1,2,3-Triazoles as Conjugative π-Linkers in Push−Pull Chromophores: Importance of Substituent Positioning on Intramolecular Charge-Transfer

Isomeric charge-transfer chromophores using 1,2,3-triazol-diyl as linker have been studied experimentally and computationally. The instability of the polarized reactants precluded the use of the Huisgen reaction and alternative synthetic methodologies were employed. Charge-transfer absorptions between an N,N-dimethylanilino and a dicyanovinyl group are modest to strong, with maxima from λmax = 400 to 453 nm depending on substituent positioning. TD-B3LYP/6-31G(d) calculations are within 0.6 eV of experiment and assign these bands as HOMO−LUMO transitions.