Synthesis and characterization of thienyl oligomeric, carbene, and nitrogen-donor complexes of gold(I)

Article abstract of DOI:10.1021/om970007y

Reaction of [AuCl(tht)] (tht = tetrahydrothiophene) with 2-(4′,5′-dihydro-4′,4′-dimethyl-2′-oxazolinyl) thien-5-yllithium or 2-(4′,5′-dihydro-4′,4′-dimethyl-2′-oxazolinyl) thien-3-yllithium afforded thienyl dimeric and trimeric oligomers of gold(I). Protonation of these compounds as well as the stable monomers obtained from [Au(C₆F₅)(tht)] or [AuCl(PPh₃)] afforded unique diorganocarbene complexes as well as nitrogen-donor compounds, the former being unusual divinylcarbene complexes. Reaction of 2-(2′-pyridyl)thien-5-yllithium with [AuCl(PPh₃)] produced, upon alkylation, organothiocarbene compounds. The molecular structure of the dimeric compound [Au{C=C(C=NCMe₂CH₂O)SCH=CH}]₂ shows a Au?Au separation of 2.8450(6) ?.

Full text of DOI:10.1021/om970007y

3324
Organometallics 1997, 16, 3324-3332
Syn th esis a n d Ch a r a cter iza tion of Th ien yl Oligom er ic,
Ca r ben e, a n d Nitr ogen -Don or Com p lexes of Gold (I)†
Mieke Desmet, Helgard G. Raubenheimer,* and Gert J . Kruger
Department of Chemistry and Biochemistry, Rand Afrikaans University,
Auckland Park 2006, South Africa
Received J anuary 7, 1997X
Reaction of [AuCl(tht)] (tht ) tetrahydrothiophene) with 2-(4′,5′-dihydro-4′,4′-dimethyl-
2′-oxazolinyl)thien-5-yllithium or 2-(4′,5′-dihydro-4′,4′-dimethyl-2′-oxazolinyl)thien-3-yllith-
ium afforded thienyl dimeric and trimeric oligomers of gold(I). Protonation of these
compounds as well as the stable monomers obtained from [Au(C6F5)(tht)] or [AuCl(PPh3)]
afforded unique diorganocarbene complexes as well as nitrogen-donor compounds, the former
being unusual divinylcarbene complexes. Reaction of 2-(2′-pyridyl)thien-5-yllithium with
[AuCl(PPh3)] produced, upon alkylation, organothiocarbene compounds. The molecular
structure of the dimeric compound [Au{CdC(CdNCMe2CH2O)SCHdCH}]2 shows a Au‚‚‚Au
separation of 2.8450(6) Å.
In tr od u ction
size carbene complexes in which the nucleophilic het-
eroatom in the precursor complex is located outside the
coordinated ring system and is separated from the
coordinated carbon by several bonds. More importantly,
this procedure has also led to the synthesis of the first
gold carbene complexes that contain no R heteroatom
and also to the synthesis of oligomeric 6-membered and
18-membered thienyl gold compounds.
Carbene complexes of gold are accessible by mainly
four types of transformation, namely the addition of
alcohols or amines to coordinated isocyanides,1,2 the
cleavage of electron-rich olefins,3 carbene transfer from
tungsten, molybdenum, or chromium pentacarbonyl
complexes,4 and protonation or alkylation of gold azolyl
compounds.5-9
Lithiation of the bifunctional 4′,5′-dihydro-4′,4′-dim-
ethyl-2′-(2-thienyl)oxazoline10 compound at C3 or C5
unexpectedly led to the isolation of fascinating dimeric
and trimeric gold complexes. The crystal and molecular
structure of both complexes were determined by X-ray
single-crystal diffraction methods. However, only the
structure of the former complex will be discussed here.
Most known bicyclic Au(I) compounds are derived from
phosphorus ylides and have been widely studied, mainly
in the research groups of Schmidbaur11 and Fackler,12
due to the Au‚‚‚Au attractive interactions which they
display. The new dimeric thienyl gold complex also has
a short Au‚‚‚Au separation of 2.845(6) Å.
Protonation of the dimeric gold compound led to the
formation of a bis(carbene) complex, albeit in low yield,
as well as a nitrogen coordinated complex. Since the
products between [AuCl(PPh3)] or [Au(C6F5)(tht)] (tht
) tetrahydrothiophene) and lithiated 2-(2′-oxazolinyl)-
thien-3-yllithium should not necessarily oligomerize,
this alternative route was investigated toward the
preparation of carbene complexes, both of which are
without any R heteroatom. In contrast, lithiation in the
C5 position produced an imine complex. Finally, reac-
tion with 2-(2′-pyridyl)thien-5-yllithium afforded, after
alkylation, an organothiocarbene complex of gold.
The latter method, developed in our laboratory,
involves the addition of gold(I) chloride or (tetrahy-
drothiophene)(pentafluorophenyl)gold complexes to lithi-
ated azoles, such as thiazoles,5,6 imidazoles,9 pyrazoles,
and isothiazole,7 as well as lithiated pyridine.8 These
precursor complexes are then alkylated or protonated
to form aminothio-, diamino-, organothio- as well as
aminoorganocarbene complexes. In the thiazolinylidene,
imidazolinylidene, and pyridinylidene complexes, the
nucleophilic nitrogen atom is situated R to the coordi-
nated carbon atom, while in the isothiazolinylidene and
pyrazolinylidene complexes, this nitrogen atom is situ-
ated in the γ position. In all of the above methods of
synthesis, however, the isolated carbene complexes
contain at least one R heteroatom.
Utilizing the consecutive transmetalation-alkylation
or -protonation approach, but using different bicyclic
organic compounds, we have now been able to synthe-
† Dedicated to Prof. Dieter Seebach on the occasion of his 60th
birthday.
X Abstract published in Advance ACS Abstracts, May 15, 1997.
(1) Minghetti, G.; Baratto, L.; Bonati, F. J . Organomet. Chem. 1975,
102, 397.
(2) Minghetti, G.; Bonati, F. Gazz. Chim. Ital. 1972, 102, 205.
(3) Cetinkaya, B.; Lappert, M. F.; Turner, T. J . Chem. Soc., Chem.
Commun. 1972, 851.
(4) Aumann, R.; Fischer, E. O. Chem. Ber. 1981, 144, 1853.
(5) Raubenheimer, H. G.; Scott, F.; Roos, M.; Otte, R. J . Chem. Soc.,
Chem. Commmun. 1990, 1722.
