New Binuclear Copper Complexes [(9S3)Cu(CN)Cu(9S3)]Xn (X=BF4, n=1; X=TCNQ, n=2) (9S3=1, 4, 7-trithiacyclononane): Syntheses, Crystal Structures and Magnetic Properties

• Published in: Zeitschrift für anorganische und allgemeine Chemie (1950) 2004-12, Vol.630 (15), p.2725-2730
• Main Authors: Naito, T., Nishibe, K., Inabe, T.
• Format: Article
• Language: English
• Subjects: Copper; Copper(I/II) mixed valency; Crystal structure; Cyanide-bridge; Magnetic properties; Thiacrown ether
• ISSN: 0044-2313; 1521-3749
• DOI: 10.1002/zaac.200400313

The binuclear Cu complex salts of 1, 4, 7‐trithiacyclononane (9S3) with an inorganic anion (BF4)‐ 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](BF4) (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 C2/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 CuI/II sites. The two CuI/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. Neue zweikernige Kupfer‐Komplexe [(9S3)Cu(CN)Cu(9S3)]Xn (X=BF4, n=1; X=TCNQ, n=2) (9S3=1, 4, 7‐trithiacyclononan): Synthesen, Kristallstrukturen und magnetische Eigenschaften Zweikernigen Kupfer‐Komplexsalze von 1, 4, 7‐Trithiacyclononan (9S3) mit dem anorganischen Anion (BF4)‐ und dem organischen Radikalanion TCNQ‐ (7, 7′, 8, 8′‐tetracyanoquinodimethanid) wurden synthetisiert und ihre Molekül‐ und Kristallstrukturen sowie magnetischen Eigenschaften wurden bestimmt. Das neue komplexe Kation [Cu(9S3)CN(9S3)Cu]+ variiert seine Ladungen und magnetischen Eigenschaften in Abhängigkeit von den Gegenionen. [Cu(9S3)CN(9S3)Cu](BF4) (1) bildet diamagnetische, farblose Kristalle, während [Cu(9S