Investigation of cobalt (1,10-phenanthroline)-bis-(3,6-di-tert-butyl-o-benzosemiquinolate) by X-ray diffraction, IR and ESR spectroscopy, magnetochemistry, and precision calorimetry

Abstract

The bistable cobalt complex containing two symmetrical 3,6 di tert butyl o benzoquinone and one 1,10 phenanthroline moieties as ligands (1) was synthesized. Complex 1 was isolated in the individual state and characterized by IR and ESR spectroscopy, X ray diffraction, magnetochemical studies, and precision calorimetry. A change in temperature causes the re versible metal-ligand electron transfer and spin crossover (redox isomerism) in complex 1 in the crystalline state. The redox isomeric transformation at ∼250 K is accompanied by the phase transition. The structural study at two temperatures confirmed the changes in the molecular and crystal structure associated with the redox isomeric transformation.

Electrical conductivity of vacuum deposited films and crystals of redox-isomeric о-semiquinonato cobalt complexes

“…1, was performed by known procedures [1,7]. Crystals of the complexes suitable for electric measurements (Fig.…”

“…[2,3]. Analysis of the crystal structure of semiquinonato cobalt complexes with 2,2 0 -bipyridine [1] and 1,10-phenanthroline [3,7] exhibit a prominent onedimensionality.…”

“…Теmperature dependences of heat capacity (red circles) and magnetic moment (blue triangles) of complexes 1 (left) and 2 (right)[1,7,12]. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.…”

Adducts of manganese diketonates with redox-active ligands: Computational modeling of valence tautomeric systems

“…Interaction of benzoquinone imine with Mn II (hfacac) 2 complexes [17,[46][47][48]. The attempts to find the Mn IV -Cat isomer with a metal atom in the oxidation level +4 failed.…”

“…5). This isomer represents a molecular complex and is characterized by the high energy of stabilization of 26.8 kcal/mol (Table 2) [17,[46][47][48]. A special feature of the adduct II (R=H) is the predicted stabilization of all principal (Scheme 3) electromeric forms, including located on the quartet PES the energy richest structure 28 HS Mn IV -L 2-containing managanese ion in the +4 oxidation state and the ligand in its L 2-form.…”