Synthesis, characterization and anticandidal activity of dioxomolybdenum(VI) complexes of the type [MoO2{ON=C(CH3)Ar}2] and [MoO2{OC(R)CHC(R’)=NC6H5}2]

Interaction of [MoO₂(acac)₂] with internally functionalized oximes like HON=C(CH₃)Ar (Ar = C₄H₃S, C₄H₃O or C₅H₄N) and Schiff's Bases derived from β – diketones like HOC(R)CHC(R′)=NC₆H₅ (R = R’ = CH₃ or C₆H₅; R = CH₃ and R’ = C₆H₅) led to the formation of yellow dioxomolybdenum(VI) complexes of the type [MoO₂{ON=C(CH₃)Ar}₂] and [MoO₂{OC(R)CHC(R′)=NC₆H₅}₂]. Oximes were synthesized by green methodology. The newly synthesized complexes were characterized on basis of elemental analysis and various spectral findings.

Anticandidal activity of [MoO₂{ON=C(CH₃)C₆H₄N}₂] clearly reveals that the complex is biologically active against fungal diseases.

Nitric oxide functionalized molybdenum(0) pyrazolone Schiff base complexes: thermal and biochemical study

This work describes the synthesis and characterization of three molybdenum dinitrosyl Schiff base complexes of the general formula [Mo(NO)₂(L)(OH)], where L is N-(dehydroacetic acid)-4-aminoantipyrene (dha-aapH), N-(4-acetylidene-3-methyl-1-phenyl-2-pyrazolin-5-one)-4-aminoantipyrine (amphp-aapH) or N-(3-methyl-1-phenyl-4-propionylidene-2-pyrazolin-5-one)-4-aminoantipyrine (mphpp-aapH). The complexes were formulated on the basis of spectroscopic analyses, elemental composition, magnetic susceptibility measurements, molar conductance behaviour and determination of the respective decomposition temperatures. A comparative experimental-theoretical approach was followed to elucidate the structure of the complexes. Fourier transform infra-red (FT-IR) spectroscopy, thermo-gravimetry (TG) and electronic spectral insights were mainly focused on the confirmation of the formation of the complexes. The computational density functional theory (DFT) calculations evaluated in the study involve the molecular specification for the use of LANL2DZ/RB3LYP formalism for metal atoms and 6-311G/RB3LYP for the remaining non-metal atoms. The study reveals a suitable cis-octahedral geometry for the complexes. The TG curve of one of the representative complexes was evaluated to find the respective thermodynamic and kinetic parameters using various physical methods. The Freeman & Carroll (FC) differential method, the Horowitz and Metzger (HM) approximation method, the Coats–Redfern method and the Broido method were employed to present a comparative thermal analysis of the complex. The Broido method proved the best fit to the results for the compound under question. In addition to structural and thermal analyses, the study also deals with the in vitro antimicrobial and anticancer sensitivity of the complexes. The results revealed potent biological properties of the representative complex containing dha-aapH. Cell toxicity tests against COLO-205 human cancer cell line using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay showed an IC₅₀ value of 53.13 μgm mL⁻¹ for the Schiff base and 10.51 μgm L⁻¹ for the respective complex. Similarly the same complex proved to be an effective antimicrobial agent against Aspergillus, Pseudomonas, E. coli and Streptococcus. The results indicated a more pronounced activity against Pseudomonas and Streptococcus than the other two microbial species.

This work describes the thermal and biological implications of three pyrazolone-dinitrosylmolybdenum(0) complexes.

Interaction Site and Proton Transfer Equilibrium in the 4-Aminoantipyrine-Pentachlorophenol Hydrogen–Bonded Adduct

The hydrogen-bonding interaction site between 4-aminoantipyrine (4AAP) and pentachlorophenol (PCP) was investigated in the crystalline form using FT-IR and in solution using FT-IR, UV-Vis and 1H,13C NMR spectroscopies.