Chiral cis-dioxidomolybdenum(VI) complexes with Schiff bases possessing two alkoxide groups: Synthesis, structure, spectroscopic studies and their catalytic activity in sulfoxidation and epoxidation
| Autor: | Marta Karman, Grzegorz Romanowski, Michał Wera |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Circular dichroism
Dibasic acid 010405 organic chemistry Chemistry Thioanisole Cyclohexene Crystal structure 010402 general chemistry 01 natural sciences Medicinal chemistry 0104 chemical sciences Inorganic Chemistry chemistry.chemical_compound Alkoxide Octahedral molecular geometry Materials Chemistry Molecule Physical and Theoretical Chemistry |
| Zdroj: | Polyhedron. 187:114653 |
| ISSN: | 0277-5387 |
| Popis: | New chiral mononuclear cis-dioxidomolybdenum(VI) complexes, [MoO2(HL1-9)] and [MoO2(HL10)(CH3OH)], have been synthesized by the reaction of MoO2(acac)2 with tetradentate Schiff bases derived from various substituted salicylaldehydes and R(+)-3-amino-1,2-propanediol. All complexes have been characterized by elemental analysis, circular dichroism, electronic, IR and NMR (1H, 13C) spectroscopy. The molecular and crystal structure of [MoO2(HL10)(CH3OH)] elucidated by single-crystal X-ray diffraction revealed a six-coordinate distorted octahedral geometry and coordination of methanol molecule leaving one hydroxyl group uncoordinated. Surprisingly, NMR measurements made for [MoO2(HL1-9)] undoubtedly show that Schiff bases behave as dibasic tetradentate ONOO donor ligands and no solvent coordination has been observed. The catalytic activity studies have been also performed for all complexes in asymmetric sulfoxidation of thioanisole and epoxidation of styrene, cyclohexene and two monoterpenes, i.e. S(−)-limonene and (−)-α-pinene, using aqueous 30% H2O2 or tert-butyl hydroperoxide (TBHP) as the oxygen source. |
| Databáze: | OpenAIRE |
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