Trinuclear Au2Ag and Au2Cu complexes with mesityl bridging ligands. X-ray structure of the chain polymer [{Au(μ-mes) AsPh3}2Ag] (ClO4)

Article abstract of DOI:10.1021/om9602062

The reaction of the complex [Au(mes)L] (mes = mesityl, L = PPh₃, AsPh₃) with Ag(OSO₂-CF₃), Ag(OClO₃), or [Cu(CNMe)₄]PF₆, in molar ratio 2:1, affords trinuclear derivatives [{Au-(

Full text of DOI:10.1021/om9602062

Organometallics 1996, 15, 4939-4943
4939
Tr in u clea r Au 2Ag a n d Au 2Cu Com p lexes w ith Mesityl
Br id gin g Liga n d s. X-r a y Str u ctu r e of th e Ch a in P olym er
[{Au (µ-m es)AsP h 3}2Ag](ClO4)
Mar´ıa Contel,† J ulia´n Garrido,† M. Concepcio´n Gimeno,‡ Peter G. J ones,§
Antonio Laguna,‡ and Mariano Laguna*,‡
Departamento de Quı´mica Aplicada, Universidad Pu´blica de Navarra,
E-31006 Pamplona, Spain, Departamento de Qu´ımica Inorga´nica, Instituto de Ciencia de
Materiales de Arago´n, Universidad de Zaragoza-CSIC, E-50009 Zaragoza, Spain, and Institut
fu¨r Anorganische und Analytische Chemie der Technischen Universita¨t, Postfach 3329,
D-38023 Braunschweig, Germany
Received March 19, 1996X
The reaction of the complex [Au(mes)L] (mes ) mesityl, L ) PPh3, AsPh3) with Ag(OSO2-
CF3), Ag(OClO3), or [Cu(CNMe)4]PF6, in molar ratio 2:1, affords trinuclear derivatives [{Au-
-
-
-
(µ-mes)L}2M]A [M ) Ag, L ) PPh3, A ) SO3CF3 (1); L ) AsPh3, A ) ClO4 (2a ), SO3CF3
-
(2b); M ) Cu, A ) PF6 L ) PPh3 (3), AsPh3 (4)]. Complexes 1 and 2 react further with
,
various ligands in a 1:1 molar ratio to give the dinuclear compounds [AuAg(µ-mes)-
(PPh3)L]SO3CF3 (L ) PPh3, tetrahydrothiophene, 2,2′-bipyridine, or SPPh3) or [AuAg(µ-
1
mes)(AsPh3)L]A (L ) AsPh3, A ) SO3CF3-; L ) /2 Ph2AsCH2AsPh2, A ) ClO4-). The
structure of [{Au(µ-mes)AsPh3}2Ag](ClO4) (2a ) has been determined by a single-crystal X-ray
diffraction study, which shows an Au-Ag distance of 2.7758(8) Å; the trinuclear species are
connected by short Au‚‚‚Au contacts of 3.132 Å to form a chain polymer.
In tr od u ction
silver(I) or copper(I) centers with gold complexes that
are nucleophilic either at the gold atoms (e.g. [{AuAg-
(C6F5)2(C6H6)}n],8 [Au13Ag12Cl8{P(C6H4Me-p)3}10]PF6,9
[Pt(AgNO3){Au(PPh3)}8][NO3]2,10[Pt(CuCl){Au(PPh3)}8]-
[NO3]219) or at other donor atoms such as phosphorus
(e.g. [{Au(mes)}2(µ-dppm)2Ag]ClO417), nitrogen (e.g.
[(Au P P h 3)2{µ-C(P P h 3)(C5H 4N)}{µ-Ag(O2NO)(OCl-
O3)}]5,6), or carbon (e.g. [{(Ph3P)Au(µ-mes)Ag(tht)}2][SO3-
CF3]2,7 NBu4[Au3Cu3(C2Ph)6]20). The former type gives
heteronuclear complexes with unbridged gold-metal
bonds, whereas the latter forms heteronuclear com-
plexes with bridging ligands and with short contacts
between the metallic centers.
Recent studies of hypercoordinated derivatives of
representative elements with Au(PR3) fragments have
shown that weak gold-gold interactions,1 frequently
observed in gold clusters and in some gold(I) complexes,
contribute significantly to the stability of these species
and are indeed the sole explanation for the formation
of some of them (e.g. [N(AuPMe3)5‚AuClPMe3]2). These
interactions, which can be compared in strength to a
typical hydrogen bond (29-33 kJ mol-1 3
and are
)
brought about by relativistic effects,4 have also been
observed recently in heteronuclear gold-silver5-18 and
gold-copper18-22 derivatives. Most of these hetero-
nuclear complexes have been obtained by reacting acidic
In this paper we report the synthesis of trinuclear
Au2Ag and Au2Cu derivatives obtained by the reaction
of [Au(mes)L] (mes ) mesityl, L ) PPh3, AsPh3) with
† Universidad Pu´blica de Navarra.
