Synthesis and characterization of sulfur-ylide complexes of gold(I). Observance of intermolecular gold(I) - Gold(I) interactions in solution

Article abstract of DOI:10.1021/om960748j

Under PTC/OH^- (PTC = phase-transfer catalysis) conditions, the reaction of Au₂(dppm)Cl₂ (dppm = l,l-bis(diphenylphosphino)methane) with [Me₂S(O)NMe₂]BF₄ produces a greenish luminescent compound [Au₂(dppm)[(CH₂)₂S(O)NMe₂]]BF ₄, 1, and a colorless tetranuclear compound [Au₄(dppm)(Ph₂PCHPPh₂)[(μ-CH)(CH ₂)S(O)NMe₂]]BF₄, 2. Both compounds 1 and 2 also can be synthesized from [Au₄(dppm)(Ph₂PCHPPh₂)Cl₃], 3, which can be produced simply by the reaction of Au₂(dppm)Cl₂ with OH^- in the presence of a PTC. For Au₂(dppe)Cl₂ (dppe = 1,2-bis(diphenylphosphino)ethane) and Au₂(dmpm)Cl₂ (dmpm = 1,1-bis(dimethylphosphino)methane), only [Au₂(dppe)[(CH₂)₂S(O)NMe₂]]PF ₆, 4, and [Au₂(dmpm)[(CH₂)₂S-(O)NMe₂]]BF ₄, 5, are obtained as the major product, respectively. Compounds 1-4 are characterized by single-crystal X-ray analyses. Two C₂-related cations of 1 are packed in a row with the intermolecular Au - Au distance (2.959 A?) shorter than the intramolecular Au - Au distance (2.984 A?). Compound 2 has one of the ylide carbon atoms bridging two gold(I) atoms. The tetragold cluster of 3 is formed by an Au - C linkage between [ClAu(μ-Ph₂PCH₂-PPh₂)Au]⁺ and [ClAu(μ-Ph₂PCHPPh₂)AuCl]^-. The digold cation of 4 is a nine-membered dimetallocycle. In acetonitrile solution, dimerization of 1 and 5 through intermolecular Au - Au interaction occurs as evidenced by concentration-dependent absorption spectroscopic studies. Concentration-dependent absorption spectra of 1 and 5 suggest that equilibriums between the monomer and dimer exist with equilibrium constants of 33 ± 9 and 52 ± 7 M^-1 in acetonitrile, respectively. Digold(I) compounds 1, 4, and 5 luminesce in the solid state.

Full text of DOI:10.1021/om960748j

Organometallics 1997, 16, 901-909
901
Syn th esis a n d Ch a r a cter iza tion of Su lfu r -Ylid e
Com p lexes of Gold (I). Obser va n ce of In ter m olecu la r
Gold (I)-Gold (I) In ter a ction s in Solu tion
Da-Fa Feng, Shaw Shiah Tang, C. W. Liu, and Ivan J . B. Lin*
Department of Chemistry, Fu-J en Catholic University, Hsinchuang, Taipei 242, Taiwan
Yuh-Sheng Wen and Ling-Kang Liu*
Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan
Received August 28, 1996X
Under PTC/OH- (PTC ) phase-transfer catalysis) conditions, the reaction of Au2(dppm)Cl2
(dppm ) 1,1-bis(diphenylphosphino)methane) with [Me2S(O)NMe2]BF4 produces a greenish
luminescent compound [Au2(dppm)[(CH2)2S(O)NMe2]]BF4, 1, and a colorless tetranuclear
compound [Au4(dppm)(Ph2PCHPPh2)[(µ-CH)(CH2)S(O)NMe2]]BF4, 2. Both compounds 1 and
2 also can be synthesized from [Au4(dppm)(Ph2PCHPPh2)Cl3], 3, which can be produced
simply by the reaction of Au2(dppm)Cl2 with OH- in the presence of a PTC. For Au2(dppe)Cl2
(dppe ) 1,2-bis(diphenylphosphino)ethane) and Au2(dmpm)Cl2 (dmpm ) 1,1-bis(dimethyl-
phosphino)methane), only [Au2(dppe)[(CH2)2S(O)NMe2]]PF6, 4, and [Au2(dmpm)[(CH2)2S-
(O)NMe2]]BF4, 5, are obtained as the major product, respectively. Compounds 1-4 are
characterized by single-crystal X-ray analyses. Two C2-related cations of 1 are packed in a
row with the intermolecular Au-Au distance (2.959 Å) shorter than the intramolecular Au-
Au distance (2.984 Å). Compound 2 has one of the ylide carbon atoms bridging two gold(I)
atoms. The tetragold cluster of 3 is formed by an Au-C linkage between [ClAu(µ-Ph2PCH2-
PPh2)Au]+ and [ClAu(µ-Ph2PCHPPh2)AuCl]-. The digold cation of 4 is a nine-membered
dimetallocycle. In acetonitrile solution, dimerization of 1 and 5 through intermolecular Au-
Au interaction occurs as evidenced by concentration-dependent absorption spectroscopic
studies. Concentration-dependent absorption spectra of 1 and 5 suggest that equilibriums
between the monomer and dimer exist with equilibrium constants of 33 ( 9 and 52 ( 7 M-1
in acetonitrile, respectively. Digold(I) compounds 1, 4, and 5 luminesce in the solid state.
In tr od u ction
and the use of these compounds in organic6 and organo-
metallic reactions led us to this study.
One of the most intriguing characteristics of the
metal-ylide complexes is that the rich coordination
modes of ylides can provide a variety of structural
information.1 According to the latest review article2
written by Kaska and Ostoja Starzewski, more than 13
different coordination modes have been observed in the
phosphorus-ylide-metal complexes. For example, the
ylidic carbon atom can act as a bridging atom to form
homo- and/or heterometal clusters.3 In contrast to the
numerous examples known for the phosphorus-ylide-
metal complexes,1-4 examples of a similar bonding mode
for the sulfur-ylide complexes are extremely rare.5,14 The
potential richness of sulfur-ylide compounds in bonding
Earlier we have used the phase-transfer catalysis
(PTC) technique to synthesize sulfur-ylide complexes of
palladium and platinum.7 Lately we have extended the
technique to the synthesis of gold compounds.8 Not only
is this technique is simple, but also the synthesis of
sulfur-ylide complexes under PTC conditions may be
relevant to the biosynthesis of presqualene pyrophos-
phate in water.9 In our preliminary report,8 we have
(4) (a) Cerrada, E.; Gimeno, M. C.; J imenez, J .; Laguna, A.; Laguna,
M. Organometallics 1994, 13, 1470. (b) Bardaji, M.; Gimeno, M. C.;
J ones, P. G.; Laguna, A.; Laguna, M. Organometallics 1994, 13, 3415.
(c) Bardaji, M.; J ones, P. G.; Laguna, A.; Laguna, M. Organometallics
1995, 14, 1310.
(5) (a) Fackler, J . P., J r.; Paparizos, C. J . Am. Chem. Soc. 1977, 99,
2363. (b) Stein, J .; Fackler, J . P., J r.; Paparizos, C.; Chen, H.-W. J .
Am. Chem. Soc. 1981, 103, 2192. (c) Yamamoto, Y. Bull. Chem. Soc.
J pn. 1987, 60, 1189. (d) Konno, H.; Yamamoto, Y. Bull. Chem. Soc.
J pn. 1987, 60, 2561.
(6) (a) Corey, E. J .; Chaykovsky, M. J . Am. Chem. Soc. 1965, 87,
1353. (b) Trost, B. M.; Melvin, L. S. Sulfur Ylide; Academic Press:
New York, 1966.