(6) Raubenheimer, H. G.; Scott, F.; Kruger, G. J .; Toerien, J . G.;
Otte, R.; van Zyl, W.; Taljaard, I.; Olivier, P.; Linford, L. J . Chem. Soc.,
Dalton Trans. 1994, 2091.
It is not an easy task to choose the correct terminology
as well as the correct manner in which the new ‘carbene
complexes’ should be represented. Definitions such as
(7) Raubenheimer, H. G.; Desmet, M; Kruger, G. J . J . Chem. Soc.,
Dalton Trans. 1995, 2067.
(8) Raubenheimer, H. G.; Toerien, J . G.; Kruger, G. J .; Otte, R.; van
Zyl, W.; Olivier, P. J . Organomet. Chem. 1994, 466, 291.
(9) Raubenheimer, H. G.; Lindeque, L.; Cronje, S. J . Organomet.
Chem. 1996, 511, 177.
(10) Carpenter, A. J .; Chadwick, D. J . J . Chem. Soc., Perkin Trans.
I 1985, 175.
(11) Schmidbaur, H.; Hartmann, C.; Riede, J .; Huber, B.; Muller,
G. Organometallics 1986, 5, 1952 and references therein.
(12) Murray, H. H.; Fackler, J . P.; Porter, L. C.; Mazany, A. M. J .
Chem. Soc., Chem. Commun. 1986, 321 and references therein.
S0276-7333(97)00007-1 CCC: $14.00 © 1997 American Chemical Society

Donor Complexes of Gold(I)
Organometallics, Vol. 16, No. 15, 1997 3325
13
‘a carbene molecule attached to a substrate’ and
14
‘ligands bound through a disubstituted carbon atom’
have been used. This terminology has been used even
though these complexes neither give rise to nor are
made from free carbenes. Most authors draw a metal-
carbon double bond,15 others use Lewis adducts (with
arrows),7,16 and some draw a dipolar metal-carbon
double bond (Lewis structure)17 to represent these so-
called carbene complexes. Still, other authors draw
single bonds between all of the atoms bonded to the
carbene carbon.18 There is general consensus that
π-back-donation in carbene, carbonyl, and isocyanide
complexes of gold occurs only to a limited extent,19,20
and thus, representation of these compounds by a
metal-carbon double bond is certainly inaccurate. In
this paper, we have chosen to call a number of the new
compounds carbene complexes and have chosen to
represent them by single metal-carbon bonds, as well
as positive charges being located on the nitrogen atoms.
Heterolytic metal-carbon bond cleavage would afford
ligands which can be written in the form of free
carbenes.
Resu lts a n d Discu ssion
The spectroscopic data for all of the new compounds
described are collected in Tables 1 and 2 and are
discussed where relevant. To simplify the drawings in
the schemes, the counter ion, CF3SO3j, is not included
when cationic complexes are displayed. In assigning the
spectroscopic data below, the numbering in Scheme 1
and Scheme 5 was used.
(Th ien yl)oxa zolin e Bin u clea r , Tr in u clea r , Ni-
t r ogen -Don or , a n d Ca r b en e Com p lexes of Gold .
The reaction of 2-(4′,5′-dihydro-4′,4′-dimethyloxazolin-
2′-yl)thien-3-yllithium with 1 equiv of [AuCl(tht)] at -60
°C in diethyl ether afforded, after crystallization, the
neutral dimeric gold compound 1 (Scheme 1). The
yellow crystals were suitable for an X-ray crystal-
lographic investigation. Attempts to form the bis-
(thienyl)aurate compound 1a by adding two or more
equivalents of the lithiated bicyclic compound also only
resulted in the formation of the dimer 1 (Scheme 1).
Protonation of the cyclic compound 1 at -60 °C with
2 molar equiv of CF3SO3H afforded the nitrogen-
coordinated (thienyl)oxazoline complex 2 (Scheme 1).
The solvent was removed, and complex 2 was extracted
with methylene chloride, filtered through Celite, and
crystallized at -20 °C. A 1H NMR study of the reaction
mixture before crystallization showed the presence of
the unreacted dimer 1, the diimine complex 2, and the
cationic carbene complex 3 (Scheme 1). The carbene
(13) Cotton, F. A.; Lukehart, C. M. Prog. Inorg. Chem. 1972, 16,
489.
(14) Collman, J . P.; Hegedus, L. S.; Norton, J . R.; Finke, R. G.
Principles and Applications of Organotransition Metal Chemistry;
University Science Books: Mill Valley, CA, 1987; p 119.
(15) Fischer, H.; Do¨tz, K. H.; Weiss, K.; Hofmann, P.; Schubert, U.;
Kreissl, F. R. In Transition Metal Carbene Complexes; Bieel, P. J ., Ed.;
Verlag Chemie: Weinheim, Germany, 1983; pp 2-68.
(16) Hermann, W. A.; Elison, M.; Fischer, J .; Ko¨cher, C.; Artus, G.
R. J . Angew. Chem., Int. Ed. Engl. 1995, 34, 2371.
(17) Arduengo, A. J ., III; Rasika Dias, H. V.; Calabrese, J . C.;
Davidson, F. Organometallics 1993, 12, 3405.
(18) Grohmann, A.; Schmidbaur, H. In Comprehensive Organome-
tallic Chemistry II; Abel, E. W., Stone, F. G., Wilkinson, G., Eds.;
Pergamon: New York, 1995; p 47.
(19) Banditelli, G.; Bonati, F.; Calogero, S.; Valle, G.; Wagner, F.
E.; Wordel, R. Organometallics 1986, 5, 1346.
(20) Arduengo, A. J ., III; Gamper, S. F.; Calabrese, J . C.; Davidson,
F. J . Am. Chem. Soc. 1994, 4391.

3326 Organometallics, Vol. 16, No. 15, 1997
Desmet et al.
Sch em e 1
complex 3 could not, however, be isolated in a pure form
or characterized satisfactorily as its yield was too low.
The (thienyl)oxazoline compound was also lithiated
at C5 with LDA at -80 °C. The addition of one or more
molar amounts of [AuCl(tht)] to a solution of the thien-
5-yllithium in THF (tetrahydrofuran) surprisingly also
produced a neutral trimeric complex 4, which was
crystallised at room temperature from THF/diethyl
ether using vapor diffusion methods (Scheme 2). The
molecular structure of this 18-membered ring was
determined by X-ray diffraction, but this will be reported
elsewhere together with the results for an ab initio
theoretical study. Burini et al. have previously postu-
lated trimeric compounds for simple gold imidazolyls.21,22
Protonation of complex 4 in the presence of triph-
enylphosphine afforded the (thienyl)oxazolium cation 5
(Scheme 2) and a homoleptic gold phosphine complex
that was not further characterized. Complexes 1, 2, and
4 are thermally stable in air at room temperature and
are soluble in methylene chloride, THF, and acetone.