‡ Universidad de Zaragoza.
§ Technische Universita¨t Braunschweig.
X Abstract published in Advance ACS Abstracts, October 1, 1996.
(1) (a) J ones, P. G. Gold Bull. 1981, 14, 102; 1983, 16, 1142; 1986,
19, 46. (b) J iang, Y.; Alvarez, S.; Hoffmann, R. Inorg. Chem. 1985, 24,
749. (c) Scherbaum, F.; Grohmann, A.; Mu¨ller, G.; Schmidbaur, H.
Angew. Chem., Int. Ed. Engl. 1989, 28, 463. (d) Schmidbaur, H. Gold
Bull. 1990, 23, 11.
(11) Uso´n, R.; Laguna, A.; Laguna, M.; Uso´n, A.; J ones, P. G.;
Erdbru¨gger, C. F. Organometallics 1987, 6, 1778.
(12) Abu-Salah, O. M.; Knobler, C. B. J . Organomet. Chem. 1986,
302, C10.
(13) Teo, B. K.; Keating, K. J . Am. Chem. Soc. 1984, 106, 2224.
(14) Kappen, T. G. M. M.; Schlebos, P. P. J .; Bour, J . J .; Bosman,
W. P.; Smits, J . M. M.; Beurskens, P. T.; Steggerda, J . J . Inorg. Chem.
1994, 33, 754.
(15) Copley, R. C. B.; Mingos, D. M. P. J . Chem. Soc., Dalton Trans.
1992, 1755.
(16) Teo, B. K.; Zhang, H.; Shi, X. J . Am. Chem. Soc. 1993, 115,
8489.
(17) Contel, M.; Garrido, J .; Gimeno, M. C.; J ime´nez, J .; J ones, P.
G.; Laguna, A.; Laguna, M. Inorg. Chim. Acta, in press.
(18) Henkel, G.; Krebs, B.; Betz, P.; Fietz, H.; Saatkamp, K. Angew.
Chem., Int. Ed. Engl. 1988, 27, 1326.
(19) Schoondergang, M. F. J .; Bour, J . J .; Schlebos, P. P. J .; Vermeer,
A. W. P.; Bosman, W. O.; Smits, J . M. M.; Beurskens, P. T.; Steggerda,
J . J . Inorg. Chem. 1991, 30, 4704.
(2) Argermaier, K.; Schmidbaur, H. Inorg. Chem. 1995, 34, 3120.
(3) Schmidbaur, H.; Graf, W.; Mu¨ller G. Angew. Chem., Int. Ed.
Engl. 1988, 27, 417.
(4) (a) Pyykko, P.; Desclaux, J . P. Acc. Chem. Res. 1979, 12, 276.
(b) Pitzer, K. S. Acc. Chem. Res. 1979, 12, 271. (c) Pyykko, P. Chem.
Rev. 1988, 88, 563. (d) Li, J .; Pyykko P. Chem. Phys. Lett. 1992, 197,
586.
(5) Vicente, J .; Chicote, M. T.; Lagunas, M. C.; J ones, P. G. J . Chem.
Soc., Chem. Commun. 1991, 1730.
(6) Vicente, J .; Chicote, M. T.; Lagunas, M. C. Inorg. Chem. 1993,
32, 3748.
(7) Contel, M.; J ime´nez, J .; J ones, P. G.; Laguna, A.; Laguna, M. J .
Chem. Soc., Dalton Trans. 1994, 2515.
(8) Uso´n, R.; Laguna, A.; Laguna, M.; Manzano, B. R.; J ones, P. G.;
Sheldrick, G. M. J . Chem. Soc., Dalton Trans. 1984, 285.
(9) Teo, B. K.; Zhang, H. Angew. Chem., Int. Ed. Engl. 1992, 31,
445.
(10) Kanters, R. P. F.; Schlebos, P. P. J .; Bour, J . J .; Bosman, W P.;
Smits, J . M. M.; Beurskens, P. T.; Steggerda, J . J . Inorg. Chem. 1990,
29, 324.
(20) Abu-Salah, O. M.; Al-Ohaly, A. R. A.; Knobler, C. B. J . Chem.
Soc., Chem. Commun. 1985, 1502.
(21) Coucouvanis, D.; Kanodia, S.; Swenson, D.; Chen, S.-T.; Stu-
demann, T.; Baenziger, N. C.; Pedelty, R.; Chu, M. J . Am. Chem. Soc.
1993, 115, 11271.
(22) Brown, S. S. D.; Salter, I. D.; Adatia, T. J . Chem. Soc., Dalton
Trans. 1993, 559.
S0276-7333(96)00206-3 CCC: $12.00 © 1996 American Chemical Society

4940 Organometallics, Vol. 15, No. 23, 1996
Contel et al.
