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New Binuclear Copper Complexes [(9S3)Cu(CN)Cu(9S3)]X n (X=BF 4 , n=1; X=TCNQ, n=2) (9S3=1, 4, 7‐trithiacyclononane): Syntheses, Crystal Structures and Magnetic Properties
Author(s) -
Naito T.,
Nishibe K.,
Inabe T.
Publication year - 2004
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.200400313
Subject(s) - triclinic crystal system , monoclinic crystal system , crystallography , diamagnetism , chemistry , copper , antiferromagnetism , crystal structure , magnetic susceptibility , stacking , space group , ion , stereochemistry , x ray crystallography , diffraction , physics , magnetic field , condensed matter physics , organic chemistry , quantum mechanics , optics
Abstract The binuclear Cu complex salts of 1, 4, 7‐trithiacyclononane (9S3) with an inorganic anion (BF 4 ) ‐ and with an organic radical anion TCNQ ‐ (7, 7′, 8, 8′‐tetracyanoquinodimethanide) were synthesized and their molecular and crystal structures were examined in connection with the magnetic properties. The new complex cation [Cu(9S3)CN(9S3)Cu] + varies its charges and magnetic properties depending on the counter anions; [Cu(9S3)CN(9S3)Cu](BF 4 ) ( 1 ) was obtained as diamagnetic colorless crystals, while [Cu(9S3)CN(9S3)Cu](TCNQ) 2 ( 2 ) was obtained as dark blue crystals with antiferromagnetic properties. Complex 1 crystallized in the monoclinic space group C 2/c with a = 26.863(2), b = 7.0878(5), c = 13.4864(8) Å, β = 116.318(2)°. Complex 2 crystallized in the triclinic space group P1¯ with a = 12.521(1), b = 20.2698(8), c = 8.0205(4) Å, α = 100.688(4), β = 93.846(5), γ = 94.953(4)°. Both complexes are comprised of cyano‐bridged two Cu(9S3) ions with tetrahedral coordination. The X‐ray structural study revealed that 1 has two crystallographically equivalent copper(I) atoms, while 2 has two crystallographically independent Cu I/II sites. The two Cu I/II sites could not be distinguished from the X‐ray structural study. For 2 the IR spectra show that both crystallographically independent TCNQ species were monoanions and are strongly dimerized due to π‐stacking, which well explains their diamagnetic contribution to the magnetic susceptibility and the highly insulating property of this salt. The temperature‐dependent magnetic susceptibility of 2 showed a deviation from the Curie‐Weiss behaviour around 60 K, which indicates a strong antiferromagnetic intermolecular interaction between the copper complexes and that such intermolecular interaction should partly occur via the TCNQ radical anion dimer.