2-(Aminomethyl)phenyl complexes of Au(III), mixed Au(III)/Ag(I), and Pd(II) with the 2,2-diacetyl-1,1-ethylenedithiolato ligand: Dancing of palladacycles around a juggler ligand

Article abstract of DOI:10.1021/ic101188z

The reaction of [Tl₂{μ-S,S-S₂C=C{C(O)Me} ₂}] with [Au(C,N-C₆H₄CH₂NMe ₂-2)Cl₂] (1:1) gives [{Au(C,N-C₆H ₄CH₂NMe₂-2)}{S,S-S₂C=C{C(O)Me} ₂}] (1) which, in turn, reacts with AgClO₄ (1:1) to give [{Au(C,N-C₆H₄CH₂NMe₂-2)} {Ag(OClO₃)}{S₂C=C{C(O)Me}₂}] (2). Complexes [{Au(C,N-C₆H₄CH₂NMe₂-2)}{Ag(X) (PPh₃)}{S₂C=C{C(O)Me}₂}] [X = OClO₃ (3), ONO₂ (4)] have been obtained by reaction of 1 with PPh ₃ and AgClO₄ or AgNO₃, respectively (1:1:1). Complex 3 can also be obtained by reacting 2 with PPh₃ (1:1). Complexes [Pd(C,N-C₆H₄CH₂NR₂-2) (μ-Cl)]₂ (R = Me, H) react (i) with [Tl₂{S ₂C=C{C(O)Me}₂}] and [PPN]Cl (0.5:1:1, PPN = Ph ₃P=N=PPh₃) to form PPN[Pd(C,N-C₆H ₄CH₂NR₂-2){S,S-S₂C=C{C(O)Me} ₂}] [R = H (5a), Me (5b)], or (ii) with [Tl₂{S ₂C=C{C(O)Me}₂}] (1:1) to form [{Pd(C,N-C₆H ₄CH₂NR₂-2)}₂{μ-S,S,O-S ₂C=C{C(O)Me}₂}] [R = H (6a), Me (6b)]. The trinuclear complexes [{Pd(C,N-C₆H₄CH₂NR ₂-2)}₃{μ₃-O,S,S,O-S₂C=C{C(O)Me} ₂}]ClO₄ [R = H (7a), Me (7b)] can be prepared by reacting the corresponding dinuclear complex 6a or 6b with [Pd(C,N-C₆H ₄CH₂NR₂-2)(NCMe)₂]ClO₄ (1:1). The crystal structures of 1, 6b CH₂Cl₂, and 7b CH₂Cl₂ have been determined. NMR studies have been carried out to explain the solution behavior of these complexes. VT-NMR and line shape analysis for the species where R = Me (5b, 6b, 7b) have allowed the estimation of the activation parameters for these exchange processes.

Full text of DOI:10.1021/ic101188z

Inorg. Chem. 2010, 49, 8099–8111 8099
DOI: 10.1021/ic101188z
2-(Aminomethyl)phenyl Complexes of Au(III), Mixed Au(III)/Ag(I), and Pd(II)
with the 2,2-Diacetyl-1,1-Ethylenedithiolato Ligand: Dancing of Palladacycles
around a Juggler Ligand†
ꢀ
ꢀ
´
´
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´
Jose Vicente,* Marıa-Teresa Chicote,* Eloısa Martınez-Viviente,* Antonio-Jesus Martınez-Martınez, and
ꢀ
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Nicolas Sanchez-Moya
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Grupo de Quımica Organometalica, Departamento de Quımica Inorganica, Universidad de Murcia,
Apdo. 4021, Murcia, 30071 Spain
Peter G. Jones*
€
Institut fu€r Anorganische und Analytische Chemie der Technischen Universitat Braunschweig Postfach 3329,
38023 Braunschweig, Germany
Received June 14, 2010
The reaction of [Tl2{μ-S,S-S2CdC{C(O)Me}2}] with [Au(C,N-C6H4CH2NMe2-2)Cl2] (1:1) gives [{Au(C,N-C6H4CH2-
NMe2-2)}{S,S-S2CdC{C(O)Me}2}] (1) which, in turn, reacts with AgClO4 (1:1) to give [{Au(C,N-C6H4CH2NMe2-
2)}{Ag(OClO3)}{S2CdC{C(O)Me}2}] (2). Complexes [{Au(C,N-C6H4CH2NMe2-2)}{Ag(X)(PPh3)}{S2CdC{C-
(O)Me}2}] [X = OClO3 (3), ONO2 (4)] have been obtained by reaction of 1 with PPh3 and AgClO4 or AgNO3,
respectively (1:1:1). Complex 3 can also be obtained by reacting 2 with PPh3 (1:1). Complexes [Pd(C,N-C6H4CH2NR2-
2)(μ-Cl)]2 (R = Me, H) react (i) with [Tl2{S2CdC{C(O)Me}2}] and [PPN]Cl (0.5:1:1, PPN = Ph3PdNdPPh3) to form
PPN[Pd(C,N-C6H4CH2NR2-2){S,S-S2CdC{C(O)Me}2}] [R = H (5a), Me (5b)], or (ii) with [Tl2{S2CdC{C(O)Me}2}]
(1:1) to form [{Pd(C,N-C6H4CH2NR2-2)}2{μ-S,S,O-S2CdC{C(O)Me}2}] [R = H (6a), Me (6b)]. The trinuclear
complexes [{Pd(C,N-C6H4CH2NR2-2)}3{μ3-O,S,S,O-S2CdC{C(O)Me}2}]ClO4 [R = H (7a), Me (7b)] can be
prepared by reacting the corresponding dinuclear complex 6a or 6b with [Pd(C,N-C6H4CH2NR2-2)(NCMe)2]ClO4
(1:1). The crystal structures of 1, 6b CH2Cl2, and 7b CH2Cl2 have been determined. NMR studies have been carried
3
3
out to explain the solution behavior of these complexes. VT-NMR and line shape analysis for the species where R = Me
(5b, 6b, 7b) have allowed the estimation of the activation parameters for these exchange processes.
Introduction
photophysical properties,3-5 including solvatochromic beha-
vior and luminescence,6-9 and are thus potential photo-
catalysts in light-to-chemical energy conversion.10 Additionally,
Transition metal complexes containing unsaturated dithio-
lato ligands attract considerable attention because of their
electronic, magnetic, and redox properties.1 1,1-Ethylene-
dithiolato complexes have been less studied2 than their 1,2
structural isomers (I and II, Chart 1), probably because the
former are less prone to undergo facile redox transformations.
Some 1,1-ethylenedithiolato complexes show interesting
(4) Smith, D.; Taylor, P. J. J. Chem. Soc., Perkin Trans. 2 1979, 1376.
ꢀ
(5) Vicente, J.; Chicote, M. T.; Gonzalez-Herrero, P.; Jones, P. G.;
Humphrey, M. G.; Cifuentes, M. P.; Samoc, M.; Luther-Davies, B. Inorg.
Chem. 1999, 38, 5018.
(6) Zuleta, J. A.; Chesta, C. A.; Eisenberg, R. J. Am. Chem. Soc. 1989,
111, 8916. Zuleta, J. A.; Burberry, M. S.; Eisenberg, R. Coord. Chem. Rev. 1990,
97, 47. Zuleta, J. A.; Bevilacqua, J. M.; Eisenberg, R. Coord. Chem. Rev. 1991,
111, 237. Zuleta, J. A.; Bevilacqua, J. M.; Rehm, J. M.; Eisenberg, R. Inorg.
Chem. 1992, 31, 1332. Bevilacqua, J. M.; Zuleta, J. A.; Eisenberg, R. Inorg.
Chem. 1994, 33, 258. Bevilacqua, J. M.; Eisenberg, R. Inorg. Chem. 1994, 33,
1886. Bevilacqua, J. M.; Eisenberg, R. Inorg. Chem. 1994, 33, 2913. Vicente, J.;
† Dedicated to Prof. Dr. Aurelia Arcas on the occasion of her 60th birthday
*To whom correspondence should be addressed. E-mail: jvs1@um.es,
(J.V.), mch@um.es (M.-T.C.), eloisamv@um.es (E.M.-V.), p.jones@tu-bs.de
(P.G.J.).
(1) Karlin, K. D.; Stiefel, E. I. Dithiolene Chemistry: Synthesis, Properties,
and Applications; Karlin, K. D., Stiefel, E. I., Eds.; Progress in Inorganic
Chemistry Series Published Online; Wiley-Interscience: New York, 2004; Vol. 52
(2) Coucouvanis, D. Prog. Inorg. Chem. 1970, 11, 233. Coucouvanis, D.
Prog. Inorg. Chem. 1979, 26, 301.
ꢀ
ꢀ
Gonzalez-Herrero, P.; García-Sanchez, Y.; Jones, P. G.; Bardají, M. Inorg. Chem.
ꢀ
ꢀ
2004, 43, 7516. Vicente, J.; Gonzalez-Herrero, P.; Perez-Cadenas, M.; Jones,
P. G.; Bautista, D. Inorg. Chem. 2005, 44, 7200.
(7) Bevilacqua, J. M.; Zuleta, J. A.; Eisenberg, R. Inorg. Chem. 1993, 32,
3689.
(8) Huertas, S.; Hissler, M.; McGarrah, J. E.; Lachicotte, R. J.; Eisenberg,
R. Inorg. Chem. 2001, 40, 1183.
(9) Vicente, J.; Gonzalez-Herrero, P.; Perez-Cadenas, M.; Jones, P. G.;
(3) Mohanalingam, K.; Nethaji, M.; Das, P. K. J. Mol. Struct. 1996, 378,
€
177. Sandstrom, J.; Wennerbeck, I. Acta Chem. Scand. 1970, 24, 1191. Colonna,
€
€
ꢀ
ꢀ
F. P.; DiStefano, G.; Sandstrom, J.; Sjostrand, U. J. Chem. Soc., Perkin Trans. 2
€
1978, 279. Sandstrom, J.; Sjostrand, U. Tetrahedron 1978, 34, 3305.
Bautista, D. Inorg. Chem. 2007, 46, 4718.
r
2010 American Chemical Society
Published on Web 07/26/2010
pubs.acs.org/IC