Sch em e 1
-
weakly coordinated silver or copper compounds such as
Ag(OSO2CF3), Ag(OClO3), or [Cu(CNMe)4]PF6 in molar
ratio 2:1. The X-ray diffraction analysis of [{Au(µ-mes)-
AsPh3}2Ag](ClO4) shows the central silver atom to be
coordinated to two Au-Ag-bridging mesityl groups. The
trinuclear molecules are connected through intermo-
lecular gold-gold contacts of 3.132 Å, giving rise to a
chain polymer. The reaction of the trinuclear Au2Ag
derivatives [{Au(µ-mes)L}2Ag](A) with various neutral
ligands in 1:1 ratio affords dinuclear complexes [AuAg-
(µ-mes)(PPh3)L′]SO3CF3 (L′ ) PPh3, tetrahydrothiophene,
2,2′-bipyridine, or SPPh3) or [AuAg(µ-mes)(AsPh3)L′]A
(L′ ) AsPh3, A ) SO3CF3-; L′ ) 1/2 Ph2AsCH2AsPh2, A
) ClO4-).
SO3CF3 (2b)) can be synthesized starting from [Au-
(mes)AsPh3].
Complexes 1 and 2 are air- and moisture-stable yellow
(2a ) or pale yellow solids. Acetone solutions display
conductivities typical of 1:1 electrolytes,23 and the IR
-
spectra show absorptions arising from the SO3CF3
counterions24 at 1275 (vs, br), 1221 (m), and 1142 (s)
cm-1 (1) and 1292 (vs, br), 1223 (s), and 1152 (s) cm-1
-
(2b). Absorptions assigned25 to ClO4 appear at 1094
(vs, br) and 623 cm-1 (2a ). The absorptions from the
mesityl groups are present at 1596 (m), 847 (m) cm-1
(1), 1596 (m), 855 (m) cm-1 (2a ), and 1594 (w), 851 (m)
cm-1 (2b). These signals are shifted to higher energy
than in the starting products, as was observed in other
mesityl-bridged complexes.7,26 Their 1H NMR spectra
show three singlets for the mesityl ligand, slightly
displaced from the resonances of the starting material,
and in a consistent ratio with the phenyl resonances of
the ancillary ligands. The singlet at 43.4 ppm in the
31P{1H} NMR spectrum of 1 is high-field displaced from
the signal of the starting material, as in other poly-
nuclear gold complexes with mesityl bridges. The mass
spectra (FAB+) show, for all the compounds, the ion
peak [M - SO3CF3]+ at m/z 1266 (23%, 1) and 1352
(27%, 2b) or [M - ClO4]+ at m/z 1352 (52%, 2b).
Resu lts a n d Discu ssion
Recently7 we have shown that mesityl in mononuclear
derivatives [Au(mes)L] (mes ) mesityl, L ) PPh3,
AsPh3) can replace poorly coordinated ligands such
OClO3 or OSO2CF3 in Ag(OClO3)L and Ag(OSO2CF3)L
affording dinuclear [AuAg(µ-mes)(PPh3)L]SO3CF3 (L )
PPh3, tetrahydrothiophene). The mass spectrum of the
bis(triphenylphosphine) derivative showed, besides the
parent ion peak [M - SO3CF3]+, an ion at m/z 1266
(11%) assignable to [Au2Ag(mes)2(PPh3)2]+. This indi-
cates that an ion of this type could be stable, and thus
a similar reaction involving [Au(mes)PPh3] and Ag(OSO2-
CF3) in a 2:1 ratio is a potential method of synthesis of
this complex. The reaction works well in diethyl ether,
affording bright yellow solutions from which the tri-
nuclear Au2Ag derivative [{Au(µ-mes)PPh3}2Ag]SO3CF3
(1) (see reaction i, Scheme 1) can be obtained. However,
[{Au(µ-mes)PPh3}2Ag](ClO4) cannot be isolated in pure
form using Ag(OClO3), because the final solid also
contains [AuAg(µ-mes)(PPh3)2](ClO4). The novel com-
The structure of complex 2a has been determined by
an X-ray diffraction study (Figures 1 and 2); selected
bond lengths and angles are given in Table 1. The
molecule exhibits inversion symmetry with the silver
atom on the special position (0.5, 0.5, 0.5). The silver
center is bonded to the ipso carbon atoms of the mesityl
(23) Geary, W. J . Coord. Chem. Rev. 1971, 7, 81.
(24) J ohnston, D. H.; Shriver, D. F. Inorg. Chem. 1993, 32, 1045.
(25) Gowda, M. N.; Naikar, S. B.; Reddy, G. K. N. Adv. Inorg. Chem.
Radiochem. 1984, 28, 255.
(26) Uson, R.; Laguna, A.; Fernandez, E. J .; Ruiz, M. E.; J ones, P.
G.; Lautner, J . J .Chem. Soc., Dalton Trans. 1989, 2127.
