Unexpected ring-opening reaction to a new cyanamide-thiolate ligand stabilized as a dinuclear gold complex

Article abstract of DOI:10.1021/om010866t

We have synthesized the gold complexes [Au(C₆F₅)(2-amt)], 1, [Au(C₆F₅)(2-amt)], 2, and [Au(2-amt)(PPh₃)]{CF₃SO₃), 3, where 2-amt = 2-aminothiazoline (2-amino-4,5-dihydrothiazole) by displacement of labile ligands from corresponding gold(III) and gold(I) precursors. The reaction of 2-amt with [Au(acac)(PPh₃)] evolves to an unprecedented ring-opening reaction to give the new ligand (2-cyanamide)ethylthiolate, stabilized as a dinuclear gold(I) coordination derivative, [(AuPPh₃)₂(μ-SCH₂CH₂N-CN)], 4. The molecular structure of complexes 1 and 4 has been confirmed by X-ray diffraction studies. Complex 4 displays short gold-gold distances of 3.0821(3), 3.17618(19), and 3.2867(2) A?(three different molecules in two different crystal forms) and secondary sulfur-gold or nitrogen-gold bonds. Complexes 3 and 4 luminesce intensely in the solid state at low temperature.

Full text of DOI:10.1021/om010866t

Organometallics 2002, 21, 1877-1881
1877
Un exp ected Rin g-Op en in g Rea ction to a New
Cya n a m id e-Th iola te Liga n d Sta bilized a s a Din u clea r
Gold Com p lex
Manuel Bardaj´ı, Antonio Laguna,* and M. Reyes Pe´rez
Departamento de Quı´mica Inorga´nica, Instituto de Ciencia de Materiales de Arago´n,
Universidad de Zaragoza-CSIC, E-50009 Zaragoza, Spain
Peter G. J ones
Institut fu¨r Anorganische und Analytische Chemie der Technischen Universita¨t,
Postfach 3329, D-38023 Braunschweig, Germany
Received October 3, 2001
We have synthesized the gold complexes [Au(C6F5)3(2-amt)], 1, [Au(C6F5)(2-amt)], 2, and
[Au(2-amt)(PPh3)](CF3SO3), 3, where 2-amt ) 2-aminothiazoline (2-amino-4,5-dihydrothia-
zole) by displacement of labile ligands from corresponding gold(III) and gold(I) precursors.
The reaction of 2-amt with [Au(acac)(PPh3)] evolves to an unprecedented ring-opening
reaction to give the new ligand (2-cyanamide)ethylthiolate, stabilized as a dinuclear gold(I)
coordination derivative, [(AuPPh3)2(µ-SCH2CH2N-CN)], 4. The molecular structure of
complexes 1 and 4 has been confirmed by X-ray diffraction studies. Complex 4 displays short
gold-gold distances of 3.0821(3), 3.17618(19), and 3.2867(2) Å (three different molecules in
two different crystal forms) and secondary sulfur-gold or nitrogen-gold bonds. Complexes
3 and 4 luminesce intensely in the solid state at low temperature.
In tr od u ction
because of their established activity against rheumatoid
arthritis and tumors.4
The synthesis of monocyclic and condensed thiazoles
has attracted much attention because of their biological,
synthetic, and pharmaceutical importance.1 However,
ring-opening reactions of thiazoles are not common,
although some have been well studied, such as the
hydrolysis of thiazolidines (tetrahydrothiazoles) to give
aldehydes and amino-thiols by cleavage of C-S bonds.1,2
Metal complexes of thiazoles have been utilized as
models to investigate the relationship between medici-
nal effectiveness and coordination properties to metal
centers.3 Gold complexes have also been synthesized
Here we report the synthesis of mononuclear gold-
(III) and gold(I) complexes of 2-aminothiazoline (2-
amino-4,5-dihydrothiazole or 2-amt). We further report
the unprecedented ring-opening reaction of 2-amino-4,5-
dihydrothiazole (2-amt) to give the new ligand (2-
cyanamide)ethylthiolate stabilized as a dinuclear gold(I)
coordination derivative, which moreover shows very
short gold-gold distances. It has been shown that these
contacts play an important role, for instance, in the
stabilization of hypercoordinated phosphinogold(I) de-
rivatives around oxygen, sulfur, nitrogen, or carbon
centers.5 In addition we have demonstrated that some
of the new derivatives are photoluminescent in the solid
state at low temperature.