8100 Inorganic Chemistry, Vol. 49, No. 17, 2010
Vicente et al.
1,1-ethylenedithiolato ligands have attracted interest in their
ability to stabilize high oxidation states,11,12 to form homo-13-15
or heteropolynuclear complexes,9,14,16-18 clusters,15,19 or con-
densed thiolato ligands,9,12,20 and because of the variety of
coordination modes they display. In particular, for the S2CdC-
{C(O)Me}2 ligand coordination modes A-D (Chart 1), have
been reported.5,8,14,17,18,21,22 However, there are still very few
examples of organometallic 1,1-ethylenedithiolato com-
plexes, and in all of them the organic ligand is a neutral
species (cod,7,14,23 isocyanide,18,24 carbene,18 vinylidene25
Chart 1
(10) Paw, W.; Cummings, S. D.; Mansour, M. A.; Connick, W. B.;
Geiger, D. K.; Eisenberg, R. Coord. Chem. Rev. 1998, 171, 125. Cummings,
S. D.; Eisenberg, R. Inorg. Chim. Acta 1996, 242, 225. Hissler, M.; McGarrah,
J. E.; Connick, W. B.; Geiger, D. K.; Cummings, S. D.; Eisenberg, R. Coord.
Chem. Rev. 2000, 115.
(11) Hollander, F. J.; Caffery, M. L.; Coucouvanis, D. J. Am. Chem. Soc.
1974, 96, 4682. Hollander, F. J.; Pedelty, R.; Coucouvanis, D. J. Am. Chem. Soc.
1974, 96, 4032. Coucouvanis, D.; Hollander, F. J.; Caffery, M. L. Inorg. Chem.
1976, 15, 1853. Coucouvanis, D.; Hollander, F. J.; Pedelty, R. Inorg. Chem. 1977,
16, 2691.
ꢀ
ꢀ
(12) Vicente, J.; Gonzalez-Herrero, P.; Garcıa-Sanchez, Y.; Jones, P.;
´
Bardaji, G. Eur. J. Inorg. Chem. 2006, 115.
(13) Weigand, W.; Saumweber, R.; Schulz, P. Z. Naturforsch., B 1993, 48,
1080. Buchweitz, J.; Gompper, R.; Polborn, K.; Robl, C.; Sailer, M. T.; Weigand,
W. Chem. Ber. 1994, 127, 23. Fackler, J. P., Jr.; Staples, R. J.; Assefa, Z. J. Chem.
Soc., Chem. Commun. 1994, 431. Kang, B.-S.; Chen, Z.-N.; Su, C.-Y.; Lin, Z.;
Wen, t.-B. Polyhedron 1998, 17, 2497. Xiong, R. G.; Zuo, J. L.; You, X. Z. Inorg.
Chem. 1997, 36, 2472. Schubert, K.; Goerls, H.; Weigand, W. Heteroat. Chem.
2005, 16, 369.
or carbonyl24,26,27) or a η5-Cp group.28 The only exceptions
are the 1,1-ethylenedithiolato Pd(II) complexes 6b and 7b
(Scheme 2) that we have preliminarily reported,22 which
were the first containing an anionic σ C-donor ligand,
namely, C6H4CH2NMe2-2. In this paper we report (1) the
synthesis of the mononuclear Pd(II) complex that com-
pletes this series and its homologous Au(III) complex, (2)
the use of the latter as a metallaligand toward Ag(I), (3) the
synthesis of the three Pd(II) homologues with the ligand
C6H4CH2NH2-2, and (4) an extensive investigation of
the dynamic behavior of all these complexes in solution.
The synthesis of these Au and Pd complexes was devised
with the aim of finding novel structural and/or chemical
features, associated with the significant trans effect of
the aryl group. Indeed, we had previously found that
such influence produces interesting fluxional behaviors
in [Au(C,N-C6H4CH2NMe2-2)2Cl]29 and in the trinuclear
Pd(II) complex 7b (Scheme 2),22 where the dithiolato acts
as a “juggler” ligand that moves the three “[Pd(C,N-
C6H4CH2NMe2-2)]” fragments around all the coordina-
tion positions. We have already reported the activation
parameters for this process and suggested a possible
mechanism.22 In this paper we put these results into context
with the complete DNMR investigation of the behavior in
solution of the mono-, di-, and trinuclear Pd(II) complexes.
(14) Vicente, J.; Chicote, M. T.; Huertas, S.; Bautista, D.; Jones, P. G.;
Fischer, A. K. Inorg. Chem. 2001, 40, 2051.
ꢀ
ꢀ
(15) Vicente, J.; Gonzalez-Herrero, P.; Garcıa-Sanchez, Y.; Jones, P. G.
´
Inorg. Chem. 2009, 48, 2060.
(16) Coucouvanis, D.; Baenziger, N. Z.; Johnson, S. M. Inorg. Chem.
1974, 13, 1191. Caffery, M. L.; Coucouvanis, D. J. Inorg. Nucl. Chem. 1975, 37,
2081.
(17) Vicente, J.; Chicote, M. T.; Huertas, S.; Jones, P. G.; Fischer, A. K.
Inorg. Chem. 2001, 40, 6193.
(18) Vicente, J.; Chicote, M. T.; Huertas, S.; Jones, P. G. Inorg. Chem.
2003, 42, 4268.
(19) Hollander, F. J.; Coucouvanis, D. J. Am. Chem. Soc. 1977, 99, 6268.
McCandlish, L. E.; Bissell, E. C.; Coucouvanis, D.; Fackler, J. P., Jr.; Knox, K.
J. Am. Chem. Soc. 1968, 90, 7357. Birker, P. J. M. W. L.; Verschoor, G. C.
J. Chem. Soc., Chem. Commun. 1981, 322. Dietrich, H.; Storck, W.; Manecke,
G. J. Chem. Soc., Chem. Commun. 1982, 1036. Coucouvanis, D.; Swenson, D.;
Baenziger, N. C.; Pedelty, R.; Caffery, M. L.; Kanodia, S. Inorg. Chem. 1989, 28,
2829. Fackler, J. P., Jr.; Staples, R. J.; Liu, C. W.; Stubbs, R. T.; Lopez, C.; Pitts,
J. T. Pure Appl. Chem. 1998, 70, 839. Hong, M. C.; Su, W. P.; Cao, R.; Jiang,
F. L.; Liu, H. Q.; Lu, J. X. Inorg. Chim. Acta 1998, 274, 229. Su, W. P.; Hong,
M. C.; Cao, R.; Chen, J. T.; Wu, D. X.; Liu, H. Q.; Lu, J. X. Inorg. Chim. Acta
1998, 267, 313. Liu, C. W.; Staples, R. J.; Fackler, J. P., Jr. Coord. Chem. Rev.
1998, 174, 147. Su, W. P.; Hong, M. C.; Weng, J. B.; Liang, Y. C.; Zhao, Y. J.; Cao,
R.; Zhou, Z. Y.; Chan, A. S. C. Inorg. Chim. Acta 2002, 331, 8. Liu, C. W.; Liaw,
B. J.; Wang, J. C.; Liou, L. S.; Keng, T. C. J. Chem. Soc., Dalton Trans. 2002,
1058.
ꢀ
ꢀ
(20) Vicente, J.; Gonzalez-Herrero, P.; Garcıa-Sanchez, Y.; Bautista, D.
´
Inorg. Chem. 2008, 47, 10662.
ꢀ
(21) Vicente, J.; Chicote, M. T.; Gonzalez-Herrero, P.; Jones, P. G. Chem.
Commun. 1997, 2047.
(22) Vicente, J.; Chicote, M. T.; Martinez-Viviente, E.; Martı
nez-Martınez,
´ ´
A. J.; Jones, P. G. Inorg. Chem. 2006, 45, 10434.
(23) Elduque, A.; Navarro, N.; Oro, L. A.; Pinillos, M. T. An. Quim., Int.
Ed 1996, 92, 349.
Experimental Section
IR spectroscopy, elemental analyses, conductance mea-
surements in acetone solution, melting point determinations,
(24) Herberhold, M.; Haumaier, L. Chem. Ber. 1982, 115, 1399.
(25) Umland, H.; Behrens, U. J. Organomet. Chem. 1984, 273, C39.
(26) Adams, R. D.; Chen, L.; Wu, W. Organometallics 1994, 13, 1257.
(27) Ma, Y.-Q.; Yin, N.; Li, J.; Xie, Q.-L.; Miguel, D. J. Organomet.
Chem. 2004, 689, 1949. Alvarez-Toledano, C.; Delgado, E.; Donnadieu, B.;
Hernandez, E.; Martin, G.; Zamora, F. Inorg. Chim. Acta 2003, 351, 119.
Weidmann, T.; Sunkel, K.; Beck, W. J. Organomet. Chem. 1993, 459, 219.
Broadhurst, P. V.; Johnson, B. F. G.; Lewis, J.; Raithby, P. R. J. Chem. Soc.,
Chem. Commun. 1982, 140. Banerjee, S. R.; Nagasawa, A.; Zubieta, J. Inorg.
Chim. Acta 2002, 340, 155. Connelly, N. G.; Locke, J.; McCleverty, J. A. Inorg.
Chim. Acta 1968, 2, 411. Connelly, N. G.; McCleverty, J. A. J. Chem. Soc. A
1970, 1621. Green, M.; Osborn, R. B. L.; Stone, F. G. A. J. Chem. Soc. A 1970,
944.
(28) McCleverty, J. A.; James, T. A.; Wharton, E. J. Inorg. Chem. 1969, 8,
1340. Hong, M.; Cao, R.; Kawaguchi, H.; Tatsumi, K. Inorg. Chem. 2002, 41,
4824. Yang, K.; Veerran, R. L.; Bott, S. G.; Richmond, M. G. J. Coord. Chem.
1996, 38, 75. McCleverty, J. A.; James, T. A. J. Chem. Soc. A 1970, 3308.
McCleverty, J. A.; Orchard, D. G. J. Chem. Soc. A 1970, 3315. Casey, A. T.;
Raynor, J. B. J. Chem. Soc., Dalton Trans. 1983, 2057. Hackelberg, O.;
Kramolowsky, R. Z. Naturforsch., B 1975, 30B, 219.
ꢀ
ꢀ
ꢀ
(29) Vicente, J.; Bermudez, M. D.; Sanchez-Santano, M. J.; Paya, J.
Inorg. Chim. Acta 1990, 174, 53.

