Preparation and solid state characterization of isostructural bifunctional 1,2,3,5-dithiadiazolyls with benzene, bithiophene, and piperazine spacers

by Cordes, A. Wallace; Haddon, Robert C.; Mackinnon, Craig D.; Oakley, Richard T.; Patenaude, Gregory W.; Reed, Robert W.; Rietveld, T.; Vajda, Kristen E.

The preparation of the bis(1,2,3,5-dithiadiazolyl) radicals [S(2)N(2)C]-X-[CN(2)S(2)], where X is a heterocyclic bridging group (X = piperazine, thiophene, bithiophene) is described. Crystal structures of the piperazine- and bithiophene-bridged diradicals have been determined by single-crystal X-ray diffraction. The two compounds are isostructural, belonging to the monoclinic space group P2(1)/n; for the piperazine derivative a = 5.9913(6) Angstrom, b = 19.1958(16) Angstrom, c = 9.1244(6) Angstrom, beta = 100.314(7)degrees, and Z = 4. For the bithiophene derivative a = 5.9907(17) Angstrom, b = 24.272(3) Angstrom, c = 9.1740(14) Angstrom, beta = 102.961(18)degrees, and Z = 4. The diradicals associate as cofacial dimers which adopt a herringbone packing pattern analogous to that observed previously for the 1,4-phenylene-bridged derivative. in all three structures the herringbone arrays are characterized by a series of close interdimer S-S contacts along the spine. Consistently, the results of extended Huckel band structure calculations indicate highly developed two-dimensional electronic structures.

Journal
Inorganic Chemistry
Volume
35
Issue
26
Year
1996
Start Page
7626
ISBN/ISSN
1520-510X; 0020-1669
DOI
10.1021/ic960659z