84645-79-4Relevant academic research and scientific papers
Fluorogenic probes for aldol reactions: Tuning of fluorescence using π-conjugation systems
Katsuyama, Isamu,Chouthaiwale, Pandurang V.,Akama, Hiroyuki,Cui, Hai-Lei,Tanaka, Fujie
supporting information, p. 74 - 78 (2014/01/06)
Fluorogenic aldehydes or probes for monitoring of the progress of aldol reactions have been developed. Fluorescence of benzaldehydes conjugated with aryl groups via a double or triple bond and of their aldol products was evaluated in aqueous solutions. Ba
Synthesis and photoluminescent properties of conjugated aryl-vinyl dioctyl 2,6-dimethylbenzofuro[5,6-b]furan-3,7-dicarboxylate derivatives
Bosiak, Mariusz J.,Rakowiecki, Marcin,Or?owska, Katarzyna J.,K?dziera, Dariusz,Adams, J?rg
, p. 803 - 811 (2013/09/12)
The synthesis of highly fluorescent conjugated benzodifuran aryl-vinyl systems, containing four double bonds and at least four phenyl rings, is described. The ethyl groups of diethyl 2,6-dimethylbenzofuro[5,6-b]furan-3,7- dicarboxylate, obtained by the Michael type condensation of p-benzoquinone and ethyl acetoacetate, were replaced by octyl groups via the transesterification reaction to improve the desired product solubility in common organic solvents. The dioctyl ester was brominated and used for the Wittig reaction with stilbene aldehydes, obtained by the Heck reaction of 4-bromobenzaldehyde and an appropriate styrene. The products, obtained in 48-92% yield, exhibit the UV-Vis fluorescence with high quantum yields, 58-69%.
Imidazole as a central π-linkage in Y-shaped push-pull chromophores
Kulhánek, Ji?í,Bure?, Filip,Mikysek, Tomá?,Ludvík, Ji?í,Pytela, Old?ich
, p. 48 - 55 (2011/12/04)
Twelve imidazole based Y-shaped push-pull chromophores have been designed, synthesised and fully characterised featuring 4,5-bis(N,N-dimethylanilino) imidazole as a donor moiety, a systematically enlarged π-linker and nitro and cyano groups as acceptors.
Conformational gating of long distance electron transfer through wire-like bridges in donor-bridge-acceptor molecules
Davis,Ratner,Wasielewski
, p. 7877 - 7886 (2007/10/03)
A series of five donor-bridge-acceptor (DBA) molecules in which the donor is tetracene, the acceptor is pyromellitimide, and the bridge molecules are oligo-p-phenylenevinylenes (OPV) of increasing length has been shown to undergo electron transfer (ET) by means of two mechanisms. When the bridge is short, strongly distance dependent superexchange dynamics dominates, whereas when the bridge is longer, bridge-assisted hopping dynamics prevails. The latter mechanism results in relatively soft distance dependence for ET in which the OPV oligomers act effectively as molecular wires. We now report studies on the critical influence that bridge dynamics have on electron transfer through these oligomers. The temperature dependence of the charge separation (CS) rates in all five molecules does not appear to obey the predictions of standard ET theories based upon the Condon approximation. All five molecules show behavior consistent with CS being "gated" by torsional motion between the tetracene donor and the first bridge phenyl ring. This is based on the near equivalence of the CS activation energies measured for all five molecules with the frequency of a known vibrational mode in 5-phenyltetracene. In the molecule containing a trans-stilbene bridge, a competition occurs between the tetracene-phenyl torsional motion and one that occurs between the vinyl group and the phenyls linked to it. This results in complex temperature-dependent CS that exhibits both activated and negatively activated regimes. The charge recombination (CR) reactions within the molecules which have the two shortest bridges, namely phenyl and trans-stilbene, show a weaker dependence on these molecular motions. The three molecules with the longest bridges all display complex temperature dependencies in both their rates of CS and CR, most likely because of the complex torsional motions, which arise from the multiple phenyl-vinyl linkages. The data show that long-distance electron transfer and therefore wire-like behavior within conjugated bridge molecules depend critically on these low-frequency torsional motions. Molecular device designs that utilize such bridges will need to address these issues.