Article
Inorganic Chemistry, Vol. 49, No. 17, 2010 8101
Chart 2
0.10 mmol) in acetone (8 mL) was added dropwise to a solution
of 1 (48.1 mg; 0.10 mmol) in the same solvent (4 mL). The
resulting suspension was stirred in the dark for 5 h and then
filtered. The pale yellow solid obtained was washed with Et2O
(2 ꢀ 5 mL) and suction-dried to give 2. Yield (%): 77. Dec. point
(°C): 194. IR (cm-1): 1642 m, 1607 vs, 1545 w, 1254 s, 1205 m,
1112 s, br, 1045 s, 974 m, 926 m, 852 s, 779 s, 622 s, 605 s, 468 w,
429 w, 358 w. Anal. Calcd for C15H18AgAuClNO6S2: C, 25.28;
H, 2.55; N, 1.97; S, 9.00. Found: C, 25.56; H, 2.47; N, 2.00;
S, 8.93.
Synthesis of [{Au(C,N-C6H4CH2NMe2-2)}{Ag(OClO3)-
(PPh3)}{μ-S,S,O-S2CdC{C(O)Me}2}] (3). A solution of Ag-
ClO4 (35.5 mg, 0.16 mmol) in acetone was added dropwise to a
solution of 1 (80 mg, 0.16 mmol) in acetone (15 mL). The reaction
mixture was stirred for 5 h, and then a solution of PPh3 (41.4 mg,
0.16 mmol) in acetone (15 mL) was added. After stirring for 5 h
the reaction mixture was filtered through Celite. The solution was
concentrated under vacuum (3 mL), and Et2O (20 mL) was added
to precipitate a pale yellow solid that was filtered, washed with
Et2O (5 mL), and suction-dried to give 3. Yield (%): 84. Mp (°C):
164. 1H NMR (600 MHz, CDCl3, 25 °C): δ 2.18 (s, 3 H,
Z-C(O)Me), 2.48 (s, 3 H, E-C(O)Me), 3.09 (s, 6 H, NMe2), 4.29
(s, 2 H, CH2), 7.06-7.09 (m, 2 H, H15, H16), 7.20-7.23 (m, 1 H,
H13), 7.23-7.26 (m, 1 H, H14), 7.35-7.40 (m, 6 H, m-H, PPh3),
7.41-7.47 (m, 9 H, o-H, p-H, PPh3). 31P{1H} NMR (242,9 MHz,
CDCl3, 25 °C): δ 12.9 (br s), 15.6 (br s); (-60 °C): δ 12.0 [pd,
JP109Ag =554 Hz, JP107Ag =482 Hz]; (CD2Cl2, -90 °C):δ11.4[pd,
JP109Ag = 710 Hz, JP107Ag = 615 Hz], 15.2 [pd, JP109Ag = 623 Hz,
JP107Ag = 540 Hz]. 13C{1H} NMR (150.9 MHz, CDCl3, 25 °C): δ
30.5 (Z-C(O)Me), 32.7 (E-C(O)Me), 51.9 (NMe2), 73.2 (CH2),
124.4 (CH13), 128.0 (CH15), 128.4 (CH16), 128.6 (CH14), 129.5
(m-CH, PPh3), 130.1 (v br, i-C, PPh3), 131.3 (p-CH, PPh3), 134.2
(br, o-CH, PPh3), 137.9 (=C(C(O)Me)2), 146.7 (C12), 150.4
(C11), 194.0 (Z-CO), 200.5 (E-CO). IR (cm-1): 1660 w, 1625
m, 1250 m, 1202 m, 1093 s, br, 1056 s, 840 m, 620 m, 602 m, 509 m,
422 w, 349 w. Anal. Calcd for C33H33AgAuClNO6PS2: C, 40.65;
H, 3.41;N, 1.44;S, 6.58. Found:C, 40.95;H, 3.36;N, 1.47;S, 6.31.
Synthesis of [{Au(C,N-C6H4CH2NMe2-2)}{Ag(ONO2)-
(PPh3)}{μ-S,S,O-S2CdC{C(O)Me}2}] (4). AgNO3 (20.8 mg,
0.12 mmol) and PPh3 (32.0 mg, 0.122 mol) were successively
added to a solution of 1 (62.0 mg, 0.12 mmol) in acetone (25 mL).
The resulting solution was stirred in the dark for 1 h and then
filtered through Celite. The filtrate was concentrated (2 mL) and
n-hexane (15 mL) was added to precipitate a white solid that was
recrystallized from acetone/n-hexane to give 4. Yield (%): 71. Mp
and NMR spectroscopy were carried out as described
elsewhere.30 AgClO4 (Aldrich), acetylacetone (Scharlau),
PPh3 (Fluka), C6H5CH2NR2 (R = H, Me, Merck), LinBu
(Aldrich), and CS2 (Fluka) were obtained from commercial
sources and used without further purification. Complexes
[Tl2{S2CdC{C(O)Me}2],5 [Au(C,N-C6H4CH2NMe2-2)Cl2],31
[Pd(C,N-C6H4CH2NR2-2)(μ-Cl)]2 (R=H,32 Me33), [Pd(C,N-
C6H4CH2NR2-2)(NCMe)2]ClO4,34 6b and 7b22 were prepared
following the methods reported in the literature. Chemical
shifts are referenced to TMS (1H, 13C{1H}) or H3PO4
(31P{1H}). Chart 2 shows the atom numbering used for
the assignment of NMR resonances. The notation pd means
pair of doublets. The assignment of the 1H and 13C NMR
resonances was carried out with the help of APT, 1H-DQF-
COSY, 1H-NOESY, HMBC, and HMQC experiments.
Some of these spectra are reproduced in the Supporting
Information. The phase-sensitive 1H-NOESY measurements
were carried outwith mixing times D8= 600 ms-1 s. The VT
NMR studies of 7b have been reported.22 The details of the
calculation of the activation parameters can be found in the
Supporting Information.
Synthesis of [{Au(C,N-C6H4CH2NMe2-2)}{S,S-S2CdC{C-
(O)Me}2}] (1). [Tl2{S2CdC{C(O)Me}2}] (495.8 mg, 0.85 mmol)
was added to a solution of [Au(C,N-C6H4CH2NMe2-2)Cl2]
(342.0 mg, 0.85 mmol) in acetone (25 mL). The resulting
suspension was stirred for 4 h. The solvent was removed under
vacuum, the residue extracted with CH2Cl2 (20 mL), and the
suspension filtered through Celite. The yellow solution was
concentrated to 3 mL under vacuum, and Et2O (20 mL) was
added to precipitate a yellow solid that was filtered, washed with
Et2O (5 mL), and suction-dried to give 1. Yield (%): 74. Mp
1
1
(°C): 112. H NMR (600 MHz, CDCl3, 25 °C): δ 2.18 (s, 3 H,
(°C): 148. H NMR (600 MHz, CDCl3, 25 °C): δ 2.25 (s, 3 H,
Z-C(O)Me), 2.53 (s, 3 H, E-C(O)Me), 3.09 (s, 6 H, NMe2), 4.28(s,
2 H, CH2), 7.09-7.13 (m, 1 H, H15), 7.14-7.16 (m, 1 H, H16),
7.20-7.22 (m, 1 H, H13), 7.22-7.26 (m, 1 H, H14), 7.39-7.45 (m,
12 H, m-H, o-H, PPh3), 7.45-7.50 (m, 3 H, p-H, PPh3). 31P{1H}
NMR (242.9 MHz, CDCl3, 25 °C): δ 14.7 (v br s), 17.5 (v br s);
(-60 °C):δ 10.7 [pd, JP109Ag =536Hz, JP107Ag =465Hz], 14.1 [pd,
JP109Ag = 751 Hz, JP107Ag = 651 Hz]. 13C{1H} NMR (150.9 MHz,
CDCl3, 25 °C): δ 30.3 (Z-C(O)Me), 32.8 (E-C(O)Me), 51.6
(NMe2), 73.1 (CH2), 124.1 (CH13), 127.9 (CH15), 128.3
C(O)Me), 2.55 (s, 3 H, C(O)Me), 3.06 (s, 6 H, NMe2), 4.25 (s,
2 H, CH2), 7.12-7.15 (m, 1 H, H15), 7.18-7.24 (m, 3 H, H13,
H14, H16). 13C{1H} NMR (150.9 MHz, CDCl3, 25 °C): δ 30.2
(Z-C(O)Me), 32.8 (E-C(O)Me), 51.5 (NMe2), 73.0 (CH2), 124.0
(CH13), 127.8 (CH15), 128.1 (CH14), 129.0 (CH16), 136.1
(=C(C(O)Me)2), 146.5 (C12), 151.8 (C11), 180.7 (CS2), 194.2
(Z-CO), 199.7 (E-CO). IR (cm-1): 1636 s, 1623 s, 1350 s, 1282 s,
1198 m, 862 m, 843 m, 811 w, 615 m, 599 w, 574 w, 421 w, 354 w.
Anal. Calcd for C15H18AuNO2S2: C, 36.65; H, 3.59; N, 2.77; S,
12.69. Found: C, 36.55; H, 3.84; N, 3.15; S, 12.30. Crystals
suitable for an X-ray diffraction study were obtained by slow
diffusion of n-hexane into a solution of 1 in CDCl3.
3
(CH14), 128.8 (CH16), 129.5 (d, m-CH, PPh3, JPC = 11 Hz),
130.3 (v br, i-C, PPh3), 131.3 (p-CH, PPh3), 134.1 (d, o-CH, PPh3,
3JPC = 17 Hz), 137.1 (=C(C(O)Me)2), 146.5 (C12), 151.0 (C11),
175.8 (CS2), 193.9 (Z-CO), 200.0 (E-CO). IR (cm-1): 1644 s, 1626
m, 1354 s, 1288s, 1202m, 1052s, 846m, 694 s, 602 m, 516 s, 422 w,
349 w. Anal. Calcd for C33H33AgAuN2O5PS2: C, 42.28; H, 3.55;
N, 2.99; S, 6.84. Found: C, 42.61; H, 3.35; N, 2.64; S, 7.31.
Synthesis of PPN[Pd(C,N-C6H4CH2NR2-2){μ-S,S-S2CdC-
{C(O)Me}2}] [R = H (5a), Me (5b)]. [Tl2{S2CdC{C(O)Me}2}]
(5a: 269.6 mg, 0.46 mmol; 5b: 236.7 mg, 0.41 mmol) and [PPN]Cl
(5a: 254.3 mg, 0.46 mmol; 5b: 233.1 mg, 0.41 mmol) were
successively added to a solution of [Pd(C,N-C6H4CH2NR2-
2)(μ-Cl)]2 (5a: 114.6 mg, 0.23 mmol; 5b: 112.1 mg, 0.20 mmol)
in CH2Cl2 (20 mL, for 5a freshly distilled under N2). A yellow
Synthesis of [{Au(C,N-C6H4CH2NMe2-2)}{Ag(OClO3)}{μ-
S,S,O-S2CdC{C(O)Me}2}] (2). A solution of AgClO4 (19.7 mg;
(30) Vicente, J.; Abad, J. A.; Lopez-Saez, M.-J.; Jones, P. G. Chem.—Eur.
J. 2010, 16, 661.
(31) Vicente, J.; Chicote, M. T.; Bermudez, M. D. J. Organomet. Chem.
1984, 268, 191.
€
(32) Vicente, J.; Saura-Llamas, I.; Grunwald, C.; Alcaraz, C.; Jones,
P. G.; Bautista, D. Organometallics 2002, 21, 3587.
(33) Pfeffer, M. Inorg. Synth. 1986, 26, 212.
ꢀ
(34) Fornies, J.; Navarro, R.; Sicilia, V. J. Organomet. Chem. 1988, 7,
2659.

