The reaction of primary selenoamides with bisacyl chlorides in the presence of Et3N was investigated. By the reaction with malonyl chloride, 6-hydroxy-1,3-selenazin-4-ones were provided in high yield. By the reactions with succinyl chloride, glutaryl chloride, and phthaloyl chloride, the corresponding selenoanhydrides were obtained in moderate yields, respectively.
2,5-Bis(4,5-ethylenedithio-1,3-dithiol-2-ylidene)-2,5-dihydroselenophe++ne (BEDTâBDTS), a selenophenoquinonoid-extended analogue of bis(ethylenedithio)tetrathiafulvalenes (BEDTâTTF), has been synthesized as a promising candidate for an electron-donating component of highTc organic superconductors. BEDTâBDTS is air-stable and has a significantly enhanced electron-donating ability compared with that of BEDTâTTF. The molecular and crystal structures of BEDTâBDTS have been determined by single crystal X-ray analysis in which short intermolecular SS contacts have been found in the side-by-side directions of the donor arrangements. A 1:1 TCNQ complex and a 3:1 I3â radical cation salt of BEDTâBDTS have been obtained and proved to exhibit fairly high room temperature conductivities.
Various diacyl selenides, diacyl diselenides and selenocarboxylates were synthesized by reaction of several acyl chlorides with LiAlHSeH. Reaction of diacyl chloride with LiAlHSeH afforded cyclic selenoanhydrides. In the 77Se NMR spectra, we found that the chemical shifts of the diacyl selenides and the diacyl diselenides could facilitate their distinction.
2,5-Bis(1,3-dithiol-2-ylidene)-2,5-dihydroselenophene (BDTS) and its ethylenedithio (EDT-BDTS) and bis(ethylenedithio) (BEDT-BDTS) derivatives, novel extended donors with a central selenium atom, have been synthesized by convenient methods. Of these, EDT-BDTS and BEDT-BDTS having outer chalcogen atoms afforded highly conducting molecular complexes with TCNQ (σ = 13 Scm−1 on a compressed pellet).