Search

Reaction of the p-hydroquinone derivative H₂Na₄bicah·4H₂O with either VIVOSO₄·3H₂O and NaVVO₃ in equivalent quantities or with NaVVO₃ yields the tetranuclear VIVO2+ macrocycle–semiquinonate compound Na₆{(VIVO)₄(μ₂-O)₂[μ₂-bicas·(−5)-N,O,O,O]₂}·Na₂SO₄·20H₂O (1·Na₂SO₄·20H₂O) and the dinuclear cis-VVO₂+–hydroquinone species Na₄{(VVO₂)₂[μ₂-bicah(−6)-N,O,O,O]}·11H₂O (2·11H₂O) respectively. Compounds 1·Na₂SO₄·20H₂O and 2·11H₂O were characterized by X-ray structure analysis and ab initio calculations.

Reaction of the amidate ligand N-{2-[(2-pyridylmethylene)amino]phenyl}pyridine-2-carboxamide (Hcapca) with [VOCl₂(thf)₂] and MeONa in 1∶1∶1 molar ratio in MeCN affords the compound trans-[VOCl(capca)] 1, while reaction of 1 with NEt₄NCS, MeCO₂NHEt₃ and imidazole yields the complexes trans-[VO(NCS)(capca)] 2, trans-[VO(Me-CO₂)(capca)] 3 and trans-[VO(im)(capca)]⁻ 4 respectively; the X-ray crystal structure of 1 is reported; Cw EPR studies of compounds 1–3 reveal a novel phenomenon of the reduction of their A_z components by ca. 10% compared to N₄ reference compounds.

Reaction of the diamidate ligand H2bpb with VCl3 depending on the base affords either the compound NHEt3{trans-[VIIICl2(bpb)] } 1 or [VIII(Hbpb)3]·2CHCl3 2; aerial oxidation–hydrolysis of 1 gives the dimeric species [VOCl(Hbpb)]2·2MeNO2 3; the X-ray crystal structures of 1, 2 and 3 are reported.

Reaction of the dipeptides H2Gly-Tyr and H2Gly-Phe with VCl3 and 1,10-phenanthroline affords the compounds [V(Gly-Tyr)(phen)]Cl·3MeOH 1 and [V(Gly-Phe)(phen)]Cl·3MeOH 2; aerial oxidation of the complexes 1 and 2 gives their oxovanadium(IV) analogues [VO(Gly-Tyr)(phen)] 3 and [VO(Gly-Phe(phen)] 4, respectively; the X-ray crystal structure of 3 is reported.