8102 Inorganic Chemistry, Vol. 49, No. 17, 2010
Vicente et al.
suspension formed immediately, which was stirred for 3 h (5a) or
1.5 h (5b) and then filtered through Celite. The resulting yellow
(5a) or orange (5b) solution was concentrated under vacuum
(3 mL), and Et2O (20 mL) was added. For 5a an oily material
formed, which was converted into a solid upon stirring with
Et2O in an ice/water bath for 15 min. This solid was filtered and
dried, first under a N2 stream and then in an oven at 60 °C for 4 h
6.67-6.89 (several m, 8 H, C6H4). (90 °C): δ 2.23 (br s, 6 H, Me),
2
4.01 (t, 4 H, CH2, JNH = 5.6 Hz), 5.04 (br s, 4 H, NH2),
6.71-6.88 (several m, 7 H, C6H4), 7.3 (m, 1 H, C6H4). 13C{1H}
RMN (75.4 MHz, d6-dmso, 25 °C): 28.1 (C(O)Me), 32.2
(C(O)Me), 50.9 (CH2), 52.1 (CH2), 121.1 (br, CH13,23), 123.9
(br, CH14,24), 124.7 (br, CH15,25), 133.0 (br, CH16,26), 135.2
(=C(C(O)Me)2), 143-144 (several br, C11,21,12,22), 183.7 (br
s, CO), 195.6 (s, CS2), 203.2 (br s, CO). IR (cm-1): 3324 m, 3266
w, 1702 s, 1686 s, 1552 s, 1224 m, 1208 m, 1042 m, 1024 m, 866 w,
636 w, 592 w, 532 w, 470 w. Anal. Calcd for C20H23N2O2.5Pd2S2:
C, 39.50; H, 3.81; N, 4.60; S, 10.54. Found: C, 39.75; H, 3.72; N,
4.43; S, 10.10.
6b. Yield (%): 67. Dec. point (°C): 212. 1H NMR (600 MHz,
CD2Cl2, 25 °C): δ 2.04 (s, 3 H, C(O)MeB), 2.58 (s, 3 H,
C(O)MeA), 2.64 (s, 6 H, NMe2C), 2.78 (s, 6 H, NMe2C), 3.85
(s, 2 H, CH2D), 3.98 (s, 2 H, CH2C), 6.85-6.90 (m, 3 H,
H15,25,16), 6.94-7.00 (m, 4 H, H13, H23, H14, H24), 7.08 (d,
1 H, H26, 3JHH = 7.0 Hz). 13C{1H} NMR (150.9 MHz, CDCl3,
25 °C): δ 29.0 (C(O)MeB), 32.1 (C(O)MeA), 50.2 (NMe2C), 51.9
(NMe2D), 72.2 (CH2C), 72.7 (CH2D), 122.2 (CH13), 122.7
(CH23), 124.6 (CH14,24), 125.1 (CH25), 125.8 (CH15), 134.3
(CH16), 134.5 (CH26), 135.4 (C2), 144.0 (C21), 147.0 (C11),
147.4 (C12), 148.2 (C22), 184.5 (COB), 194.5 (C1), 203.8 (COA).
IR (cm-1): 1677 s, 1531 s, 1198 m, 875 m, 844 s, 813 w, 637 m, 560
w, 514 w, 379 w. ΛM (Ω-1 cm2 mol-1): 3. Anal. Calcd for
C24H30N2O2Pd2S2: C, 43.98; H, 4.61; N, 4.27; S, 9.78. Found: C,
44.20; H, 4.86; N, 4.31; S, 9.56.
to give 5a 0.5CH2Cl2. 5b precipitated as a yellow solid, which
3
was filtered, washed with Et2O (5 mL) and suction-dried.
1
5a 0.5CH2Cl2: Yield (%): 83. Mp (°C): 98. H NMR (400
3
MHz, CDCl3, 25 °C): δ 2.33 (s, 2 H, NH2), 2.45 (s, 6 H, Me),
4.12 (br s, 2 H, CH2), 5.30 (s, 1 H, CH2Cl2), 6.79 (br t, 1 H, C6H4,
3
4
3JHH = 7.2 Hz), 6.85 (td, 1 H, C6H4, JHH = 7.3 Hz, JHH
=
1.3 Hz), 6.92 (br d, 1 H, C6H4, 3JHH = 7.7 Hz), 7.05 (br d, 1 H,
C6H4, 3JHH = 6.5 Hz), 7.40-7.51 (m, 24 H, PPN), 7.64-7.69 (m,
6 H, PPN). 31P{1H} NMR (121.4 MHz, CDCl3, 25 °C): δ 21.6 (s).
13C{1H} NMR (100.6 MHz, CDCl3): δ 31.9 (Me), 53.2 (CH2Cl2),
77.2 (CH2), 120.5 (CH13), 123.0 (CH14), 124.5 (CH15), 126.8 (m,
i-C, PPN), 129.5 (m, m-CH, PPN), 131.9 (m, o-CH, PPN), 133.4
(CH16), 133.8 (p-C, PPN), 138.1 (=C(C(O)Me)2), 150.9 (C12),
155.2 (C11), 198.4 (CS2), 199.0 (v br s, CO). IR (cm-1): 1688 m,
1575 m, br, 1300 m, 1266 m, 1114 s, 998 m, 850 w, 820 w, 798 w,
624 m, 548 s, 534 s, 500 s, 394 w, 322 w. ΛM (Ω-1 cm2 mol-1): 108.
Anal. Calcd for C49.5H45ClNO2P2PdS2: C, 61.42; H, 4.69; N,
2.89; S, 6.62. Found: C, 61.31; H, 4.95; N, 2.81; S, 6.97.
5b: Yield (%): 68. Mp (°C): 110. 1H NMR (600 MHz, CD2Cl2,
25 °C): δ 2.36 (s, 6 H, C(O)Me), 2.75 (s, 6 H, NMe2), 3.85 (s,
2 H, CH2), 6.80 (t, 1 H, H15, 3JHH = 7.3 Hz), 6.86 (t, 1 H, H14,
3JHH = 7.3 Hz), 6.91 (d, 1 H, H16, 3JHH = 7.0 Hz,), 6.95 (d, 1 H,
Synthesis of [{Pd(C,N-C6H4CH2NR2-2)}3{μ-O,S,S,O-S2Cd
C{C(O)Me}2}]ClO4 [R = H (7a), Me (7b)]. The appropriate
[Pd(C,N-C6H4CH2NR2-2)(NCMe)2]ClO4 (7a: 52.6 mg, 0.13
mmol; 7b: 145.1 mg, 0.34 mmol) was added to a solution of 6
(a: 80.0 mg, 0.13 mmol; b: 225.3 mg, 0.34 mmol) in CH2Cl2
(20 mL, for 7a freshly distilled under N2), and the resulting
solution was stirred for 40 min. For 7a an abundant deep yellow
suspension formed; the solid was filtered off, washed with Et2O,
3
H13, JHH = 7.3 Hz), 7.47-7.50 (m, 24 H, o-H, m-H, PPN),
7.65-7.68 (m, 6 H, p-H, PPN). (-90 °C): δ 2.35 (s, 3 H, C(O)Me),
2.42 (s, 3 H, C(O)Me), 2.78 (s, 6 H, NMe2), 3.91 (s, 2 H, CH2),
6.83 (br s, 2 H, H15, H16), 6.96 (br t, 1 H, H14, 3JHH = 6.5 Hz),
3
7.06 (d, 1 H, H13, JHH = 6.5 Hz), 7.52 (m, 12 H, o- or m-H,
PPN), 7.59-7.65 (m, 12 H, m- or o-H, PPN), 7.70 (br t, 6 H, p-H,
3
PPN, JHH = 7.2 Hz). 31P{1H} NMR (121.4 MHz, CDCl3,
and dried in an oven at 80 °C for 4 h to give 7a CH2Cl2. For 7b,
3
25 °C): δ 21.5 (s). 13C{1H} NMR (100.6 MHz, CD2Cl2, 25 °C):
δ 31.8 (C(O)Me), 51.8 (NMe2), 73.1 (CH2), 121.6 (CH13), 123.0
(CH14), 124.9 (CH15), 127.4 (d, i-C, PPN, JCP = 109.6 Hz),
the solution was concentrated under vacuum (3 mL), and Et2O
(20 mL) was added to precipitate a yellow solid that was
recrystallized from CH2Cl2 and Et2O, filtered, washed with
Et2O (2 ꢀ 10 mL), and suction-dried.
1
129,8 (m, m-CH, PPN), 132.5 (m, o-CH, PPN), 133.5 (CH16),
134.1 (p-CH, PPN), 139.2 (=C(C(O)Me)2), 149.4 (C12), 156.8
(C11), 197.5 (CS2), 198.9 (br s, CO). IR (cm-1): 1680 m, 1580 m,
br, 1261 m, 1100 m, 995 m, 846 m, 817 w, 795 vw, 623 m, 542 m,
525 m, 492 m, 392 w, 321 w. ΛM (Ω-1 cm2 mol-1): 109. Anal.
Calcd for C51H48N2O2P2PdS2: C, 64.25; H, 5.07; N, 2.94; S, 6.73.
Found: C, 64.22; H, 5.09; N, 2.88; S, 6.67.
1
7a CH2Cl2. Yield (%): 68. Dec. point (°C): 197. H RMN
3
(400 MHz, d6-dmso, 25 °C): δ 1.93-2.07 (several br s, 6 H, Me),
3.80-4.05 (br m, 6 H, CH2), 5.16 (br s, 2 H, NH2), 5.31 (s, 2 H,
CH2Cl2), 5.43 (br s, 2 H, NH2), 5.75 (br s, 2 H, NH2), 6.56-7.05
3
(several m, 11 H, C6H4), 7.40 (d, 1 H, H36, JHH = 7.2 Hz).
(60 °C): δ 2.00-2.37 (v br m, 6 H, Me), 4.00 (br s, 6 H, CH2), 5.16
(br s, 4 H, NH2), 5.62 (br s, 2 H, NH2), 6.63-6.74 (m, 2 H,
C6H4), 6.74-7.04 (m, 9 H, C6H4), 7.34 (d, 1 H, H36, 3JHH = 7.4
Synthesis of [{Pd(C,N-C6H4CH2NR2-2)}2{μ-S,S,O-S2Cd
C{C(O)Me}2}] [R = H (6a), Me (6b)]. Solid [Tl2{S2Cd
C{C(O)Me}2}] (6a: 252.4 mg, 0.43 mmol; 6b: 345.8 mg; 0.59
mmol) was added to a solution of the appropriate [Pd(C,N-
C6H4CH2NR2-2)(μ-Cl)]2 (6a: 215.0 mg, 0.43 mmol; 6b: 327.5
mg, 0.59 mmol) in CH2Cl2 (20 mL; for 6a freshly distilled under
N2). A yellow suspension formed immediately, which was
stirred for 1.5 h. For 6a the suspension was concentrated to
dryness, and the residue was extracted in a Soxhlet with acetone
until the extract was colorless. The yellow solution was concen-
trated (2 mL), and Et2O (20 mL) was added to precipitate a dark
yellow solid, which was filtered and dried in an oven at 80 °C for
Hz). (90 °C): δ 2.24 (br s, 6 H, Me), 4.01 (br t, 6 H, CH2, 3JHH
=
5.1 Hz), 5.04 (br s, 4 H, NH2), 5.50 (br s, 2 H, NH2), 6.71 (s, 2 H,
C6H4), 6.78-7.00 (m, 9 H, C6H4), 7.28 (br s, 1 H, H36). 13C{1H}
RMN (75.4 MHz, d6-dmso, 25 °C): δ 28.2 (br, C(O)Me), 32.2
(br, C(O)Me), 51.2 (CH2), 53.2 (CH2Cl2), 121.2 (br), 121.6
(CH13, CH23, CH33), 124.0 (br), 124.5 (br), 124.8 (v br),
125.2, and 125.4 (CH14, CH24, CH34 and CH15, CH25,
CH35), 132.5 and 133.1 (br) CH16, CH26, CH36), 135.4 (C2),
143.0-154.1 (several br, C11, C21, C31, C12, C22, C32), 183.9
(br, CO), 195.1 (C1), 203.3 (br, CO). IR (cm-1): 3306 s, 3250 m,
1585 s, br, 1266 s, 1084 s, 995 m, 1044 m, 1024 m, 850 w,
624 m, 470 w, 430 w. ΛM (Ω-1 cm2 mol-1) 143. Anal. Calcd for
C28H32Cl3N3O6Pd3S2: C, 33.76; H, 3.23; N, 4.13; S, 6.44.
Found: C, 33.38; H, 2.94; N, 4.29; S, 6.76.
4 h to give 6a 0.5H2O. For 6b the suspension was filtered
3
through Celite, the resulting solution was concentrated under
vacuum (3 mL), and n-hexane (20 mL) was added to precipitate
a lemon yellow solid that was filtered, washed with n-hexane
1
(5 mL), and air-dried.
7b. Yield (%): 91. Dec. point (°C): 170 °C. H RMN (600
1
MHz, CD2Cl2, 25 °C): δ 2.54 (br s, 6 H, C(O)Me); 2.84 (br s, 18
H, NMe2); 4.04 (br s, 6 H, CH2); 6.72 (br s, 3 H, C6H4);
6.94-7.00 (m, 6 H, C6H4); 7.20 (br s, 3 H, C6H4). (400 MHz,
CD2Cl2, -80 °C): δ 2.47 (s, 3 H, C(O)MeB), 2.66 (br s, 3 H,
MeE), 2.71 (s, 3 H, C(O)MeA), 2.79 (br s, 3 H, MeC28), 2.85 and
2.87 (br s, 3 H, MeD), 3,02 (br s, 3 H, MeC29), 3.04 (br s, 3 H,
6a 0.5H2O. Yield (%): 57. Dec. point (°C): 185. H RMN
3
(400 MHz, d6-dmso, 25 °C): δ 1.54 (s, 1 H, H2O), 1.93 (s br, 3 H,
C(O)Me), 2.53 (br s, 3 H, C(O)Me), 3.94 (br s, 2 H, CH2), 3.99
(br s, 2 H, CH2), 5.17 (br s, 2 H, NH2), 5.46 (br s, 2 H, NH2),
6.63-6.88 (several m, 8 H, C6H4). (60 °C): δ 2.23 (v br s, 6 H,
Me), 3.99 (t, 4 H, CH2, 2JNH = 5.7 Hz), 5.16 (br s, 4 H, NH2),

