Bond lengths tetrahydrothiophen complex

Treatment of 77 with one equivalent of [AuCl(tht)] (tht = tetrahydrothiophene) leads to the type III AuCl bridged pincer complex 79 in high yield (counterion is Cl ) [149]. The unique complex 79 is the only heterodimetallic compound with two metal atoms attached at a carbodiphosphorane carbon(O) atom. The environment at the central carbon atom is planar in 77 and pyramidal in 78 and 79. P-C bond lengths and P-C-P angles in the dication 78 are closely related to those in the neutral Pt complex 36 (Fig. 25). The two metals of 79 attached to the carbon atom are coimected via a very short d -d ° pseudo closed shell interaction with a Pd-Au bond length of 2.8900(3) A a similar bonding situation (aurophilic attraction) is found in the gold complex 29 shown in Fig. 23. 

Gold-mercury cluster compounds have been obtained by different groups. Fackler et al. first prepared two Au-Hg-bonded complexes 143 and 145 in 1988 (Scheme 12.42) [97]. The two complexes are isomeric and the Au-Hg bond lengths are 3.088(1) and 2.989(1) A, respectively. Compound 144 could also be converted into 146 by treating with Au(THT)Cl (THT = tetrahydrothiophene) without T1 salt. The solid structure of 146 showed the Hg-Au distances of 3.310(1) and 3.361(1) A. 

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