* Corresponding author. Tel: + 34 976 761185. Fax: + 34 976
761187. E-mail: alaguna@posta.unizar.es.
(1) (a) Dondoni, A.; Merino P. In Comprehensive Heterocyclic
Chemistry II; Katritzky, A. R., Rees, C. W., Scriven, E. R. V., Eds.;
Pergamon: Oxford, 1996; Vol. 3, p 376. (b) Metzger, J . V. In Compre-
hensive Heterocyclic Chemistry; Katritzky, A. R., Rees, C. W., Eds.;
Pergamon: Oxford, 1984; Vol. 6, p 235. (c) Uchikawa, O.; Fukatsu,
K.; Aono, T. J . Heterocycl. Chem. 1994, 31, 877.
Resu lts a n d Discu ssion
As outlined in Scheme 1, 2-amt displaces the labile
tetrahydrothiophene or triflate ligands in gold(III) and
gold(I) precursors to give the mononuclear gold com-
plexes 1-3.
IR spectroscopy clearly established the presence of
N-H and pentafluorophenyl in organometallic com-
plexes 1 and 2 and triflate anion in complex 3. 19F NMR
spectroscopy of 1 and 2 showed the presence of a unique
Au-(C6F5)3 or Au-C6F5 unit. The 31P{1H} NMR spec-
trum of 3 showed a singlet at 33.3 ppm. In the proton
(2) (a) Dondoni, A.; Marra, A.; Perrone, D. J . Org. Chem. 1993, 58,
275, and references therein. (b) Dondoni, A. Pure Appl. Chem. 1990,
62, 643. (c) Altman, L. J .; Richeimer, S. L. Tetrahedron Lett. 1971,
4709. (d) Meyers, A. I.; Durandetta, J . L. J . Org. Chem. 1975, 40, 2021.
(e) Mukaiyama, T.; Narasaka, K.; Furusato, M. J . Am. Chem. Soc.
1972, 94, 8641. (f) Luhowy, R.; Meneghini, F. J . Am. Chem. Soc. 1979,
101, 420. (g) Fife, T. H.; Natarajan, R.; Shen, C. C.; Bembi, R. J . Am.
Chem. Soc. 1991, 113, 3071.
(3) (a) Deguchi, S.; Fujioka, M.; Okamoto, Y.; Yasuda, T.; Nakamura,
N.; Yamaguchi, K.; Suzuki, S. J . Chem. Soc., Dalton Trans. 1996, 1967,
and references therein. (b) Raper, E. S.; Creighton, J . R.; Oughtred,
R. E. Inorg. Chim. Acta 1984, 87, 19. (c) Stocker, F. B.; Fadden, P.;
Dreher, S.; Britton, D. Inorg. Chem. 1999, 38, 3251. (d) Bolos, C. A.;
Fanourgakis, P. V.; Christidis, P. C.; Nikolov, G. St. Polyhedron 1999,
18, 1661. (e) Casanova, J .; Alzuet, G.; Borra´s, J .; Carugo, O. J . Chem.
Soc., Dalton Trans. 1996, 2239. (f) Kubiak, M.; Duda, A. M.; Ganadu,
M. L.; Kozlowski, H. J . Chem. Soc., Dalton Trans. 1996, 1905. (g) Tian,
Y.-N.; Yang, P.; Wang, H.-F.; Feng, Y.-L.; Liu, S.-X.; Huang, J .-L.
Polyhedron 1996, 15, 2721.
(4) Parish, R. V. Interdisciplinary Sci. Rev. 1992, 17, 221.
(5) (a) Bardaj´ı, M.; Laguna A. J . Chem. Educ. 1999, 76, 201. (b)
Pyykko¨, P. Chem. Rev. 1997, 97, 597. (c) Schmidbaur, H. Gold Bull.
2000, 33, 3.
10.1021/om010866t CCC: $22.00 © 2002 American Chemical Society
Publication on Web 04/02/2002

1878 Organometallics, Vol. 21, No. 9, 2002
Barda´ı et al.
