Radical cation-radical anion salts: Molybdenum complexes containing the [TCNQ] •− or [TCNE] •− radical anions. X-ray crystal structure of [Mo(Et 2NCS 2) 4](TCNQ)

• Published in: Polyhedron 1995-07, Vol.14 (13), p.1741-1750
• Main Authors: Decoster, M., Conan, F., Guerchais, J.E., Le Mest, Y., Sala Pala, J., Jeffery, J.C., Faulques, E., Leblanc, A., Molinie, P.
• Format: Article
• Language: English
• Subjects: Chemical Sciences; Coordination chemistry; Inorganic chemistry
• ISSN: 0277-5387; 0277-5387
• DOI: 10.1016/0277-5387(94)00487-Y

The reactions between the molybdenum(IV) complexes [Mo(dtc) 4] 1 (dtc = Et 2NCS 2 for 1a and Me 2NCS 2 for 1b) and TCNQ produced the 1 : 1 derivatives [Mo(dtc) 4](TCNQ) 2. Subsequent reaction of 2 with TCNQ gave the 1 : 2 complexes 3 [Mo(dtc) 4](TCNQ) 2. Complexes 1 reacted with TCNE under nitrogen to give the 1 : 1 compounds [Mo(dtc) 4](TCNE) 4 while under ambient conditions the pentacyanopropenide derivatives [Mo(dtc) 4](NC) 2CC(CN)C(CN) 2] 5 were obtained. In solution, cyclic voltammetry and ESR studies revealed the presence for all types of complexes of the molybdenum(V) radical cation [Mo(dtc) 4] •− which is associated with the radical anion TCNX •− in 2 (X = Q) and 4 (X = E) and with a 1:1 mixture of neutral and anionic TCNQ species in 3. Complex 2a has been studied by single crystal X-ray diffraction. The crystal structure consists of monomeric TCNQ •− radical anions and [Mo(dtc) 4] •+ cations with a triangular dodecahedral arrangement of S atoms and a point group symmetry which is approximately D 2 d .