-
plexes [{Au(µ-mes)AsPh3}2Ag](A) (A ) ClO4 (2a ) and

Trinuclear Au2Ag and Au2Cu Complexes
Organometallics, Vol. 15, No. 23, 1996 4941
F igu r e 3. Representation of the two-electron three-center
Au-C(mesityl)-Ag bond.
bonds, such as [Au13Ag12Cl8{P(C6H4Me-4)3}10]PF6 (aver-
age 2.883 Å),9 [{AuAg(C6F5)2(C6H6)}n] [2.702(2), 2.792-
(2) A],8 or [Pt(AgNO3){Au(PPh3)}8](NO3)2 [2.714(5)-
2.786(5) Å].10 Thus an appreciable silver-gold bonding
interaction should be postulated in 2a . Short, presum-
ably bonding, interactions also exist in other complexes
with bridging mesityl groups, e.g. [Au5(mes)5]27 where
the gold-gold contacts are 2.692(1) and 2.708(2) Å and
there is great deviation from linearity at the gold atoms.
In [Ag4(mes)4]27 the silver-silver interactions are 2.733(3)
and 2.755(3) Å with angles of 169.0(9)° at the silver
center. Short Au-Au contacts have been found in
complexes with other bridging aromatic groups such as
[C5H5FeC5H4(AuPPh3)2]+ [2.768(2) A]28 or [C6F3H2-
(AuPPh3)2]+ [2.759(1) Å].29 The deviation from linearity
at the gold atom [C(1)-Au-As 166.8(4)°] is only moder-
ate.
F igu r e 1. Perspective view of the individual molecule of
complex 2a showing the atom-numbering scheme. Dis-
placement parameter ellipsoids represent 50% probabily
surfaces. H atoms are omitted for clarity.
The M-C bond lengths were not determined with
high precision, but the values Au-C(1) 2.09(2) Å and
Ag-C(1) 2.27(2) Å are similar to those found in the
complexes mentioned above. The Ag-C-Au angle at
the bridging carbon is acute [78.9(7)°] as has been
observed in complexes for which 3c,2e- bonding is post-
ulated: [Al2Ph6],30 77°; [Al2Ph2Me4],31 77.8°; [Cu4R4]32
(R ) C6H4NMe2), 71.35°, and related complexes.
The most important orbital interactions for the Au-
C-Ag bridge are shown in Figure 3a,b. The former
shows that there is a bond not only between C and Ag
but also between the metal atoms. The latter (Figure
3b), displays a nonbonding contribution between the
gold and silver atoms, but it is responsible for the
commonly found orientation of a bridging aryl perpen-
dicular to the metal‚‚‚metal vector as occurs in complex
2a . It is noteworthy that the mesityl bridge it is not
symmetrically disposed [Au-C(1)-C(4) 163.3°, Ag-
C(1)-C(4) 110.7°] in contrast to the usual symmetrical
disposition of the aryl ligand in the examples above
mentioned. Preliminary extended Huckel calculations33
show not very important changes in energy depending
on this angle, the lowest energy being at the Au-C(1)-
C(4) angle of 150°. The small deviation between the
observed and theoretical values could be due to the
crystal packing to form a unidimensional chain polymer
parallel to the y axis by intermolecular gold-gold
contacts (related by a 2-fold axis) of 3.132(2) Å.
F igu r e 2. Part of the polymeric chain of complex 2a .
Ta ble 1. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 2a a
Au-C(1)
Au-Ag
Ag-C(1)
As-C(11)
2.09(2)
2.7758(8)
2.27(2)
Au-As
2.425(2)
3.132(2)
1.927(11)
1.941(10)
Au-Au1
As-C(31)
As-C(21)
1.928(11)
C(1)-Au-As
166.8(4)
120.14(6)
100.13(6)
180.0
132.4(6)
103.2(7)
104.0(6)
106.9(5)
119(2)
C(1)-Au-Ag
C(1)-Au-Au1
Ag-Au-Au1
C(1)-Ag-Au
Au-Ag-Au2
C(31)-As-C(21)
C(31)-As-Au
C(21)-As-Au
C(2)-C(1)-Au
C(2)-C(1)-Ag
Au-C(1)-Ag
53.5(5)
90.2(5)
136.08(4)
47.6(6)
As-Au-Ag
As-Au-Au1
C(1)-Ag-C(1)2
C(1)2-Ag-Au
C(31)-As-C(11)
C(11)-As-C(21)
C(11)-As-Au
C(2)-C(1)-C(6)
C(6)-C(1)-Au
C(6)-C(1)-Ag
180.0
104.2(6)
118.7(5)
118.0(5)
116.4(12)
105.4(9)
78.9(7)
122.1(13)
100.2(11)
a
Symmetry transformations used to generate equivalent at-
oms: (1) -x + 1, y, -z + 3/2; (2) -x + 1, -y + 1, -z + 1.
