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Syntheses, Crystal Structures and Spectroscopic Studies of Bis[1‐methyl‐3‐(methoxycarbonylmethyl)‐benzimidazolium] 2+ [CuBr 4 ] 2− and [ZnBr 4 ] 2− Compounds
Author(s) -
Czekański Łukasz,
Hoffmann Stanisław K.,
Barczyński Piotr,
Gąsowska A.,
Zalewska Alina,
Goslar Janina,
RatajczakSitarz Małgorzata,
Katrusiak Andrzej
Publication year - 2017
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201701716
Subject(s) - chemistry , delocalized electron , crystallography , orthorhombic crystal system , electron paramagnetic resonance , crystal structure , monoclinic crystal system , hydrogen bond , tetrahedral symmetry , unpaired electron , spectroscopy , molecule , nuclear magnetic resonance , physics , organic chemistry , quantum mechanics , mechanics , rotational symmetry
X‐ray diffraction structure of two new bis [1‐methyl‐3‐(methoxycarbonylmethyl) benzimidazolium] 2+ [CuBr 4 ] 2− and [ZnBr 4 ] 2− compounds has been determined. Zn‐crystal is monoclinic with perfect T d symmetry of the ZnBr 4 tetrahedron, whereas the Cu‐compound is orthorhombic with D 2d symmetry of CuBr 4 tetrahedron. The difference in these structures is described as due to the static Jahn‐Teller effect. Vibrational spectroscopy (1800–3200 cm −1 ) identified hydrogen bond network. NIR‐UV‐Vis spectra (5000–50000 cm −1 ) are dominated by ligand‐to‐metal bands with d‐d transition contribution. EPR results (Q‐band) analyzed in terms of the MO‐theory showed a very strong delocalization of unpaired electron density on ligands accompanied by the Cu(II) 4p z orbital contribution. This effect is partially compensated by charge transfer transitions to the EPR g‐factor.