Sch em e 1
Ta ble 1. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for Com p lex 1
Au-C(11)
Au-C(21)
Au-N(1)
Au-C(31)
S-C(3)
2.016(2)
2.063(2)
2.0664(18)
2.068(2)
1.751(2)
S-C(2)
1.821(3)
1.301(3)
1.470(3)
1.336(3)
1.518(3)
N(1)-C(3)
N(1)-C(1)
N(2)-C(3)
C(1)-C(2)
C(11)-Au-C(21)
C(11)-Au-N(1)
C(21)-Au-N(1)
C(11)-Au-C(31)
87.93(8)
176.63(7)
89.23(8)
92.26(8)
C(3)-N(1)-Au
C(1)-N(1)-Au
124.91(15)
121.17(14)
N(1)-C(1)-C(2) 107.79(19)
C(1)-C(2)-S
104.59(17)
C(21)-Au-C(31) 179.18(8)
N(1)-C(3)-N(2) 124.6(2)
N(1)-Au-C(31)
C(3)-S-C(2)
C(3)-N(1)-C(1)
90.61(8)
90.03(11) N(2)-C(3)-S
113.16(18)
N(1)-C(3)-S
115.47(16)
119.94(17)
stronger trans influence of pentafluorophenyl. Within
the molecule, the contacts N(2)-H(01)‚‚‚F(10) (2.61 Å,
158°) and, possibly, ‚‚‚Au (2.91 Å, 110°) might be
classified as hydrogen bonds. The intermolecular con-
tact N(1)-H(02)‚‚‚F(5) (2.22 Å, 151°) is more clear-
cut.
F igu r e 1. Molecular structure of complex 1.
NMR spectra the methylene protons of 2-amt are seen
as triplets and the amino group as a broad singlet. The
LSI MS mass spectra show the peaks at m/z (complex,
% abundance, assignment): 799 (1, 13, [M - H]+), 401
(2, 15, [Au(2-amt)2]+), 561 (3, 12, [M - CF3SO3]+).
We have also carried out reactions of 2-amt with [Au-
(acac)(PPh3)], which were intended to provide its con-
jugate base, where the imino tautomer becomes impor-
tant, in a complex involving the phosphino-gold(I) frag-
ment. Surprisingly, a mixture was obtained containing
free 2-amt and complex 4; the reaction in the 1:2 molar
ratio led to pure complex 4 (see Scheme 1), which is
formed by cleavage of the heterocyclic C-S bond and
subsequent rearrangement to give a 2-cyanamide-ethyl-
thiolate bridging ligand. As a first reaction step, we
propose that the amt conjugate base is obtained and the
phosphino-gold unit coordinates to the exocyclic nitro-
gen; a search in the Cambridge Structural Database
shows that metals are often coordinated by both nitro-
gen atoms of the amt conjugate base, but gold could be
coordinated by the exocyclic nitrogen and the sulfur
because it is a soft metal with a high affinity for sulfur.
Thus gold could promote the cleavage of the C-S bond
and the formation of an -NdCdNH unit, which could
be deprotonated and rearranged to the more stable
cyanamide group, stabilized by a second phosphino-gold.