(27) Meyer, E. M.; Gambarotta, S.; Floriani, C.; Chiesi-Villa, C.;
Guastini, C. Organometallics 1989, 8, 1067.
groups and also bridges the two gold fragments with
an Ag-Au distance of 2.7758(8) Å. This distance is
shorter than those found in complexes where a formally
nonbonding Ag‚‚‚Au interaction has been proposed, e.g.
[Ag(µ-dppm)2{Au(mes)}2]ClO4 [2.944(2) and 2.946(2)
Å],17 [(AuPPh3)2{µ-C(PPh3)(C5H4N)}{µ-Ag(O2NO)(OCl-
O3)}] [2.926(1), 3.006(1) Å],5 or [{(Ph3P)Au(µ-mes)Ag-
(tht)}2](SO3CF3)2 [2.8245(6) Å],7 but is of the same order
as those found in complexes with formal silver-gold
(28) Nesmenayov, A. N.; Perevolova, E. G.; Grandberg, K. I.;
Lemenovskii, D. A.; Bankova, T. V.; Afanassova, O. B. J . Organomet.
Chem. 1974, 65, 131.
(29) Uso´n, R.; Laguna, A.; Ferna´ndez, E. J .; Mend´ıa, A.; J ones, P.
G. J . Organomet. Chem. 1988, 350, 129.
(30) Malone, J . F.; McDonald, V. S. J . Chem. Soc., Chem. Commun.
1967, 444.
(31) Malone, J . F.; McDonald, V. S. J . Chem. Soc., Chem. Commun.
1970, 280.
(32) J anssen, D. M.; Corsten, M. A.; Spek, A. L.; Grove, D. M.; van
Koten, G. Organometallics 1996, 15, 2810 and references therein.
(33) Meali, C.; Proserpio, D. M. J . Chem. Educ. 1990, 67, 399.

4942 Organometallics, Vol. 15, No. 23, 1996
Contel et al.
Reactions of [Cu(CH3CN)4]PF6 with [Au(mes)L] (L )
PPh3, AsPh3) in a 1:2 ratio afford trinuclear gold-copper
complexes [{Au(µ-mes)L}2Cu](PF6) (L ) PPh3 (3), AsPh3
(4)) as white solids in good yield (reaction ii). They are
air- and moisture-stable solids, and their acetone solu-
tions show conductivity values for a 1:1 electrolyte.
ligand is bonded to the silver atom). The latter appears
at 37.17 ppm as a broad doublet (3J Ag-P ) 78.1 Hz)
because the coupling with 107Ag and 109Ag is not
resolved. The mass spectra show the parent ion peak
[M - SO3CF3]+ at m/z 841 (79%, 7), 981 (31%, 8), or
1037 (13%, 9). The mass spectra of 10 do not show the
parent ion peak, probably because of its dicationic
character. It is noteworthy that the mass spectra of 7-9
contain the trinuclear ions [{Au(µ-mes)L}2Ag]+ which
have been formed under mass spectral conditions, as
reported for [AuAg(µ-mes)(PPh3)2]SO3CF3.
1
Their H NMR spectra are very similar to those of the
silver-gold complexes, and again the resonance as-
signed to PPh3 ligand in 3 appears very close to that in
1, 43.7 ppm. Their IR spectra, besides the PF6 absorp-
tions34 at 839 (vs, br) (3) and 838 (vs, br) cm-1 (4), show
bands at 1597 (m) (3) and 1595 (m) cm-1 (4) assignable
to the mesityl ligand; the band at ca. 840 cm-1 is
presumably overlapped by the PF6 absorption. The
mass spectra show the parent ion peak [M - PF6]+ at
m/z 1218 (27%, 3) and 1307 (15%, 4). All these data
indicate a structure for these complexes similar to that
of the silver-gold derivative 2a , but the lack of color
could imply a different packing. Unfortunately, we were
not able to obtain suitable single crystals of these
materials.
Exp er im en ta l Section
The starting materials [AgOClO3],35 [AgOSO2CF3],35 [Au-
36
(mes)PPh3],7 [Au(mes)AsPh3],7 and [Cu(CH3CN)4]PF6 were
prepared as described previously. All other reagents were
commercially available. All reactions were performed by
avoiding light exposure.
The C, H, N, and S analyses were carried out on a Perkin-
Elmer Model 2400 microanalyzer. Conductivities were mea-
sured in approximately 5 × 10-4 mol dm-3 acetone solutions,
with a J enway Model 4010 conductimeter. The infrared
spectra were recorded (4000-400 cm-1) on a Nicolet 510 FT-
IR spectrometer using Nujol mulls between polyethylene
sheets. The 1H NMR spectra were recorded on a Varian Unity
200 spectrometer, whereas 31P NMR spectra were recorded on
a Varian Unity 300 and Bruker ARX 300 spectrometer, in
CDCl3. Chemical shifts are cited relative to SiMe4 (1H) and
85% H3PO4 (external 31P). Mass spectra were recorded on a
VG Autospec with FAB technique using 3-nitrobenzyl alcohol
as matrix.