(7) (a) Lin, I. J . B.; Lai, H. Y. C.; Wu, S. C. J . Organomet. Chem.
1986, 309, 225. (b) Wu, R. F.; Lin, I. J . B.; Lee, G. H.; Cheng, M. C.;
Wang, Y. Organometallics 1990, 9, 126. (c) Lai, J . S.; Wu, R. F.; Lin,
I. J . B.; Cheng, M. C.; Wang, Y. J . Organomet. Chem. 1990, 393, 433.
(8) Lin, I. J . B.; Liu, C. W.; Liu, L.-K.; Wen, Y.-S. Organometallics
1992, 11, 1447.
X Abstract published in Advance ACS Abstracts, February 1, 1997.
(1) (a) J ohnson, A. W. Ylides and Imines of Phosphorus; J . Wiley &
Sons: New York, 1993. (b) Kaska, W. C. Coord. Chem. Rev. 1983, 48,
1.
(2) (Kaska, W. C.; Ostoja Starzewski, K. A. In Ylides and Imines of
Phosphorus; J . Wiley & Sons: New York, 1993; Chapter 14, p 485.
(3) (a) Churchill, M. R.; Young, W. J . Inorg. Chem. 1981, 20, 382.
(b) Uedelhoven, W.; Neugebaure, D.; Kreissl, F. R. J . Orgamet. Chem.
1981, 217, 183. (c) J effery, J . C.; Navarro, R.; Razay, H.; Stone, F. G.
A. J . Chem. Soc., Dalton Trans. 1981, 2471. (d) Konig, H.; Menu, M.
J .; Dartiguenave, M.; Dartiguenave, Y.; Klein, H. F. J . Am. Chem. Soc.
1990, 112, 5351. (e) Cramer, R. E.; Maynard, R. B.; Gilje, J . W. J .
Am. Chem. Soc. 1978, 100, 5562.
(9) Cohen, T.; Herman, G.; Chapman, T. M.; Kuhn, D. J . Am. Chem.
Soc. 1974, 96, 5627.
S0276-7333(96)00748-0 CCC: $14.00 © 1997 American Chemical Society

902 Organometallics, Vol. 16, No. 5, 1997
Feng et al.
Sch em e 1
demonstrated that the PTC technique enables us to
synthesize an annular eight-membered digold(I) sulfur-
ylide complex and a tetranuclear gold(I) sulfur-ylide
complex. The former dimerizes in the solid state with
the intermolecular Au-Au distance shorter than the
intramolecular Au-Au distance, and the latter has one
of the ylidic carbon atoms bridging two Au(I) atoms.
Recently, the influence of Au-Au interactions on the
photophysical and -chemical properties of gold(I) com-
pounds has received much attention.10 Annular gold(I)
complexes, which are eight-membered rings, have been
of special interest because the constrained Au-Au
interactions may enhance photoluminescence.11 The
digold(I) sulfur-ylide complex 1 reported in this work
indeed shows a bright green luminescence in the solid
under daylight. The bright green emission in the solid
state is probably due to the linear Au4 unit. It would
be of interest to compare the nature of Au-Au interac-
tions with that in the eight-membered and that in the
nine-membered annular digold(I) compounds.
Resu lts a n d Discu ssion
Syn t h esis. Under various PTC/OH- conditions,
reaction of Au2(dppm)Cl2 (dppm ) 1,1-bis(diphenylphos-
phino)methane) with [Me2S(O)NMe2]BF4 produced a
greenish luminescent compound [Au2(dppm)[(CH2)2S-
(O)NMe2]]BF4, 1, a colorless tetranuclear compound
[Au4(dppm)(Ph2PCHPPh2)[(µ-CH)(CH2)S(O)NMe2]]-
BF4, 2, and another colorless tetranuclear compound
[Au4(dppm)(Ph2PCHPPh2)Cl3], 3 (see Scheme 1). For-
mation of compound 1 was favored by the reaction of
Au2(dppm)Cl2 with a 5-fold excess of sulfoxonium salt
and NaOH. Compound 2 was the favorable product
when the base was increased to a 100-fold excess. When
the molar ratios of sulfoxonium salt, NaOH, and Au2-
(dppm)Cl2 were 1.0:0.5:1.0, the major product was
compound 3. Compound 3 could also be produced by
the reaction of Au2(dppm)Cl2 with OH- in the presence
of a PTC. When Au2(dppe)Cl2 (dppe ) 1,2-bis(di-
phenylphosphino)ethane) instead of Au2(dppm)Cl2 was
reacted with [Me2S(O)NMe2]BF4 under PTC/OH- condi-
tions, only [Au2(dppe)[(CH2)2S(O)NMe2]]PF6, 4, was
obtained as the major product after treatment with
NH4PF6 (see Scheme 1).
It appears that compounds 1, 4, and 5 are formed
from the direct reaction of Au2[R2P(CH2)nR2]Cl2 (R )
Ph, Me; n ) 1 or 2) with sulfur ylides. Under PTC/OH-
conditions, deprotonation of the [Me2S(O)NMe2]+ in the
aqueous phase produces sulfur ylides. The ylide will
then diffuse into the organic layer to react with
Au2(dppm)Cl2, Au2(dppe)Cl2, or Au2(dmpm)Cl2 (dmpm
) 1,1-bis(dimethylphosphino)methane). The monoden-
tate Au(I) ylide intermediates undergo transylidation
to produce 1, 4, and 5. This type of reaction has been
successfully demonstrated in our previous work,7 where
the sulfur ylide normally acts as a monodentate or a
chelating ligand in palladium(II) and platinum(II) com-
plexes. Here the sulfur ylide acts as a bidentate
Here we report the details of the synthesis and
characterization of the eight- and nine-membered di-
gold(I) complexes of sulfur ylides together with two
tetranuclear Au(I) compounds. The photoluminescent
properties of digold(I) complexes are included. Interest-
ingly, we are able to show that molecular association of
eight-membered annular digold(I) compounds occurs in
solution.
(10) (a) Assefa, Z.; McBurnett, B. G.; Staples, R. J .; Fackler, J . P.,
J r.; Assmann, B.; Angermaier, A. K.; Schmidbaur, H. Inorg. Chem.
1995, 34, 75. (b) Shieh, S. J .; Hong, X.; Peng, S. M.; Che, C. M. J .
Chem. Soc., Dalton Trans. 1994, 3067. (c) Yam, V. W. W.; Choi, S. W.
K. J . Chem. Soc., Dalton Trans. 1994, 2057. (d) Yam, V. W. W.; Lee,
W. K. J . Chem. Soc., Dalton Trans. 1993, 2097. (e) Yam, V. W. W.;
Lai, T. F.; Che, C. M. J . Chem. Soc., Dalton Trans. 1990, 3747. (f)
Che, C. M.; Kwong, H. L.; Yam, V. W. W.; Poon, C. K. J . Chem. Soc.,
Dalton Trans. 1990, 3215.
(11) (a) King, C.; Wang, J . C.; Khan, Md. N. I.; Fackler, J . P., J r.
Inorg. Chem. 1989, 28, 2145. (b) Che, C. M.; Kwong, H. L.; Yam, V.
