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Indian Journal of Chemistry -Section A (IJC-A) >
IJC-A Vol.48A [2009] >
IJC-A Vol.48A(01) [January 2009] >
| Title: | Coordination equilibria of mixed ligand complexes of Cuˡˡ with glycylglycine and biguanide |
| Authors: | Barman, T Roy
Mukherjee, G N |
| Keywords: | Solution chemistry
Coordination equilibria
Mixed ligand complexes
Copper
Glycylglycine
Biguanide |
| Issue Date: | Jan-2009 |
| Publisher: | CSIR |
| 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. |
| Page(s): | 38-44 |
| ISSN: | 0376-4710 |
| Source: | IJC-A Vol.48A(01) [January 2009]
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