TY - JOUR

T1 - New oxidovanadium(IV) complexes with 2,2′-bipyridine and 1,10-phenathroline ligands

T2 - Synthesis, structure and high catalytic activity in oxidations of alkanes and alcohols with peroxides

AU - Fomenko, Iakov S.

AU - Gushchin, Artem L.

AU - Abramov, Pavel A.

AU - Sokolov, Maksim N.

AU - Shul’pina, Lidia S.

AU - Ikonnikov, Nikolay S.

AU - Kuznetsov, Maxim L.

AU - Pombeiro, Armando J.L.

AU - Kozlov, Yuriy N.

AU - Shul’pin, Georgiy B.

N1 - Publisher Copyright: © 2019 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2019/3/1

Y1 - 2019/3/1

N2 - Reactions of [VCl 3 (thf) 3 ] or VBr 3 with 2,2′-bipyridine (bpy) or 1,10‐-phenanthroline (phen) in a 1:1 molar ratio in air under solventothermal conditions has afforded polymeric oxidovanadium(IV) four complexes 1‒4 of a general formula [VO(L)X 2 ] n (L = bpy, phen and X = Cl, Br). Monomeric complex [VO(DMF)(phen)Br 2 ] (4a) has been obtained by the treatment of compound 4 with DMF. The complexes were characterized by IR spectroscopy and elemental analysis. The crystal structures of 3 and 4a were determined by an X‐-ray diffraction (XRD) analysis. The {VOBr 2 (bpy)} fragments in 3 form infinite chains due to the V = O…V interactions. The vanadium atom has a distorted octahedral coordination environment. Complexes 1‒4 have been tested as catalysts in the homogeneous oxidation of alkanes (to produce corresponding alkyl hydroperoxides which can be easily reduced to alcohols by PPh 3 ) and alcohols (to corresponding ketones) with H 2 O 2 or tert‐-butyl hydroperoxide in MeCN. Compound 1 exhibited the highest activity. The mechanism of alkane oxidation was established using experimental selectivity and kinetic data and theoretical DFT calculations. The mechanism is of the Fenton type involving the generation of HO • radicals.

AB - Reactions of [VCl 3 (thf) 3 ] or VBr 3 with 2,2′-bipyridine (bpy) or 1,10‐-phenanthroline (phen) in a 1:1 molar ratio in air under solventothermal conditions has afforded polymeric oxidovanadium(IV) four complexes 1‒4 of a general formula [VO(L)X 2 ] n (L = bpy, phen and X = Cl, Br). Monomeric complex [VO(DMF)(phen)Br 2 ] (4a) has been obtained by the treatment of compound 4 with DMF. The complexes were characterized by IR spectroscopy and elemental analysis. The crystal structures of 3 and 4a were determined by an X‐-ray diffraction (XRD) analysis. The {VOBr 2 (bpy)} fragments in 3 form infinite chains due to the V = O…V interactions. The vanadium atom has a distorted octahedral coordination environment. Complexes 1‒4 have been tested as catalysts in the homogeneous oxidation of alkanes (to produce corresponding alkyl hydroperoxides which can be easily reduced to alcohols by PPh 3 ) and alcohols (to corresponding ketones) with H 2 O 2 or tert‐-butyl hydroperoxide in MeCN. Compound 1 exhibited the highest activity. The mechanism of alkane oxidation was established using experimental selectivity and kinetic data and theoretical DFT calculations. The mechanism is of the Fenton type involving the generation of HO • radicals.

KW - Alkanes

KW - Alkyl hydroperoxides

KW - DFT calculations

KW - Fenton mechanism

KW - Heterocyclic diimines

KW - Hydrogen peroxide

KW - Oxidovanadium(IV) complexes

KW - Reaction mechanism

KW - alkyl hydroperoxides

KW - alkanes

KW - CRYSTAL-STRUCTURE

KW - hydrogen peroxide

KW - VANADIUM COMPLEXES

KW - O-2-H2O2-VANADIUM DERIVATIVE-PYRAZINE-2-CARBOXYLIC ACID

KW - HYDROCARBON OXYGENATIONS

KW - heterocyclic diimines

KW - reaction mechanism

KW - AEROBIC OXIDATION

KW - HYDROGEN-PEROXIDE

KW - PYRAZINE-2-CARBOXYLIC ACID

KW - oxidovanadium(IV) complexes

KW - SCHIFF-BASE LIGANDS

KW - H2O2-VANADIUM COMPLEX-PYRAZINE-2-CARBOXYLIC ACID

KW - OXOVANADIUM(IV) COMPLEXES

UR - http://www.scopus.com/inward/record.url?scp=85063428080&partnerID=8YFLogxK

U2 - 10.3390/catal9030217

DO - 10.3390/catal9030217

M3 - Article

AN - SCOPUS:85063428080

VL - 9

JO - Catalysts

JF - Catalysts

SN - 2073-4344

IS - 3

M1 - 217

ER -