Synthesis, crystal structure and bonding features of a trinuclear cluster [Mo3X(S-2)(3)(dtp)(3)I-3] (X = O, S) with layer-like packing

The reaction of Mo3OS3(dtp)(4)(H2O) (dtp=S2P(OC2H5)(2)) with CuI yielded th e new trimolybdenum cluster [Mo-3(mu(3)-X)(mu(2)- S-2)(3)(dtp)(3)I-3] (X = 58%O + 42%S). Crystal structure analysis showed that the compound has a [Mo 3X(S-2)(3)](4+) cluster core, and the I-3(-) group functions as a two-way c oordinated ligand which links the three out-of-{Mo-3} plane S atoms in the cluster core at one end (I-S similar to 3.3 Angstrom) and two adjacent trin uclear clusters at the other (I ... S similar to 3.6 Angstrom), thus formin g a [Mo3X(S-2)(3)] cluster layer. The bonding features of the cluster chara cteristic of a semiconductor are demonstrated by energy band and density fu nctional calculations. (C) 2000 Elsevier Science Ltd All rights reserved.