Complex 1 reacts with triphenylphosphine and tet-
rahydrothiophene (reaction iii) to give in nearly quan-
titative yield the previously reported complexes [AuAg-
(µ-mes)(PPh3)L]SO3CF3 (L ) PPh3, tht) and [Au(mes)-
PPh3], which can be easily separated because of the
solubility of the latter in diethyl ether. The same
reaction starting from 2a ,b gives a mixture of com-
plexes, probably due to ligand exchange between silver
and gold. Similar results have been achieved using
complexes 3 and 4 as starting materials, and in these
cases disproportionation of the copper(I) complexes also
occurs. These substitution reactions can be used to
synthesize novel di- or polynuclear derivatives, depend-
ing on the chosen ligand. Thus, complex 1 reacts with
2,2′-bipyridine and SPPh3 to give, besides [Au(mes)-
PPh3], [AuAg(µ-mes)(PPh3)L]SO3CF3 (L ) bipy (7),
SPPh3 (8)). Complex 2a reacts with AsPh3 affording
[AuAg(µ-mes)(AsPh3)2]SO3CF3 (9), and complex 2b re-
acts with Ph2AsCH2AsPh2 (dpam), in a 2:1 ratio, to give
[Au2Ag2(µ-mes)2(AsPh3)2(dpam)](SO3CF3)2 (10). In both
cases [Au(mes)AsPh3] can be recovered from the mother
liquors.
Caution: Perchlorate salts of metal complexes with organic
ligands are potentially explosive. Only small amounts of
material should be prepared and all samples handled with
great caution.
-
Syn th eses. [{Au (µ-m es)L}2Ag]A [L ) P P h 3, A ) SO3CF3
-
-
(1); L ) AsP h 3, A ) ClO4 (2a ), A ) SO3CF 3 (2b)]. To a
dichloromethane (30 cm3) solution of [Au(mes)PPh3] (0.1157
g, 0.2 mmol) or [Au(mes)AsPh3] (0.1245 g, 0.2 mmol) was added
a solution of AgOClO3 (0.0207 g, 0.1 mmol) or AgOSO2CF3
(0.0257 g, 0.1 mmol) in diethyl ether (10 cm3). The reactions
were instantaneous. The resulting bright yellow solutions
were concentrated to ca. 5 cm3. Addition of n-hexane (20 cm3)
led to the precipitation of complexes 1 and 2b as pale yellow
solids, whereas by addition of diethyl ether (20 cm3) compound
2a was obtained as a yellow solid. Yield (%): 88 (1), 78 (2a ),
Complexes 7-10 are white solids that are conducting
in acetone solution, showing values characteristic of 1:1
electrolytes (complexes 7-9) or 2:1 in the case of 10.
The infrared spectra show absorptions at 1273 (vs, br),
1223 (vs, br), 1146 (s) (7), 1266 (vs, br), 1223 (s, br), 1106
(s) (8), and 273 (vs, br), 1225 (s), 1154 (s) cm-1 (9)
assignable to SO3CF3- and 1094 (vs, br), 623 cm-1 (10)
assignable to perchlorate anion, as well as absorptions
at 1588 (w), 857 (m) (7), 1596 (w), 1586 (w), 859 (m),
847 (m) (8), 1596 (w, br), 1581 (w, br), 851(w, br) (9),
and 1594 (w), 1580 (w), 851 (w, br) cm-1 (10) charac-
teristic of mesityl bridging groups. 1H and 31P{1H}
spectra are in accordance with the proposed formula-
tion, both by the position of the resonances and by their
ratio, the most notable features being the low-field
position, 7.13 ppm, of the meta H of 7 (which may
indicated a bridging position for the mesityl group) and
the existence of coupling between the P atom of SPPh3
and the silver atoms in 8 (which shows that the new
97 (2b ). Data for 1 are as follow. Anal. Calcd for C55H52
Au2AgP2F3SO3: C, 46.70; H, 3.70; S, 2.25. Found: C, 46.40;
H, 3.35; S, 2.00. ΛM: 122 Ω-1 cm2 mol-1 1H NMR: δ ) 7.6-
-
.
7.2 (m, 30H, Ph), 6.88 (s, 4H, H-m), 2.36 (s, 12H, o-me), and
2.18 (s, 6H, p-me). 31P NMR: δ ) 43.4 (s). Data for 2a are as
follow. Anal. Calcd for C54H52Au2AgAs2ClO4: C, 44.65; H,
3.60. Found: C, 44.25; H, 3.70. ΛM: 126 Ω-1 cm2 mol-1. 1H
NMR: δ ) 7.6-7.2 (m, 30H, Ph), 6.91 (s, 4H, H-m), 2.44 (s,
12H, o-me) and 2.22 (s, 6H, p-me). Data for 2b are as follow.