We have monitored our reaction by NMR at -90 °C;
the phosphorus spectrum shows several resonances
We have confirmed the molecular structure of the
gold(III) complex 1 by X-ray diffraction studies (see
Figure 1). Suitable crystals were obtained from dichlo-
romethane-hexane. Selected bonds and angles are
shown in Table 1. The main features are (a) the gold-
(III) center displays a slightly distorted square planar
coordination with CAuC and CAuP angles ranging
from 87.93(8)° to 92.26(8)°; (b) 2-amt is coordinated
through the ring nitrogen atom with an Au-N distance
of 2.0664(18) Å; (c) the amino C-N bond length of
1.336(3) Å indicates a C-N bond order intermediate
between 1 (for instance N(1)-C(1) is 1.470(3) Å) and 2
(for instance N(1)-C(3) is 1.301(3) Å) but closer to a
double bond, which implies some electron density de-
localization as reported for similar complexes;3 (d)
the Au-C bond length trans to 2-amt (2.016(2) Å)
is shorter than that trans to pentafluorophenyl
(2.063(2) and 2.068(2) Å), as expected because of the

A New Cyanamide-Thiolate Ligand
Organometallics, Vol. 21, No. 9, 2002 1879
Ta ble 2. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for Com p lex 4a
Au(1)-P(1)
Au(1)-S
Au(1)-Au(2)
Au(2)-N(1)
Au(2)-P(2)
2.2757(11)
2.3031(10)
3.0821(3)
2.053(3)
S-C(1)
1.822(4)
1.313(5)
1.484(5)
1.519(6)
1.169(5)
N(1)-C(3)
N(1)-C(2)
C(1)-C(2)
C(3)-N(2)
2.2389(10)
P(1)-Au(1)-S
170.14(4)
P(1)-Au(1)-Au(2) 102.17(3)
C(3)-N(1)-C(2)
114.6(3)
C(3)-N(1)-Au(2) 121.5(3)
C(2)-N(1)-Au(2) 121.7(3)
S-Au(1)-Au(2)
N(1)-Au(2)-P(2)
N(1)-Au(2)-Au(1)
P(2)-Au(2)-Au(1) 113.91(3)
C(1)-S-Au(1) 108.91(14)
87.44(3)
172.02(10) C(2)-C(1)-S
72.35(9)
115.6(3)
111.7(3)
179.5(5)
N(1)-C(2)-C(1)
N(2)-C(3)-N(1)
Selected bond and angles for 4a and 4b are summarized
in Tables 2 and 3. All three molecules display two
phosphino-gold units bonded to the new 2-cyanamide-
ethyl-thiolate as bridging ligand, through an amide-
thiolate bridge. The main difference between the three
molecules are the angles at gold, the gold(I)‚‚‚gold(I)
distances, the presence or absence of a secondary
sulfur-gold(I) bond, and the conformations of the ring
Au(1)‚‚‚Au(2)-N(1)-C(2)-C(1)-S. The geometry around
the gold centers is linear, but with some distortions [4a :
P(1)-Au(1)-S 170.14(4)°, N(1)-Au(2)-P(2) 172.02-
(10)°; 4b: P(1)-Au(1)-S(1) 176.02(3)°, 178.75(3)°, N(1)-
Au(2)-P(2) 167.51(7)°, 162.54(8)°] with short gold-gold
distances of 3.0821(3), 3.17618(19), and 3.2867(2) Å,
respectively, and a secondary sulfur-gold(I) contact of
3.764(1), 3.0485(7), and 2.9533(8) Å, respectively. Thus
in 4a the shorter gold-gold distances are associated
with the much longer sulfur-gold distance, which is
unlikely to represent a significant interaction; there
is however in this case a short contact to nitrogen,
Au(1)‚‚‚N(1) 3.143(3) Å. The rings Au(1)‚‚‚Au(2)-N(1)-
C(2)-C(1)-S all display a distorted boat form, but in
4a Au(2) and C(1) lie out of the plane of the other four
atoms, whereas in 4b Au(1) and C(2) lie out of the plane.
This is clearly recognizable in the figures and correlates
with the Au‚‚‚S contacts. It is noteworthy that the
thiolate ligand shows C-N bond lengths of ca. 1.16,
1.31, and 1.47 Å corresponding to the CN, N-CN, and
N-CH2 fragments, respectively.
The solid state emission and excitation spectra have
been studied at 298 and 77 K. There is no emission at
room temperature. At low temperature complexes 1 and
2 do not luminesce, while complexes 3 and 4 luminesce
intensely. The dinuclear phosphino-thiolato complex 4
shows the emission maximum at 479 nm and the exci-
tation maximum at 350 nm, which in similar complexes
has been related (a) to the gold interactions, metal to
metal centered transition; (b) sulfur to gold transition,
ligand to metal charge transfer transition; (c) to the
S-Au‚‚‚Au unit, ligand to metal charge transfer modi-
fied by the gold-gold interactions.6 The mononuclear
amino-phosphino complex 3 displays the emission maxi-
mum at 444 nm with a shoulder at 515 nm and the
excitation maximum at 333 nm. Luminescent mono-
F igu r e 2. Molecular structure of complex 4: (a) 4a
(acetone solvate); (b) 4b (one independent molecule).
apart from the final product, whereas at -30 °C only
complex 4 is observed.
