Abstract

Potentiometric Study Of Vanadyl (IV) Complexes Of Non-Steroidal Anti-Inflammatory Drug (NSAIDs) In Methanol At Different Temperatures And In Different Metal/Ligand Ratios

Author(s): Saqib Ali, Saira Shahzadi

The reactions between flurbiprofen and VOSO4⋅3H2O in 1:1, 1:2, 1:3 molar ratios in methanol was investigated at 35oC, 22oC and 0oC. The pKa values have been found as 8.52, 6.32 and 4.2 at 35oC, 8.35, 6.31 and 4.18 at 22oC, 8.34, 6.26 and 4.16 at 0oC. In various pH conditions, the different complexes which are formulated as VO(H2O)3L, VO(H2O)L2 and VL3 have been formed by titration of VOSO4⋅3H2O and ligand (Flurbiprofen) mixture with NaOH. The stability constant of each complex have been calculated and general mechanism have been proposed with regard to the formation of these complexes. The order of stability is 1:1 > 1:2 > 1:3 which is justified with proposed mechanism also.