Few novel compounds of transition metals have been synthesized by complexing copper surfactants with bio-potent nitrogen and sulphur donor ligands. All the complexes were synthesized in refluxed reaction with (1:2, M: L ratio).The yield percentage of formed complex is ranging from 80-95%. The complexes are coloured solids and of the type (Cu2(C15H31COO)4L2 and Cu2(C7H15COO)4L2 where L is substituted 2-amino 6 bromo benzothiazole). They were characterized through elemental analyses and spectroscopy (IR, NMR, Mass and ESR). Their purity was confirmed by thin layer chromatography techniques. In special reference to the study of their physico-chemical parameters, “density” was deeply investigated in benzene-propanol mixtures. The measurements were done by springel pyknometer to understand the solute-solvent interactions of different copper soap complexes. Such investigations help us to understand the nature, critical micelle concentration (cmc) and micelle concentrations of complexes. The cmc was calculated and found to decrease with increase in molecular size and average molecular weight of the soap complex. The studies of aforesaid interactions suggest that solute-solvent interaction increases with the increase in carbon composition of fatty acid and lowering of molecular weight whereas solute-solute interaction decreases.