Synthesis, structure and properties of a new unsymmetric tetranuclear mixed-valence vanadium(IV/V) complex containing distinct V 2O 33+ cores

Abstract

The synthesis, X-ray crystal structure, spectroscopic, and electrochemical properties of a new tetranuclear vanadium(IV,V,IV,V) complex [ ( VO) 4( btppnol) 2( μ-O) 2]( ClO 4) 2·2 DMF·2 H 2 O ( 1 ) utilizing the previously described unsymmetrical dinucleating ligand N-(2-hydroxybenzyl)- N, N ′, N ′-tris(2-pyridylmethyl)-1,3-diaminopropan-2-ol (H 2btppnol) are reported. The complex comprises two different [V 2O 3] 3+ core structures: one [V 2O 3] 3+ core in a syn-dioxo-μ-O(alkoxo) configurarion and another [V 2O 3] 3+ core in an anti-dioxo-μ-oxo configuration, as well as being composed of non-equivalent vanadium centers as a consequence of the use of an unsymmetrical ligand. This complex represents the first example in the literature of a vanadium complex with this particular structure and its interesting electrochemical and spectroscopic properties were investigated.