Comprehensive catalytic and biological studies on new designed oxo- and dioxo-metal (IV/VI) organic arylhydrazone frameworks

Abstract

Aryl Schiff base hydrazone have strong ability to form high stable complexes with transition metals with numerous applicability in catalysis and biology. For that, mononuclear pincer complexes of oxo/dioxo high valent metal ions (MoO22+, UO22+ and VO2+ ions, as MoO2Lhz, UO2Lhz and VOLhz, respectively) with aryl Schiff base hydrazone ligand (H2Lhz) were synthesized. H2Lhz and its MOxLhz complexes were characterized within alternative considerable tools. The complexes were formed in 1: 1 M ratios of MOx2+ (X = 1 or 2) ion to H2Lhz with octahedral geometries of cis-MoO2- and cis-UO2-complexes, and a square pyramidal geometry of VO-complex. The catalytic potential of MOxIILhz was estimated in the productive redox system of benzyl alcohol using H2O2 in an aerobic homogeneous phase. High productivity was progressed affording the corresponded aldehyde (benzaldehyde) with all catalysts. VOLhz displays the highest affectivity by 95 % of benzaldehyde (at 70 °C, after 2 h), MoO2Lhz represents an excellent action with 91 % (at 80 after 2 h). However, UO2Lhz shows the less efficacy with 80 % after 4 h of benzaldehyde. Hence, the catalytic performance depends upon the metal ion type (MOx2+ in the complex catalyst) in the proposed mechanism (oxygen transfer). For the bio-chemical assays, the anticancer and antimicrobial action of H2Lhz and its MOxLhz complexes were examined versus various microbes and human tumor cell lines. Their bio-interaction was also explored with ctDNA (calf thymus DNA) spectrophotometrically and the viscometric changes. All MOxLhz complexes exhibited higher inhibiting potential against the current microorganism growth (depending on the inhibiting zone in mm and MIC in μM values) and the human cancer cells over their free ligand H2Lhz. The ctDNA interaction was evaluated within Kb, the binding constants, and also the Gibbs’ free energy values for all studied compounds, exploring their role within the type and nature of MOx2+ ion for enhancement of their ctDNA interaction mode.