Push–pull chromophores comprising benzothiazolium acceptor and thiophene auxiliary donor moieties: Synthesis, structure, linear and quadratic non-linear optical properties

Abstract

a b s t r a c tNovel, push-pull chromophores combining a cationic benzothiazolium acceptor moiety and either one or two thiophene rings as a part of the conjugated p-system between the donor and the acceptor moieties have been synthesized and characterized. The chromophores displayed pronounced quadratic NLO activity with their first molecular hyper polarizabilities in agreement with their linear spectral properties.

Symmetrical and Nonsymmetrical Chromophores with Tröger’s Base Skeleton: Chiroptical, Linear, and Quadratic Nonlinear Optical Properties—A Joint Theoretical and Experimental Study

“…[33] We have also recently shown the efficiency of a particular combination consisting of a benzothiazolium acceptor and thiophene auxiliary donor. [34]…”

Fundamental aspects of property tuning in push–pull molecules

“…Hence, the benzothiazolium ion can be considered as a stronger electron acceptor than the pyridinium ion. Further property tuning in 68-69 has been achieved by extension of the central olenic spacer, which could also be substituted by thienylene units, as demonstrated by Clays et al 90 a Absorption/emission maxima (toluene). b vs. POPOP (F ¼ 0.93 in cyclohexane).…”

Heteroaromatic Cation‐Based Chromophores: Synthesis and Nonlinear Optical Properties of Alkynylazinium Salts

“…[2] In this context, organic chromophores containing different acceptor units, such as nitro, [3] nitrile, [4] sulfonyl, [5] polycyanovinyl [6] and phosphonate [7] salts, inter alia, have been explored previously. The use of charged moieties as acceptor units is restricted to diazonium salts [8] and some heteroaromatic cations; for example, benzothiazolium [9] and pyridinium salts [10] have been studied as cationic and dicationic acceptors in a few push-pull systems such as those shown in Figure 1.…”