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Electronic spectra of [(CH 3 ) 2 NH 2 ] 5 Cd 2 CuCl 11 crystals
Author(s) -
Kapustianik V.,
Batiuk A.,
Czapla Z.,
Podsiadła D.,
Czupiński O.
Publication year - 2004
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200302055
Subject(s) - octahedron , crystal (programming language) , copper , crystallography , absorption spectroscopy , chemistry , crystal structure , ion , phase transition , halogen , spectral line , single crystal , analytical chemistry (journal) , condensed matter physics , physics , alkyl , organic chemistry , quantum mechanics , computer science , programming language , chromatography , astronomy
The temperature evolution of Cu 2+ ion environment in the solid solutions of ((CH 3 ) 2 NH 2 ) 5 Cd 2 CuCl 11 is studied on the basis of absorption spectroscopy data. For the detailed analysis of experimental data the special program package Crys Tool 1.0 based on quantum‐mechanical models, first of all on the model of normalized spherical harmonics (NSH), has been employed. It has been found that similarly to the crystal of ((CH 3 ) 2 NH 2 ) 5 Cd 3 Cl 11 (DMACC) the investigated solid solution contains tetragonally distorted octahedral metal–halogen complexes of two types and the degree of their distortion is changed considerably at the temperatures of phase transitions (PTs). The parameters of crystal field, angular overlap model, as well as the copper–chlorine distances, show continuous changes at T 1 = 176 K that should be related to the second‐order transition, whereas the jump‐like anomalies of the spectral parameters at T 2 = 115 K (on cooling) are characteristic of the first‐order PTs. Introduction of the copper ions into the structure of the host DMACC crystal induces the shifts of these PTs toward low temperatures by 3.5 and 5 K, respectively. The observed structural changes around T 0 = 313 K are connected with a complex co‐operative effect involving weakening of the hydrogen bonds and modification of the Jahn–Teller distortion with temperature. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)