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Publication Type
Journal Article
Author, Analytic
Bakir, Mohammed A.; Lawrence, Mark A./McBean, S.
Author Affiliation, Ana.
n/a
Article Title
Spectroscopic and electrochemical properties of group 12 acetates of di-2-pyridylketone thiophene-2-carboxylic acid hydrazone (dpktch-H) complexes. The structure of [Cd(g3-N,N,O-dpktch-H)2]ö Spectrochimica Acta Part A
Medium Designator
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Connective Phrase
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Journal Title
Molecular and Biomolecular Spectroscopy
Translated Title
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Reprint Status
Refereed
Date of Publication
2015
Volume ID
146
Issue ID
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Page(s)
323-330
Language
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Connective Phrase
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Location/URL
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ISSN
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Notes
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Abstract
The reaction between [dpktch] and [M(OAc)2] (M=group 12 metal atom) in refluxing CH3CN gave [M(?(2)-O,O-OAc)(?(3)-N,N,O-dpktch-H)]ĚnH2O (n=0 or 1). The infrared and (1)H NMR spectra are consistent with the coordination of [?(2)-O,O-OAc] and [?(3)-N,N,O-dpktch-H](-) and the proposed formulations. The electronic absorption spectra of [M(?(2)-O,O-OAc)(?(3)-N,N,O-dpktch-H)]ĚnH2O measured in non-aqueous solvents revealed a highly intense intra-ligand-charge transfer (ILCT) transition due to p-p* of dpk followed by dpk?thiophene charge transfer. The electronic transitions of [M(?(2)-O,O-OAc)(?(3)-N,N,O-dpktch-H)]ĚnH2O are solvent and concentration dependent. Spectrophotometric titrations of dmso solutions of [M(?(2)-O,O-OAc)(?(3)-N,N,O-dpktch-H)]ĚnH2O with benzoic acid revealed irreversible inter-conversion between [M(?(2)-O,O-OAc)(?(3)-N,N,O-dpktch-H)]ĚnH2O and it conjugate acid [M(?(2)-O,O-OAc)(?(3)-N,N,O-dpktch)]ĚnH2O pointing to ligand exchange between the acetate and benzoate anions. When CH2Cl2 solutions of [M(?(2)-O,O-OAc)(?(3)-N,N,O-dpktch-H)]ĚnH2O were titrated with dmso, changes appeared pointing to solvolysis or ligand exchange reactions. Electrochemical measurements on dmso solutions of [M(?(2)-O,O-OAc)(?(3)-N,N,O-dpktch-H)]ĚnH2O divulged irreversible redox transformations consistent with electrochemical decomposition of [M(?(2)-O,O-OAc)(?(3)-N,N,O-dpktch-H)]ĚnH2O. The solid state structure of a single crystal of [Cd(?(3)-N,N,O-dpktch-H)2] obtained from a dmso solution of [Cd(?(2)-O,O-OAc)(?(3)-N,N,O-dpktch-H)]ĚnH2O confirmed the ligand scrambling of [M(?(2)-O,O-OAc)(?(3)-N,N,O-dpktch-H)]ĚnH2O. The extended structure of [Cd(?(3)-N,N,O-dpktch-H)2] revealed stacks of [Cd(?(3)-N,N,O-dpktch-H)2] locked via a network of hydrogen bonds. A significant amount of empty space (35.5%) was observed in the solid state structure of [Cd(?(3)-N,N,O-dpktch-H)2].....
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