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Electron spin resonance and relaxation of tetrahedrally coordinated copper(11) in some complex halides
Author(s) -
Vaughan R. A.
Publication year - 1972
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.2220490123
Subject(s) - electron paramagnetic resonance , chemistry , copper , ion , halide , relaxation (psychology) , crystallography , analytical chemistry (journal) , spin–lattice relaxation , nuclear magnetic resonance , inorganic chemistry , nuclear quadrupole resonance , social psychology , psychology , physics , organic chemistry , chromatography
Electron spin resonance and relaxation measurements are reported for some copper salts in which the Cu 2+ ion has tetrahedral coordination. For the CuCl 4 2− ion in Cs 2 CuCl 4 , the results are in some respects at variance with those previously reported [1]. The crystallographic cell parameters for [(C 4 H 9 ) 4 N] 2 CuBr 4 have been measured, and in this material a single broad asymmetric ESR line is reported, about 145 G wide at X‐band, having principal g ‐values of 2.068, 2.053, and 2.220. Spin‐lattice relaxation times measured by both pulse and continuous saturation methods yielded values of T 1 in the range 60 μs at 4.2 K to 140 μs at 1.7 K. These are compared with the much larger values predicted for copper in other tetrahedrally coordinated materials [2]. The ESR spectra of CuCl 4 2− and CuBr 4 2− ion adsorbed on an ion exchange resin are compared with those from powdered samples of the above two complexes. Measurements of T 1 for the CuBr 4 2− ion on the resin yielded values of 100 μs at 4.2 K and 280 μs at 1.86 K. It is concluded that the complex halides are not a suitable system in which to study relaxation behaviour of Cu 2+ in a tetrahedral crystal field.