Article
Inorganic Chemistry, Vol. 49, No. 17, 2010 8103
Table 1. Crystallographic Data for 1, 6b CH2Cl2, and 7b CH2Cl2
3
3
1
6b CH2Cl2
3
7b CH2Cl2
3
formula
Fw
temperature (K)
crystal system
space group
a (A)
b (A)
c (A)
R (deg)
β (deg)
C15H18AuNO2S2
505.39
173(2)
monoclinic
P21/c
11.561(3)
15.624(3)
9.317(2)
90
105.97(2)
90
1618.0(6)
4
2.075
9.353
968
C25H32Cl2N2O2Pd2S2
740.35
143(2)
triclinic
P1
11.3598(12)
11.6148(12)
11.6365(12)
101.931(3)
92.169(3)
108.554(3)
1415.2(3)
2
C34H44Cl3N3O6Pd3S2
1080.39
133(2)
triclinic
P1
12.0425(11)
13.1177(11)
13.2231(11)
92.137(4)
95.079(4)
105.373(4)
2002.2(3)
2
γ (deg)
volume (A3)
Z
F
calcd (Mg m-3
)
1.737
1.633
740
1.792
1.683
1076
μ (Mo KR)(mm-1
F(000)
)
crystal size (mm)
θ range (deg)
no. of rflns coll
0.40 ꢀ 0.35 ꢀ 0.10
3.19 to 25.00
5935
0.37 ꢀ 0.19 ꢀ 0.19
1.80 to 30.03
16952
0.30 ꢀ 0.09 ꢀ 0.07
1.55 to 30.51
43418
no. of indep rflns/Rint
transmissn
restraints/parameters
goodness-of-fit on F2
R1 (I > 2σ(I ))
2843/0.0439
0.999 and 0.305
32/194
0.994
0.0250
8208/0.0294
0.970 and 0.684
31/350
1.046
0.0220
12150/0.0406
0.8913 and 0.7309
0/468
1.033
0.0347
wR2 (all reflns)
largest diff. peak/hole (e A-3
0.0551
1.283/-0.860
0.0543
0.569/-0.797
0.0815
1.297/-1.345
)
MeD), 3.60 (d, 1 H, CH2E), 3.83 (br t, 2 H, CH2C,D), 4.44-4.54
(m, 3 H, CH2C,D,E), 6.47 (t, 1 H, H35, 3JHH = 6.9 Hz), 6.56 (d,
1 H, H16, 3JHH = 7.5 Hz), 6.70 (t, 1 H, H15, 3JHH = 7.1 Hz),
6.85 (t, 1 H, H34, 3JHH = 7.0 Hz), 6.93 (d, 1 H, H33, 3JHH =7.0Hz),
Scheme 1
6.99 (t, 1 H, H14, 3JHH = 7.1 Hz), 7.02 (br t, 1 H, H25, 3JHH
=
7.0 Hz), 7.07 (d, 1 H, H13, 3JHH = 7.0 Hz), 7.10-7.16 (m, 2 H,
H23,24), 7.18 (d, 1 H, H26, 3JHH = 7.3 Hz), 8.10 (d, 1 H, H36,
3JHH = 7.7 Hz). 13C{1H} RMN (150.9 MHz, CD2Cl2, 25 °C):
32.3 (br s, C(O)Me), 52.0 (br s, NMe2), 72.7 (br s, CH2), 123.3 (br
s, CH13, CH23, CH33), 125.8 and 126.0 (br s, CH14, CH24,
CH34 and CH15, CH25, CH35), 134.3 (br s, CH16, CH26,
CH36), 148.3 (br s, C12, C22, C32). IR (cm-1): 1614 s, 1522 s,
1278 m, 1100 s, br, 990 m, 846 m, 622 m, 516 w, 424 w, 384 w. ΛM
(Ω-1 cm2 mol-1) 124. Anal. Calcd for C33H42ClN3O6Pd3S2: C,
39.82; H, 4.25; N, 4.22; S, 6.44. Found: C, 39.68; H, 4.24; N,
4.07; S, 5.91.
X-ray Crystallographic Analysis of 1, 6b CH2Cl2, and 7b CH2Cl2.
3
3
Crystals suitable for X-ray analyses were obtained by slow
diffusion of n-hexane into a solution of 1 in CDCl3 or by slow
diffusion of Et2O into CH2Cl2 solutions of 6b. The crystal struc-
ture of 7b CH2Cl2 has been reported in a preliminary communi-
3
cation.22 Crystal data and refinement details are shown in Table 1.
Intensity measurements were recorded using monochromated
Mo KR radiation on a Siemens P4 (1) or SMART 1000 diffracto-
meter. Absorption corrections were performed on the basis of ψ-
scans (1) or multiscans. Structures were refined anisotropically
on F2 using the program SHELXL-97;35 hydrogen atoms were
included using a riding model or rigid idealized methyl groups.
For 6b, the dichloromethane molecule is disordered over two
positions.
1,1-dithiolato complex (PPN)2[Au2{μ-S,S-S2CdC{C-
(O)Me}2}] by reacting PPN[Au(acac)2] (acac = acetyl-
acetonate) and CS2. However, after refluxing a mixture
of [Au(acac)(C,N-C6H4CH2NMe2-2)Cl]36 and NEt3
(1:5) in CS2 (5 mL) for 3 h, the starting materials were re-
covered and neither 1 nor the intermediate complex
[Au(C,N-C6H4CH2NMe2-2)Cl{SC(=S)CH{C(O)Me}2}]
were even detected by NMR spectroscopy. Thereaction of
Results and Discussion
Synthesis. The reaction of [Au(C,N-C6H4CH2NMe2-2)-
Cl2]31 with [Tl2{S2CdC{C(O)Me}2}]5 (Scheme 1) caused
the immediate precipitation of TlCl and the formation of
[Au(C,N-C6H4CH2NMe2-2){S,S-S2CdC{C(O)Me}2}] (1),
which was isolated in good yield (74%). We have previously
described21 the synthesis of the non-organometallic Au(I)
(36) Vicente, J.; Bermudez, M. D.; Chicote, M. T.; Sanchez-Santano,
(35) Sheldrick, G. M. Acta Cristallogr., Sect. B 2008, 64, 112.
M. J. J. Chem. Soc., Dalton Trans. 1990, 1945.

8104 Inorganic Chemistry, Vol. 49, No. 17, 2010
Vicente et al.
Scheme 2
Figure 1. Thermal ellipsoid representation plot (50% probability) of
complex 1. Selected bond lengths (A) and angles (deg): Au-C(11)
2.029(5), Au-N 2.140(5), Au-S(1) 2.3646(15), Au-S(2) 2.2846(16),
S(1)-C(1) 1.754(6), S(2)-C(1) 1.761(5), C(1)-C(2) 1.361(8), C(2)-C(3)
1.474(7), C(2)-C(5) 1.488(7), O(1)-C(3) 1.232(7), O(2)-C(5) 1.223(6);
C(11)-Au-N 82.3(2), N-Au-S(1) 104.20(13), S(2)-Au-S(1) 74.86(5),
C(11)-Au-S(2) 98.46(17).
[{Pd(C,N-C6H4CH2NR2-2)}2{μ-S,S,O-S2CdC{C(O)Me}2}]
[R = H (6a), Me (6b)] were obtained. Whereas 6b was
easily separated from TlCl, 6a precipitated as a hemihy-
drate insoluble in CH2Cl2 and only slightly soluble in
acetone. This required repeated extraction with acetone
in a Soxhlet, which restricted the yield (57%). 6a 0.5H2O
could not be dehydrated even by heating it in an oven at
80 °C for 4 h.
3
1 with AgClO4 (1:1, in acetone) afforded in good yield
(77%) the heterodinuclear complex, [{Au(C,N-C6H4-
CH2NMe2-2)}{Ag(OClO3)}{S,S,O-S2CdC{C(O)Me}2}]n
(2), the insolubility of which in all common organic
solvents prevented its characterization by NMR or X-ray
diffraction studies. In Scheme 1 we show a reasonable
representation of its structure as a polymeric complex. The
reaction of 2 with PPh3 (1:1, in acetone) gave the soluble
complex [{Au(C,N-C6H4CH2NMe2-2)}{Ag(OClO3)(PPh3)}-
{S,S,O-S2CdC{C(O)Me}2}] (3) in 68% yield, along with
an insoluble material that could not be identified. Com-
plex 3 can also be obtained by reacting 1 with AgNO3
and PPh3 (1:1:1, in acetone, 84% yield). Similarly, the
analogous complex [{Au(C,N-C6H4CH2NMe2-2)}{Ag-
(ONO2)(PPh3)}{S,S,O-S2CdC{C(O)Me}2}] (4) was iso-
lated in 60% yield from the reaction of 1 with AgNO3
and PPh3 (1:1:1, in acetone). The behavior in solution of
3 and 4 shows equilibria between various complexes (see
below). Scheme 1 shows the structure of one of them.
We have tried to obtain mixed valence Au(III)/Au(I)
derivatives by reaction of the labileAu(I) complexes [AuCl-
The reaction of [Pd(C,N-C6H4CH2NMe2-2)(μ-Cl)]2
with [Tl2{S2C2{C(O)Me}2}] and AgClO4 (1.5:1:1), or
with 6b and AgClO4 (0.5:1:1) was expected to afford the
tripalladated complex 7b (Scheme 2) but, instead, com-
plex mixtures of products formed, among which 7b could
not be identified.22 Nevertheless, the tripalladated com-
plexes [{Pd(C,N-C6H4CH2NR2-2)}3{μ-O,S,S,O-S2C2-
{C(O)Me}2}]ClO4 [R = H (7a), Me (7b)] could be ob-
tained in good yield by displacement of the labile nitrile
ligands in [Pd(C,N-C6H4CH2NR2-2)(NCMe)2}]ClO4 by
the corresponding dinuclear complex 6, acting as an S,O
chelating ligand. Complex 7a precipitated in situ as
7a CH2Cl2, which was isolated in 70% yield by filtra-
3
tion. The CH2Cl2 solvent molecule could not be removed
even by heating at 80 °C for 4 h. The low solubility of
complexes 6a 0.5H2O and 7a CH2Cl2, together with their
3
3
tendency to crystallize with solvent molecules, differenti-
ates them from their NMe2 homologues (soluble and
unsolvated), which suggests the presence of significant
hydrogen bonds involving the NH2 fragments in the a
derivatives.
(tht)] (tht = tetrahydrothiophene)37 or [Au(NH3)2]ClO4
38
with 1 under various reaction conditions. However, all
these reactions led to mixtures of products that could not
be separated or even identified. The attempt to replace
Ag(I) by Au(I) in complex 2 by reaction with [AuCl(tht)]
led to massive decomposition.
The reaction of [Pd(C,N-C6H4CH2NR2-2)(μ-Cl)]2 with
[Tl2{S2CdC{C(O)Me}2}] and [PPN]Cl (1:2:2) afforded
PPN[Pd(C,N-C6H4CH2NR2-2){S,S-S2CdC{C(O)Me}2}]
[R = H (5a), Me (5b)] (Scheme 2). When complexes [Pd(C,
N-C6H4CH2NR2-2)(μ-Cl)]2 were reacted with 1 equiv
of [Tl2{S2CdC{C(O)Me}2}] the dinuclear complexes
Crystal Structures. The crystal structures of complexes
1 (Figure 1) and 6b CH2Cl2 (Figure 2) have been deter-
3
mined. That of 7b CH2Cl2 (Figure 3) was reported in a
3
preliminary communication.22
The dithiolato ligand in 1 is S,S-chelating and adopts an
E,Z conformation while in 6b and 7b is Z,Z and S,S-
chelating toward Pd(1) and, simultaneously, S,O-chelating
toward Pd(2) (6b) or, in addition, toward Pd(3) (7b). A
Re26 complex is the only example of a dithiolato ligand
adopting the same coordination mode as that of S2Cd
C{C(O)Me}2 in 6b, while the coordination mode found in
7b is unprecedented.
ꢀ
(37) Uson, R.; Laguna, J.; Vicente, J. J. Organomet. Chem. 1977, 131, 471.
(38) Vicente, J.; Chicote, M. T.; Guerrero, R.; Jones, P. G.; Ramırez de
Arellano, M. C. Inorg. Chem. 1997, 36, 4438.
The metal atoms are in all these complexes in essentially
planar environments. While the best coordination planes
´