W. W.; Cho, K. C. J . Chem. Soc., Chem. Commun. 1989, 885.

Gold(I) Sulfur-Ylide Complexes
Organometallics, Vol. 16, No. 5, 1997 903
bridging ligand. Attempts to isolate the monodentate
Au(I) ylide intermediates by methods other than the
PTC technique have not been successful to date. In fact
this type of complex has been reported only on two
occasions.5c,12 The monodentate Au(III) sulfur-ylide
complex has been structurally characterized by Fackler
et al.5a,b
formation of 1 or 2 from 3. In the formation of 1 from
3, the Au-C bond in 3 is cleaved in the presence of
sulfur ylide. That the deprotonation of a ylidic meth-
ylene proton producing an ylidic anion which coordi-
nates to another metal atom is unknown for metal
sulfur-ylide complexes prior to this work. Only recently
has the formation of a hypercoordinate ylidic carbon
atom from the stepwise deprotonation of ylidic methyl-
ene protons with acac followed by metalation with
Au(PPh3)+ units been communicated.12 The remarkable
ease of formation of multinuclear gold compounds has
been attributed to the auriophilicity.17
Formation of 3 from Au2(dppm)Cl2 under PTC/OH-
conditions is believed to be a major reaction; further
reaction of 3 with sulfur ylide yields 1 and 2. Another
major reaction is likely the direct reaction of Au2(dppm)-
Cl2 with sulfur ylide to produce 1. This reaction is also
the only major reaction in the reaction of sulfur ylide
with Au2(dppe)Cl2 in which dppe can not be deproton-
ated under PTC/OH- conditions. Although 2 can be
produced either from 1 or 3, the simple product obtained
from 3 and the complicated products obtained from 1
suggest that the most likely route of formation of 2 is
through 3.
Normally we used the trimethyloxosulfonium salt as
a sulfur-ylide precursor in the synthesis of palladium(II)
and platinum(II) complexes under PTC conditions.7
However we did not succeed in the formation of Au(I)
sulfur-ylide compounds using the same ylide precursor.
Fortunately, the N,N′-dimethyl-substituted dimethyl-
sulfoximine salt gave satisfactory results. Schmidbaur
et al. pioneeringly used the sulfoximine salt as a sulfur-
ylide precursor to react with main group elements,13 the
reaction being carried out under drastically anaerobic
conditions. Weber also reported a similar reaction in
the formation of a chromium compound.14 Several
Pd(II) and Pt(II) sulfur-ylide complexes with the same
type of ylide also have been isolated under PTC condi-
tions. The details will be reported in elsewhere. It is
interesting to note that Vicente et al. successfully
synthesized Au(I) sulfur-ylide complexes from the reac-
tion of [Me3S(O)]ClO4 with Au(acac)PPh3 (acac ) acetyl-
acetonato) in acetone at room temperature.12
Compound 3 is formed by the deprotonation of a
bridging dppm methylene proton of the Au2(dppm)Cl2
to give [Au2(Ph2PCHPPh2)Cl2]- followed by the reaction
of the anion with a second molecule of Au2(dppm)Cl2.
Deprotonation of a methylene proton on the coordinated
dppm molecule is facile.15 Further coordinating the
deprotonated dppm ligand to various metal ions includ-
ing the Au(I) ion has been reported.15 It is conceivable
that the isolobal relationship between the proton unit
and L-Au(I) unit (L ) a general tertiary phosphine)
makes the reaction facile.16
One may imagine that 2 can be produced by the
consecutive deprotonations of a dppm methylene proton
and an ylidic methylene proton from 1 and the stepwise
reactions with Au2(dppm)Cl2. Therefore formation of
2 is favored by the high concentration of base. When 1
is reacted with OH- in the presence of Au2(dppm)Cl2,
it indeed produces 2, although in poor yield. Alterna-
tively, one may also imagine that 2 can be produced by
the reaction of 3 with sulfur ylide to form a monodentate
Au(I) ylide intermediate, followed by successive trans-
ylidation and deprotonation of a ylidic methylene pro-
ton. When 3 is reacted with sulfoxonium salt in a 1:1
molar ratio under similar PTC/OH- conditions, 2 is
produced in a 50% yield. However, when 3 is reacted
with sulfoxonium salt in a 1:5 molar ratio under PTC/
OH- conditions, 1 instead of 2 results in a 80% yield.
Thus, the amount of sulfoxonium salt controls the
All dinuclear Au(I) compounds 1, 4, and 5 show a
simple singlet in the 31P NMR spectra. The chemical
shifts are at 36.44, 35.79, and 15.97 ppm, respectively.
The tetranuclear compound 2 shows an ABCD pattern
in the 31P NMR spectrum. Two doublets centered at
36.44 ppm and 36.33 ppm, both having coupling con-
stants of 14 Hz, can be reasonably assigned as the
chemical shifts of the triply bridging dppm P atoms. The
resonance of the P atom trans to the methine carbon
atom is at 32.87 ppm which is a doublet of triplets.
Another doublet centered at 28.00 ppm (2J PP ) 52 Hz)
is the resonance of the remaining P atom. The 31P NMR
spectrum of compound 3 shows a typical AA′BC pattern.
The resonance of the two chemically equivalent phos-
phorus nuclei of the triply bridging dppm ligand is at
30.36 ppm. The coupling constant between these two
P atoms and the third P atom trans to the methine
carbon atom is 15 Hz. A doublet of triplets at 35.53 ppm
(2J PP ) 63 Hz, 3J PP ) 15 Hz) is observed for the third P
atom. A doublet centered at 24.73 ppm (2J PP ) 63 Hz)
is the resonance of the fourth P atom. All the complexes
1
but 3 show complicated H NMR spectra. Compound 1
has a ABX2 pattern for the dppm methylene protons and
a AA′BB′XX′ pattern for the ylidic methylene protons.
The latter pattern for the ylidic methylene protons also
is observed in compounds 4 and 5. In the 1H NMR
spectrum of 3 the resonance due to the CH proton
appears as a triplet of doublets at 4.59 ppm (2J PH ) 12
3
Hz, J PH ) 7 Hz) while a triplet centered at 3.35 ppm
corresponds to the resonance of the dppm methylene
protons.
(12) Vicente, J .; Chicote, M. T.; Guerrero, R.; J ones, P. G. J . Am.
Chem. Soc. 1996, 118, 699.
Str u ctu r es. The crystal structure of 1 consists of
-
(13) Schmidbaur, H.; Kammel, G. Chem. Ber. 1971, 104, 3252.
(14) Weber, L. Angew. Chem., Int. Ed. Engl. 1983, 22, 516.
(15) (a) Uson, R.; Laguna, A.; Laguna, M.; Manzano, B. R.; J ones,
P. G.; Sheldrick, G. M. J . Chem. Soc., Dalton Trans. 1984, 839. (b)
Uson, R.; Laguna, A.; Laguna, M.; Manzano, B. R.; J ones, P. G.;
Fittschen, C.; Sheldrick, G. M. J . Chem. Soc., Chem. Commun. 1986,
509. (c) Van der Velden, J . W. A.; Bour, J . J .; Vollenbrock, B. P. T.;
Smiths, J . M. M. J . Chem. Soc., Chem. Commun. 1979, 1162. (d) Uson,
R.; Laguna, A.; Laguna, M.; Lazaro, I.; J ones, P. G. Organometallics
1987, 6, 2326. (e) Falvello, L. R.; Fornies, J .; Navarro, R.; Reuda, A.;
Urriolabeitia, E. P. Organometallics 1996, 15, 309.
discrete digold cations and BF4 anions. Shown in
Figure 1 is an ORTEP presentation of the digold cation
dimer with selected bond angles and bond distances
given in the figure caption. The cation is an eight-
membered dimetallocycle with two Au atoms being
-
doubly bridged with a (CH2)2S(O)NMe2 ligand and a
dppm ligand, the P-Au-C fragments being linear. The
(16) (a) Lauher, J . W.; Wald, K. J . J . Am. Chem. Soc. 1981, 103,
7648. (b) Hoffmann, R. Angew. Chem., Int. Ed. Engl. 1982, 21, 711.
