Heterometallic Cuboidal Clusters M3M‘Q4 (M = Mo, W; M‘= Sn, Pb, As, Sb; Q = S, Se): From Coordination Compounds to Supramolecular Adducts

Reactions of the incomplete cuboidal clusters [M3Q4(acac)3(py)3]+ (M = Mo, W; Q = S, Se) with group 14 and 15 metal complexes with the s2p0 electronic configuration (AsPh3, SbPh3, SbCl3, SbI3, PbI3-, SnCl3-) led to heterometal incorporation with the formation of cuboidal clusters of the type [M3(EX3)Q4(acac)3(py)3]n+ (n = 0 for Sn, Pb; n = 1 for As, Sb), whose structures were determined by X-ray diffraction. The cuboidal clusters can be described as complexes of the cluster tridentate ligand [M3Q4(acac)3(py)3]+ (μ2-chalcogen atoms as donors) with the EX3, where the E atom attains a distorted octahedral coordination. Analysis based on the bond distances E−Q gives the following sequence of affinity: As < Sb; Pb < Sn ≈ Sb; SbPh3 < SbI3 ≈ SbCl3; W3S4 < W3Se4. Interaction energies at the gas phase between [W3Q4(acac)3(py)3]+ (Q = S, Se) and SbX3 (X = I, Ph) were computed at the DFT level (BP86/TZP). The magnitude of the interaction depends strongly on the substituents at Sb, and the replacement of iodine by the phenyl group decreases the interaction energy from −9.21 to −2.70 kcal/mol and from −12.73 to −3.85 kcal/mol for the W3SbS4 and W3SbSe4 cores, respectively.