Article
Inorganic Chemistry, Vol. 49, No. 17, 2010 8105
Chart 3
a less crowded one because the C/S transphobia39 is larger
than the C/O one. In most of the structurally characteri-
zed Pd(II) complexes bearing simultaneously C-, O-, and
S-donor ligands, C is trans to O,40 and the few cases with
C trans to S are forced by the geometry of the ligands, or
by the C/C-41 or C/P42 transphobia being higher than the
C/S one, with only two exceptions.43,44
The M-S bond distances trans to C are significantly
longer than those trans to N, as expected for the larger
trans influence of C- than of N-donor ligands, which is
partly responsible for the differences in the activation
energy of the dynamic processes capable of interconvert-
ing in solution the {M(C,N-C6H4CH2NMe2-2)} groups in
complexes 6 and 7 and making equivalent the two acetyl
groups in all complexes.
The bond distances within the dithiolato fragments
are within the intervals found for other 2,2-diacetyl-1,1-
ethylenedithiolato complexes5,8,14,17,18,21 and reflect some-
how the different contribution of the resonance forms A-C
(see Chart 3), depending on the coordination mode of the
ligand, the electronegativity of the metal, and the neutral
(1, 6b) or charged (7b) nature of the complex. Thus, the
C(1)-C(2) bond distances are intermediate between the
C(sp3)-C(sp3) and C(sp2)dC(sp2) typical values,45 and
increase with the number of metal centers. The coordina-
tion of one acetyl group to Pd(2) in 6b or 7b causes
the lenghthening the C(3)-O(1) and the shortening of
C(2)-C(3) [6b: 1.258(2) and1.432(2); 7b: 1.250(4), and,
1.445(4) A, respectively] although, surprisingly, the acetyl
group coordinated to Pd(3) in 7b shows parameters
[C(5)-O(2) 1.234(4), C(2)-C(5) 1.493(4) A] more similar
Figure 2. Thermal ellipsoid representation plot (50% probability) of
complex 6b omitting the solvent. Selected bond lengths (A) and angles
(deg): Pd(1)-C(11) 1.9887(15), Pd(2)-C(21) 1.9875(15), Pd(1)-N(1)
2.1037(13), Pd(2)-N(2) 2.1061(13), Pd(1)-S(1) 2.4422(4), Pd(1)-S(2)
2.2908(4), Pd(2)-S(1) 2.2459(4), Pd(2)-O(1) 2.0886(11), S(1)-C(1)
1.7462(15), S(2)-C(1) 1.7479(16), C(1)-C(2) 1.382(2), C(2)-C(3)
1.432(2), C(2)-C(5) 1.514(2),C(5)-C(6) 1.497(3), O(1)-C(3) 1.258(2),
O(2)-C(5) 1.217(2); C(11)-Pd(1)-N(1) 82.35(6), C(11)-Pd(1)-S(2)
96.83(5), N(1)-Pd(1)-S(1) 108.16(4), S(2)-Pd(1)-S(1), 72.940(14),
C(21)-Pd(2)-N(2) 83.06(6), O(1)-Pd(2)-N(2) 89.11(5), C(21)-
Pd(2)-S(1) 94.79(4), O(1)-Pd(2)-S(1) 92.33(3).
(39) Vicente, J.; Arcas, A.; Bautista, D.; Jones, P. G. Organometallics
1997, 16, 2127. Vicente, J.; Abad, J. A.; Frankland, A. D.; Ramírez de Arellano,
M. C. Chem.—Eur. J. 1999, 5, 3066. Vicente, J.; Arcas, A.; Blasco, M. A.;
Lozano, J.; Ramírez de Arellano, M. C. Organometallics 1998, 17, 5374. Vicente,
ꢀ
J.; Abad, J. A.; Frankland, A. D.; Lopez-Serrano, J.; Ramírez de Arellano, M. C.;
ꢀ
ꢀ
Jones, P. G. Organometallics 2002, 21, 272. Vicente, J.; Arcas, A.; Galvez-Lopez,
M. D.; Jones, P. G. Organometallics 2006, 25, 4247. Vicente, J.; Arcas, A.;
ꢀ
ꢀ
ꢀ
ꢀ
Galvez-Lopez, M.-D.; Julia-Hernandez, F.; Bautista, D.; Jones, P. G. Organo-
metallics 2008, 27, 1582.
(40) CSD version 5.31 (Nov. 2009)
Figure 3. Thermal ellipsoid representation plot (50% probability) of
complex 7b omitting the solvent and the anion. Selected bond lengths (A)
and angles (deg): Pd(1)-C(11) 1.981(3), Pd(2)-C(21) 1.971(3), Pd(3)-
C(31) 1.971(3), Pd(1)-N(1) 2.112(3), Pd(2)-N(2) 2.110(3), Pd(3)-N(3)
2.097(3), Pd(1)-S(1) 2.4798(8), Pd(1)-S(2) 2.2873(8), Pd(2)-O(1)
2.101(2), Pd(2)-S(1) 2.2342(8), Pd(3)-O(2) 2.181(2), Pd(3)-S(2)
2.3068(8), S(1)-C(1) 1.711(3), S(2)-C(1) 1.776(3), C(1)-C(2) 1.391(4),
C(2)-C(3) 1.445(4), C(2)-C(5) 1.493(4), O(1)-C(3) 1.250(4), O(2)-C(5)
1.234(4); C(11)-Pd(1)-N(1) 82.06(11), C(11)-Pd(1)-S(2) 94.39(9),
S(2)-Pd(1)-S(1) 71.56(3), N(1)-Pd(1)-S(1) 113.00(8), C(21)-Pd(2)-
N(2) 82.47(11), O(1)-Pd(2)-N(2) 93.01(9), O(1)-Pd(2)-S(1) 91.83(6),
C(21)-Pd(2)-S(1) 93.72(9), C(31)-Pd(3)-N(3) 81.92(12), N(3)-
Pd(3)-O(2) 96.79(9), O(2)-Pd(3)-S(2) 79.40(6), C(31)-Pd(3)-S(2)
(41) Ara, I.; Fornies, J.; Navarro, R.; Sicilia, V.; Urriolabeitia, E. P.
Polyhedron 1997, 16, 1963.
ꢀ
ꢀ
ꢀ
(42) Uson, R.; Fornies, J.; Navarro, R.; Uson, M. A.; Garcia, M. P.;
Welch, A. J. J. Chem. Soc., Dalton Trans. 1984, 345. Osakada, K.; Ozawa, Y.;
Yamamoto, A. Bull. Chem. Soc. Jpn. 1991, 64, 2002. Chooi, S. Y. M.; Hor,
ꢀ
T. S. A.; Leung, P. H.; Mok, K. F. Inorg. Chem. 1992, 31, 1494. Fornies, J.;
Martínez, F.; Navarro, R.; Urriolabeitia, E. P.; Welch, A. J. J. Chem. Soc., Dalton
Trans. 1995, 2805. Hua, R.; Takeda, H.; Onozawa, S. Y.; Abe, Y.; Tanaka, M.
J. Am. Chem. Soc. 2001, 123, 2899. Leung, P. H.; Qin, Y.; He, G. S.; Mok, K. F.;
Vittal, J. J. J. Chem. Soc., Dalton Trans. 2001, 309. Daugulis, A.; Brookhart, M.;
White, P. S. Organometallics 2002, 21, 5935. Qin, Y.; White, A. J. P.; Williams,
D. J.; Leung, P. H. Organometallics 2002, 21, 171. Qin, Y.; Lang, H. F.; Vittal,
J. J.; Tan, G. K.; Selvaratnam, S.; White, A. J. P.; Williams, D. J.; Leung, P. H.
Organometallics 2003, 22, 3944. Cabrera, S.; Arrayas, R. G.; Carretero, J. C.
Angew. Chem., Int. Ed. 2004, 43, 3944.
102.26(10). Pd(1) H(36) 2.55.
3 3 3
(43) Hejl, A.; Trnka, T. M.; Day, M. W.; Grubbs, R. H. Chem. Commun.
2002, 2524.
of Pd(1) and Pd(2) in 7b are almost coplanar (11°), that
of Pd(3) is nearly perpendicular to them, because of
(44) Kim, M.; Gabbai, F. P. Dalton Trans. 2004, 3403.
the steric hindrance between arenes C(11) C(16) and
C(31) C(36), which adopt this disposition instead of
(45) Allen, F. H.; Kennard, O.; Watson, D. G.; Brammer, L.; Orpen,
A. G.; Taylor, R. J. Chem. Soc., Perkin Trans. 2 1987, S1.
3 3 3
3 3 3

8106 Inorganic Chemistry, Vol. 49, No. 17, 2010
Vicente et al.
Scheme 3
Figure 4. Sections of the phase-sensitive 1H-EXSY spectra (600 MHz,
CDCl3, room temperature) of complexes 3 (a) and 1 (b), showing,
respectively, the presence or absence of exchange cross-peaks between
the two acetyl groups.
to those found for the uncoordinated groups in 6b (see
above) and in 1 [C(3)-O(1) 1.232(7), C(5)-O(2) 1.223(6),
C(2)-C(3) 1.474(7), C(2)-C(5) 1.514(2) A]. This anomaly
must be accounted for in terms of the additional influence
of steric effects caused, in part, by transphobic reasons
(see above).
In the absence of X-ray diffraction data we tentatively
assign a polymeric structure to 2 in the solid state,
although a dimeric chair structure as that found in some
silver-palladium or silver-platinum 2,2-diacetyl-1,1-
ethylenedithiolato complexes cannot be ruled out.14
NMR Spectra of Gold Complexes. Complexes 1 and 2.
The 1H NMR spectrum of 1 in CDCl3 at room tempera-
ture shows the two expected resonances for the acetyl
protons. In contrast, a single 1H resonance is observed for
both the methyl and the methylene protons of the
CH2NMe2 fragment, suggesting that in solution there is
free rotation of the acetyl groups around the C-C(O)Me
bonds, as well as sulfur inversion, a common process in
organosulfur transition metal complexes.22,46 Similarly,
the 13C{1H} NMR spectrum of 1 in CDCl3 shows two
resonances for the acetyl groups and a single resonance
for the NMe2 group.
acetyl and one NMe2 and CH2 resonances. However, a
1H-EXSY spectrum of 3 in CDCl3 reveals the presence of
a slow exchange process between the two C(O)Me groups
(Figure 4a).47 This dynamic behavior is not observed in
1
the H-EXSY spectrum of 1, under the same conditions
(Figure 4b). It is reasonable to assume that the exchange
between the two acetyl groups in complex 3 takes place
by process P1 (Scheme 3), involving the cleavage of
the weakest Au-S bond, namely, that trans to aryl, to
give intermediates I/I0, followed by 180° rotation around
the other Au-S bond to give II/II0 and recoordina-
tion of S to Au.48 Simultaneously, a fast exchange of
the [Ag(PPh3)(OClO3)] moiety between the two S atoms
(process P2) explains (1) the observation of only two
acetyl resonances, instead of the four expected for the two
isomers 3a1 and 3a2, and (2) the different behavior in
solution of 1 and 3, caused by the additional weakening of
both Au-S bonds arising from the coordination of Ag to
S. This kind of fluxionality is typical in the coordination
chemistry of Ag, and there are precedents for such rapid
site exchange of Ag between S-donors of the same ligand
even at 213 K.49 More details of this process will be
discussed below. The 31P NMR resonances of 3 at room
temperature appear as two very broad signals (Figure 5).
Complex 2 is insoluble in most common solvents. The
1H NMR spectrum in d6-dmso is identical to the spectrum
of complex 1 in the same solvent, suggesting that dmso
coordinates to Ag, displacing the dithiolene ligand to give
1 and some Ag-dmso complex. Interestingly, in these 1H
NMR spectra of complexes 1 and 2 in dmso there is only a
single 1H resonance for the two C(O)Me groups, suggest-
ing that the dmso cleaves the Au-N and/or Au-S bonds,
allowing the exchange of coordination positions around
the Au atom.
Complex 3. Room Temperature Spectra. The 1H and
13C NMR spectra of the mixed (Au,Ag) dinuclear com-
plex 3 in CDCl3 are similar to those of complex 1: two
(46) Abel, E. W.; Bhargava, S. K.; Orrell, K. G. Prog. Inorg. Chem. 1984,
32, 1. Abel, E. W.; Cooley, N. A.; Kite, K.; Orrell, K. G.; Sik, V.; Hursthouse,
H. B.; Dawes, H. M. Polyhedron 1987, 6, 1261. Abel, E. W.; Orrell, K. G.; Poole,
M. C.; Sik, V. Polyhedron 1999, 18, 1345.
(47) Exchange cross-peaks are distinguished from possible NOE peaks
because they have the same phase as diagonal peaks. No NOE peaks are
observed between the two acetyl groups, neither for 1 nor for 3. For more
information on EXSY/NOESY spectra see: Claridge, T. O. W. High
Resolution NMR Techniques in Organic Chemistry, 2nd ed.; Elsevier: Boston,
2009.
(48) Another possible mechanism for the slow exchange of the two
C(O)Me groups would be rotation around the C-C bond of the dithiolene,
thanks to the contribution of resonance forms B and C shown in Chart 3.
However, the coordination of Ag to S in complex 3 would favor the
resonance form A making the exchange process less favored in 3 than in 1,
which is not the case. Consequently, we think that process P1 in Scheme 3 is
the most likely mechanism for the exchange.
(49) Bailey, P. J.; Dawson, A.; McCormack, C.; Moggach, S. A.; Oswald,
I. D. H.; Parsons, S.; Rankin, D. W. H.; Turner, A. Inorg. Chem. 2005, 44,
8884.