It is clear that the neutral free (thienyl)oxazoline
(7.56, H3; 7.40 H5; 7.03, H4; 4.06, CH2; 1.35, CMe2) and
the neutral gold compounds 1 and 4 (Table 1) have
comparable proton chemical shifts, while the proton
shifts of the cationic gold complexes 2 and 3 are similar
to those of the cationic (thienyl)oxazolium compound 5.
The 13C chemical shifts of the coordinated carbon in
the neutral heterometallacyclic complexes 1 and 4
(Table 2) occur at δ 169.0 and 165.3, respectively. They
are shifted ∆δ 38.9 and 35.9 ppm downfield relative to
the corresponding carbons in free (thienyl)oxazoline (δ
130.1, C3; 129.4, C5).
(21) Bonati, F.; Burini, A.; Pietroni, B. R. J . Organomet. Chem. 1991,
408, 271.
(22) Bonati, F.; Burini, A.; Pietroni, B. R. J . Organomet. Chem. 1989,
375, 147.

Donor Complexes of Gold(I)
Sch em e 2
Organometallics, Vol. 16, No. 15, 1997 3327
Sch em e 3
polymeric compounds exist as cyclic trimers.21,22 Inter-
estingly, the (thienyl)oxazoline gold complex 6 does not
oligomerize even though a very stable analogous dimer,
complex 1 (Scheme 1), spontaneously forms in the
reaction of [AuCl(tht)] with lithiated (thienyl)oxazoline.
The mass spectrum of complex 6 does not exhibit a
molecular ion, however, m/ z values corresponding to
the dimer and fragments thereof are observed, indicat-
ing that the expected reaction does occur in the mass
spectrometer.
The carbon atom of the counterion CF3SO3j is not
normally visible in 13C{1H} NMR spectra since the
signal is split as a result of coupling to the fluorine
atoms.6-9 Interestingly, the quartet exhibited by this
carbon is clearly observable in the spectrum of complex
5 (Table 2). This is probably due to the high solubility
of this compound in the deuterated solvent, giving a very
favorable concentration for higher resolution.
The molecular ion peak at m/ z 754 is also the base
peak in the mass spectrum of the dimeric complex 1.
The fragmentation pattern is not very complex, and m/ z
values corresponding to [dimer - Au]+, [monomer -
Me]+, [(thienyl)oxazoline]+, and [(thienyl)oxazoline -
Me]+ are observed. The complex cation in the nitrogen-
coordinated complex 2 is observed at m/ z 559. The
dimerized thienyl(oxazoline) cation at m/ z 360, the
ionized (thienyl)oxazoline ligand at m/ z 181, and the
fragment [(thienyl)oxazoline - Me] at m/ z 166 are also
present for this complex.
Neu tr a l P h osp h in e-Con ta in in g 3-(Th ien yl)ox-
a zolin e a n d Ca tion ic Ca r ben e Com p lexes of Gold .
The neutral thienyl complex 6 was prepared by reacting
[AuCl(PPh3)] with 2-(4′,5′-dihydro-4′,4′-dimethyloxazo-
lin-2′-yl)thien-3-yllithium in diethyl ether at -80 °C
(Scheme 3). The solvent was removed, and complex 6
was extracted with methylene chloride, filtered through
Celite, and crystallized using vapor diffusion methods.
Off-white, needle-like crystals were obtained.
Substitution of the phosphine occurs in the analogous
neutral thiazolyl6 and imidazolyl9 gold complexes, which
undergo dissociative polymerization. As mentioned
earlier, Burini and co-workers have suggested that such
The neutral thienyl complex 6 was readily protonated
with CF3SO3H in THF at -65 °C to form the cationic
diorganocarbene complex 7 (Scheme 3). Crystallization
from methylene chloride/diethyl ether afforded colorless
needles of complex 7. This diorganocarbene complex is
unique in that its formation conclusively demonstrates
that an R-heteroatom is not a requirement for stable
gold carbene complexes. It also represents the first gold
carbene complex obtained according to our methodology,
which is derived from a precursor complex in which the
nitrogen atom is located outside the coordinated ring
system.
The 13C{1H} NMR data for the neutral complex 6
shows that the coordinated carbon resonates at δ 175.8
and that it is shifted downfield with respect to the
corresponding carbon (C3) of free (thienyl)oxazoline
resonating at δ 130.1 (∆δ ) 45.7 ppm). This downfield
shift is of the same order of magnitude as that shown
by isothiazole/isothiazolyl (∆δ ) 41.4 ppm)7 and 1-phe-
nylpyrazole/pyrazolyl (∆δ ) 45.1 ppm) upon deproto-
nation and coordination. All of these shifts are much
larger than those experienced by the same carbon atoms
on coordination to the CpFe(CO)2 cationic unit. Trans-
metalation reactions between azolyl compounds and
CpFe(CO)2Cl complexes give neutral azolyl com-
pounds.23-25 Similar comparisons of the eventually
coordinated carbon atom resonance before and after

3328 Organometallics, Vol. 16, No. 15, 1997
Desmet et al.
lithiated at C5 with LDA at -70 °C and CF3SO3H
(Scheme 4). The solvent was removed under vacuum,
and complex 9 was extracted with diethyl ether before
filtration through Celite. Crystallization from diethyl
ether/pentane afforded off-white crystals of complex 9.
The expected monocarbene complex was not obtained.
The well-established lability of bicovalent sulfur-donor
complexes of gold(I) and gold(III),26 the stability of the
gold-imine linkage in various compounds,27-30 as well
as the clear preference of gold(I) for the nitrogen atom
Sch em e 4
in the ligand [MeSCdNCMedCHS],31 led us to postu-
late the formation of nitrogen- rather than sulfur-
coordinated products 2 and 9.
Complex 8 is only soluble in THF, while complex 9 is
soluble in diethyl ether and most other polar organic
solvents. Both compounds are stable in solution in air
for a limited period only.
