Synthesis and characterization of new mono-, di-, and trinuclear copper(II) triethanolamine-carboxylate complexes

Raphael M. Escovar, John H. Thurston, Teyeb Ould-Ely, Arvind Kumar, Kenton H. Whitmire

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33 Citations (Scopus)

Abstract

A series of triethanolamine copper(II) carboxylate complexes have been synthesized and characterized both structurally and spectroscopically. The structures of the compounds and the nuclearity of the resulting coordination complexes are influenced both by the stoichiometry of the reagents and the steric and electronic influences of the anionic ligands present in the copper coordination spheres. The complexes can be prepared in high yields and purity as highly crystalline solids. Herein we report the spectroscopic and structural data for [NaCu(CF3COO)3(TEAH3)] (1), [Cu(C 6H5COO)(TEAH2)]2·2H 2O (2), [Cu3(CH3COO)4(TEAH 2)2] (3), [Cu3(HCOO)4(TEAH 2)2] (4) and [Cu3(CF3OO) 2(TEAH2)2-(CH3OH) 2][CF3CO2]2 (5) (TEAH3 = triethanolamine (N(CH2CH2OH)3); [TEAH 2]- = mono-deprotonated ion; [TEAH]2- = doubly deprotonated ion). Two approaches to these compounds were employed:direct reaction of copper(II) carboxylates with TEAH3 and reaction of the tetrameric compound [{Cu(TEAH)}4] (6) with copper(II) carboxylates. Compound 1 is polymeric in the solid state, being a double salt of sodium trifluoroacetate and (triethanolamine)copper(II) trifluoroacetate, while 2 exists as a simple dimer. Compounds 3, 4 and 5 are trinuclear complexes with Cu3 chains connected by bridging carboxylate and triethanolamine ligands. 3 was characterized as three crystal modifications: an unsolvated form and as a methanol solvate 3.2MeOH that was found to exist in both monoclinic and orthorhombic forms. 4 was also found to exist as a methanol solvate, 4.1.70 MeOH. 5 shows coordination isomerism compared to compounds 3 and 4 in that two of the carboxylate ligands in the metal coordination spheres on the end copper atoms have been replaced by solvent methanol. The magnetic behavior of the di- and trinuclear species has been probed and reveals that at low temperatures the metal centers exhibit strong ferromagnetic coupling, which, on warming, switches to simple paramagnetic behavior.

Original languageEnglish
Pages (from-to)2867-2876
Number of pages10
JournalZeitschrift fur Anorganische und Allgemeine Chemie
Volume631
Issue number13-14
DOIs
Publication statusPublished - Nov 16 2005

Keywords

  • Copper
  • Copper triethanolamine-carboxylate complexes

ASJC Scopus subject areas

  • Inorganic Chemistry

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