(Universidad de Zaragoza, Spain) for helpful discussions.
Figure 3. 77 K solid-state emission spectra of complex 4 with
excitation frequency going from 380 nm (a) to 460 nm (i) in 10 nm
increments.
Supporting Information Available: X-ray crystallographic files
in CIF format for complex [(µ-dpmp)(AuCl)3]. This material is available
free of charge via the Internet at http://pubs.acs.org.
excitation state due to the influence of gold(I) interactions on
ligand to metal charge-transfer excited states, complicated by
IC9914342