We have repeated the reaction in acetone in 1:1 molar
ratio, and rapidly a white precipitate was formed. The
solution contained free ligand and a small amount of
complex 4, while the solid was complex 4. The well-
known higher stability of thiolato gold(I) versus imino
gold(I) derivatives and the formation of the cyanamide
group should be the driving force of the reaction and
the reason we have not obtained a mononuclear imino
gold(I) complex.
The IR spectrum of derivative 4 shows no N-H
absorption, whereas an absorption at 2145 cm-1 associ-
ated with the cyano group is clearly seen. The proton
NMR spectrum shows methylene resonances as pseudo-
triplets with a smaller coupling constant than in the
previous 2-amt derivatives (5 Hz, cf. 7.5 Hz), and no
amino resonance is seen even at -90 °C. In the phos-
phorus NMR spectrum only a singlet is observed at 35.2
ppm, which broadens on lowering the temperature to
-90 °C but does not split into the two expected sig-
nals. The mass spectrum shows peaks at 1019 (5%)
corresponding to [M + H]+ and 1409 (8%) due to
[S(AuPPh3)3]+; the base peak at 459 is [AuPPh3]+.
Acetone solutions are nonconducting.
To confirm the structure of the new bridging cyana-
mide-thiolate ligand, we have determined the X-ray
structure (see Figure 2). Suitable crystals were obtained
from acetone-diethyl ether-petroleum ether (40:60).
Complex 4 crystallizes as two different solvates; 4a is
an acetone monosolvate, and 4b contains two indepen-
dent molecules of 4 and a partially occupied water site.
(6) (a) Forward, J . M.; Fackler, J . P., J r.; Assefa, Z. In Optoelectronic
Properties of Inorganic Compounds; Roundhill, D. M., Fackler, J . P.,
J r., Eds.; Plenum Press: London, 1998; pp 195-230. (b) Yam, V. W.-
W.; Lo, K. K.-W. Chem. Soc. Rev. 1999, 28, 323, and references therein.
(c) Bardaj´ı, M.; Laguna, A.; Vicente, J .; J ones, P. G. Inorg. Chem. 2001,
40, 2675. (d) J ones, W. B.; Yuan, J .; Narayanaswamy, R.; Young, M.
A.; Elder, R. C.; Bruce, A. E.; Bruce M. R. M. Inorg. Chem. 1995, 34,
1996. (e) Forward, J . M.; Bohmann, D.; Fackler, J . P., J r.; Staples, R.
J . Inorg. Chem. 1995, 34, 6330.

1880 Organometallics, Vol. 21, No. 9, 2002
Ta ble 3. Selected Bon d Len gth s (Å) a n d An gles (d eg) for Com p lex 4b
Barda´ı et al.
Au(1)-P(1)
Au(1)-S(1)
Au(1)-Au(2)
Au(2)-N(1)
Au(2)-P(2)
S(1)-C(1)
N(1)-C(3)
N(1)-C(2)
N(2)-C(3)
C(1)-C(2)
2.2577(7)
2.3072(7)
3.17618(19)
2.066(2)
2.2373(7)
1.824(3)
1.315(4)
1.469(3)
1.157(4)
1.515(4)
Au(3)-P(101)
Au(3)-S(101)
Au(3)-Au(4)
Au(4)-N(101)
Au(4)-P(102)
S(101)-C(101)
N(101)-C(103)
N(101)-C(102)
N(102)-C(103)
C(101)-C(102)
2.2650(7)
2.3128(7)
3.2867(2)
2.071(2)
2.2327(7)
1.824(3)
1.318(4)
1.464(4)
1.151(4)
1.509(5)
P(1)-Au(1)-S(1)
P(1)-Au(1)-Au(2)
S(1)-Au(1)-Au(2)
N(1)-Au(2)-P(2)
N(1)-Au(2)-Au(1)
P(2)-Au(2)-Au(1)
C(1)-S(1)-Au(1)
C(3)-N(1)-C(2)
