Structurally characterized group 4 metal alkoxides modified with the pyridyl-based ligands 2-mercapto pyridine n-oxide and 3,3′-dihydroxy-2,2′-bipyridine

Abstract

An investigation of a series of substituted pyridyl-based ligands was undertaken using 2-mercapto pyridine n-oxide (H-2MPO) and 3,3′-dihydroxy-2,2′-bipyridine (H 2-OBPy) as the modifying reagents of a series of titanium alkoxides. The resultant products were identified as (2MPO) 2Ti(OR) 2 [OR = OCHMe 2 ( 1), OCH 2CMe 3 ( 2), OCMe 3 ( 3)] and [(OR) 2M(μ c-OBPy)] 3 where M⧹OR = Ti⧹OCH 2CMe 3 ( 4) along with Zr⧹OCMe 3 ( 5) from Zr(OCMe 3) 4 (μ c = chelating bridging). The structure of 1– 3 were found to adopt similar monomeric structures with octahedrally (Oh) bound Ti metal centers using two terminal OR and two chelating 2MPO derivatives. Switching to the OBPy ligand, cyclic trinuclear species with Oh bound metals that employed two terminal OR and two μ c-OBPy ligands were isolated. The two rings of the bridging OBPy were rotated such that one O and one N from different rings chelate to a single metal. The synthesis and characterization of these compounds and comparison to appropriate literature species are presented.