The 1H NMR data of the neutral diorganocarbene
complex 8 and the cationic diorganocarbene complex 7
are surprisingly similar. The H4, H5, and Me protons
have essentially the same chemical shifts, while the CH2
resonances differ by only 0.2 ppm. Usually a decrease
in positive charge is accompanied by an upfield shift of
the proton resonances. One is tempted to ascribe the
unexpected downfield position of the protons of the
neutral complex 8 to the deshielding effect of the C6F5
group. However, if this was the case, then the proton
chemical shifts of the neutral nitrogen-coordinated
complex 9, which also contains a C6F5 group, should also
appear at a more downfield position to make them
comparable to those in the cationic diimine complex 2
(Scheme 1). This, however, is not true. As expected,
the proton resonances of the latter complex 2 lie far
downfield from those of the neutral complex 9. The
similarity of the 1H NMR chemical shifts in the two
carbene complexes 7 and 8 suggests that the electronic
distribution in the framework of the two compounds is
very similar and probably implies that complex 8
contains a dominant resonance structure in which there
is a negative charge located mainly on the Au as well
as an equal but positive charge located mainly on the
nitrogen atom. In 7, the situation in the ring system is
identical but the gold itself is approximately neutral.
In the 13C{1H} NMR spectra of complexes 8 and 9,
the signals of the C6F5 ligand are very weak and are
partly visible as a series of multiplets due to coupling
of the 19F nuclei with the carbon nuclei. The 13C
chemical shifts of the neutral and cationic carbene
complexes 7 and 8 are once again very similar. The
carbene carbon of complex 8, however, resonates at a
somewhat lower field than that of the cationic carbene
complex, similar to the situation found in thiazoli-
nylidene, imidazolinylidene, and isothiazolinylidene cat-
ionic and neutral compounds.6-9
coordination in iron complexes show that for isothiazole/
isothiazolyl24 this difference is only ∆δ 14.1 ppm, for
pyrazole/pyrazolyl it is ∆δ 18.6 ppm, for (thienyl)-
oxazoline/3-thienyl(oxazoline) it is ∆δ 19.6 ppm, and for
(thienyl)oxazoline/3-thienyl(oxazoline) it is ∆δ 18.7 ppm.25
The downfield shifts of ∆δ 38.9 and 35.9 ppm exhibited
by complexes 1 and 4 are somewhat smaller than those
occurring in triphenylphosphine gold compounds, but
they are still much larger than those measured for
cyclopentadienyl iron complexes. The difference in the
13C{1H} NMR chemical shifts of the coordinated carbon
in the precursor neutral complex 6 and the cationic
diorganocarbene complex 7 is ∆δ 15.1 ppm. This is
large compared to the ∆δ 5.4 ppm obtained previously
for the corresponding isothiazolyl/isothiazolinylidene
gold phosphine complexes.7 It is not possible to compare
the corresponding chemical shift difference in the thia-
zolyl/thiazolinylidene6 and imidazolyl/imidazolinylidene9
systems due to complicating reactions, such as polym-
erization and homoleptic rearrangement, which prevent
the isolation of the carbene complexes.
A Neu tr a l Dior ga n oca r ben e Com p lex a n d
a
Nitr ogen -Coor din ated Com plex of P en taflu or oph e-
n ylgold . The neutral (thienyl)oxazolinyl monocarbene
complex 8 was prepared by treating [Au(C6F5)(tht)] with
(thienyl)oxazoline lithiated at C3 in diethyl ether fol-
lowed by direct protonation at -60 °C of the interme-
diately formed aurate complex with CF3SO3H (Scheme
4). The white precipitate was collected, washed several
times with diethyl ether, redissolved in methylene
chloride, and filtered through Celite. Crystallization
afforded colorless, needle-like crystals of complex 8.
The diorganocarbene complex 8, unlike the analogous
thiazolinylidene, isothiazolinylidene, pyrazolinylidene,
and imidazolinylidene complexes, does not undergo
homoleptic rearrangement in solution.6-9 It is also the
first diorganocarbene complex of gold to be synthesized.
The neutral nitrogen-coordinated pentafluorophe-
nylgold complex 9 resulted from sequential treatment
of [Au(C6F5)(tht)] with the (thienyl)oxazoline compound
Since the compounds are isomeric, the same molec-
ular ion peak at m/ z 545 was observed for both
(26) Hass, A.; Helmbrecht, J .; Niemann, U. Handbuch der Prapa¨ra-
tiven Anorganischen Chemie, erd ed.; Ferdinand Enke: Stuttgard,
1975; p 1014.
(27) Bovio, B.; Cologero, S.; Wagner, F. E.; Burini, A.; Pietroni, B.
R. J . Organomet. Chem. 1994, 470, 275.
(28) Bovio, B.; Bonati, F.; Banditelli, G. Inorg. Chim. Acta 1984, 87,
25.
(29) Papasergio, R. I.; Raston, C. L.; White, A. H. J . Chem. Soc.,
Dalton Trans. 1987, 3085.
(30) Scherbaum, F.; Huber, B.; Mu¨ller, G.; Schmidbaur, H. Angew.
Chem., Int. Ed. Engl. 1988, 27, 1542.
(31) Cronje, S.; Raubenheimer, H. G. Unpublished results.
(23) Raubenheimer, H. G.; Scott, F.; Cronje, S.; van Rooyen, P. H.;
Psotta, K. J . Chem. Soc., Dalton. Trans. 1992, 1009.
(24) Toerien, J . G.; Desmet, M.; Kruger, G. J .; Raubenheimer, H.
G. J . Organomet. Chem. 1994, 479, C12.
(25) Raubenheimer, H. G.; Desmet, M.; Olivier, P.; Kruger, G. J . J .
Chem. Soc., Dalton. Trans. 1996, 4431.

Donor Complexes of Gold(I)
Sch em e 5
Organometallics, Vol. 16, No. 15, 1997 3329
F igu r e 1. The molecular structure of complex 1. The
thermal ellipsoids are drawn at 50% probability limit.
Ta ble 3. Selected Bon d Len gth s (Å) a n d Bon d
An gles (d eg), w ith Esd in P a r en th eses, for
Com p lex 1
Au1-Au2
Au1-N2
Au1-C12
S1-C11
2.8450(6)
2.065(8)
2.01(1)
1.73(1)
1.71(1)
1.35(1)
1.44(1)
1.28(1)
1.51(1)
1.37(1)
1.46(1)
1.40(1)
1.36(2)
1.51(2)
1.54(2)
1.53(2)
Au2-N1
Au2-C22
S2-C21
2.091(8)
2.04(1)
1.72(1)
1.71(1)
1.36(1)
1.47(1)
1.30(1)
1.53(1)
1.39(1)
1.45(1)
1.39(1)
1.36(2)
1.51(2)
1.53(1)
1.49(1)
compounds 8 and 9. The fragmentation patterns of
complex 8 consist of the loss of either the (thienyl)-
oxazoline ligand or the C6F5 ligand while that of complex
9 only shows the loss of the (thienyl)oxazoline ligand.
The fragment [(thienyl)oxazoline - Me]+ at m/ z 166
forms the base peak in both spectra.