C(3)-N(1)-Au(2)
C(2)-N(1)-Au(2)
C(2)-C(1)-S(1)
N(1)-C(2)-C(1)
N(2)-C(3)-N(1)
176.02(3)
112.12(2)
65.328(19)
167.51(7)
84.04(7)
107.326(19)
104.75(9)
115.5(2)
118.34(19)
125.26(17)
114.61(18)
113.4(2)
P(101)-Au(3)-S(101)
P(101)-Au(3)-Au(4)
S(101)-Au(3)-Au(4)
N(101)-Au(4)-P(102)
N(101)-Au(4)-Au(3)
P(102)-Au(4)-Au(3)
C(101)-S(101)-Au(3)
C(103)-N(101)-C(102)
C(103)-N(101)-Au(4)
C(102)-N(101)-Au(4)
C(102)-C(101)-S(101)
N(101)-C(102)-C(101)
N(102)-C(103)-N(101)
178.75(3)
118.225(19)
60.75(2)
162.54(8)
87.03(8)
107.91(2)
104.76(10)
116.7(3)
120.5(2)
122.6(2)
114.7(2)
112.6(3)
178.7(4)
178.8(3)
Ta ble 4. Deta ils of Cr ysta l Da ta a n d Str u ctu r e Refin em en t for Com p lexes 1 a n d 4
1
4a
4b
empirical formula
fw
C
21H6AuF15N2S
C42H40Au2N2OP2S
1076.69
C39H34.36Au2N2O0.18P2S
1021.86
800.30
temperature/K
wavelength/Å
cryst syst
space group
a/Å
133
0.71073
triclinic
P1h
9.4658(8)
9.8107(8)
12.8953(11)
75.409(3)
80.164(3)
88.393(3)
1141.74(17)
2
2.328
133
0.71073
133
0.71073
orthorhombic
P212121
10.0414(8)
10.3564(8)
37.010(3)
90
monoclinic
P21/n
16.4127(11)
13.5924(8)
31.2528(18)
90
93.218(3)
90
6961.1(7)
8
b/Å
c/Å
R/deg
â/deg
90
90
γ/deg
volume/Å3
Z
3848.8(5)
4
1.858
7.788
2072
density(calcd)/Mg/m3
abs coeff/mm-1
F(000)
1.950
8.604
3902
6.672
752
cryst habit
cryst size/mm
θ range for data collection
index ranges
colorless square prism
0.33 × 0.19 × 0.18
1.66 to 30.03
-13 e h e 13, -13 e k e 13,
-18 e l e 18
23 792
6643 [R(int) ) 0.0196]
0.564 and 0.371
6643/104/369
1.047
colorless needle
0.45 × 0.08 × 0.04
2.04 to 30.04
-14 e h e 14, -14 e k e 14,
-52 e l e 52
77 204
11 265 [R(int) ) 0.0684]
0.862 and 0.497
11265/133/454
0.957
colorless tablet
0.35 × 0.26 × 0.11
1.31 to 30.03
-23 e h e 23,-19 e k e 19,
-44 e l e 44
141 032
20 341 [R(int) ) 0.0478]
0.564 and 0.309
20341/254/834
0.983
no. of reflns collected
no. of ind reflns
max. and min. transmn
no. of data/restraints/params
goodness-of-fit on F2
R1 [I>2σ(I)]a
0.0177
0.0451
3.398, -0.908
0.0245
0.0471
1.871 and -0.929
0.0224
0.0512
1.401 and -0.908
wR2 (all data)b
largest diff peak and hole/e Å-3
a
b
2
2
R1(F) ) ∑||Fo| - |Fc||/∑|Fo|. wR2(F2) ) [∑{w(Fo - Fc2)2}/∑{w(Fo2)2}]0.5; w-1 ) σ2(Fo2) + (aP)2 + bP, where P ) [Fo + 2Fc2]/3 and a
and b are constants adjusted by the program.
recorded on a Bru¨ker ARX‚300 or GEMINI 2000 apparatus
in CDCl3 solutions (if no other solvent is stated); chemical
shifts are quoted relative to SiMe4 (external, 1H), CFCl3
(external, 19F), and 85% H3PO4 (external, 31P). C, H, N, and S
analyses were performed with a Perkin-Elmer 2400 microana-
lyzer. Conductivities were measured in acetone solution with
a Philips PW 9509 apparatus. Mass spectra were recorded on
a VG Autospec using LSI MS technique (with a Cs gun) and
3-nitrobenzyl alcohol as matrix. The luminescence spectra were
recorded on a Perkin-Elmer LS-50B spectrofluorometer.