Article
Inorganic Chemistry, Vol. 49, No. 17, 2010 8107
Scheme 4
at 243 K are still exchanging rapidly the [Ag(PPh3)-
(OClO3)] moiety between the two S atoms (P2 in
Schemes 3 and 4). The JP109 value in B (554 Hz) is
Ag
indicative of a tetracoordinated complex52,54 such as 3b1
(Scheme 4). The tri- (3a1/3a2) and tetracoordinated (3b1)
isomers of complex 3 would be in fast exchange at room
temperature (process P3, Scheme 4).
Below 243 K the pd A starts broadening and virtually
disappears at 213 K (while the pd B remains55) reappear-
ing at lower temperatures (CD2Cl2, Figure 5b) as two
new sharp pd, A1(2) and A2(9), which we assign to 3a1
and 3a2, respectively. This assignment is based on the
JPAg values: both correspond to tricoordinated species
Figure 5. VT 31P NMR spectra (242.9 MHz) of complex 3 in CDCl3 (a)
and CD2Cl2 (b).
Low Temperature 31P NMR Spectra. When the tem-
perature is decreased, the two broad 31P resonances
transform into four resonances that at 243 K resolve into
two pairs of doublets (pd),50 A(b) and B(O) (Figure 5).
(JP109 = 623 and 710 Hz, respectively, at 183 K) and
Ag
JPAg(A1) < JPAg(A2). This relationship suggests that the
pd A1 corresponds to the isomer with S trans to C (3a1) in
which a weaker S-Au bond induces a stronger S-Ag
interaction and therefore a weaker Ag-P bond and
a lower JPAg. The bond strength sequence S-Ag3a1 > S-
Ag3a2 is also in agreement with 3a1 being more abundant
than 3a2 (1H NMR spectra, see below). For this reason,
the most probable structure for the tetracoordinated isomer
3b1 is that with S[Ag] trans to aryl, as drawn in Scheme 4.
The JP109 value in A (713 Hz) is similar to others
Ag
reported in the literature for tricoordinated Ag
complexes51,52 with one P-donor ligand.53 Thus, the pd
A seems to correspond to the species 3a1 and 3a2, which
(50) A(b): δ 13.4 ppm, J(31P,109Ag) = 713 Hz, J(31P,107Ag) = 634 Hz (at
253 K) and B(O): δ 12.2 ppm, J(31P,109Ag) = 554 Hz, J(31P,107Ag) = 484 Hz
(at 243 K).
A
31P-EXSY spectrum at 183 K (Figure 6a) still reveals
exchange cross-peaks between A1 and A2, showing that
even at this very low temperature the exchange process P2
is active, although slow. Probably, this exchange occurs
through a non-dissociative mechanism involving the mo-
mentary coordination of the Ag to both S atoms
(Scheme 4; 3* represents the transition state), as otherwise
a complete dissociation of the [Ag] moiety would allow
the exchange between tri- and tetracoordinated species
(ASB, P3), which according to the 31P NMR spectra
clearly has a higher activation energy than process P2
(A1SA2). Below 213 K the pd B starts broadening and at
183 K only some humps are visible, suggesting the
existence of additional dynamic processes involving 3b1
and other species (Scheme 4, 3bx), which presumably
(51) Calhorda, M. J.; Costa, P. J.; Crespo, O.; Gimeno, M. C.; Jones,
P. G.; Laguna, A.; Naranjo, M.; Quintal, S.; Shi, Y.-J.; Villacampa, M. D.
Dalton Trans. 2006, 4104. Carmona, D.; Oro, L. A.; Lamata, M. P.; Jimeno,
M. L.; Elguero, J.; Belguise, A.; Lux, P. Inorg. Chem. 1994, 33, 2196. Santini, C.;
Pettinari, C.; Lobbia, G. G.; Spagna, R.; Pellei, M.; Vallorani, F. Inorg. Chim.
Acta 1999, 285, 81. Aguado, J. E.; Canales, S.; Gimeno, M. C.; Jones, P. G.;
Laguna, A.; Villacampa, M. D. Dalton Trans. 2005, 3005. Crespo, O.; Brusko,
V. V.; Gimeno, M. C.; Tornil, M. L.; Laguna, A.; Zabirov, N. G. Eur. J. Inorg.
Chem. 2004, 423.
(52) Effendy; Lobbia, G. G.; Marchetti, F.; Pellei, M.; Pettinari, C.;
Pettinari, R.; Santini, C.; Skelton, B. W.; White, A. Inorg. Chim. Acta 2004,
357, 4247.
(53) The presence of a second P-donor ligand usually results in lower
J(Ag,P) values. Similarly, the presence of S-donor ligands also decreases the
J(Ag,P) values. This effect is stronger as the number of P- or S- donor ligands
increases.
(54) Santini, C.; Lobbia, G. G.; Pettinari, C.; Pellei, M.; Valle, G.;
Calogero, S. Inorg. Chem. 1998, 37, 890. Canales, S.; Crespo, O.; Fortea, A.;
Gimeno, M. C.; Jones, P. G.; Laguna, A. J. Chem. Soc., Dalton Trans. 2002,
€
2250. Rombke, P.; Schier, A.; Schmidbaur, H. Z. Naturforsch., Sect. B 2003, 58,
(55) 31P NMR of complex 3 part B at 213 K in CD2Cl2: δ 14.3 ppm,
J(31P,109Ag) = 558 Hz, J(31P,107Ag) = 485 Hz.
168.

8108 Inorganic Chemistry, Vol. 49, No. 17, 2010
Vicente et al.
Figure 6. Section of the low-temperature 31P-EXSY spectra (242.9 MHz)
of complexes 3 (a) and 4 (b). The absence of mixed 31P-109Ag/31P-107Ag
cross-peaks is an indication that the exchange occurs without phosphine
dissociation.
would also be tetracoordinated. These dynamic pro-
cesses should also be non-dissociative, as discussed for
process P2.
Low Temperature 1H NMR Spectra. Figure 7 and
1
Supporting Information, Figure SI1 show the VT H
NMR spectra of 3. As the temperature is decreased, the
C(O)Me signal at lower frequency broadens faster than
the rest of the spectrum. We assign this resonance to the
MeZ (pseudo-cis to the NMe2 moiety, Scheme 4), which is
more affected by the dynamic process P3. Below 213 K
1
(Figure 7) we can observe a gradual splitting of the H
resonances into two major sets, in about 1.5:1 molar ratio,
which we assign to 3a1(2) and 3a2(9). Some additional
very broad resonances would correspond to 3b1/3bx
(Supporting Information, Figure SI1). Interestingly, each
of the two room temperature acetyl resonances resolves at
183 K into a narrow and a broad resonance. We assign the
broad resonances to the Me groups cis to the [Ag] moiety
in each of the isomers, that is, MeZ in 3a1(2) and MeE in
3a2(9) (Scheme 4), as the rotation of these acetyl groups
around the C-C(O)Me bonds should be slowed down by
the presence of the bulky [Ag] fragment.
Complex 4. For the mixed (Au,Ag) nitrate complex 4
the room temperature 1H and 13C NMR spectra in CDCl3
are almost identical to those of 3, with two acetyl signals
and single resonances for the NMe2 and CH2 groups.
Supporting Information, Table SI1 provides a compari-
son of the NMR data of 1, 3, and 4. However, the room
temperature 1H-EXSY spectrum of 4 (Supporting Infor-
mation, Figure SI2a) does not show exchange cross-
peaks47 between the two C(O)Me groups, as opposed to
3 and in analogy with 1 (Figure 4). Nonetheless, when the
temperature is increased to 333 K (Supporting Informa-
tion, Figure SI2b) such cross-peaks appear, reflecting a
slow exchange between the two acetyl groups and, corre-
spondingly, a higher activation energy for this process in 4
than in 3. This observation is in agreement with the
stronger Ag-O bond expected for Ag-ONO2 compared
to Ag-OClO3,56 which would weaken the AuS-Ag bond
in 4 and strengthen the Au-SAg bond, resulting in a
higher activation energy for the exchange of the two
Figure 7. Section of the VT 1H NMR spectra of 3 (600 MHz, CD2Cl2).
The verticalscalingofthe spectra is differentin the upper(293-213K) and
lower (213-183K) part of the figure.
acetyl groups in 4 with respect to 3, according to the
mechanism proposed for process P1 in Scheme 3.
The VT 31P NMR spectra of 4 in CDCl3 and CD2Cl2
are shown in Figure 8. At the higher temperatures the
spectra are similar to those of 3: two broad humps that
resolve below 243 K into two pd’s A(b) (JP109Ag = 751 Hz)
and B(O) (JP109Ag = 536 Hz) (CDCl3, 223 K). However, at
the lower temperatures these 31P resonances do not split
or disappear (in contrast to 3), although the pd A broad-
ens below 220 K. The VT 1H NMR spectra of 4 (Figure 8)
are also similar to those of 3 for the higher temperatures
but again, upon cooling, the resonances do not split, even
at 168 K. These data agree with the mentioned weaker
S-Ag bonds in 4 than in 3, that decrease the activation
energy for the [Ag] exchange within the tricoordinated
isomers. A 31P-EXSY spectrum of 4 at 223 K (Figure 6b)
shows that the exchange between the 3- and 4-coordinated
isomers (4a S 4b, P3) also occurs without dissociation of
the PPh3 (similar to the site exchange process 3a1 S3a2,
P2, Scheme 4).
NMR Spectra of Palladium Complexes. In contrast to
its analogous Au(III) complex 1 (and its derivatives 3 and
4), the mononuclear Pd(II) complexes 5a,b show only
1
one C(O)Me resonance in the H and 13C NMR spectra
at room temperature. This is because the Pd(II)-S bond
is weaker than the Au(III)-S bond, which causes a faster
exchange of the acetyl groups in 5a,b with respect to 3
(process P1, Scheme 3). However, complexes 5a,b resemble
(56) Ashworth, R. S.; Prout, C. K.; Domenicano, A.; Vaciago, A.
J. Chem. Soc. A 1968, 93. Lin, C.-J.; Hwang, W.-S.; Chiang, M. Y. 2001, 20, 3275.