Anal. Calcd for C55H52Au2AgAs2F3SO3: C, 44.00; H, 3.50; S,
2.15. Found: C, 43.80; H, 3.10; S, 1.95. ΛM: 127 Ω-1 cm2
mol-1
.
1H NMR: δ ) 7.6-7.2 (m, 30H, Ph), 6.91 (s, 4H, H-
m), 2.45 (s, 12H, o-me), and 2.23 (s, 6H, p-me).
[{Au (µ-m es)L}2Cu ]P F 6 [L ) P P h 3 (3), AsP h 3 (4)]. To a
dichloromethane (30 cm3) solution of [Au(mes)PPh3] (0.1157
g, 0.2 mmol) or [Au(mes)AsPh3]3 (0.1245 g, 0.2 mmol) was
4
added a solution of [Cu(CH3CN)4]PF6 (0.0372 g, 0.1 mmol) in
dichloromethane (10 cm3). The reactions were carried out at
0 °C. After 15 min of stirring, the slightly yellow solutions
(34) Nakamoto, K. Infrared Spectra of Inorganic and Coordination
Compounds, 4th ed.; Wiley Interscience: New York, 1992; p 150.
(35) Long, D. A.; Seele, D. Spectrochim. Acta 1968, 24A, 1125.
(36) Kubas, G. J . Inorg Synth. 1990, 28, 68.

Trinuclear Au2Ag and Au2Cu Complexes
Organometallics, Vol. 15, No. 23, 1996 4943
were concentrated to ca. 5 cm3. Addition of n-hexane (20 cm3)
gave 3 and 4 as white solids. Yield (%): 62 (3), 82 (4). Data
for 3 are as follow. Anal. Calcd for C54H52P2Au2CuPF6: C,
47.50; H, 3.85. Found: C, 47.15; H, 3.65. ΛM: 129 Ω-1 cm2
Ta ble 2. Deta ils of Da ta Collection a n d Str u ctu r e
Refin em en t for Com p lex 2a
compd
2a ‚CH2Cl2
C55H54AgAs2Au2Cl3O4
monoclinic
0.45 × 0.30 × 0.20
C2/c
20.634(2)
21.431(2)
15.7216(11)
121.992(5)
5896.2(7)
4
chem formula
cryst habit
cryst size/mm
space group
a/Å
mol-1 1H NMR: δ ) 7.6-7.2 (m, 30H, Ph), 6.80 (s, 4H, H-m),
.
2.35 (s, 12H, o-me), and 2.12 (s, 6H, p-me). 31P NMR: δ )
1
43.7 (s) (Au-P) and -144.1 (sep, J P-F ) 713.3 Hz). Data for
4 are as follow. Anal. Calcd for C54H52As2Au2CuPF6: C, 44.65;
b/Å
c/Å
H, 3.60. Found: C, 44.15; H, 3.65. ΛM: 135 Ω-1 cm2 mol-1
.
1H NMR: δ ) 7.6-7.2 (m, 30H, Ph), 6.84 (s, 4H, H-m), 2.38
â/deg
(s, 12H, o-me) and 2.28 (s, 6H, p-me). 31P NMR: δ ) -144.1
V/Å3
1
(sep, J P-F ) 713.3 Hz).
Z
Dc/Mg m-3
M
1.731
1536.97
2952
[Au Ag(µ-m es)(P P h 3)L]SO3CF 3 [L ) P P h 3 (5), th t (6),
bip y (7), SP P h 3 (8)]. To dichloromethane solutions of 1
(0.1414 g, 0.1 mmol) were added PPh3 (0.0262 g, 0.1 mmol),
tht (8.82 µL, 0.1 mmol), bipy (0.0156 g, 0.1 mmol), and SPPh3
(0.0294 g, 0.1 mmol). The mixtures were stirred for 20 min
and the solutions concentrated to ca. 5 cm3. Addition of
n-hexane (20 cm3) (5, 6) or diethyl ether (20 cm3) (7, 8) gave
the corresponding complexes as white solids. Yields (%): 82
(5), 95 (6), 73 (7), 56 (8). Data for 7 are as follow. Anal. Calcd
for C38H34AuAgN2PF3SO3: C, 46.05; H, 3.45; N, 2.80; S, 3.25.
Found: C, 45.85; H, 3.40; N, 2.85; S, 3.05. ΛM ) 122 Ω-1 cm2
F(000)
T/°C
-100
2θmax/deg
µ(Mo KR)/mm-1
transm
50
6.58
0.785-0.937
5208
5059
0.084
0.085
0.223
125
67
1.089
2.24
no. of reflcns measd
no. of unique reflcns
Rint
Ra (F, F > 4σ(F))
wRb (F2, all reflcns)
no. of params
no. of restraints
Sc
mol-1 1H NMR: δ ) 8.39 (dd, 2H, H3 bipy), 8.18 (dd, 2H, H6
.
bipy), 8.05 (td, 2H, H5 bipy); 7.6-7.2 (m, 15H, Ph; td, 2H, H4
bipy); 7.13 (s, 2H, H-m), 2.70 (s, 6H, o-me), 2.37 (s, 3H, p-me).