P r ep a r a tion of Com p ou n d s. [Au (C6F 5)x(2-a m t)], x ) 3
(1), x ) 1 (2). To a 15 mL dichloromethane or diethyl ether
solution of [Au(C6F5)x(tht)]7,8 (tht ) tetrahydrothiophene; 0.1
nuclear gold(I) complexes usually are three-coordinated
or display short gold-gold distances.6a In addition, the
2-amt ligand displays an emission centered at 457 nm
with the excitation maximum at 287 nm, which indi-
cates that the emission of complex 3 could be ligand
centered but modified by the phosphino-gold(I) unit.
Exp er im en ta l Section
Gen er a l P r oced u r es. All the reactions were carried out
under an argon atmosphere at room temperature. IR spectra
were recorded on a Perkin-Elmer 883 spectrophotometer, over
the range 4000-200 cm-1, by using Nujol mulls between
1
polyethylene sheets. H, 19F, and 31P{1H} NMR spectra were
(7) Uso´n, R.; Laguna, A.; Laguna, M. Inorg. Synth. 1989, 26, 87.

A New Cyanamide-Thiolate Ligand
Organometallics, Vol. 21, No. 9, 2002 1881
g; x ) 3, 0.13 mmol; x ) 1, 0.22 mmol) was added the
ligand 2-amt (13 mg, 0.13 mmol; 22 mg, 0.22 mmol). After
stirring for 2 h, the solution was concentrated to ca. 3 mL.
Addition of cold hexane afforded complexes 1 and 2 as white
solids, which were washed with cold hexane. Yield of 1: 80
mg (79%). Data for 1: 1H NMR δ 5.60 (s, 2H; NH2), 3.98 (t,
3J (H,H) ) 7.6 Hz, 2H; CH2), 3.47 (t, 2H; CH2); 19F NMR δ
-123.43 (m, 2Fo), -124.49 (m, 4Fo), -156.91 (t, 3J (F,F) ) 20.1
Hz, 2Fp), -157.79 (t, 3J (F,F) ) 20.1 Hz, 1Fp), -161.27 (m, 4Fm),
-162.47 (m, 2Fm); IR 3516, 3410 (N-H), 964, 816, 797 (C6F5)
cm-1. Anal. Calcd for C21H6AuF15N2S (800.3): C, 31.5; H, 0.75;
N, 3.5; S, 4.0. Found: C, 31.6; H, 0.8; N, 3.59; S, 3.75. LSI MS
(m/z (%, assignment)): 799 (13, [M - H]+), 466 (100, [M -
2(C6F5)]+). Λ: 2.1 Ω-1 cm2 mol-1. Yield of 2: 97 mg (95%). Data
mg, 0.2 mmol), and the mixture was stirred for about 1 h. The
solution was concentrated to ca. 2 mL, and the addition of
petroleum ether afforded 4 as a white solid. Yield: 82 mg
1
3
(80%). H NMR: δ 7.5-7.3 (m, 30H; Ph), 3.78 (‘t’, N(H,H) )
5.0 Hz, 2H; CH2), 3.27 (‘t’, 2H; CH2). 1H NMR (CD2Cl2, -90
°C): δ 7.5-7.3 (m, 30H; Ph), 3.79 (br, 2H; CH2), 3.25 (br, 2H;
CH2). 31P{1H} NMR: δ 35.2 (s). 31P{1H} NMR (CD2Cl2, -90
°C): δ 34.9 (br). IR: 2145 cm-1 (CN). Anal. Calcd for C39H34
-
Au2N2P2S (1018.7): C, 46.0; H, 3.35; N, 2.75; S, 3.15. Found:
C, 45.7; H, 3.25; N, 2.65; S, 3.0. LSI MS (m/z (%, assign-
ment)): 459 (100, [AuPPh3]+), 721 (47, [Au(PPh3)2]+), 1019 (5,
[M + H]+), 1147 (16, [S(AuPPh3)3 - PPh3]+), 1409 (8, [S(Au -
PPh3)3]+). Λ: 5 Ω-1 cm2 mol-1
.
