Synthesis and structure of pentacoordinate tin(IV) complexes

Abstract

Ten complexes formulated as Ph 2SnL, where L is RC 6H 4C(O)N 2CHC 6H 4O with R = H, p-NO 2, p-Cl, p-Br, p-CH 3, p-OCH 3, o-NH 2, m-NO 2, m-OCH 3, and 3,5-dinitro, have been prepared and were characterized by 1H NMR, IR, and mass spectroscopy and elemental analyses. A single crystal X-ray diffraction study of the complex with R= o-NH 2 confirms the molecular structure. The crystals are triclinic, space group P 1 with a 9.608(2), b 11.826(4), c 21.478(6) Å, α 76.17(2), β 76.53(2), γ 88.91(2)°, V 2302.7(4) Å 3, Z = 4, D c 1.52 g/cm 3. The final discrepancy factors are R = 0.050 and R w = 0.057 for 3129 observed independent reflections. The tin atom has a distorted trigonal bipyramidal coordination. The two SnO bonds of 2.073(6) and 2.116(6) Å, respectively and one SnN bond (of 2.143(7) Å) 1 1 The bond distances and anles quoted in the text all refer to the averaged values of two independent molecules. are shorter than those found in related complexes. A comparison of the IR spectra of the ligands with those of the corresponding complexes, reveals that the disappearance of the bands assigned to carbonyl unambiguously confirms that the ligands coordinate with the tin in the enol form.