(17) (a) J ones, P. G. Gold Bull. 1981, 14, 1021; 1986, 19, 46. (b)
Schmidbaur, H. Gold Bull. 1990, 23, 11.

904 Organometallics, Vol. 16, No. 5, 1997
Feng et al.
F igu r e 1. ORTEP plot of the dimeric structure of digold
complex 1. Selected bonded distances (Å): Au1-P1 2.289(3),
Au-C1 2.088(12), Au2-P2 2.274(4), Au2-C2 2.097(14),
Au1--Au1′ 2.959(1), Au1--Au2 2.984(1). Selected bond
angles (deg): P1-Au1-C1 172.8(4), P2-Au2-C2 176.7(4).
Selected torsional angles (deg): P1-Au1--Au2-P2 -11.1(1),
P1-Au1--Au2-C2 165.7(4), C1-Au1--Au2-P2 174.4(3),
C1-Au1--Au2-C2 -8.9(5), P1-Au1--Au1′-P1′ 94.5(1),
P1-Au1--Au1′-C1′ -90.6(3), C1-Au1--Au1′-C1′ 84.3(4).
F igu r e 2. ORTEP plot of the tetragold cluster cation of
2. Selected bond lengths (Å) and angles (deg): Au1-P1
2.264(7), Au1-C3 2.05(3), Au2-P3 2.305(8), Au2-C4
2.11(3), Au3-P4 2.293(7), Au3-C3 2.08(2), Au4-P2 2.295(7),
Au4-C2 2.15(3), Au1--Au2 3.394(2), Au1--Au3 3.035(2),
Au1--Au4 3.711(2), Au2--Au3 2.993(2), Au2--Au4 3.922(2),
Au3--Au4 3.635(2); P1-Au1-C3 174.2(7), P3-Au2-C5
176.6(8), P4-Au3-C3 167.5(7), P2-Au4-C2 170.2(8),
Au1-C3-Au3 94.4(10).
eight-membered ring is in a boat conformation with the
S atom and methylene C atom of dppm as the head and
tail. The most interesting features of the structure are
that two C2-related cations are packed together such
that four Au atoms are in a row, with the intermolecular
Au1-Au1′ distance (2.959 Å) shorter than the intra-
molecular Au1-Au2 distance (2.984 Å), and the six-
atom plane (Au1, Au2, P1, P2, C1, and C2) in one cation
is perpendicular to the corresponding plane in C2-related
strained ylidic C3 is revealed [angle Au1-C3-Au3 )
94.4(10)°]. It is noticeable that the bond distances
between the S and two ylidic carbon atoms are different.
S-C3, 1.69(3) Å, is shorter than S-C4, 1.75(3) Å.
The crystal structure of compound 3 consists of
neutral tetragold clusters and CH3CH2OH molecules in
a 1:1 ratio. The ORTEP plot of compound 3 in Figure
3 clearly shows that the tetragold cluster is formed by
an Au-C linkage between [ClAu(µ-Ph2PCH2PPh2)Au]+
and [ClAu(µ-Ph2PCHPPh2)AuCl]-. Selected bond angles
and bond distances are given in the figure caption. The
structural parameters in the Au-PCH2P-Au portion
of the former conform closely to the reported values (vide
infra), e.g., torsional angle P1-Au1--Au2-P2 of 11.1(1)°
with Au-Au distance of 3.188(1) Å; those in the Au-
PCHP-Au portion of the latter exhibit noted deviations
toward higher valuess26.4(1)° and 3.247(1) Åsin a
corresponding order, presumably due to a strain in
joining an Au atom to the original methylene C atom of
dppm. There is a substantial trans influence in Au3-
P3 (2.277(5) Å, which is trans to the carbon atom) in
comparison with the remaining Au-P distances (aver-
aged 2.233(5) Å, trans to the chloride atom).
The crystal structure of compound 4 consists of
discrete monomeric digold cations, PF6- anions, and two
CH2Cl2 molecules. One of the CH2Cl2 molecules is
disordered with more than one orientation in the solid
state. Two types of PF6- anions exist in the structure:
one is located on a crystallographic center and the other
is on a general position with half the occupancy.
Revealed in Figure 4, the digold cation exhibits a nine-
membered dimetallocycle with two Au centers doubly
bridged by a (CH2)2S(O)NMe2- ligand and a dppe ligand.
Selected bond angles and bond distances are given in
the figure caption. Both P-Au-C fragments are ap-
proximately linears173.2(1) and 174.9(1)° bond angles.
The Au-Au distance, 3.119(2) Å, is much longer than
that in 1, 2.984 Å. The shortest intermolecular Au-
-
cation. Compound 4 with a PF6- anion instead of BF4
has also been structurally characterized by X-ray dif-
fraction. A similar digold cation dimer has also been
found with the intermolecular Au-Au distance being
shorter than the intramolecular Au-Au distance (2.913
Å vs 2.956 Å).18
The crystal structure of compound 2, as determined
by X-ray crystallography, includes discrete tetragold
cluster cations, BF4- anions, and H2O molecules. Shown
in Figure 2 is the ORTEP plot of a tetragold cluster
cation with selected bond angles and bond distances
given in the figure caption. A deprotonated dppm ligand
bridges three Au atoms (Au2, Au3, and Au4) through
two P atoms and one methylene C atom, and a sulfur-
ylide dianion also bridged three Au atoms through ylidic
carbon atoms C3 and C4 (C3 bonded to both Au1 and
Au3 and C4 to Au2). The arrangement is a triangular
geometry (Au1, Au2, and Au3) with Au-Au contacts at
2.993, 3.035, and 3.394 Å. The fourth gold atom (Au4)
is positioned at much longer Au-Au contacts with the
above three (>3.635 Å). Bridging triangular Au com-
plexes have been known in which the Au-Au distances
are normally in the range of 3.2-3.4 Å.19 If one
disregards the Au-Au contacts, each Au atom seems
to connect one C atom and one P atom, with P-Au-C
angles ranging from 167.5(7) to 176.6(8)°. A highly
(18) Lin, I. J . B.; Liu, L. K. Unpublished result.
(19) (a) Minghetti, G.; Bonati, F. Inorg. Chem. 1974, 13, 1600. (b)
Tiripicchio-Camellini, M.; Minghtti, G. J . Organomet. Chem. 1979, 171,
399. (c) Murray, H. H.; Raptis, R. G.; Fackler, J . P., J r. Inorg. Chem.
1988, 27, 26. (d) Raptis, R. G.; Fackler, J . P., J r. Inorg. Chem. 1990,
29, 5003.

Gold(I) Sulfur-Ylide Complexes
Organometallics, Vol. 16, No. 5, 1997 905
F igu r e 4. ORTEP plot of the digold cation of 4. Selected
bond distances (Å): Au1--Au2 3.119(2), Au1-P1 2.250(11),
Au1-C1 2.04(4), Au2-P2 2.248(10), Au2-C2 2.00(4), S-C1
1.71(4), S-C2 1.69(4). Selected bond angles (deg): P1-
Au1-C1 173.2(11), P2-Au2-C2 174.9(10), O-S-N
104.1(19), O-S-C1 116.9(21), O-S-C2 108.5(19), N-S-
C1 114.1(21), N-S-C2 113.9(23), C1-S C2 99.6(22).
