Synthesis, Spectral Characterization and Crystal Structures of Dioxidomolybdenum(VI) Complexes Derived from Nicotinoylhydrazones

摘要

Cis-dioxidomolybdenum(VI) complexes [MoO2L1(DMSO)] (1), [MoO2L2(H2O)]DMF (2) and [MoO2L3(DMF)] (3) were synthesized by solution based reactions of aroylhydrazones (H2L1=5-chloro-2-hydroxybenzaldehyde nicotinoylhydrazone, H2L2=2-hydroxy-5-iodobenzaldehyde nicotinoylhydrazone and H2L3=3,5-dichloro-2-hydroxybenzaldehyde nicotinoylhydrazone) with bis(acetylacetonato)dioxidomolybdenum(VI) complex, [MoO2(acac)(2)] in presence of DMSO or DMF. The synthesized aroylhydrazones and their molybdenum complexes were characterized by elemental analysis, spectroscopic techniques (FT-IR, UV-Vis, H-1 NMR) and conductivity measurements. Finally the three dimensional structures of the complexes were confirmed by single crystal X-ray diffraction studies. Crystal structures of 1, 2 and 3 were solved by direct methods and refined with full-matrix least-squares calculations using the SHELXS97 and SHELXL2014 software programs respectively. Complex 1 got crystallized in monoclinic space group, P2(1)/c with Z=4, whereas complexes 2 and 3 in triclinic space group, P1with Z=2. The ligands, H2L1-3 showed coordination to the metal ion in a dibasic tridentate manner through deprotonated phenolate oxygen, azomethine nitrogen and enolate oxygen.