Photoinduced processes in macrocyclic isoalloxazine–anthracene systems

Redox Properties and Interchromophoric Electronic Interactions in Isoalloxazine−Anthraquinone Dyads

“…At more negative potentials, the second reductions of both flavin and quinone units take place and give rise, in all cyclophanes, to a 2 electron reduction peak ‐ labelled with III in the CV curves of Figure and Figure . As already observed in the previous investigation of similar isoalloxazine‐naphthalene cyclophanes,, the voltammetric pattern displays, at the level of such reduction peak, irreversible features associated to slow heterogeneous electron transfer kinetics (see also Table S1 and Figure S2 for MA4 , in the SI), likely involving the quinone units, affecting in particular the CV behavior at high scan rates. Such kinetic compliance made the quantitative evaluation of the inter‐moiety interaction, based on the analysis of the second reduction processes, less straightforward and was not attempted.…”

“…Herein we have turned our attention towards closed cyclophane‐like structures in order to somehow control the distance and orientation of the two chromophores involved in a simple model of the QR active centers ,,. Reports on cyclophanes containing isoalloxazines, and dyads of isoalloxazines bridged with naphthalene, anthracene and pyrene are available and we have recently reported a series of cyclophanes containing isoalloxazine with naphthalene, anthraquinone and anthracene ,,.…”

“…Herein we have turned our attention towards closed cyclophane‐like structures in order to somehow control the distance and orientation of the two chromophores involved in a simple model of the QR active centers ,,. Reports on cyclophanes containing isoalloxazines, and dyads of isoalloxazines bridged with naphthalene, anthracene and pyrene are available and we have recently reported a series of cyclophanes containing isoalloxazine with naphthalene, anthraquinone and anthracene ,,. To tackle such important issues, we have then chosen to investigate supramolecular, systems made of flavins and aromatic moieties, comparing the behavior of model anthaquinones Q1 and Q2 and isoalloxazine AL (Scheme ), with that of macrocycles MA and MQ where (CH 2 ) n spacers connect the two interacting units.…”

Investigating the spectral and electrochemical properties of novel flavin‐pyrene dyads separated via variable spacer

“…In general, the tricyclic core chemical structure offers its N10,N3‐nitrogen atoms or the phenyl ring as the site for covalent attachment and a number of donor–acceptor models have been synthesized and reported. [ 13–25 ] Donor molecules such as porphyrin, phthalocyanine, phenothiazine, pyrene, oligothiophene, naphthalene, dialkylaniline, anthraquinone, anthracene, tryptophan and tyrosine, etc. have been covalently linked with flavin moiety and investigated for their photophysical behavior.…”

“…have been covalently linked with flavin moiety and investigated for their photophysical behavior. [ 13–25 ] These models have been reported for their efficient photo‐induced electron transfer capabilities and offer an interesting insight for potential application for the development of molecular optoelectronic devices. Furthermore, the electron transfer dynamic of any donor–acceptor system significantly depends on the distance separating the donor and the acceptor entities [ 26,27 ] and demand careful scrutiny of the synthetic models.…”