Polymorphism of 1,3-Phenylene Bis(Diselenadiazolyl) - Solid-State Structural and Electronic-Properties of Beta-1,3-[(Se2n2c)C6h4(Cn2se2)]
by Cordes, A. W.; Haddon, R. C.; Hicks, R. G.; Oakley, R. T.; Palstra, T. T. M.; Schneemeyer, L. F.; Waszczak, J. V.
The solid-state characterization of a second or beta-phase of the 1,3-phenylene-bridged diselenadiazolyl diradical 1,3-[(Se2N2C)C6H4(CN2Se2)] is reported. Crystals of this beta-phase are monoclinic, space group P2(1)n, with a = 9.108 (6), b = 15.233 (13), c = 16.110 (5) angstrom, beta = 103.37 (5)-degrees, Z = 8. The crystal structure consists of chain-like arrays of discrete dimers (4 per unit cell), although one intradimer Se-Se linkage is notably longer (3.411 angstrom) than the other three (3.125, 3.196, 3.204 angstrom). The dimer units lie in chains that are linked by a complex three-dimensional array of Se-Se contacts. Variable-temperature single-crystal conductivity measurements on this phase indicate a band gap of 0.77 eV. Consistent with the conductivity measurements, extended Huckel band structure calculations suggest a relatively isotropic electronic structure.
- Journal
- Journal of the American Chemical Society
- Volume
- 114
- Issue
- 5
- Year
- 1992
- Start Page
- 1729-1732
- URL
- https://dx.doi.org/10.1021/ja00031a028
- ISBN/ISSN
- 1520-5126; 0002-7863
- DOI
- 10.1021/ja00031a028