Studies on the stabilities of some mixed ligand complexes of nickel(II) involving dopamine/dopa and sulphur containing ligands

Abstract

<span style="font-size:12.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-ansi-language:="" en-in;mso-fareast-language:en-in;mso-bidi-language:ar-sa"="" lang="EN-IN">Stability constants for the mixed ligand species of the types NiAB, NiABH and NiABH₂ (where A=dopamine and dopa; <span style="font-size:12.0pt; font-family:" times="" new="" roman";mso-fareast-font-family:hiddenhorzocr;mso-ansi-language:="" en-in;mso-fareast-language:en-in;mso-bidi-language:ar-sa"="" lang="EN-IN">B=L-cysteine, <span style="font-size:12.0pt;font-family:" times="" new="" roman";mso-fareast-font-family:="" "times="" roman";mso-ansi-language:en-in;mso-fareast-language:en-in;="" mso-bidi-language:ar-sa"="" lang="EN-IN">D-penicilamine and L-cysteic acid) have been detennined. In the NiAB, the mode of coordination of A and B is <span style="font-size:12.0pt;font-family:" times="" new="" roman";mso-fareast-font-family:="" hiddenhorzocr;mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:="" ar-sa"="" lang="EN-IN">exactly <span style="font-size:12.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-ansi-language:="" en-in;mso-fareast-language:en-in;mso-bidi-language:ar-sa"="" lang="EN-IN">similar to their binding in the respective binary complexes. In NiABH, the extra proton is attached to A. In NiABH₂ (where A=dopamine) one proton is attached to A and other resides with B, while in the NiABH₂ (where A=dopa) both the protons are with dopa.</span></span></span></span></span>