Synthesis and Characterization of Thieno[3,4‑<i>b</i>]pyrazine-Based Terthienyls: Tunable Precursors for Low Band Gap Conjugated Materials

Synthetic methods have been developed for the preparation of new 2,3-dihalo- and 2,3-ditriflato-5,7-bis­(2-thienyl)­thieno­[3,4-<i>b</i>]­pyrazines. From these reactive intermediates, a variety of new 2,3-difunctionalized 5,7-bis­(2-thienyl)­thieno­[3,4-<i>b</i>]­pyrazines have been produced as precursors to conjugated materials. Structural, electronic, and optical characterization of these new analogues illustrate the extent to which the electronic nature of the functional groups can be used to tune the electronic properties of these thieno­[3,4-<i>b</i>]­pyrazine-based terthienyl units

Synthesis, Characterization, and Electropolymerization of Extended Fused-Ring Thieno[3,4-b]pyrazine-Based Terthienyls

The synthesis, characterization, and electropolymerization of a series of extended fused-ring thieno[3,4-b]pyrazine-based terthienyls are reported. The target terthienyls contain a central extended thieno[3,4-b]pyrazine analogue containing 2-thienyl units at the reactive α-positions of the central thiophene. The extended fused-ring thieno[3,4-b]pyrazine analogues studied include acenaphtho[1,2-b]thieno[3,4-e]pyrazine, dibenzo[f,h]thieno[3,4-b]quinoxaline, and thieno[3′,4′:5,6]-pyrazino[2,3-f][1,10]phenanthroline. Comparison of the electrochemical and photophysical properties to simple thieno[3,4-b]pyrazine-based terthienyls and their polymeric analogues are reported in order to provide structure-function relationships within this series of compounds and materials