82025-66-9Relevant academic research and scientific papers
Chromium(III) and chromium(IV) tetraphenylporphine complexes
Zaitseva,Zdanovich,Golubchikov
, p. 843 - 847 (2008/10/08)
Stable chromium complex (AcO)CrTPP was synthesized through the reaction of meso-tetraphenylporphine with chromium(II) acetate in boiling phenol. Coordination properties of chromium porphyrin in reaction with imidazole and pyridine in o-xylene were studied by electronic absorption spectroscopy and computer modeling. A single-electron oxidation of chromium(III) complex was found to be affected by peroxide compounds. The stability of an extra complex depends on the basic properties of the extra ligand and oxidation number of the central metal atom. The complex stability correlates with the calculated energy of formation of the metal-extra ligand bond. The geometrical structure and energy parameters of hexacoordinated chromium porphyrins were calculated using the quantum-chemical method. The effect of the cis and trans position of ligands in the composition of a macrocyclic compound was established to be significant only in the extra complexes (AcO)CrTPP.
Coordination of pyridine by (acetato)chromium(III)tetraphenylporphine
Tipugina,Lomova
, p. 978 - 982 (2008/10/08)
meso-Tetraphenylporphine reacts with chromium(III) acetate in benzonitrile under reflux to form the (AcO)CrIIITPP chelate. The equilibrium process of pyridine coordination by this complex, studied by spectrophotometric titration and chemical kinetics methods, is characterized by the equilibrium constants K1 = 400 l/mol and K2 = 2.8 l/mol and the rate constant k1298 K = 0.197 s-1 mol-1/2 l1/2. At the first stage of the reaction with K1, one pyridine molecule interacts with two (AcO)CrTPP molecules. Based on the thermodynamic and kinetic properties of the reaction system, the structure of the product with the Py bridge, [(AcO)CrTPP]2Py, is suggested. In the second equilibrium (K2), the 1:1 extracomplex is formed.
