Pergamon ~ol~~lwrlro,~ Vol. 17. Nos. I I 12. pp. 202’) 2035. 1998 , IYYX Elsevw Scmce Ltd All rights reserved. Printed m Great Bntain PI1 : SO277-5387(97)00473-7 0277-5387;98 $19.00+0.00 Gold complexes with mono- or di-chalcogenides of bis(diphenylphosphino)methanide ligands. X-ray crystal structure of IAu(C~F5)2((S~~h2)*C(AuAsPh~)z}l~l04 Beatriz Alvarez,” Eduardo J. Fernhdez,” M. Concepcibn Gimeno,b Peter G. Jones,’ Antonio Lagunab* and Jo& M. Lbpez-de-Luzuriaga” ” Departamento de Quimica, Universidad de La Rioja, Obispo Bustamante 3, E-26001 Logrorio, Spain ’ Departamento de Quimica Inorganica, ICMA. Universidad de Zaragoza-CSIC. E-50009 Zaragoza, Spain ’ lnstittit fur Anorganische und Analytische Chemie der Technischen Universitat, Postfach 3329. D-38023 Braunschweig, Germany (Received 18 September 1997 ; accepted 12 November 1997) Abstract-The reaction between the chalcogenide derivatives [Au(C,FJj(PPh2CH2PPhlE)] (E = S, 0) and [Au(acac)PPh,] or [Au(TfO)PPh,] leads to the dinuclear compounds [Au(C,Fj)JPPhZCH(AuPPh,)PPh,Ei] (E = S. 0) or [Au(C,F&{PPh,CH,PPh,(SAuPPh,))], respectively. When the phosphine disulphide complex [Au(C,F~)~(SPP~~CH,PP~$S)] is employed, the reaction with [Au(acac)PPh,] promotes the double substitution of the methylenic protons. The reaction of [Au(acac)L] (L = PPh,, AsPh,) with the six-membered auracycle [Au(C,F5)2{(SPPh2)2CHzilClo, leads to the double substitution of both methylenic protons by [AuL]+ frag- ments, keeping the auracycle intact. The crystal structure of one such product, [Au(C,F,),j(SPPhz),C(Au- AsPh,)z)]C1O, has been established by X-ray diffraction studies. Starting from the methanide derivative [Au(C,F,),(SPPh,CHPPhS)], the reaction with [Au(acac)PPh,] leads to the synthesis of the four-membered ring methanide [Au(C,F,), (SPPhC(AuPPh,)PPh,S)1 r 1998 Elsevier Science Ltd. All rights reserved zyxwvutsrqponm Kcy~~wt/i: gold ; diphosphinedichalcogenide ; diphosphinemonochalcogenide ; methanide : crystal structure In the last few years there has been a renewed interest in the chemistry of diphosphine chalcogenide ligands and their methanide derivatives [I-S]. which can be attributed to the tendency of the diphosphine chal- cogenides to charge delocalization, thus enhancing the acidity of the methylenic protons as well as the lability of the chalcogenmetal bonds [6]. This lability can give rise to dynamic processes and thus renders these ligands appropiate for catalytic applications [7710]. The introduction of oxygen or sulfur atoms at one or both phosphorus centres in bis(di- phenylphosphino)methane after or prior to metal complexation can change the character of the donor * Author to whom correspondence should be addressed. atom or lead to metallacycle ring expansion, depend- ing on the starting complex employed. This may have a significant infiuence on the coordination properties or on the reactivity of these products. The present paper reports the synthesis of some gold(II1) derivatives containing mono- or di-chal- cogenides of bis(diphenylphosphino)methane and their reactivity towards reagents of the type [Au (acac)L] (acac = acetylacetonate) forming methanide complexes. We employed tris(pentafluoro- phenyl)gold(lll) derivatives, which afford non-cyclic methanides in a different way from that recently described [I 11 or [Au(C,Fj)JSPPh,CH,PPhzs)lC104 [12], from which we have synthesized methanediide species containing a six-membered metallacycle. These last products are not accessible through other 2029