Synthesis and characterization of three tetranuclear clusters containing a[Mo3OS3Sn](6+) cubane-like core

Three heterometallic cubane-like clusters, [Mo-3(mu (3)-O)(mu (3)-S)(3)(SnC l3)(dtp)(3)(py)(3)] (dtp = S2P(OC2H5)(2)(-), py = C5H5N) (1), (PPN)[Mo-3(mu (3)-O)(mu (3)-S)(3)(SnCl3)(dtp)(3)(mu -OAc)(py)] (OAc = CH3COO-, PPN = (C6 H5)(3)PNP(C6H5)(3)(+)) (2), and (Et4N)[Mo-3(mu (3)-O)(mu (3)-S)(3)(SnCl3)(d tp)(2)(mu -OAc)(2)(py)] (3) have been prepared by the reaction of [Mo-3(mu (3)-O)-(mu -S)(3)(dtp)(4)(H2O)] (4), [Mo-3(mu (3)-O)(mu -S)(3)(dtp)(3)(OAC) (py)] (5), and [Mo-3(mu (3)-O)(mu -S)(3)(dtp)(2)(OAC)(2) (py)] (6) with Sn Cl2, respectively. They have been characterized by IR, UV-vis, P-31 NMR, Mo -95 NMR, and X-ray structure analysis. All of these heterometallic clusters have a [Mo3OS3Sn](6+) core but contain a different arrangement of peripher al ligands. As far as the neutral cluster 1 is concerned, there is no bridg ing OAc ligand, while only one bridging OAc ligand is observed for cluster 2 and two are for cluster 3. The Mo-Mo distances are about 0.03-0.04 Angstr om shorter than those of the starting trimolybdenum clusters. This indicate s that the incorporation of SnCl3-fragment into (Mo3) clusters makes the Mo -Mo bonding enhanced. Crystal data for 1: triclinic, space group P-1, a = 1 0.7423(2) Angstrom, b = 14.0357(1) Angstrom, c = 16.9346(2) Angstrom, a = 8 4.054(1)degrees, beta = 87.095(1)degrees, gamma = 84.517(1)degrees, V = 252 5.82(6) Angstrom (3), Z = 2, R = 0.038 for 5584 reflections (I > 2.0 sigma (I)). Crystal data for 2: triclinic, space group P-1, a = 12.9529(1) Angstr om, b = 15.6324(2) Angstrom, c = 19.6355(1) Angstrom, alpha = 92.083(1)degr ees, beta = 97.908(1)degrees, gamma = 110.337(1)degrees, V = 3677.41(6) Ang strom (3), Z = 2, R = 0.034 for 8665 reflections (I > 2.0 sigma (I)). Cryst al data for 3: monoclinic, space group P2(1)/n, a = 14.0852(5) Angstrom, b = 15.1324(5) Angstrom, 23.2691(7) Angstrom, beta = 97.371(1)degrees, V = 49 18.7(3) Angstrom (3), Z = 4, R = 0.049 for 4970 reflections (I > 2.0 sigma (I)).