133296-86-3Relevant academic research and scientific papers
Temperature dependence of aryl butatriene fluorescence: Barrier to twisting on S1 for 1,1,4,4-tetraphenylbutatriene
Connors, Robert E.,Chynwat, Veeradej,Clifton, Christine H.,Coffin, Tracy L.
, p. 107 - 113 (1998)
The temperature dependence of aryl butatriene fluorescence is assigned to a competition between radiative decay and butatriene chain rotation against a barrier followed by radiationless decay from S1. Fluorescence quantum yields were measured as a function of temperature for 1,1,4,4-tetraphenylbutatriene (TPBT) in a series of n-alkane solvents. Application of the medium-enhanced barrier model and transition state theory allow the observed barrier to be expressed in terms of an intrinsic and solvent-induced contribution (ΔH(obsd)/(+) = ΔH(t)/(+) + ΔH(v)/(+)). It is found that there is little or no intrinsic barrier to rotation (ΔH(t)/(+) = 0.075 ± 0.155 kcal/mol) on S1 for TPBT. The solvent-induced component is related to E(η), the activation energy for viscous flow, by ΔH(v)/(+) = aE(η) with a = 0.86 ± 0.06 for TPBT. This is in contrast to twisting on S1 for trans-stilbene for which a significant intrinsic barrier has been reported. AM1 molecular orbital calculations for gas phase TPBT show a twist angle of ~O°on S0 with a barrier to rotation of 20.1 kcal/mol. Consistent with the experimental results, the calculations show that TPBT undergoes a barrierless relaxation on S1 from its Franck-Condon structure to a minimum with a twist angle of 85.6°.
Novel Cyclo-oligomerization of Nickel Carbenoids: a Sample and Efficient Synthesis of Radialenes
Iyoda, Masahiko,Mizusuna, Akira,Kurata, Hiroyuki,Oda, Masaji
, p. 1690 - 1692 (1989)
Novel cyclo-oligomerization of nickel methylenecarbenoids generated from 1,1-dihalogenoethenes with chemically activated nickel gives -, -, and -radialenes directly under mild conditions.
SYNTHESIS OF SUBSTITUTED BUTATRIENES AND NOVEL STRUCTURES OF THEIR 02-OXIDATION PRODUCTS
Iyoda, Masahiko,Nishioka, Kazuhiko,Nose, Masanori,Tanaka, Shigeyoshi,Oda, Masaji
, p. 131 - 134 (2007/10/02)
Synthesis of three 2,3-diiodo-1,3-dienes and conversion of these dienes into butatrienes are described. 2,5-Dimethylhexa-2,3,4-triene polymerizes on exposure to air to give the polymeric peroxide (C6H12O2)n which is reassigned as the structure containing
A NEW AND CONVENIENT SYNTHESIS OF ARYL-SUBSTITUTED BUTATRIENES USING NICKEL-CATALYZED COUPLING OF ARYL-SUBSTITUTED 1,1-DIBROMOETHENES
Iyoda, Masahiko,Sakaitani, Masahiro,Miyazaki, Tatsuya,Oda, Masaji
, p. 2005 - 2006 (2007/10/02)
The reactions of aryl-substituted 1,1-dibromoethenes with in situ generated tetrakis(triphenylphosphine)nickel(0) in the presence of tetraethylammonium iodide give aryl-substituted butatrienes.
