Manganese(III)-carboxylate binding: chemistry and structure of a hydrated pyridinedicarboxylate

Chandra, Swapan Kumar ; Chakraborty, Partha ; Chakravorty, Animesh (1992) Manganese(III)-carboxylate binding: chemistry and structure of a hydrated pyridinedicarboxylate Proceedings of the Indian Academy of Sciences - Chemical Sciences, 104 (3). pp. 351-360. ISSN 0253-4134

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Official URL: http://www.ias.ac.in/j_archive/chemsci/104/1/351-3...

Related URL: http://dx.doi.org/10.1007/BF02839544

Abstract

The reaction of Mn(CH3COO)3 2H2O with the carboxyl-rich ligand pyridine-2,6-dicarboxylic acid (H2L) in methanol affords a high-spin (S = 2) hydratedbis-complex. Structure determination has revealed the solid to be [MnIII(H2 L)(L)] [MnIIIL2] 5H2 O: space group P-1;Z = 2;a = 7.527(3)Å3,b= 14.260(4)Å,c = 16.080(6)Å,α = 91.08(3)°,β = 103.58(3)°,λ= 105.41(3)° and V= 1611.2(10)Å3. Each ligand is planar and is bonded in the tridentate O2N fashion. The MnO4N2 coordination spheres show large distortions from octahedral symmetry. The lattice is stabilised by an extensive network of O···O hydrogen-bonding involving water molecules and carboxyl functions. Upon dissolution in water, protic redistribution occurs and the complex acts as the mono-basic acid Mn(HL)(L) (pK, 4.3 ± 0.05). The deprotonated complex displays high metal reduction potentials: MnIVL2-MnIIIL 2- , 1.05V; MnIIIL 2 - MnIIL 2 2- -, 0.28V vs. SCE.

Item Type:Article
Source:Copyright of this article belongs to Indian Academy of Sciences.
Keywords:Manganese(III) Pyridinedicarboxylate; Metal Reduction Potential; Protic Redistribution
ID Code:6885
Deposited On:26 Oct 2010 05:16
Last Modified:16 May 2016 17:10

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