Electrometric Study on Nature and Stability of CoII, NiII and CuII Complexes with 5-Sulfosalicylic Acid in DMSO-Water Mixtures

Background: The bioavailability of an element and its toxicity based on its chemical species. According to IUPAC the concept of chemical speciation is defined as it is a form of an element according to its oxidation state, isotopic composition, or complex and molecular structure. The speciation studies are profoundly plays a major role in studying the nature of trace elements in a human organism. Speciation of an element has a noticeable impact on bioavailability, distribution and toxicity. These studies have vital role in medical and pharmaceutical sciences. Materials and Methods: The present investigation conducted by using pH meter, processing of data done by Gran titration. To obtain best-fit chemical models, a modelling strategy such as SCPHD is used and a computer program MINIQUAD 75 is also employed for the refinement of results. Results: In the present investigation we considered the effect of dielectric constants of Dimethyl sulfoxide (DMSO) on stability constants of CoII, Ni” and CuII with 5-Sulfosalicylic acid (5-SSA) complexes. The formed binary complex species are ML, MLH and ML2 and obtained skewness values range from -0.15-0.71 for CoII, -0.27-0.32 for Ni” and -0.41-0.32 for CuII describes the distribution curves are left skewed and right skewed. The peak of the distribution curves shows platykurtic and leptokurtic with regards to the obtained values ranging from 2.89-6.14. Conclusion: It is observed that there is a significant influence of co-solvent, Dimethyl Sulfoxide (DMSO)-water mixtures on the stability constants of metal-ligand complexes, also studied how some factors such as changes in concentrations of ligand, acid, base log F and volume of the solution have influence on the protonation constants.