Meier, Herbert; Gerold, Juergen; Kolshorn, Heinz; Muehling, Bastian published the artcile< Extension of conjugation leading to bathochromic or hypsochromic effects in OPV series>, SDS of cas: 112-63-0, the main research area is donor acceptor OPV conjugation bathochromic hypsochromic effect.
Four OPV series 1-4 (a-d) defined as: A-p-C6H4-[CH:CH-C6H4-p-]n-N[CH2CH(hexyl)2]2 (with n = 1-4 as 1-4; A = H, CN, CHO, NO2 as a-d) with a terminal dialkylamino group as electron donor were prepared by Wittig-Horner reactions. To study the influence of the push-pull effect on the long-wavelength absorption, three of the four series contained terminal acceptor groups (CN, CHO, NO2). The length of the chromophores strongly affects the intramol. charge transfer (ICT)-an effect which superimposes upon the extension of the conjugation. Increasing numbers n of repeat units cause an overall bathochromic shift for the purely donor-substituted series 1a-4a and the series 1b-4b with CN as weak acceptor. The two effects annihilate each other in the series 1c-4c with terminal CHO groups, so that the absorption maxima are almost independent of the length of the chromophore. A hypsochromic shift is observed for the series 1d-4d, which contains the strong acceptor group NO2. This anomaly disappears on protonation of the dialkylamino group because the push-pull effect disappears in the ammonium salts. The results can be explained by semiempirical quantum mechanics (AM1, INDO/S). The HOMO-LUMO transition, which is mainly responsible for the ICT, becomes less important in the electron transitions S0→S1 when the distance between donor and acceptor is increased. The commonly used VB model, which contains an electroneutral and a zwitterionic resonance structure, is contrasted with a MO model with dipole segments at both ends of the OPV chains. The latter model turned out to be more appropriate-at least for donor-acceptor-substituted OPVs with n ≥ 2.
Chemistry – A European Journal published new progress about Bathochromic effect. 112-63-0 belongs to class esters-buliding-blocks, and the molecular formula is C19H34O2, SDS of cas: 112-63-0.
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics