22915-73-7Relevant articles and documents
Dipole-Dipole Interactions between the Terminal Groups of l,n-Diarenecarboxy Alkanes, n=1, 2, ..., 6
Macanita, Antonio L.,Magalhaes, Jorge,Dias, Antonio,Teles, Henrique,Iglesias, Emilia
, p. 4011 - 4016 (1990)
The mutual interaction between the end groups of bichromophoric molecules is studied using absorption and fluorescence techniques (steady-state and time-resolved).With three series of di-1,n-arenecarboxyalkanes (arene = benzene, naphthalene and anthracene; n = 1,2,3,5 and 6) and a series of 1-pyrenecarboxy, n-(N-methyl, N-phenylamino) alkanes (n = 2,3,4,5,6 and 9), it is found that model compounds such as the methyl, ethyl and hexyl esters of benzene, naphthalene, anthracene and pyrene differ from the bichromophoric compounds in their absorption and emission spectra, molar absorption coefficients and radiative rate constants.These differences decrease with the mean value of the sixth power of the end-to-end distance, being attributed to dipole-dipole interactions between the end groups.The terminal group induces mixing of the lowest excited singlet state with higher energy states and increases the local polarizability of the medium.Two methods for evaluating the unquenched fluorescence lifetimes of bichromophoric compounds are discussed.
Metal-free transesterification catalyzed by tetramethylammonium methyl carbonate
Hatano, Manabu,Tabata, Yuji,Yoshida, Yurika,Toh, Kohei,Yamashita, Kenji,Ogura, Yoshihiro,Ishihara, Kazuaki
supporting information, p. 1193 - 1198 (2018/03/27)
Environmentally benign metal-free tetramethylammonium methyl carbonate is effective as a catalyst for the chemoselective, scalable, and reusable transesterification of various esters and alcohols in common organic solvents. In situ-generated highly active species, tetramethylammonium alkoxides, can greatly avoid self-decomposition at ≤110 °C, and are reusable. In particular, chelating substrates, such as amino alcohols, diols, triols, sugar derivatives, alkaloids, α-amino acid esters, etc., which deactivate conventional metal salt catalysts, can be used. A 100 gram scale biodiesel production was also demonstrated.
Odd-even effect of dopant molecules on clearing temperatures of nematic liquid-crystal phases
Kishikawa, Keiki,Haga, Yuri,Inoue, Takahiro,Watanabe, Tomohiro,Takahashi, Masahiro,Kohmoto, Shigeo
supporting information, p. 1465 - 1467 (2013/01/16)
Nematic liquid-crystal phases doped with the novel dopant compounds 1 (C6F5COO(CH)nOCOC6F5, n = 17) and 2 (C6H5-COO(CH)nOCOC6H 5, n = 17) showed an "opposite odd-even effect" on clearing temperatures. The tendency was exactly opposite to that reported for liquid-crystal dimers. A mechanism is postulated on the basis of the difference in the formation of molecular aggregations of even- and odd-number-dopant molecules in the host liquid-crystal molecules.
