Simple charge transfer complexes of some new and of some known heterocyclic compounds of selenium and tellurium

Article abstract of DOI:10.1016/S0022-328X(00)99047-8

Charge transfer (CT) complexes (1:1) of 2,5-dihydrotellurophene and the 3-methyl and 3,4-dimethyl compounds with TCNQ and tetrachlorobenzoquinone (TCB) are reported.The organotellurium compounds failed to give complexes with p-dinitrobenzene (DNB).The variation of solid state (disc) conductivity with temperature and as a function of methyl substituents is considered.The complexes show semi-conducting behaviour and a consideration of these data, together with IR and UV spectroscopic data, in comparison with those for 1,3-dihydro-2-telluraindene given the following order of donor power with respect to TCNQ: With respect to a given donor, the order of acceptor power os TCNQ > TCB > DNB. 1,3-Dihydro-2-selenaindene forms a complex with TCNQ.The molecular ionisation potential of the selenaindene is 7.4 eV (by mass spectroscopy) and it has been shown that the compound may be electrochemically oxidized to materials such as C8H8SePF6.New quinoxalino-1-chalcogenacyclopentanes are reported; namely those derived from selenium, and the 7,8-dimethyl series, those based on both selenium and tellurium.Their preparation and characterisation are described, and their chemistry shown to be strongly analogous to that of quinoxalino-1-telluracyclopentane.CT complexes of the new Se^II and Te^II compounds (1:1) are prepared with TCNQ which are believed to be strongly ionic.