Please use this identifier to cite or link to this item:
|Title:||Coordination equilibria of mixed ligand complexes of Cuˡˡ with glycylglycine and biguanide|
|Authors:||Barman, T Roy|
Mukherjee, G N
Mixed ligand complexes
|Abstract:||Spectrophotometric and computer based pH metric investigations on the mixed ligand complex formation equilibria of Cuˡˡ with glycylglycine [(H₃⁺NCH₂CONHCH₂COO⁻), HGG±] and biguanide [(H₂¹N C(=²NH) ³NH C(=⁴NH) ⁵NH₂), Bg] in aqueous solution at 25±1ºC at a fixed ionic strength, I = 0.1 mol dm⁻³ (NaNO₃) in different molar proportions, indicate the formation of [Cu(GG)(H₂O)₂], [Cu(GG-H)(H₂O)], [Cu(Bg-H)(OH)], [Cu(GG-H)(Bg)], [Cu(GG-H)(Bg-H)-], [Cu₂ (GG-H)₂(Bg)], [Cu₂(GG-H)₂(Bg-H)⁻], [Cu₂(GG-H)₂(Bg-2H)²⁻] complexes. Shifting of electronic spectral λmax of Cuˡˡ with increase in pH correlates with a meridonial-facial isomeric equilibrium in the coordination modes of amide deprotonated glycylglycinate dianion, GG-H²⁻, in [Cu(GG-H)(Bg)]. Existence of the binuclear mixed ligand complexes indicates basket-like bridging double bidentate [(H₂¹N, =⁴NH), (=²NH, ⁵NH₂)] mode of chelation by the biguanide species.|
|Appears in Collections:|| IJC-A Vol.48A(01) [January 2009]|
Items in NOPR are protected by copyright, with all rights reserved, unless otherwise indicated.