F igu r e 3. ORTEP plot of compound 3. Selected bonded
lengths (Å): Au1--Au2 3.188(1), Au1-P1 2.235(5), Au1-
Cl1 2.289(5), Au2-P2 2.234(5), Au2-Cl2 2.279(5), Au3--
Au4 3.2474(14), Au3-P3 2.277(5), Au3-C1 2.122(17),
Au4-P4 2.230(5), Au4-Cl3 2.268(5). Selected bond angles
(deg): P1-Au1-Cl1 173.2(2), P2-Au2-Cl2 176.7(2), P3-
Au3-C1 173.8(5), P4-Au4-Cl3 175.2(2). Selected torsion
angles (deg): P1-Au1--Au2-P2 -1.1(1), P1-Au1--Au2-
Cl2 178.1(2), Cl1-Au1--Au2-P2 177.2(1), Cl1-Au1--Au2-
Cl2 -3.6(2), P2-Au3--Au4-P4 169.8(1), P2-Au3--Au4-
Cl3 -8.5(1), P3-Au3--Au4-P4 26.4(1), P3-Au3--Au4-Cl3
-152.0(1), Cl-Au3--Au4-P4 -157.7(3), Cl-Au3--Au4-Cl3
24.0(3).
Selected torsion angles (deg):
P1-Au1--Au2-P2
20.7(3), P1-Au1--Au2-C2 -164.5(11), C1-Au1--Au2-P2
-164.8(12), C1-Au1--Au2-C2 10.0(16), O-S-N-C5 2.1(47),
O-S-N-C6 -178.8(46), P1-C3-C4-P2 -108.0(23)°.
tion. Second, a chainlike molecule with Au(I) eight-
membered dimetallocycles normally exhibits a shorter
intermolecular than intramolecular Au-Au distance. In
sharp contrast, compound 1 is a discrete digold(I) dimer
in the solid state. The best description of 1 may be a
tetranuclear Au(I) dication in which two dimetallocycles
are linked together by the strong Au-Au interaction.
Third, compound 1 is a discrete Au(I) molecule having
four gold atoms in a row. The structures of gold
complexes having four gold atoms in a row have been
reported.23 A pentanuclear gold complex that has a
linear chain of gold atoms in different oxidation states,
[Au(II)]2-Au(I)-[Au(II)]2, has been reported by Uson et
al.24
Au distance is 5.696(3) Å. Yet the torsional angle of
P-Au--Au-P in 4 is 20.7(3)°, much larger than the
corresponding angle of 11.1(1)° in 1. The torsional angle
of P1-C3-C4-P2 is 108.0(2)°, C3 and C4 being on
different sides of the Au2P2 plane. The nature of the
(CH2)2S(O)NMe2- ligand in 4 is found to have a planar
N atom, the sum of surrounding angles around N being
359°. Furthermore the pπ-dπ-pπ interactions of the
N, S, and O atoms are strong, as evidenced by the
coplanarity of the SdO vector and the SNC2 skeleton;
the torsional angles O-S-N-C5 and O-S-N-C6 are
2.1(5) and 178.8(5)°, respectively. On the contrary, the
The Au-Au interaction in 4 is regarded to be a
relatively weak one, and that in 1, a strong one.
Attractive Au-Au interactions of ca. 3 Å are often
compared in strength to a typical hydrogen bond (7-8
kcal/mol),25 and the parallel has been made between the
-
N atom of the (CH2)2S(O)NMe2 ligand in 1 is clearly
pyramidal: the sum of angles around N is 340.9° with
torsional angle O-S-N-C5 ) 177.6° and O-S-N-C6
) -51.1°. The N atom of the (CH2)2S(O)NMe2- ligand
in 2 is also pyramidal: the sum of angles around N is
345.0° with two corresponding torsional angles of -176.2
and 47.4°. The bonding geometry of the S atom in 4 is
distorted from a tetrahedron, i.e., C1-S-C2 ) 99.6(2)°.
The corresponding angles are 107.5(7) and 106.3(1)° in
1 and 2, respectively.
(21) Schmidbaur, H.; Wohlleben, A.; Schubert, U.; Frank, A.; Hutt-
ner, G. Chem. Ber. 1977, 110, 2751.
(22) Lawton, S. L.; Rohrbaugh, W. J .; Kokotailo, G. T. Inorg. Chem.
1972, 11, 2227.
(23) (a) The structure of [Au2{µ-(CH2)2PPh2}(µ-S2CNEt2)]23b also has
been established by X-ray crystallography. Two molecules are bonded
through an intermolecular gold-gold interaction, thus forming a linear
chain (the maximum deviation from the linearity is 6.5°) of four gold
atoms with Au-Au(intramolecular) 2.867, 2.868 Å and Au-Au (in-
termolecular) 2.984 Å. (b) Bardaji, M.; Connelly, N. G.; Gimeno, M.
C.; J imenez, J .; J ones, P. G.; Laguna, M.; Laguna, A. J . Chem. Soc.,
Dalton Trans. 1994, 1163. (c) Li, D.; Che, C. M.; Peng, S. M.; Liu, S.
T.; Zhou, Z. Y.; Mak, T. C. W. J . Chem. Soc., Dalton Trans. 1993, 189.
(24) Uson, R.; Laguna, M.; Laguna, A.; J imenez, J .; J ones, P. G.
Angew. Chem., Int. Ed. Engl. 1991, 30, 198.
Several structural features observed in compound 1
need to be further discussed. First, the boat conforma-
tion of the eight-membered ring is unique in the
dimetallocycle Au(I) chemistry. Most of the complexes,
e.g. [Au(CH2)2PR2]2 (R ) alkyl, Ph),20 [Au2(dppm)2]2+ 21
,
and [Au(S2P(OC3H7)2)]2,22 etc., have a chair conforma-
(20) Schmidbaur, H.; Mandl, J . E.; Richter, W.; Bejenke, V.; Franke,
A.; Huttner, G. Chem. Ber. 1977, 110, 2236.
(25) Schmidbaur, H.; Graf, W.; Muller, G. Angew. Chem., Int. Ed.
Engl. 1988, 27, 417.

906 Organometallics, Vol. 16, No. 5, 1997
Feng et al.
On the other hand, a CSD search for the connectivity
of Au-PCH2CH2P-Au has resulted in 16 reliable X-ray
structures with R < 10% (as Supporting Information).
Among the 21 occurrences, the majority totaling 12 with
2.9 Å < Au-Au < 6.3 Å exhibit a gauche conformation
of P-Au--Au-P (the torsional angles range from 26.5
to 72.4°). The large range of Au-Au distances is
indicative of less Au-Au interaction. Only two frag-
ments with Au-Au of ca. 2.82 Å in length and as part
of a metal cluster show a cis conformation of P-Au--
Au-P. The rest are 4 fragments with Au-Au > 6.8 Å
in addition to a trans P-C-C-P linkage and, hence,
are probably not relevant in the above discussion on the
conformation of P-Au--Au-P. If each crystallographi-
cally observed conformation is regarded as a sample
point of the molecular potential energy surface, the
minimum energy geometry for Au-PCH2CH2P-Au is
statistically the gauche conformation along the Au-Au
axis, different from the cis conformation for Au-
PCH2P-Au.
Electr on ic Absor p tion a n d Em ission Stu d ies.
Electronic absorption studies were used to illustrate the
occurrence of molecular association of 1 and 5 in
solution. The absorption spectrum of 1 (Figure 5a) in
acetonitrile at room temperature shows a shoulder at
about 230 nm, a band at 280 nm, and a low-energy band
at about 340 nm. The absorption spectra are concentra-
tion dependent. The band at 340 nm grows faster than
expected from Beer’s law with increasing concentration.
