Design, Characterization, X-ray Single-crystal, Potentiometric Measurements, Molecular Modeling and Biomedical Applications of Thiosemicarbazones

Abstract Series of thiosemicarbazone compounds ((E)-2-((E)-1-(2-(p-tolyl)hydrazono)propan-2-ylidene)hydrazine-1-carbothioamide (TSC1), (E)-N-ethyl-2-((E)-1-(2-(p-tolyl)hydrazono)propan-2-ylidene)hydrazine-1-carbothioamide (TSC2) and (E)-N-phenyl-2-((E)-1-(2-(p-tolyl)hydrazono)propan-2-ylidene)hydrazine-1-carbothioamide)(TSC3) were synthesized and fully characterized by assistance of diverse physicochemical and spectroscopic tools like X-ray single-crystal, IR, mass, 1HNMR, Uv-Vis,…etc. potentiometric measurements, molecular modeling, as well as biological and antitumor activities screening. We have calculated and discussed the thermodynamics and protonation constants of TSC1 compound as a representative from the novel synthesized thiosemicarbazones. The solution speciation of different species was studied in accordance with pH. Molecular parameters of the optimized structures were calculated and discussed. The X-ray single crystal of TSC2 and TSC3 compounds have been established where TSC2 crystallizes in P21/c, a = 11.2343 (6) Å, b = 11.2575 (7) Å, c =11.8995 (8) Å, α = 90.00°, β = 94.476(7) °, γ = 90.0°, V = 1500.34 (16) Å3, Z = 4, however, TSC3 crystallizes in the space group P21/c, a = 27.958 (12) Å, b= 12.072 (5) Å, c = 9.833 (4) Å, α = 90.0°, β = 93.117(11) °, γ = 90.0°, V = 3486.75 Å3, Z = 7. Considering the antimicrobial activities and correlating structure-activity relationship for the synthesized compounds, TSC1 molecule behaves as a promising candidate as an antifungal agent versus Candida albicans. Consequently, that would be very helpful in the field of medicinal chemistry especially as antimicrobial agents. The results are of vital significance to the chemistry of antimicrobial agents.