1094159-78-0Relevant academic research and scientific papers
Synthesis and spectroscopic study of phenylenee (poly) ethynylenes substituted by amino or amino/cyano groups at terminal(s):Electronic effect of cyano group on charge-transfer excitation of acetylenic φ-systems
Fang, Jing-Kun,An, De-Lie,Wakamatsu, Kan,Ishikawa, Takeharu,Iwanaga, Tetsuo,Toyota, Shinji,Akita, Shin-Ichi,Matsuo, Daisuke,Orita, Akihiro,Otera, Junzo
supporting information; experimental part, p. 5479 - 5485 (2010/08/19)
To gain insight into substituent electronic effect on charge-transfer excitation of acetylenic p-systems, phenylenee(poly)ethynylenes substituted by Ph2N or Ph2N/cyano groups were synthesized by combination of Sonogashira coupling and double elimination protocol of b-substituted sulfones.These substituted phenyleneethynylenes showed large molar absorption coefficients 3, and emitted strong fluorescence upon UV light irradiation.Phenylenee(poly)ethynylenes, which involve butadiyne or hexatriyne motifs, emitted fluorescence in remarkably lower fluorescence quantum yields FF as their polyethynylene motifs e(C^C)ne expanded.The drastic decrease of fluorescence quantum yields FF were explained in terms of increasing nonradiative reaction rate constants knr, which had been determined by the corresponding fluorescence quantum yields F F and lifetime values s.The emission underwent a large bathochromic shift in polar solvents because the charge-separated excited state is more stabilized than the ground state.Comparison of slope values r in Lippert/Mataga plot for the Ph2N and Ph2N/cyano-substituted phenylenee(poly)ethynylenes revealed that the latter underwent large change of dipole moments upon photo-excitation although highly expanded acetylenic p-systems with cyano group did little.
Upon the intrinsic optical properties of oligo(p-phenyleneethynylene)s (OPEs). Synthesis of OPE3 for experimental gas-phase absorption studies
Ryhding, Torben,Suhr Kirketerp, Maj-Britt,Kadhane, Umesh,Lykkegaard, Morten K?cks,Panja, Subhasis,Nielsen, Steen Br?ndsted,Nielsen, Mogens Br?ndsted
experimental part, p. 11475 - 11479 (2009/04/11)
A new oligo(p-phenyleneethynylene) (OPE3) was synthesized by step-wise Pd-catalyzed cross-coupling reactions. The molecule incorporates an amine functionality, which allows for transfer of the protonated molecule to the gas phase by electrospray ionization leaving the OPE entity neutral. This method has allowed for the first experimental gas-phase absorption spectrum of an OPE3 by action spectroscopy, employing an electrostatic ion storage ring in combination with a laser system. The studies reveal the effect of having a positive charge in proximity to the conjugated backbone of OPE3 in the absence of any interfering solvent molecules. In addition, ionization energies and electron affinities of OPE2-OPE17 were calculated at the density functional theory (DFT) level.
