Mercurophilic interactions in heterometallic Ru-Hg carbonyl clusters

The reaction of [HRu3(CO)11]- (1) with 0.35 mol equivalents of Hg(CH3CO2)2 afforded [HgRu6(CO)22]2- (3), whereas a mixture of 3 and [Hg2Ru7(CO)26]2- (4) was obtained using 0.5 mol equivalents of Hg(CH3CO2)2 per mole of 1. A few crystals of [Ru3(CO)10(CH3COO)]- (7) were obtained as side products of the latter reaction. The reaction of 1 with one mole equivalent of Hg(CH3CO2)2 or HgCl2 afforded [Hg3Ru8(CO)30]2- (5) as the major product. By employing HgCl2, formation of 5 was accompanied by traces of the new homometallic cluster [Ru2Cl4(CO)5]2- (8). [HRu4(CO)12]3- (2) reacted with one mole equivalent of HgCl2 resulting in [Hg4Ru10(CO)32]4- (6). The molecular structures of the new clusters 3-8 were determined by single crystal X-ray diffraction (SC-XRD) as their [NEt4]2[3], [NEt4]2[4]center dot 0.5CH2Cl2, [NEt4]2[5], [NEt4]4[6], [NEt4][7], [NEt4]2[8]center dot 0.5CH3CN salts. Heterometallic Ru-Hg clusters 3-6 contain [Hg]2+, [Hg2]4+, [Hg3]6+, and [Hg4]8+ cores sta-bilized by [Ru(CO)4]2-, [Ru3CO)11]2- and [Ru4(CO)12]4- fragments. Metal-metal bonds were investigated by DFT calculations and atoms-in-molecules (AIM) analyses.