Violene/cyanine hybrids as electrochromic systems: A new variation of the general structure

The recently disclosed general structure of violene/cyanine hybrids is exte nded to a new variant. The groups X and Y complete the structure for cyanin es, oxonols or merocyanines in the formula (Scheme 2, at the right side). T herefore, both the addition and removal of two electrons is possible. To te st if this general motif is applicable to ring-closed compounds, tetrapyrid inium thiophene 4(OX)(4+) was prepared, and studied using cyclic voltammetr y, spectroelectrochemistry and PM3 calculations covering all five redox sta tes of 4.