Exploring the effect of hydroxylic and non-hydroxylic solvents on the reaction of [VIVO(β-diketonate)2] with 2-aminobenzoylhydrazide in aerobic and anaerobic conditions. Issue 33 (2nd August 2017)

• Record Type: Journal Article
• Authors: Biswas, Nirmalendu; Patra, Debashis; Mondal, Bipul; Bera, Sachinath; Acharyya, Swarnali; Biswas, Anup Kumar; Mukhopadhyay, Titas Kumar; Pal, Amrita; Drew, Michael G. B.; Ghosh, Tapas
• Is Part Of: Dalton transactions. Volume 46:Issue 33(2017)
• Page Start: 10963
• Page End: 10985
• Publication Date: 2017-08-02
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c7dt01776f
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : The role of hydroxylic/non-hydroxylic solvents in the reaction of [V IV O(β-diketonate)2 ] with 2-aminobenzoylhydrazide in the presence/absence of air was explored. Abstract : Refluxing [V IV O(β-diketonate)2 ], namely [V IV O(acetylacetonate)2 ] and [V IV O(benzoylacetonate)2 ], separately with an equivalent or excess amount of 2-aminobenzoylhydrazide (ah) in laboratory grade (LG) CH3 OH in aerobic conditions afforded non-oxidovanadium(iv ) and oxidovanadium(v ) complexes of the type [V IV (L 1 )2 ] (1 ), [V V O(L 1 )(OCH3 )]2 (3 ) and [V IV (L 2 )2 ] (2 ), and [V V O(L 2 )(OCH3 )] (4 ), respectively. (L 1 ) 2− and (L 2 ) 2− represent the dianionic forms of 2-aminobenzoylhydrazone of acetylacetone (H2 L 1 ) and benzoylacetone (H2 L 2 ), respectively, (general abbreviation, H2 L), which was formed by the in situ condensation of ah with the respective coordinated [β-diketonate] in medium-to-good yield. The yield of different resulting products was dependent upon the ratio of ah to [V IV O(β-diketonate)2 ]. For example, the yield of1 and2 complexes increased significantly associated with a decrease in the amount of3 and4 with an increase in the molar ratio of ah. Upon replacing CH3 OH by a non-hydroxylic solvent, LG CHCl3, the above reaction yielded only oxidovanadium(v ) complexes of the type [V V O(L 1 )(OH)]2 (5 ), [V V O(L 2 )(OH)] (6 ) and [VV2O3 (L)2 ] (7, 8 ) whereas, upon replacing CHCl3 by another non-hydroxylic solvent, namely LG CH3 CN, only the respective [VV2O3 (L)2 ] (7, 8 ) complex was isolated in 72–78% yield. However, upon performing the above reactions in the absence of air using dry CH3 OH or dry CHCl3, only the respective [V IV (L)2 ] complex was obtained, suggesting that aerial oxygen was the oxidising agent and the type of pentavalent product formed was dependent upon the nature of solvent used. Complexes3 and4 were converted, respectively, to7 and8 on refluxing in LG CHCl3 via the respective unstable complex5 and6 . The DFT calculated change in internal energy (Δ E ) for the reactions 2[V V O(L 2 )(OCH3 )] + 2H2 O → 2[V V O(L 2 )(OH)] + 2CH3 OH and 2[V V O(L 2 )(OH)] → [VV2O3 (L 2 )2 ] + H2 O was, respectively, +3.61 and −7.42 kcal mol −1, suggesting that the [V V O(L 2 )(OH)] species was unstable and readily transformed to the stable [VV2O3 (L 2 )2 ] complex. Upon one-electron reduction at an appropriate potential, each of7 and8 generated mixed-valence [(L)V V O–(μ-O)–OV IV (L)] − species, which showed valence-delocalisation at room temperature and localisation at 77 K. Some of the complexes showed a wide range of toxicity in a dose-dependent manner against lung cancer cells comparable with that observed with cis -platin.