Synthesis, Crystal Structure and Quantum Chemistry of the Organooxotin Cluster [(μ-O)(μ-OH)Sn2(n-Bu)4]2(C5H4NCO2)2

A novel organooxotin complex of di-mu-oxygen and di-mu-hydroxyl bridged tetra(bisbutyltin) bis(pyridine-4-carboxylate) has been synthesized by the reaction of n-Bu2SnO with pyridine-4-carboxylic acid and characterized by IR, H-1 NMR spectra and elemental analysis. The crystal structure has been determined by X-ray diffraction. It crystallizes in the monoclinic, space group P2(1)/n with a=1.306 5 (3) nm, b=10314 5 (2) nm, c=1.660 8 (3) nm, beta= 96.180(5)degrees, V=2.835 7(9) nm(3), Z=4, D-c =1.454 g.cm(-3), mu(Mo K alpha)=1.784 mm(-1), F(000)=1 248, R-1=0.0449, wR(2) = 0.124 1 (I>2 sigma(I) observed reflections) and R-1=0.088 7, wR(2)=0.175 6 (all reflections). A total of 4 885 (R-int=0.032 1) unique reflections were collected, of which 2 733 with I>2 sigma(I) were observed. The crystal structure shows that the central Sn atom is five-coordinated to assume a distorted trigonal bipyramidal configuration. The complex belongs to centrosymmetric dimer structure with four-membered central endo-cyclic Sn2O2 units in which the bridging oxygen atoms are di- and tri-coordinated, respectively. In crystal, the molecules are packed in the unit cell in two-dimensional network structure through the hydrogen bond (N ... H-O) interaction between the O4-H atom and one of the nitrogen of an adjacent molecule. CCDC: 715879.