Abstract
Experimental conditions are described for the growth of single crystals by anodic electrocrystallization of the isomorphous 1:1 chloride and bromide of 1,4,5,8-tetraselenonaphthalene (TSeN). A structural study was performed on the chloride for reasons of crystal quality, while physical studies were carried out on the more plentiful bromide, which was found to have a polycrystalline resistivity of 103-104 cm. The chloride of TSeN, [C10H4Se4]Cl, is an orthorhombic crystal of space group Cmca (D\|; No. 64) with a = 19.110 (4) Á, b = 8.574 (2) A, c = 13.437 (3) A, V = 2201.6 A3, and Z = 8. The structure, solved by Patterson and difference-Fourier syntheses, is comprised of dimers of parallel TSeN cation radicals rather than infinite chains. Curie law behavior was observed in both static magnetic susceptibility and electron spin resonance studies of the bromide. The ESR spectral envelope is an example of an orthorhombic g-tensor system for which the intrinsic line width and the hyperfine anisotropy are much smaller than that of the g tensor. The line width of the solution ESR spectrum of the TSeN cation radical and the isotropic g value show small solvent effect.