The first pentagonal-bipyramidal vanadium(iii) complexes with a Schiff-base N3O2 pentadentate ligand: synthesis, structure and magnetic properties. Issue 43 (28th October 2020)

• Record Type: Journal Article
• Authors: Bazhenova, Tamara A.; Zorina, Leokadiya V.; Simonov, Sergey V.; Mironov, Vladimir S.; Maximova, Olga V.; Spillecke, Lena; Koo, Changhyun; Klingeler, Rüdiger; Manakin, Yuriy V.; Vasiliev, Alexander N.; Yagubskii, Eduard B.
• Is Part Of: Dalton transactions. Volume 49:Issue 43(2020)
• Page Start: 15287
• Page End: 15298
• Publication Date: 2020-10-28
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d0dt03092a
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : A series of three mononuclear pentagonal-bipyramidal V(iii ) complexes with the equatorial pentadentate N3 O2 -ligand were synthesized and characterized structurally and magnetically. Abstract : A series of three mononuclear pentagonal-bipyramidal V(iii ) complexes with the equatorial pentadentate N3 O2 ligand (2, 6-diacethylpyridinebis(benzoylhydrazone), H2 DAPBH) in the different charge states (H2 DAPBH 0, HDAPBH 1−, DAPBH 2− ) and various apical ligands (Cl −, CH3 OH, SCN − ) were synthesized and characterized structurally and magnetically: [V(H2 DAPBH)Cl2 ]Cl·C2 H5 OH (1 ), [V(HDAPBH)(NCS)2 ]·0.5CH3 CN·0.5CH3 OH (2 ) and [V(DAPBH)(CH3 OH)2 ]Cl·CH3 OH (3 ). All three complexes reveal paramagnetic behavior, resulting from isolated S = 1 spins with positive zero-field splitting energy expected for the high-spin ground state of the V 3+ (3d 2 ) ion in a PBP coordination. Detailed high-field EPR measurements for compound 3 show that its magnetic properties are best described by using the spin Hamiltonian with the positive ZFS energy ( D = +4.1 cm −1 ) and pronounced dimer-like antiferromagnetic spin coupling ( J = −1.1 cm −1 ). Theoretical analysis based on superexchange calculations reveals that the long-range spin coupling between distant V 3+ ions (8.65 Å) is mediated through π-stacking contacts between the planar DAPBH 2− ligands of two neighboring [V(DAPBH)(CH3 OH)2 ] + complexes.