Mono and Tetranuclear Gold(I) Complexes of Tris(1-benzylimidazole-2-yl)phosphine

Abstract

The reaction of tris(1-benzylimidazole-2-yl)phosphine, (Bzim)(3)P, 1, with Ph(3)AsAuCl in 1:1 stoichiometric ratio produced (Bzim)(3)PAuCl, 2. The reaction of (Bzim)(3)PAuCl with NaAuCl(4) in 1:1 stoichiometry in dichloromethane gives an orange-yellow crystalline tetranuclear gold(I) cluster [{mu-N,N'-(Bzim)(3)PAuCl}(2)Au(2)][AuCl(2)][AuCl(4)], 3. Complex 4, [{mu-N,N'-(Bzim)(3)PAuCl}(2)Au(2)][AuCl(2)](2) is formed when the reaction stoichiometry of (Bzim)(3)PAuCl and AuCl(4)(-) is 2:1. The crystal structure of 3 shows the formation of a 12-membered macrocycle with Au...Au distances of approximately 3.0 A. The structures of (Bzim)(3)PAuCl and 3 show Au...H-C interactions ranging from 2.57 to 2.95 A. Complex 2 crystallizes in the monoclinic space group P2(1)/n (Z = 4), a = 9.1927(5), b = 13.528(2), c = 22.995(2) A, and beta = 94.537(5)(o). Complex 3 crystallizes in the monoclinic space group P2(1)/c (Z = 4), a = 13.785(4), b = 21.426(6), c = 25.203(8) A, and beta = 96.51(6)degrees.

Aurophilic interactions as a subject of current research: an up-date

“…This dication can be associated with one AuCl À 4 and one AuCl À 2 anion or with two AuCl À 2 anions. 169 A most unusual mix of open-chain and cyclic gold(I) thiolates has been discovered as the product of the reaction of [Au(CN) 2 ] À with isopentanedithioic acid in methanol. In the crystals obtained sinuous polymeric chains serve as a clathrate matrix for cyclic dimers of the same stoichiometry [Me 2 CHCH 2 CS 2 Au] n with n = 2 or N (84, 85).…”

“…The mode of aggregation of complexes with non-cyclic carbenes has long been known to be also strongly influenced by the substitution pattern, by the counterions, and by solvate components. 292 Recent work with pyridine-functionalized carbenes has afforded dimers and polymers featuring both intra-and interligand hydrogen bonding and aurophilic interactions with Au-Au distances of 3.255 and 3.311 A ˚ (169,170). Even subtle changes in the arrangement of the substituents or the inclusion of solvate molecules may cancel the aurophilic contact.…”

Silver and gold

“…2c). 174 Studies revealed that the Au-alkyne bond character in [(PAr 3 )Au(2-hexyne)] + or [(NHC)Au(2-hexyne)] + complexes strongly depends on the nature of phosphine or NHC ligand used. 175 The reaction of [AuCl(P t Bu 3 )]/AgSbF 6 with TMSCRC t Bu first leads to a monocationic side-on gold(I) alkyne complex, but gives a dicationic trinuclear gold(I) complex after a longer reaction time (Fig.…”

Understanding the bonding and aromaticity of [Au3{C4H4(X)4E}3]− (X = CF3, CN, BO; E = Si, Ge): trinuclear gold superhalogens

“…Gold complexes play an important role in both experimental and theoretical chemistry for their various fundamental and potential applications including supramolecular assemblies, luminescent properties, and catalytic properties. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] In the 1970s, the first planar Au(I)-CTC (cyclic trinuclear complex) was experimentally reported by Vaughan and co-workers. 19 It is well known that gold has usually three oxidation states, namely, Au +1 , Au +3 , and Au +5 , whereas, in modern gold chemistry, it is extended to the Au À1 oxidation state, which is quite surprising in the current scenario.…”