Article
Inorganic Chemistry, Vol. 49, No. 17, 2010 8109
Scheme 5. Proposed Dynamic Process in 6b
Scheme 6. Proposed Mechanism for the Dynamic Process That Ex-
changes the Three [Pd(C6H4CH2NMe2)] Moieties, and Also the Two
Acetyl Groups, in 7b
Figure 8. VT 31P NMR spectra of complex 4 in CDCl3 (a) and
CD2Cl2 (b).
1 in showing CH2 and NMe2 singlets at room temperature,
which proves the existence of sulfur inversion and free
rotation around the C-C(O)Me bonds. A series of VT 1H
NMR spectra of 5b (Supporting Information, Figure SI3)
shows that below 218 K the exchange between the two
acetyl groups is frozen (at 183 K there are two Me
resonances), while the singlet (although broadened) CH2
and NMe2 resonances remain even at 183 K.
The NMR spectra of the di- and trinuclear complexes
6a and 7a have been measured in d6-dmso because of
their insolubility in other common deuterated solvents
(Supporting Information, Figures SI6 and SI7). At 298 K
the dinuclear complex 6a shows two resonances for the
C(O)Me, CH2, and NH2 groups. When the temperature is
increased above 333 K (Supporting Information, Figure
SI6), these two sets of 1H resonances merge into a single
set, showing that a dynamic process makes equivalent the
pair of [Pd(C6H4CH2NH2)] fragments, as well as the two
acetyl groups. For the trinuclear complex 7a the 1H NMR
spectra in d6-dmso are somewhat more complicated at
room temperature (Supporting Information, Figure SI7),
while at 363 K a single set of resonances is observed except
for the three NH2 groups, which afford a 1:2 pattern,
probably caused by different NH-dmso hydrogen bond
interactions. The high melting point of dmso prevents the
further investigation of these complexes.
1
room temperature a broadening of the H resonances is
also observed, which results in the near-coalescence of
the two sets of resonances at 323 K. We attribute this
broadening to a dynamic process that would slowly make
the pair of [Pd(C6H4CH2NMe2)] fragments equivalent, as
well as the two acetyl groups, in the same way as for 6a.
1
Indeed, the H EXSY spectrum of 6b at room tempera-
ture (Supporting Information, Figure SI9) already shows
exchange cross-peaks between the two sets of resonances.
For this dynamic process we propose an equilibrium
(Scheme 5) involving the cleavage of the Pd-O and
Pd-S1 bonds (both trans to the aryl groups), rotation
around the C-S bonds and recoordination of the
[Pd(C6H4CH2NMe2)] fragments to the dithiolene. This
process is favored by the strong trans influence of the aryl
groups, the weak Pd-O bond, and the μ2 character of the
S1 atom. Indeed, in the X-ray structure of 6b the Pd1-S1
distance (2.44 A) is longer than for Pd1-S2 (2.29 A).
We have already described in a preliminary communi-
cation22 the dynamic behavior of the trinuclear complex
7b in CD2Cl2. At room temperature we found a single set
of 1H resonances for the three [Pd(C6H4CH2NMe2)]
groups, and a single resonance for the two acetyl groups
(Supporting Information, Figure SI13). Scheme 6 shows
our proposal to explain this behavior, which involves the
cleavage of Pd-O and Pd-S bonds trans to the aryl
At room temperature, the dinuclear complex 6b
(CD2Cl2) shows the same H NMR pattern as 6a (two
1
resonances for the C(O)Me, CH2, and NH2 groups).
When the temperature is decreased the CH2 and NMe2
singlets broaden, although they do not resolve even at
168 K (see Supporting Information, Figure SI8). Above

8110 Inorganic Chemistry, Vol. 49, No. 17, 2010
Vicente et al.
Table 2. Activation Parameters for the Fluxional Processes in 2a
is also in agreement with steric interactions in the transi-
tion state,58 and the ΔGq298K value of 48.1 kJ mol-1 is in
very good agreement with the values reported for sulfur
3
5b
6b
7b
inversion processes in other Pd complexes, which are
.
process
PI
PII
PI
PII
PI
PII
around 50 kJ mol-1 46
b
3
Ea
79(5)
77(4)
147(20)
d
d
d
d
54(3)
51(3)
-46(10)
64.7(0.0)
17.5 33.0(0.9) 30.9(1.5)
16.0 31.0(0.7) 29.0(1.2)
d
d
ΔHqb
ΔSqc
ΔGq
IR Spectra. The IR spectra of solid samples of com-
-72(3) -64(5)
52.5(0.2) 48.1(0.3)
plexes 1-7 show one or two bands in the 1700-1500 cm-1
region (see Experimental Section) previously assigned
in related compounds to coupled ν(CdO) and ν(CdC)
modes.4 The energy lowering of the band above
1600 cm-1 can be related to conjugation within the acetyl
and dithiolato moieties5 or to coordination of the carbo-
nyl oxygen to a metal center.17 Two intense bands in the
spectrum of 1 at 1636 and 1623 cm-1 show the extensive
conjugation allowed by the moderate rotation of both
acetyl groups out of the plane of the dithiolato ligand
observed in the crystal structure (torsion angles of
the planes C(2)-C(5)-O(2) and C(2)-C(3)-O(1) with
respect to the C(2)dC(1)S(1)S(2) plane 23° and 31°,
respectively). This data agrees with those of PPN[AuCl2-
{S2C2{C(O)Me}2}]5 containing an almost planar dithio-
lato ligand and showing only one IR absorption at
1630 cm-1. The spectra of complexes 2-4 (see Experi-
mental Section, Δν = 18-35 cm-1) suggest somewhat
larger torsion angles of both acetyl groups. In the palla-
dium complexes 5 and 6 the great separation of the two
very intense absorptions observed in the 1700-1500 cm-1
region (Δν = 100 and 144 cm-1, respectively) suggests
slight conjugation of the CdO and CdC bonds in the
dithiolato ligand as confirmed in the crystal structure
of 6a with one of the acetyl groups rotated by 69° with
respect to the C(2)dC(1)S(1)S(2) plane. The ν(C-S),
ν(S-C-S),59 and ν(Au-S)60 bands, assigned in very
b
33.2(1.6)
298K
a Standard deviationsin parentheses. b InkJ mol-1. c In J K-1 mol-1
.
3
3
3
d Not determined.
groups, followed by rotation around a C-S bond and
isomerization of one of the palladacycles before reco-
ordination to the dithiolene. Thus, if we use colors to
characterize the relative position of the groups in the
molecule, in the six-step sequence each of the pallada-
cycles (1, 2, or 3) is twice green, red, or blue, and each of
the acetyl groups is three times orange or violet.
When the temperature is decreased (Supporting Infor-
mation, Figure SI13) the H resonances resolve as ex-
1
pected for a static situation: two C(O)Me, six NMe, and
several methylenic and aromatic resonances. These have
all been assigned with the help of 2D NMR spectroscopy
at 178 K (Supporting Information, Figures SI14-16).
Notably, the resonances of the CH2NMe2 protons at
178 K are still broad, most probably because sulfur
inversion at this temperature is still slow.
Activation Parameters for Pd Complexes. As described
above, we have found in the CD2Cl2 solutions of the Pd
complexes 5b, 6b, and 7b two types of dynamic processes:
one of them (PI) makes the two acetyl groups equivalent,
as well as (for 6b and 7b) all the palladacycles (Schemes 5
and 6); the second (PII) is a sulfur inversion process, that
makes the two faces of the molecules equivalent. Support-
ing Information, Table SI3 compares the relative speed of
these processes in the three complexes, as observed in the
1H NMR spectra. A line shape analysis of some of the 1H
resonances has allowed the determination of the activa-
tion parameters shown in Table 2. The details of the
calculations can be found in the Supporting Information.
For 5b the activation energy for process PI is in
agreement with Pd-S bond dissociation energies cal-
culated for Pd complexes, which are between 60 and
few cases at 860-780, 670-712, and 380-362 cm-1
,
can not be unambiguously assigned in our complexes.
Five perchlorato bands in the spectra of 2 and 3 are
indicative of its coordination.
Conclusion
The reported complexes show the flexibility of the 2,2-
diacetyl-1,1-ethylenedithiolato ligand to coordinate one, two,
or three metal centers with different coordination modes. The
presence of the 2-(aminomethyl)phenyl ligand produces the
weakening of the M-S bond trans to the aryl carbon, which
causes interesting fluxional processes in solution. Thus, we
have found for the mixed (Au, Ag) complexes 3 and 4 three
different dynamic processes in solution. P1 (Scheme 3): in-
volving the exchange of the two acetyl groups, caused by the
cleavage of the Au-S bond trans to aryl and the coordination
to S of the [Ag] fragment. This process is only important
above room temperature and easier in 3 than in 4, that is,
Ea(P1, 3) < Ea(P1, 4). P2 (Schemes 3 and 4): in which an
exchange of the [Ag(PPh3)Y] (Y = OClO3, ONO2) moiety
between the two S atoms of the dithiolene takes place via a
non-dissociative process. This process is very fast at room
temperature and only becomes slow below 190 K; in addition,
Ea(P2, 3) > Ea(P2, 4). P3 (Scheme 4): involving the change
100 kJ mol-1 57
In the di- and trinuclear complexes 6b
.
3
and 7b, the additional palladacycles would withdraw
more electron density from the dithiolene, weakening
the Pd-S and Pd-O bonds and thus resulting in lower
Ea and ΔHq values for PI as the nuclearity increases. The
negative ΔSq values in 6b and 7b are also in agreement
with the proposed mechanisms, in which two pallada-
cycles rotate simultaneously in a highly ordered and
sterically crowded transition state. The steric interac-
tions would be more important in 7b. As for ΔGq at
298 K, this parameter finds its largest value for the di-
nuclear complex 6b, as a result of the balance between
enthalpic and entropic effects. Indeed, 6b is the only
complex in the series for which process PI is still slow at
room temperature, resulting in two C(O)Me resonances.
For the sulfur inversion process (PII), Ea and ΔHq are
low for 6b and somewhat larger for 7b, probably because
of its more rigid structure. The negative ΔSq value for 7b
(58) Murray, R.; Story, P.; Kaplan, M. J. Am. Chem. Soc. 1966, 88, 526.
Powell, J.; Jack, T. Inorg. Chem. 1972, 11, 1039.
(59) Chiari, B.; Piovesana, O.; Tarantelli, T.; Zanazzi, P. F. Inorg. Chem.
1985, 24, 366.
(60) Beurskens, P. T.; Blaauw, H. J. A.; Cras, J. A.; Steggerda, J. J. Inorg.
Chem. 1968, 7, 805.
(57) Brust, D. J.; Gilbert, T. M. 2004, 43, 1116.

Article
Inorganic Chemistry, Vol. 49, No. 17, 2010 8111
ꢀ
Fundacion Seneca (04539/GERM/06 and 03059/PI/05)
for financial support. A.J.M.M. thanks Ministerio de
ꢀ
Educacion y Ciencia (Spain) for a FPU grant.
ꢀ
between 3- and 4- coordination for the Ag atom. This process
is fast at room temperature, becomes slow around 250 K
and Ea(P3, 3) ≈ Ea(P3, 4). For complexes 3 and 4, Ea (P1) > Ea
(P3) >Ea (P2). For the complexes 5b, 6b, and7b we have found
two types of dynamic processes in solution: a sulfur inversion
process (PII) and an exchange of positions between pallada-
cycles (PI), which also makes the two acetyl groups equivalent.
Supporting Information Available: CIF files for the crystal
structures of 1, 6b CH2Cl2 and 7b CH2Cl2, additional 2D
3
3
and VT NMR spectra, tables with NMR data, details on
the line shape analysis for complexes 5b, 6b, and 7b, and
proposed mechanism for the dynamic behavior of 7b. This
material is available free of charge via the Internet at http://
pubs.acs.org.
ꢀ
Acknowledgment. We thank Ministerio de Educacion y
Ciencia (Spain), FEDER (CTQ2007-60808/BQU), and