Synthesis and AB initio study of biologically important thioamide

Thioamide group is an important part of a large number of drug structures, yet there is no description for infrared spectra and coordination behavior.Three compounds i.e. dithiooxamide ( DTO) , n- propyl ( PDTO) and Schiff base ( SDTO) derivatives of DTO were chosen for the present experimental work and theoretical treatment , in addition of copper (II) complexes of DTO and SDTO.All the prepared compounds were isolated and characterized by their melting points, vibration and electronic spectra, metal analysis, thermal analysis and magnetic measurements.The ab initio method at high level was used for calculating the relative energies and infrared spectra of the three prepared compounds ( DTO,PDTO and SDTO) , the ab initio calculations indicating the tautomeric structure of DTO and help to predict the most stable structure among the four probable. PM3 method was used for calculation of binding energies for the probable geometries of copper ( II) complexes with DTO and SDTO. AMI method was used in calculating the electrostatic potential and HOMO-LUMO of the reactant molecules; thereby the reactive sites were characterized.