Some time ago, Gray et al. reported that [Rh(CNPh)4]+
dimerizes in solution and gives a concentration-depend-
ent electronic absorption spectrum,27 in which the band
assigned to the formation of the dimer originating from
a Rh2 metal centered (MC) transition grows with
increasing concentration. Recently, concentration-
dependent UV-vis spectra of Au(PPhMe2)I were re-
ported as evidence of molecular association.28 Again,
the growing band was assigned to a MC transition
involving Au2. If we assume that the monomer 1 is in
equilibrium with the dimer of 1 (eq 1), eq 2 can be
F igu r e 5. (a) Top: Concentration-dependent absorption
spectra of 1 in acetonitrile at 298 K. Key: 7.6 × 10-3
M
M
(s), 5.7 × 10-3 M (- - -), 3.8 × 10-3 M (‚‚‚), 2.8 × 10-3
(- ‚ -), 4.5 × 10-4 M (- ‚ ‚ -). (b) Bottom: Concentration-
dependent absorption spectra of 5 in acetonitrile at 298 K.
Key: 1.8 × 10-2 M (s), 9.8 × 10-3 M (- - -), 4.7 × 10-3
M
(‚‚‚), 2.2 × 10-3 M (- ‚ -), 2.8 × 10-4 M (- ‚ ‚ -). Path length
) 0.1 cm.
2[Au2(dppm)[(CH2)2S(O)NMe2]BF4 h
[Au2(dppm)[(CH2)2S(O)NMe2]]2(BF4)2 (1)
digold unit LAu--AuL (L ) phosphine) and molecular
hydrogen26 on the reaction level.
1/2
[Au]0/A2 ) 1/(ꢀ2Kb)1/2 + 2A21/2/ꢀ2b
(2)
A search of the Cambridge Structural Database (CSD)
for the common molecular connectivity of Au-PCH2P-
Au has resulted in 40 reliable X-ray structures with R
< 10% and a total of 64 fragments (as Supporting
Information). Among these structures, the Au-Au
distances range from 2.755 to 3.711 Å (the second
largest is 3.341 Å). Out of a total 64 fragments, there
are 50 with the P-Au--Au-P torsional angle less than
20°. The mean of 64 torsional angles is 13.130°. It
seems to suggest that a dppm backbone is able to bring
the two Au centers into close proximity for a favorable
Au-Au attraction as is evidenced statistically by the
low torsional angles of P-Au--Au-P. The tendency of
P-Au--Au-P toward being planar is enhanced if more
than one cyclic link is present to connect the two Au
centers; for example, Au2(dppm)Cl2 has an angle of 2.8°
and the digold dimer cation 1 has an angle of 11.1°.
derived, where [Au]0 is the initial concentration of the
monomer, A2 is the absorbance of the dimer at 340 nm,
ꢀ2 is the absorptivity coefficient of the dimer, b is the
cell path length, and K is the equilibrium constant. A
plot of [Au]0/A21/2 vs A21/2 gives a straight line suggesting
that the assumption is correct. From the slope of this
plot the absorptivity coefficient (ꢀ2) of 9842 M-1 cm-1
for the dimer is obtained, and from the intercept an
equilibrium constant (K) of 33 ( 9 M-1 is obtained. The
analysis strongly suggests that the 340 nm absorption
originates from a Au4 1MC transition of the dimer.
Compound 5 was also examined in detail in acetonitrile
solution. The dimer of this complex absorbs at 320 nm
1/2
1/2
(Figure 5b). A plot of [Au]0/A2 vs A2 for this band
is again a straight line whose slope and intercept yield
(27) (a) Mann, K. R.; Gordon, J . G.; Gray, H. B. J . Am. Chem. Soc.
1975, 97, 3553. (b) Mann, K. R.; Lewis, N. S.; Williams, R. M.; Gray,
H. B.; Gorden, J . G. Inorg. Chem. 1978, 17, 828.
(28) Toronto, D. V.; Weissbart, B.; Tinti, D. S.; Balch, A. L. Inorg.
Chem. 1996, 35, 2484.
(26) Bruce, M. I.; Corbin, P. E.; Humphrey, P. A.; Koutsantounis,
G. A.; Liddell, M. J .; Tiekink, E. R. T. J . Chem. Soc., Chem. Commun.
1990, 674.

Gold(I) Sulfur-Ylide Complexes
Organometallics, Vol. 16, No. 5, 1997 907
The order of emission energies of these three compounds
is 1 < 5 < 4. This order can be interpreted by assigning
the nature of emission to a ligand to metal charge
transfer transition with the excitation from an orbital
primarily associated with gold to the phosphorus-based
orbital. The difference in the transition energy between
1 and 4 is due to the difference in the number of gold-
gold interactions. Red shifts of CT (S f Au) excitation
in the presence of Au-Au interactions have been
observed for gold phosphine thiolate compounds.32
Similar argument can be applied to the Au f P CT
excitation. Au-Au interaction destabilizes the filled
Au(5d) antibonding orbital and thereby decreases the
Au f P excitation transition energy. Crystal structure
results reveal that compound 1 has three short Au-Au
contacts while 4 has only one. The more the number of
Au-Au interactions the compound has, the more the
transition energy is decreased. The smaller transition
energy found in 1 compared to that of 4 is therefore
justified. Compounds 1 and 5 in acetonitrile have the
same order of equilibrium constant; therefore, they may
have the same number of molecular associations in the
solid state. The slight difference in the emission ener-
gies (858 cm-1) is likely due to the difference of
electronic effects in the phosphine substituents. The
methyl substituents in 5 are more electron donating
than the phenyl groups in 1. A blue shift is expected
for a MLCT transition from a compound with the dppm
ligand compared to the dmpm ligand. Therefore the
emission energy of 5 shifts blue with respect to that of
1.
F igu r e 6. Solid-state emission spectra of 1 (‚‚‚), 4 (s), and
5 (- - -) at 298 K.
ꢀ2 ) 2900 M-1 cm-1 and K ) 52 ( 7 M-1. The favored
association constant for 5 is likely due to the sterically
less crowded dmpm ligand, since up to the concentration
of 10-2 M the absorption spectrum of 4 shows no
additional band below 300 nm. The possibility of the
formation of the dimer of 4 is negligible consistent with
the crystal structure of 4. In a separate work, we have
also observed that electronic absorption spectra of
annular [Au2(diphosphine)(dithiolate)](PF6) are concen-
tration dependent.29 There the growing band at ∼350
nm is assigned to a MC transition from a dimer and
the monomer-dimer equilibrium constants (38 and 137
M-1) are similar to the values found in this work.
Su m m a r y
Excitation of solid samples of 1, 4, and 5 at room
temperature at λ ∼ 360 nm produces intense lumines-
cences at λmax ) 493, 463, and 473 nm, respectively. The
solid-state emission spectra of 1, 4, and 5 are shown in
Figure 6. These emissions have relatively long lumi-
nescent lifetime (>2 µs) and are structureless. Possible
sources of the emission observed in this work are
originating from (1) intraligand (IL) transitions involv-
ing the phenyl ring of phosphine or sulfur ylide ligands,
(2) charge transfer (CT) transitions, and (3) metal-
centered (MC) transitions. Although metal-perturbed
IL transitions from phenyl rings of phosphine have been
reported to occur at such similar transition energies,30
this possibility is the least likely in this system, because
5 does not have phenyl rings. Furthermore a solid
sample of the sulfoximine salt does not luminesce at
room temperature under UV light. Therefore CT and
MC transitions are the two most likely sources of
emission. MC transitions have been assigned to gold(I)
compounds having a P-Au-C moiety.31 Transition
energies between 19 531 and 23 474 cm-1 were ob-
served. Although similar transition energies (∼21 000
cm-1) have been observed for compounds 1, 4, and 5,
these energies are higher than the majority of those
reported values (∼18 000 cm-1) assigned to MC
transitions.10a,d,e,11 We therefore prefer to assign the
emissive nature of our compounds as CT transitions.