31P NMR: δ ) 44.1 (s). Data for 8 are as follow. Anal. Calcd
for C46H41AuAgP2S2F3O3: C, 48.90; H, 3.65; S, 5.70. Found:
max ∆F/e Å-3
a
b
2
R(F) ) ∑||Fo| - |Fc||/∑|Fo|. wR(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. c S )
2
C, 49.10; H, 3.50; S, 5.20. ΛM ) 105 Ω-1 cm2 mol-1 1H NMR:
.
δ ) 7.6-7.2 (m, 30H, Ph); 6.89 (s, 2H, H-m), 2.46 (s, 6H, o-me),
[∑{w(Fo - Fc2)2}/(n - p)]0.5, where n is the number of data and p
2
and 2.25 (s, 3H, p-me). 31P NMR at -55 °C: δ ) 45.8 (s) (Au-
the number of parameters.
3
P) and 37.17 (d, br) (Ag-SP) J Ag-P ) 78.1 Hz.
[Au Ag(µ-m es)(AsP h 3)2]SO3CF 3 (9). To a dichloromethane
solution of 2b (0.1502 g, 0.1 mmol) was added AsPh3 (0.0306
g, 0.1 mmol). After 20 min of stirring, the transparent solution
was concentrated to ca. 5 cm3. Addition of n-hexane (20 cm3)
gave 9 as a white solid. Yield (%): 99 (9). Anal. Calcd for
The (assumed) perchlorate and two assumed chlorines of
dichloromethane were assigned occupation factors of 0.5. They
form part of an extensive region of featureless electron density
and are probably completely disordered (except for the per-
chlorate chlorine). The perchlorate Cl-O bonds are far too
short. An alternative refinement in Cc revealed one indepen-
dent perchlorate chlorine only, with full occupation, but the
refinement suffered from near-singularity effects (nonequality
of chemically equivalent bonds, etc.). It is unlikely that X-ray
methods alone can distinguish either the space group or the
chemical nature of the disorder regions.
C
46H41AuAgAs2F3SO3: C, 46.60; H, 3.50; S, 2.70. Found: C,
46.20; H, 3.30; S, 2.20. ΛM ) 110 Ω-1 cm2 mol-1 1H NMR: δ
.
) 7.6-7.2 (m, 30H, Ph); 6.92 (s, 2H, H-m), 2.55 (s, 6H, o-me)
and 2.26 (s, 3H, p-me).
[Au 2Ag2(µ-m es)2(AsP h 3)2(P h 2AsCH2AsP h 2)](ClO4)2 (10).
To a dichloromethane solution of 2a (0.2179 g, 0.15 mmol) was
added Ph2AsCH2AsPh2 (0.0345 g, 0.075 mmol). After being
stirred for 30 min, the solution was concentrated to 5 cm3.
Addition of diethyl ether (20 cm3) resulted in the precipitation
of 10 as a white solid. Yield (%): 85 (10). Anal. Calcd for
Ack n ow led gm en t. We thank the Fonds der Che-
mischen Industrie and the Direccio´n General de Inves-
tigacio´n Cient´ıfica y Te´cnica (Grant No. PB92-1078) for
financial support and the Universidad Pu´blica de Na-
varra for a grant (to M.C).
C
79H74Au2Ag2As4Cl2O8: C, 44.50; H, 3.50. Found: C, 44.95;
H, 3.40. ΛM ) 206 Ω-1 cm2 mol-1 1H NMR: δ ) 7.6-7.2 (m,
.
45H, Ph); 6.99 (s, 4H, H-m), 2.63 (s, 12H, o-me), 2.31 (s, 6H,
p-me); 4.01 (s, 2H, CH2).
X-r a y Str u ctu r e Deter m in a tion . Numerical data are
summarized in Table 2. The crystal was mounted in inert oil
on a glass fiber. Data were collected using monochromated
Mo KR radiation (λ ) 0.710 73 Å). A Siemens P4 diffracto-
meter with LT-2 low-temperature attachment was used with
scan type ω. Cell constants were refined from the setting
angles of 61 reflections in the 2θ range 6-25°. An absorption
correction was applied on the basis of ψ-scans. The structure
was solved by the heavy-atom method and refined on F2
(program SHELXL-93)37 anisotropically for the heaviest atoms.
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal
data, data collection, and solution and refinement parameters,
positional and U parameters, bond distances and angles, and
anisotropic thermal parameters (7 pages). Ordering informa-
tion is given on any current masthead page.
OM9602062
(37) Sheldrick, G. M. SHELXL-93. A program for crystal structure
refinement. University of Go¨ttingen: Go¨ttingen, Germany, 1993.