Cr ysta l Str u ctu r e Deter m in a tion of 1 a n d 4. Crystal
data and details of data collection and structure refinement
of [Au(C6F5)3(2-amt)] 1 and [(AuPPh3)2(µ-SCH2CH2N-CN)] 4
(4a is an acetone monosolvate, 4b contains two independent
molecules of 4 and a partially occupied water site) are given
in Table 4. Data were measured on a Bruker SMART 1000
CCD diffractometer. Absorption corrections were based on
multiple scans (program SADABS). The structures were
refined anisotropically on F2 (program SHELXL-9711) using a
system of restraints (light-atom U values and local ring
symmetry). H atoms were included using a riding model.
3
for 2: 1H NMR δ 5.68 (s, 2H; NH2), 4.20 (t, J (H,H) ) 7.6 Hz,
2H; CH2), 3.54 (t, 2H; CH2); 19F NMR δ -117.50 (m, 2Fo),
-160.74 (t, 3J (F,F) ) 20.1 Hz, 1Fp), -164.16 (m, 2Fm). IR:
3513, 3488, 3460, 3379, 3352 (N-H), 954, 806 (C6F5) cm-1
.
Anal. Calcd for C9H6AuF5N2S (466.2): C, 23.2; H, 1.3; N, 6.0;
S, 6.9. Found: C, 23.05; H, 1.3; N, 6.05; S, 6.55. LSI MS (m/z
(%, assignment)): 401 (15, [Au(2-amt)2]+). Λ: 4.5 Ω-1 cm2
mol-1
.
[Au (2-a m t)(P P h 3)]CF 3SO3, 3. To a 15 mL dichloromethane
solution [Au(PPh3)(CF3SO3)] (0.2 mmol, prepared in situ by
reaction of [AuCl(PPh3)]9 with [Ag(CF3SO3)]) was added the
ligand (21 mg, 0.2 mmol). After the mixture was stirred for 1
h, the solution was concentrated to ca. 2 mL and diethyl ether
(15 mL) was added to obtain 3 as a white solid, which was
washed with diethyl ether. Yield: 107 mg (75%). Data for 3:
1H NMR δ 7.5-7.3 (m, 15H; Ph), 6.43 (br, 2H; NH2), 3.93 (t,
3J (H,H) ) 7.3 Hz, 2H; CH2), 3.42 (t, 2H; CH2). 19F NMR δ
-79.1 (s, CF3); 31P{1H} NMR δ 33.3 (s). IR: 3312, 3167 (N-
Ack n ow led gm en t. We thank the Direccio´n General
de Investigacio´n Cient´ıfica y Te´cnica (Project PB97-
1010-C02-01) and the Fonds der Chemischen Industrie
for financial support. We also thank Dr. J . Galba´n
(Universidad de Zaragoza, Zaragoza, Spain) for kindly
providing apparatus facilities.
H), 1286, 1157, 637 (CF3SO3) cm-1. Anal. Calcd. for C22H21
-
AuF3N2O3PS2 (710.5): C, 37.2; H, 3.0; N, 3.95; S, 9.05.
Found: C, 37.05; H, 2.95; N, 4.0; S, 8.8. LSI MS (m/z (%,
assignment)): 459 (100, [AuPPh3]+), 561 (12, [M - CF3SO3]+),
Su p p or tin g In for m a tion Ava ila ble: An X-ray crystal-
lographic file in CIF format for the structure determination
of complexes 1 and 4 (4a and 4b). This material is available
free of charge via the Internet at http://pubs.acs.org.
721 (60, [Au(PPh3)2]+). Λ: 110 Ω-1 cm2 mol-1
.
[(Au P P h 3)2(µ-k S,k N1-SCH2CH2N-CN)], 4. To a solution
of 2-amt (10 mg, 0.1 mmol) was added [Au(acac)(PPh3)]10 (112
OM010866T
(8) Uso´n, R.; Laguna, A.; Vicente, J . J . Chem. Soc., Chem. Commun.
1976, 353.
(9) Schmidbaur, H.; Wohlleben, A.; Wagner, F.; Orama, O.; Huttner,
G. Chem. Ber. 1977, 110, 1748.
(10) Vicente, J .; Chicote, M. T. Inorg. Synth. 1998, 32, 175.
(11) Sheldrick, G. M. SHELXL 97: A Program for Crystal Structure
Refinement; University of Go¨ttingen: Go¨ttingen, Germany, 1997.