We have demonstrated that the application of the
PTC technique leads to the successful synthesis of the
gold(I) sulfur-ylide complexes. Compounds 1-3 are
synthesized by tuning different stoichiometric amounts
of reactants. The PTC technique also promotes the
dppm deprotonation reaction. Deprotonation of a coor-
dinated dppm ligand is facile and reversible. The
deprotonated dppm promotes ylide complex formation
such that higher yields of 1 and 2 are obtained. When
sterically allowed, gold(I) sulfur-ylide compounds tend
to aggregate. Thus in the solid state, two cations of 1
are packed together such that four Au atoms are in a
row with the intermolecular Au-Au distance shorter
than intramolecular Au-Au distance. The preference
of Au-Au interactions leads to the formation of tetra-
nuclear compounds 2 and 3. The former has one of the
ylidic carbon atoms bridging two gold(I) atoms in the
structure. 1 and 5 also tend to dimerize in acetonitrile
as evidenced by the concentration-dependent electronic
absorption spectra. The existence of unsupported Au-
Au interactions in solution implies the uniqueness of
gold chemistry. The equilibrium constants, K, between
the monomer and dimer are found to be 33 and 52 M-1
,
respectively. 1 and 5 in the solid state have long-lived
emissions with high intensity under visible light. The
physical and chemical properties and the potential
usefulness of this type of compound deserve further
study.
(29) Submitted for publication.
(30) (a) Kunkely, H.; Vogler, A. Chem. Phys. Lett. 1989, 164, 621.
(b) Segers, D. P.; DeArmond, M. K.; Grutsch, P. A.; Kutal, C. Inorg.
Chem. 1984, 23, 2874.
(31) Yam, V. W. W.; Choi, W. K. J . Chem. Soc., Dalton Trans. 1994,
2057.
(32) Forward, J . M.; Bohmann, D.; Fackler, J . P., J r.; Staples, R. J .
Inorg. Chem. 1995, 34, 6330.

908 Organometallics, Vol. 16, No. 5, 1997
Ta ble 1. Cr ysta l Da ta a n d Refin em en t Deta ils for Com p ou n d s 1-4
Feng et al.
1
2
3
4
formula
fw
space group
a, Å
b, Å
c, Å
C29H32Au2NOP2SBF4
985.31
C2/c
22.799(3)
11.590(2)
24.662(5)
90
104.80(1)
90
6300.4(18)
8
2.078
3727.02
CAD4
Mo KR
9.49
0.607-0.999
4113 (2θ < 45°)
2709, I0 > 2.5 σ(I0)
73
C54H52Au4NOP4SBF4‚H2O
1779.65
P1h
C50H40Au4Cl3P4‚C2H6O
1705.04
P1h
C30H34Au2NOP2SPF6‚2CH2Cl2
1227.33
C2/c
13.064(3)
13.584(3)
16.876(3)
95.93(2)
89.90(2)
103.47(2)
2896.0(10)
2
2.041
1667.54
CAD4
Mo KR
10.27
0.640-1.000
7425 (2θ < 45°)
4867, I0 > 2.5σ(I0)
125
826
0.057
11.773(3)
16.156(4)
17.351(6)
109.55(2)
98.85(2)
111.36(2)
2749.5(13)
2
2.059
1585.57
CAD4
Mo KR
10.90
0.585-0.999
7169 (2θ < 45°)
5214, I0 > 2.5σ(I0)
111
562
0.039
29.498(7)
17.192(3)
17.321(4)
90
101.19(2)
90
8617(3)
8
1.892
4687.01
CAD4
Mo KR
7.24
0.722-0.999
5642 (2θ < 45°)
1640, I0 > 2.5σ(I0)
90
492
0.048
R, deg
â, deg
γ, deg
V, Å3
Z
Dc, g/cm3
F(000)
diffractometer
X-ray radiation
µ, mm-1
transm factors
no. of unique reflns
no. of obsns
no. of atoms
no. of params
R
325
0.034
Rw
0.040
0.067
0.048
0.052
GOF
1.80
2.48
2.80
1.74
1.53 × 10-3 mmol) added as the phase-transferring agent
followed by NaOH (13.9 µL, 1.80 N). The resultant solution
was stirred at room temperature for 1 h. Then this solution
was combined with compound 3 (0.025 g, 1.53 × 10-2 mmol)
and stirred at room temperature for an additional 12 h. The
organic layer was then separated, washed with H2O (20 mL)
three times, and dried by a rotavapor under reduced pressure.
The crude product (yield > 80%) was recrystallized from a
CH2Cl2-EtOH (95%) mixture (1:1 by volume). White crystals
were obtained. Yield: 50%. Anal. Calcd for C54H54BF4-
NO2P4SAu4: C, 36.5; H, 3.1; N, 0.8. Found: C, 36.6; H, 3.0;
Exp er im en ta l Section
The 1H and 31P{1H} NMR spectra were recorded on a Bruker
AC-F300 spectrometer at 300 and 121.5 MHz, respectively.
Chemical shifts, δ, are reported relative to the internal
1
standard TMS for H NMR and external standard 85% H3PO4
for 31P NMR. Absorption spectra were obtained by a Shimadzu
UV-2101PC spectrophotometer. Room-temperature emission
spectra and emission lifetimes on the order of microseconds
were measured on a Aminco-Bowman luminescence spectrom-
eter. Emission lifetimes up to the nanosecond range were
recorded by using an Edinburgh Analytical Instruments
CD900 spectrometer. Microanalyses were performed by the
Taiwan Instrumentation Center. Au2(dppm)Cl2,33 Au2(dppe)-
3
N, 0.8. 31P NMR (CDCl3): 36.44 (d, J PP ) 14 Hz), 36.33 (d,
2
3
3J PP ) 14 Hz), 32.87 (d, t, J PP ) 52 Hz, J PP ) 14 Hz), 28.00
(d, 2J PP ) 52 Hz). 1H NMR (CDCl3): 8.00-6.82 (m, 40H, C6H5),
3.90-3.50 (m, 4H, PCH2, PCH, SCH), 3.03 (s, 6H, NCH3), 2.54
(m, 1H, SCH), 2.34 (m, 1H, SCH). FAB/MS: m/z 1674, [M -
(BF4 + H2O)]+.
34
Cl2,33 Au2(dmpm)Cl2,31 and [Me2S(O)NMe2]]BF4 were pre-
pared by the reported methods.
[Au 2(d p p m )((CH2)2S(O)NMe2)]BF 4, 1. Meth od a . Au2-
(dppm)Cl2 (0.59 g, 0.70 mmol) and [Me2S(O)NMe2]BF4 (0.73
g, 3.50 mmol) in CH2Cl2 (10 mL) was combined with n-Bu4NCl
(0.01 g, 0.04 mmol) as the phase-transferring agent followed
by NaOH addition (3 mL, 0.46 N). The resultant solution was
stirred at room temperature for 8 h. The organic layer was
then separated, washed with H2O (10 mL) four times, and
dried by a rotavapor under reduced pressure. The crude
product (yield > 80%) was recrystallized from a CH3OH-
CH2Cl2 mixture (20:1 by volume). White crystals (compound
2) precipitated in the early stages were filtered out (20% yield).
Slow evaporation of the filtrate gives a 52% yield of greenish
crystals (compound 1).
