Triphenyl Silicon (Iv) Complexes of 1-Phenyl-3-Aryl Pyrazole-4-Carboxaldehyde Thiosemicarbazones and Semicarbazones |
Derivatives of the types R-CH=N-NH-CX-NH2 andRRC=N-NH-CX-NH2 which are usually obtained by condensation ofthiosemicarbazide or semicarbazide with suitable aldehydes and ketones, arenamed by adding ‘thiosemicarbazone’ (X = S) or ‘semicarbazone’ (X = O) afterthe name of the condensed aldehyde or ketone. It is usual also to include inthis class derivatives with substituents on the amide or thioamide nitrogen, onthe X atom, or on the ‘hydrazinic’ nitrogen.146 Thiosemicarbazones (TSC) and semicarbazones (SC) areamongst the most widely studied nitrogen and sulfur/oxygen donor legends. Theseclasses of compounds usually react with metallic cations giving complexes inwhich the TSC and SC behave as chelating ligands. Research on thecoordination chemistry, analytical applications and biological activities ofthese complexes has increased steadily for many years. These compounds haveremarkable biological activities ranging from anti-protozoa, antibacterial,antifungal, antitumoral,antiviral activities andspecially anti-HIV activity,which have since been shown to be related to theirmetal complexing ability.