Neu tr a l (Th ien yl)p yr id yl a n d (Th ien yl)p yr id i-
n ylid en e Com p lexes of (Tr ip h en ylp h osp h in e)gold .
The reaction of 1 molar equiv of 2-(2′-pyridyl)thien-5-
yllithium with [AuCl(PPh3)] at -40 °C afforded the
neutral thienyl gold complex 10 (Scheme 5). The solvent
was removed under vacuum, and the residue was
extracted with methylene chloride before filtration
through Celite. Crystallization from methylene chloride/
hexane afforded yellow crystals of complex 10.
Alkylation of the thienyl complex 10, at 0 °C with CF3-
SO3Me followed by crystallization from methylene chlo-
ride/hexane, produced orange blocks of the cationic
organothio carbene complex 11 (Scheme 5). This syn-
thesis, like that of 6 and 7, was not complicated by
homoleptic rearrangement or polymerization.
The cationic compound is only slightly soluble in
diethyl ether, while both compounds readily dissolve in
acetone, methylene chloride, and THF.
S1-C14
S2-C24
O1-C15
O1-C16
N1-C15
N1-C17
C11-C12
C11-C15
C12-C13
C13-C14
C16-C17
C17-C18
C17-C19
O2-C25
O2-C26
N2-C25
N2-C27
C21-C22
C21-C25
C22-C23
C23-C24
C26-C27
C27-C28
C27-C29
Au2-Au1-N2
N2-Au1-C12
Au1-Au2-N1
C11-S1-C14
Au2-N1-C15
Au1-N2-C25
Au1-C12-C11
C11-C12-C13
Au2-C22-C21
90.3(2)
175.6(3)
89.4(2)
Au2-Au1-C12
N1-Au2-C22
Au1-Au2-C22
C21-S2-C24
Au2-N1-C17
Au1-N2-C27
Au1-C12-C13
C21-C22-C23
Au2-C22-C23
94.0(3)
175.9(3)
94.3(3)
90.8(5)
91.6(5)
129.7(6)
130.2(7)
126.2(7)
109.8(9)
124.5(8)
123.0(7)
120.3(6)
124.0(7)
110.1(9)
125.2(8)
chemical shift of δ 182.4; this however is not surprising,
and the downfield shift of ∆δ 8.1 ppm compares to the
5.4 ppm downfield shift observed when the isothiazolyl
complex changes to the isothiazolinylidene complex.7
St r u ct u r e
of
[Au {CdC(CdNCMe2CH 2O)-
The 1H NMR data of the neutral complex 10 show
that the resonances of the protons of the thienyl ring
are similar to those of free 2′-(2-thienyl)pyridine (δ 7.72,
H3; 7.13, H4), while the proton resonances of the pyridyl
ring are shifted slightly downfield with respect to those
of 2′-(2-thienyl)pyridine (δ 7.79, H3; 7.81, H4′; 7.22, H5′;
8.52, H6′). Yet again, the proton resonances of the
neutral complex 10 are comparable to those of free 2′-
(2-thienyl)pyridine, while the resonances of complex 11
resemble those of the cationic 2′-(2-thienyl)pyridinium
compound (δ 8.21, H3; 7.34, H4; 8.06, H3′; 8.42, H4′; 7.76,
H5′; 8.82, H6′). The H3′ and H4′ proton signals of complex
10 lie under the multiplet of the phenyl ring.
The 13C resonance of the coordinated carbon of the
thienyl ring of compound 10 appears at δ 174.3 and is
shifted ∆δ 45.5 ppm downfield with respect to C5 of the
free (thienyl)pyridine. This downfield shift is similar
to those discussed previously upon formation of the
corresponding isothiazolyl complex (∆δ ) 41.4)7 and
(thienyl)oxazoline complex 6 (∆δ ) 45.7). The 13C
resonance of the carbene carbon of complex 11 has a
SCHdCH}]2, 1. The molecular structure of complex 1
is shown in Figure 1. Selected bond lengths and bond
angles are given in Table 3. The crystallographic data
discussed below refer to the numbering scheme adopted
in Figure 1.
Each gold atom is essentially linearly coordinated to
a carbon atom of a 4′,5′-dihydro-4′,4′-dimethyl-2′-(2-
thienyl)oxazoline ligand and the nitrogen atom of a
second (thienyl)oxazoline ligand to form a cyclic bi-
nuclear Au(I) compound. This is the only structure of
a C,N-coordinated six-membered edge-sharing (Au-Au)
bicyclic compound known. No intermolecular Au‚‚‚Au
interactions occur; however, the gold atoms within the
bicyclic compound are intramolecularly bound and
exhibit a short separation of 2.8450(6) Å.
The two ligands of the dimeric complex 1 are not
coplanar, and the N-donor and C-donor units are rotated
with respect to each other to give N-Au-Au-C dihe-
dral angles of 35.8(4)° and 36.8(4)°. There are two
possible reasons for this buckling (distortions that

3330 Organometallics, Vol. 16, No. 15, 1997
Desmet et al.
F igu r e 2. Representative six- and five-edge-sharing (Au-Au) bicyclic compounds.
destroy the coplanarity of the two ligands). Firstly, the
rotation reduces cyclic strain (if the ring does not buckle
then the system is strained), and secondly, it brings the
Au atoms closer together, encouraging the formation of
stronger Au‚‚‚Au interactions
carbon-nitrogen contact distance of 2.535 Å. The Au‚‚‚-
Au bond seems to cause the C-Au-N angles to “bulge”
outwards.
Six membered edge-sharing (Au-Au) bicyclics, like
those in compounds A and B and compound 1 (Figure
2), generally display longer Au‚‚‚Au separations than
comparable five-membered rings. Further investiga-
tions using the Cambridge database revealed that
typical Au‚‚‚Au bond distances in such six-membered
rings fall within the range 2.83-3.24 Å, with a mean
value of 3.02 Å, and gold atoms in five-membered rings
are separated by distances of 2.55-3.17 Å, with a mean
value of 2.76 Å.32 Complex 1, therefore, contains an
uncommonly short Au‚‚‚Au bond for a six-membered
ring. Indeed, only one six-membered ring gold com-
pound exists with a shorter Au‚‚‚Au distance, and it is
a P,P-chelate within a Au-Ru cluster.35 Compound E,36
which does not form a binuclear ring structure, forms
intermolecular Au‚‚‚Au bonds of comparable lengths to
those compounds of A and B. The C-Au-C units are
also rotated with respect to one another to form a
torsional angle of 110.9(7)°.