[Au 4(d p p m )(P h 2P CHP P h 2)Cl3], 3. [Me2S(O)NMe2]BF4
(0.05 g, 0.23 mmol) was added to a solution of Au2(dppm)Cl2
(0.20 g, 0.23 mmol) in CH2Cl2 (50 mL) followed by the addition
of n-Bu4NCl (0.006 g, 0.02 mmol) and NaOH (0.567 mL, 0.20
N). The solution was stirred for 24 h at ambient temperature
and then washed with water and dried by rotavapor under a
reduced pressure. Crystalline materials can be obtained from
recrystallization in an acetone/EtOH/CH2Cl2 mixed solvent (1:
1:1 ratio by volume). Yield: 70%. 3 also can be produced
under the same conditions without the sulfoxonium salts, but
the yield is low. Anal. Calcd for C50H43P4Cl3Au4: C, 35.9; H,
2.6. Found: C, 36.1; H, 2.6. 31P NMR (CDCl3): 35.53 (d, t,
Meth od b. 3 (0.015 g, 8.7 × 10-3 mmol) was treated with
[Me2S(O)NMe2]BF4 (0.01 g, 4.35 × 10-2 mmol) in CH2Cl2 (10
mL), and then n-Bu4NCl (0.001 g, 4.35 × 10-3 mmol) was
added as the phase-transferring agent followed by NaOH
(0.435 mL, 0.20 N). After a similar workup as mentioned in
method a, 1 can be isolated in 80% yield. Anal. Calcd for
3
3
2J PP ) 63 Hz, J PP ) 15 Hz), 30.36 (d, J PP ) 15 Hz), 24.73 (d,
2J PP ) 63 Hz). 1H NMR (CDCl3): 8.42-7.00 (m, 40H, C6H5,
2
3
2
4.60 (t, d, 1H, J HP ) 12 Hz, J HP ) 7 Hz), 3.35 (t, 2H, J HP
)
12 Hz).
[Au 2(d p p e)[(CH2)2S(O)NMe2]]P F 6, 4. Au2(dppe)Cl2 (0.32
g, 0.37 mmol) and [Me2S(O)NMe2]]BF4 (0.39 g, 1.85 mmol)
were dissolved in CH2Cl2 (30 mL). To this solution was added
n-Bu4NCl (0.006 g, 0.02 mmol) followed by NaOH (18 mL, 0.20
N). The resultant solution was stirred at room temperature
for 8 h. The organic layer was separated, washed with water
four times, and then reduced to 5 mL. To this organic solution,
5 drops of NH4PF6 saturated in EtOH was added. The white
precipitate thus formed was filtered out and recrystallized
from CH2Cl2/hexane. The yield of the colorless crystalline
material was 60%. Anal. Calcd for C30H34F6NOP3SAu2: C,
34.1; H, 3.2; N, 1.3. Found: C, 33.3; H, 3.2; N, 1.3. Mp: 150
°C dec. 31P NMR (CDCl3): 35.79 ppm. 1H NMR (CDCl3):
7.76-7.49 (m, 20H, C6H5), 3.52 (m, 2H, SCH2), 2.92 (s, 6H,
C
29H32BF4NOP2SAu2: C, 35.3; H, 3.3; N, 1.4. Found: C, 35.3;
H, 3.2; N, 1.3. Mp: 220 °C dec. 31P NMR (CDCl3): 36.44 ppm.
1H NMR (CDCl3): 7.60 (m, 20H, C6H5), 3.67 (m, 2H, SCH2),
2
2
3.41, 3.24 (t, d, 2H, J HH ) 14 Hz, J HP ) 12 Hz, PCH2), 2.94
(s, 6H, NCH3), 2.70 (m, 2H, SCH2). FAB/MS: m/z 898, (M -
BF4)+.
[Au 4(d p p m )(P h 2P CH P P h 2)[(µ-CH )(CH 2)S(O)NMe 2]]-
BF 4‚H2O, 2. [Me2S(O)NMe2]BF4 (0.003 g, 1.53 × 10-2 mmol)
was combined with CH2Cl2 (20 mL) with n-Bu4NCl (0.0004 g,
(33) Schmidbaur, H.; Wohlleben, A.; Wagner, F.; Orama, O.; Hutt-
ner, G. Chem. Ber. 1977, 110, 1748.
(34) J ohnson, C. R.; Rogers, P. E. J . Org. Chem. 1973, 38, 1793.

Gold(I) Sulfur-Ylide Complexes
Organometallics, Vol. 16, No. 5, 1997 909
NCH3), 2.80 (d, 4H, 2J HP ) 12 Hz, PCH2), 2.67 (m, 2H, SCH2).
FAB/MS: m/z 912, (M - PF6)+.
Compound 5 was synthesized in an analogous way as that
described for compound 4. Characterization data are given
below.
parameters for all non-hydrogen atoms (weight ) 1/[σ(Fo)2 +
0.0001(Fo)2], σ(Fo) from counting statistics). All the hydrogen
atoms were placed isotropically at their calculated positions
(C-H ) 1.00 Å) and fixed in the calculations. Atomic
scattering factors were taken from ref 37. For a summary of
crystal data and refinement details, see Table 1. Selected bond
distances and angles are given in the figure captions.
[Au 2(d m p m )[(CH2)2S(O)NMe2]]BF 4, 5. The yellowish mi-
crocrystals were obtained by recrystallization from CH2Cl2/
hexane. Anal. Calcd for C9H24F4BNOP2SAu2: C, 14.7; H, 3.3;
N, 1.9. Found: C, 14.6; H, 3.3; N, 2.0. Mp: 182 °C dec. 31P
NMR (CDCl3): 15.97 ppm. 1H NMR (CDCl3): 3.08 (m, 2H,
Ack n ow led gm en t. We thank the National Science
Council of Taiwan (ROC; Grant Nos. NSC 84-2113-M-
031-002 and NSC 85-2113-M-031-009) for financial
support.
2
SCH2), 2.88 (s, 6H, NCH3), 2.71, 2.40 (t, d, 2H, J HH ) 13 Hz,
2J HP ) 15 Hz, PCH2), 2.54 (m, 2H, SCH2), 1.80 (m, 12H, 2+4J HP
) 10 Hz, PCH3). FAB/MS: m/z 650, (M - BF4)+.
X-r a y Str u ctu r e An a lyses. The single-crystal X-ray dif-
fraction measurements were performed on a Nonius CAD-4
automated diffractometer using graphite-monochromated Mo
KR radiation. A total of 25 high-angle reflections were used
in a least-squares fit to obtain accurate cell constants. Dif-
fraction intensities were collected up to 2θ < 45° using the
θ/2θ scan technique, with background counts made for half
the total scan time on each side of the peak. Three standard
reflections, measured every 1 h, showed no significant decay
Su p p or tin g In for m a tion Ava ila ble: Tables giving data
collection parameters, positional and isotropic thermal pa-
rameters, anisotropic thermal parameters, and bond lengths
and angles for all of the structural analyses and data from
the Cambridge Structure Database (42 pages). Ordering
information is given on any current masthead page.
OM960748J
in intensity during data collection. The reflections with I0
>
(35) Main, P. In Crystallographic Computing 3: Data Collection,
Structure Determination, Proteins and database; Sheldrick, G. M.,
Krueger, C., Goddard, R., Eds.; Clarendon Press: Oxford, U.K., 1985;
p 206.
(36) Gabe, E. J .; Le Page, Y.; White, P. S.; Lee, F. L. Acta Crystallogr.
1987, 43A, S294.
2.0σ(I0) or 2.5σ(I0) were judged as observations and were used
for solution and structure refinement. Data were corrected
for Lorentz-polarization factors. An empirical absorption
correction based on a series of ψ scans was applied to the data.
The structure was solved by direct methods35 and refined by
a full-matrix least-squares routine36 with anisotropic thermal
(37) International Tables for X-ray Crystallography; Ibers, J . A.,
Hamilton, W. C., Eds.; Kynoch: Birmingham, U.K., 1974.