| pubmed-article:20383405 | pubmed:abstractText | A series of N?O? tripodal tetradentate ligands derived from di-/tetra-tert-butyl substituted 2-[bis(2-hydroxybenzyl)aminomethyl]X (X = pyridine and benzimidazole) (H?L(n) (n = 1-4)) and 8-[bis(3,5-di-tert-butyl-2-hydroxybenzyl)]aminoquinoline (H?L?) were synthesised through a 4-step reaction scheme involving sequential formylation, reduction, bromination and alkylation. Treatment of H?L(n) (n = 1-5) with [WO?Cl?(dme)] (dme = 1,2-dimethoxyethane) in the presence of triethylamine gave the corresponding cis-dioxotungsten(VI) complexes [WO?(L(n))] (n = 1-5). The corresponding molybdenum analogues [MoO?(L(n))] (n = 1-5) were also prepared from the reaction of [MoO?(acac)?] (acac = acetylacetonate) with H?L(n) (n = 1-3) or [MoO?Cl?(dme)] (dme = 1,2-dimethoxyethane) with H?L(n) (n = 4 and 5). All these compounds were fully characterised by a wide range of spectroscopic methods. The molecular structures of [MoO?(L(n))] (n = 2, 4) and [WO?(L²)] were also confirmed by single-crystal X-ray diffraction analysis. The catalytic activities of [MO?(L(n))] (M = Mo, W; n = 1-4) towards epoxidation of styrene were also examined. | lld:pubmed |