A search of the Cambridge data base32 revealed that
all six-membered edge-sharing (Au-Au) bicylic ring
systems are buckled with dihedral angles varying from
26.54(8) to 83.23(8)°, whereas similar five-membered
ring systems are generally not buckled or only slightly
so. They mostly contain dihedral angles ranging from
0 to 5°. Some structural information on binuclear
complexes related to complex 1 are collected in Figure
2. It is evident that this type of ring twisting occurs in
compounds A,6 B,33 and D34 (Figure 2) with dihedral
angles of 64.8(4)°, 48.12(6)°, and 15.61(3)°, respectively.
In compound D (Figure 2),34 the two rings are twisted
even though no cyclic strain is evident. It is possible,
therefore, that the two rings only twist to bring the gold
atoms closer together. It contains a very short Au‚‚‚-
Au contact of 2.64(6) Å. Compound C,29 which is also a
five-membered edge-sharing bicyclic compound, is not
twisted, probably due to the steric constraints caused
by two SiMe3 groups on each coordinated carbon atom.
Surprisingly, however, the short Au‚‚‚Au contact dis-
tance of 2.67(2) Å is longer than the coordinated
Coordination around the two central gold atoms in
complex 1 is somewhat distorted from linearity (C-
Au-N angles of 175.5(9)° and 173.8(8)°), but as depicted
in Figure 2, this is not uncommon for Au(I) compounds.
The Au-C(sp2) bond lengths of 2.07(3) and 2.04(3) Å
are in agreement with those found in other neutral gold-
(I) complexes, e.g., compound A (Figure 2) (average
(32) Allen, F. H.; Bellard, S.; Brice, M. D.; Cartwright, B. A.;
Doubleday, A.; Higgs, H.; Hummelink, T.; Hummelink-Peters, B. G.;
Kennard, O.; Motherwell, W. D. S.; Rodgers, J . R.; Watson, D. G. Acta
Crystallogr., Sect. B 1979, 39, 2331.
(33) Schmidbaur, H.; Ebner von Eschenbach, J .; Kumberger, O.;
Muller, G. Chem. Ber. 1990, 123, 2261.
(35) Brown, S. S. D.; Salter, I. D.; Dent, A. J .; Kitchen, G. F. M.;
Orpen, A. G.; Bates, P. A.; Hursthouse, M. B. J . Chem. Soc., Dalton
Trans. 1989, 1227.
(34) Fenske, D.; Baum, G.; Zinn, A.; Dehnicke, K. Z. Naturforsch.,
B: Anorg. Chem. Org. Chem. 1990, 45, 1273.
(36) Kruger, G. J .; Olivier, P. J .; Raubenheimer, H. G. Acta Crys-
tallogr. 1996, C52, 624.

Donor Complexes of Gold(I)
Organometallics, Vol. 16, No. 15, 1997 3331
2.03(1) Å),6 [Au{CdCHCHdNS}PPh3] (2.032(7) Å),7
[Au(C6F5)PPh3] (2.063(2) Å),37 and compound C (Figure
2) (2.09(3) Å).29
The Au-N(imine) distances, with lengths of 2.065(8)
and 2.091(9) Å, are normal and compare well with
similar distances in, for example, compound C (2.08 Å)21
and compound D (average 2.06 Å).34
The aromatic character of the two thienyl rings is
clearly shown by the planarity of the rings (maximum
deviation from least squares plane of 0.0017 and 0.0223
Å) and the relatively short C-C (average 1.37(1) Å) and
C-S (average 1.72(1) Å) bond lengths therein. In
addition, the bonds joining the thienyl and oxazolinyl
rings, C11-C15 and C21-C25 (average 1.46(1) Å), are
also shorter than normal single C-C bond lengths. C21,
C22, C25, and N2 all lie in the same plane with a
maximum deviation from the least squares plane of
0.0595 Å, while C11, C12, C15, and N1 are somewhat
less planar (maximum deviation from the least-squares
plane of 0.10 Å). All these results indicate that π-de-
localization occurs in complex 1.
(0.18 g, 1.00 mmol) in diethyl ether was cooled to -80 °C and
treated with standardized n-butyllithium in hexane (0.63 cm3,
1.00 mmol, 1.6 M). The light yellow solution was stirred at
-80 °C for 20 min and at -10 °C for 30 min. A solution of
[AuCl(tht)] (0.32 g, 1.00 mmol) in THF (50 cm3) was added
dropwise at -60 °C. The mixture was stirred at -60 °C for 1
h and at -10 °C for 30 min before allowing it to warm up to
room temperature. The solvent was removed under vacuum.
The residue was washed several times with diethyl ether,
redissolved in THF, and filtered through Celite. Concentration
of the yellow filtrate, slow addition of diethyl ether, and cooling
to -20 °C afforded yellow crystals of complex 1. Yield 63.9%,
mp > 155 °C (dec). Anal. Calcd for C18H20Au2N2O2S2: C,
28.66; H, 2.67; N, 3.71. Found: C, 28.7; H, 2.5; N, 3.7.
P r epar ation of [Au {NdC(CdCHCHdCHS)OCH2CMe2}2]-
[CF 3SO3] (2). A solution of 4′,4′-dimethyl-2′-(2-thienyl)-2′-
oxazoline (0.37 g, 2.02 mmol) in diethyl ether was cooled to
-80 °C and treated with standardized n-butyllithium in
hexane (1.26 cm3, 2.02 mmol, 1.6 M). The light yellow solution
was stirred at -80 °C for 20 min and at -10 °C for 30 min. A
solution of [AuCl(tht)] (0.32 g, 1.00 mmol) in THF (50 cm3)
was added dropwise at -60 °C. The mixture was stirred at
-60 °C for 2 h before the addition of CF3SO3H (0.18 cm3, 2.02
mmol). The reaction mixture was allowed to stir at this
temperature for 2 h and at -45 °C for 2 h before warming to
room temperature. The solvent was removed in vacuo, and
the yellow residue was washed several times with diethyl
ether, redissolved in CH2Cl2, and filtered through Celite.
Concentration of the light yellow filtrate, slow addition of
pentane, and cooling to -20 °C afforded yellow crystals of
complex 2. Yield 40.4%, mp > 96 °C. Anal. Calcd for
C19H22AuF3N2O5S3: C, 32.21; H, 3.13; N, 3.95. Found: C, 32.1;
H, 3.1; N, 4.1.
