Photo degradation of Lanthanum (III) Complex with 1, 2 , 4-Thiadiazole in Dimethyl Sulsoxide ( DMSO ) Solvent

5- Amino -3- [4- O- hydroxypheny Ithiosemi carbazido ] -1,2,4-thiadiazole compound has been prepared by the reaction of ( 3-mercapto -5- ami,2,4- thiadiazole) with O-hydroxyphenyl thiosemicarbazide) in mole ratios (1:1) .The ligand characterized and its structure was elucidated depending upon spectral data IR U.V-Vis spectra . Lanthanum complex formula [La( C9H10N6S2O)2Cl2]Cl through lanthanum chloride (2:1) respectively The mode bonding overall geometry determined physicochemical spectroscopic methods kinetic photo-degradation investigated it first order rate constant (Kd) at (25oC ) Further more primary quantum yields (Φ) also calculated.