Heptanuclear metal clusters

The versatile binding modes of the Cu2+ ion with coordination number from four to six due to Jahn-Teller distortion is one of the important reasons for the diverse structures of the Cu-Ln amino acid complexes. In contrast, other transition metal ions prefer the octahedral mode. For the divalent ions Co2+, Ni2+, and Zn2+, only two distinct structures were observed one is a heptanuclear octahedral [LnM6] cluster compound, and the other is also heptanuclear but with a trigonal-prismatic structure. 

Heptanuclear clusters with Au-Fe [160, 306, 370-373, 394], Au-Ru [264, 319, 328, 374—390] and Au-Os bonds [327, 391-393] have also been reported. Most common structures are based on C-centered [160, 306, 374, 375] or B-centered [376-379] octahedral frameworks with a trigonal metal face capped by a gold atom, for example, in the anion of [NEt4][ (Me3P)Au MoFe5( j.6-C)(CO)17] 147 (Figure 4.39a) [160]... 

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