Con clu sion
Unique 6-membered dimeric and 18-membered tri-
meric thienyl gold compounds as well as divinyl- and
organothiocarbene complexes have been isolated. The
divinylcarbene complexes 7 and 8 as well as the orga-
nothiocarbene complex 11 exhibit a characteristic low-
field chemical shift for the coordinated carbon. The C3
carbon atom of the thienyl(oxazoline) ligand resonates
between δ 136.7 and 140.7 when an imine compound is
formed; it resonates between δ 169.0 and 175.8 when it
is coordinated to gold and between δ 190.9 and 195.8
upon carbene complex formation. It is, thus, evident
that the coordinated carbon atom is effected during
alkylation and carbene complex formation. The carbene
complexes have been represented with a positive charge
on the nitrogen atom, as this is believed to be the
dominant resonance form. This method of representa-
tion, however, belies the fact that a characteristic low-
field chemical shift for the carbene carbon atom is
obtained.
P r ep a r a tion of [Au {CdCHCHdC(CdNCMe2CH2O)S}]3
(4). A solution of 4′,4′-dimethyl-2′-(2-thienyl)-2′-oxazoline (0.28
g, 1.52 mmol) in THF was slowly added to a solution of LDA,
prepared from diisopropylamine (0.22 cm3, 1.58 mmol) and
standardized n-butyllithium in hexane (1.00 cm3, 1.60 mmol,
1.6 M), at -78 °C. The solution was stirred at -80 °C for 30
min before [AuCl(tht)] (0.48 g, 1.50 mmol) was added at -78
°C. The mixture was stirred for 30 min at -80 °C, 1 h at -50
°C, and 30 min at room temperature. The solvent was
removed in vacuo, and the residue was washed several times
with diethyl ether and redissolved in CH2Cl2. Filtration
through Celite, concentration of the yellow filtrate, slow
addition of diethyl ether, and cooling to -20 °C afforded yellow
crystals of complex 4. Yield 72.3%, mp > 134 °C (dec). Anal.
Exp er im en ta l Section
Gen er a l Com m en ts. All reactions involving organome-
tallic reagents were performed under an atmosphere of
nitrogen using standard vacuum line and Schlenk techniques.
Melting points were determined on a standardized Buchi 535
apparatus. Mass spectra (electron impact) were recorded on
a Finnigan Mat 8200 instrument at ca. 70 eV and NMR
spectra on a Varian 200 FT spectrometer. Elemental analyses
were carried out by the Division of Energy Technology, Council
for Scientific and Industrial Research, Pretoria, South Africa.
Rea gen ts. The following starting materials were prepared
according to published procedures: 4′,4′-dimethyl-2′-(2-thie-
nyl)-2′-oxazoline,10 2′-(2-thienyl)pyridine,38 [AuCl(tht)], [AuCl-
(PPh3)], and [Au(C6F5)(tht)].26 CF3SO3Me and CF3SO3H were
purchased from Aldrich and n-butyllithium from Merck.
Tetrahydrofuran (THF) and diethyl ether were distilled under
nitrogen from sodium diphenylketyl and CH2Cl2, hexane and
pentane were distilled from CaH2.
Calcd for C27H30Au3N3O3S3: C, 28.66; H, 2.67; N, 3.71.
Found: C, 28.7; H, 2.5; N, 3.8.
P r ep a r a tion of [Au {CdC(CdNCMe2CH2O)SCHdCH}-
P P h 3] (6). A solution of 4′,4′-dimethyl-2′-(2-thienyl)-2′-oxazo-
line (0.22 g, 1.20 mmol) in diethyl ether was cooled to -80 °C
and treated with standardized n-butyllithium in hexane (0.78
cm3, 1.25 mmol, 1.6 M). The light yellow solution was stirred
at -80 °C for 20 min and at -10 °C for 30 min before [AuCl-
(PPh3)] (0.50g, 1.00 mmol) was added at -5 °C. The mixture
was stirred for 30 min at -5 °C, and THF (20 cm3) was added.
The reaction mixture was stirred at -5 °C for a further 2 h
and allowed to warm to room temperature before the solvent
was removed. The residue was washed once with diethyl
ether, redissolved in CH2Cl2, and filtered through Celite.
Concentration of the colorless filtrate, slow addition of hexane,
and cooling to -20 °C afforded colorless crystals of complex 6.
Yield 86.0%, mp 173 °C. Anal. Calcd for C27H25AuNOPS: C,
50.71; H, 3.94; N, 2.19. Found: C, 50.7; H, 3.8; N, 2.2.
P r ep a r a tion of [Au {CdC(CdNCMe2CH2O)SCHdCH}]2
(1). A solution of 4′,4′-dimethyl-2′-(2-thienyl)-2′-oxazoline
P r ep a r a tion of [Au {CCd(CN(H)CMe2CH2O)SCHdCH}-
(37) Baker, R. W.; Pauling, P. J . J . Chem. Soc., Dalton Trans. 1972,
P P h 3][CF 3SO3] (7). A solution of complex 6 (0.93 g, 1.45
mmol) in THF was cooled to -65 °C and treated dropwise with
CF3SO3H (0.13 cm3, 1.45 mmol). The mixture was stirred for
2264.
(38) Kumada, M.; Tamao, K.; Sumitani, K. Org. Synth. 1978, 58,
127.

3332 Organometallics, Vol. 16, No. 15, 1997
Desmet et al.
Ta ble 4. Cr ysta l Da ta , Collection , a n d Refin em en t
Deta ils for Com p lex 1
warming to room temperature. The solvent was removed in
vacuo, and the oily residue was redissolved in diethyl ether
and filtered through Celite. Concentration of the colorless
filtrate, slow addition of pentane, and cooling to -20 °C
afforded off-white crystals of complex 9. Yield 89.6%, mp >
97 °C (dec). Anal. Calcd for C15H11AuF5NOS: C, 33.04; H,
2.03; N, 2.57. Found: C, 33.1; H, 2.1; N, 2.4.
formula
C18H20Au2N2O2S2
cryst size, mm
cryst syst
0.26 × 0.12 × 0.11
monoclinic
space group
a, Å
P21/n
9.1976(15)
b, Å
17.8049(14)
P r ep a r a t ion
of
[Au {CdCH CHdC(CdNCHdCH -
c, Å
12.6733(18)
R, deg
90
â, deg
100.507(13)
90
4
2040.6(5)
2.456
14.03
CHdCH)S}P P h 3] (10). A solution of 2′-(2-thienyl)pyridine
γ, deg
(0.24 g, 1.49 mmol) in THF was cooled to -5 °C and treated
with standardized n-butyllithium in hexane (0.94 cm3, 1.50
mmol, 1.6 M). The solution was stirred at -5 °C for 40 min
before [AuCl(PPh3)] (0.64 g, 1.29 mmol) was added at -40 °C.
The mixture was stirred for 40 min at -40 °C and at room
temperature for 30 min before the solvent was removed. The
residue was washed once with ether, redissolved in CH2Cl2,
and filtered through Celite. Concentration of the colorless
filtrate, slow addition of hexane, and cooling to -20 °C afforded
yellow crystals of complex 10. Yield 55.8%, mp > 158 °C (dec).
Anal. Calcd for C27H21AuNPS: C, 52.35; H, 3.42; N, 2.26.
Found: C, 52.2; H, 3.5; N, 2.3.
Z
V, Å3
dc, g‚cm-3
µ, mm-1
radiation
Mo KR (0.710 73 Å)
25
temp, °C
F(000)
diffractometer
scan type
1192
Enraf-Nonius CAD 4
ω-2θ
2 e θ e 25
-10 to 10, 0-21, 0-15
5.5
60
3567
2777
235
2.196
0.027, 0.057
scan range, θ, deg
hkl ranges
max scan rate, deg min-1
max scan time per refln, s
no. of reflns measd
no. of unique reflns used
no. of params refined
goodness of fit
R, R′
P r ep a r a t ion of [Au {CdCH CHdC(CdN(Me)CHdCH -
CHdCH)S}P P h 3][CF 3SO3] (11). A solution of complex 10
(0.70 g, 1.13 mmol) in CH2Cl2 was cooled to 0 °C and treated
with CF3SO3Me (0.13 cm3, 1.13 mmol). The solution was
stirred at this temperature for 45 min and at room tempera-
ture for 1 h. The solvent was removed in vacuo, and the
residue was washed several times with diethyl ether. The
residue was redissolved in CH2Cl2 and filtered through Celite.
Concentration of the yellow filtrate, slow addition of hexane,
and cooling to -20 °C afforded orange blocks of complex 11.
a
2
R ) ∑(|Fo| - |Fc|)/∑|Fo|, R′ ) [∑w(|Fo| - |Fc|)2]/∑w|Fo| ]1/2, w )
1/σ2.
1 h at this temperature before warming to room temperature.
The solvent was removed in vacuo, and the residue was
washed several times with diethyl ether, redissolved in CH2-
Cl2, and filtered through Celite. Concentration of the colorless
filtrate, slow addition of diethyl ether, and cooling to -20 °C
afforded colorless crystals of complex 7. Yield 49.7%, mp 126-
127 °C. Anal. Calcd for C28H26AuF3NO4PS2: C, 42.59; H, 3.28;
N, 1.77. Found: C, 42.4; H, 3.3; N, 1.8.
Yield 45.90%, mp
29H24AuF3NO3PS2: C, 44.45; H, 3.09; N, 1.79. Found: C,
44.5; H, 3.0; N, 1.9.
> 150 °C (dec). Anal. Calcd for
C
X-r a y Cr ysta llogr a p h y for Com p lex 1. A yellow crystal
of 1 was mounted on a glass fiber and transferred onto the
diffractometer (Enraf-Nonius CAD4F). Data were collected
with graphite-monochromated Mo KR radiation (λ ) 0.710 73
Å) to 2θmax ) 30° and corrected for Lorentz and polarization
effects and for absorption using the Ψ-scan method. Unique
sets of data with I g 3.0σ(I) were used to solve the structure
of 1 by the heavy-atom method, placing two gold atoms
initially. The rest of the non-H atoms could be found from
difference maps and their positions refined with weighted
least-squares refinement. All non-H atoms were eventually
refined with anisotropic displacement parameters. The posi-
tions of only some of the H atoms could be found from
difference maps. Their positions were, therefore, calculated
in ideal positions. In the final cycles of refinement, the H
atoms were included with equal and constant isotropic dis-
placement parameters and no positional parameters were
refined. For structure solution and refinement, the XTAL 3.439
package was used while the H positions were calculated with
Shelx76.40 Important crystallographic parameters are given
in Table 4.
P r ep a r a t ion of [Au (C6F 5){CCd(CN(H )CMe2CH 2O)S-
CHdCH}] (8). A solution of 4′,4′-dimethyl-2′-(2-thienyl)-2′-
oxazoline (0.18 g, 1.00 mmol) in diethyl ether was cooled to
-80 °C and treated with standardized n-butyllithium in
hexane (0.63 cm3, 1.00 mmol, 1.6 M). The light yellow solution
was stirred at -80 °C for 20 min and at -10 °C for 30 min
before [Au(C6F5)(tht)] (0.45g, 1.00 mmol) was added at -75
°C. The mixture was stirred for 1 h at -80 °C and for 45 min
at -60 °C before the addition of CF3SO3H (0.10 cm3, 1.00
mmol). The reaction mixture was allowed to stir at this
temperature for 1 h before warming to room temperature. The
white precipitate was collected and washed several times with
diethyl ether, redissolved in CH2Cl2, and filtered through
Celite. Concentration of the colorless filtrate, slow addition
of diethyl ether, and cooling to -20 °C afforded colorless
needle-like crystals of complex 8. Yield 92.1%, mp > 170 °C
(dec). Anal. Calcd for C15H11AuF5NOS: C, 33.04; H, 2.03; N,
2.57. Found: C, 32.9; H, 1.9; N, 2.5.
P r ep a r a tion of [Au (C6F 5){NdC(CdCHCHdCHS)OCH2-
Su p p or tin g In for m a tion Ava ila ble: Tables of atomic
coordinates, bond distances, contact distances, bond angles,
and dihedral angles (6 pages). Ordering information is given
on any current masthead page.
CMe2}] (9). A solution of 4′,4′-dimethyl-2′-(2-thienyl)-2′-
oxazoline (0.19 g, 1.05 mmol) in THF was slowly added to a
solution of LDA, prepared from diisopropylamine (0.15 cm3,
1.06 mmol) and standardized n-butyllithium in hexane (0.67
cm3, 1.07 mmol, 1.6 M) at -70 °C. The reaction mixture was
allowed to stir at this temperature for 1 h, before [Au(C6F5)-
(tht)] (0.45g, 1.00 mmol) was added at -70 °C. The mixture
was stirred for 1 h at -70 °C and at -50 °C for 1 h before the
addition of CF3SO3H (0.10 cm3, 1.00 mmol). The reaction
mixture was allowed to stir at this temperature for 1 h before
OM970007Y
(39) Hall, S. R.; King, G. S. D.; Stewart, J . M. XTAL 34 Reference
Manual; Universities of Western Australia: Perth, 1995.
(40) Sheldrick, G. M. Program for Crystal Structure Determination;
University of Cambridge: England, 1978.