96327-77-4Relevant academic research and scientific papers
Synthesis and Mesomorphic Properties of Novel Bent-shaped Naphthyl Diketones
Buljan, An?ela,Kne?evi?, Anamarija,Dokli, Irena,Lesac, Andreja
, p. 173 - 179 (2019/12/12)
The synthesis and liquid-crystalline properties are reported for novel naphthyl-based diketones incorporating variant terminal chains and lateral fluoro- substitution. Newly prepared materials exhibit a broad temperature range of the nematic phase. The study demonstrates how subtle structural modifications can be exploited to alter the efficiency of molecular packing and consequently the thermal behaviour.
Preparation and properties of oxadiazole-containing polyacetylenes as electron transport materials
Wang, Xin,Guan, Shanyi,Xu, Hongyao,Su, Xinyan,Zhu, Xuhui,Li, Chun
scheme or table, p. 1406 - 1414 (2011/03/19)
A series of functional polyacetylenes (PAs) bearing diphenyl oxadlazole pendant groups (P1-P4) were prepared, and the resultant polymers are completely soluble In common organic solvents, Their structures and properties were characterized and evaluated by
Regioselective and quantitative modification of cellulose to access cellulose-based advanced materials: Cellulose-based glyeoclusters
Yamashita, Erika,Okubo, Kiyomi,Negishi, Kaori,Hasegawa, Teruaki
supporting information; experimental part, p. 122 - 123 (2010/02/16)
Regioselective and quantitative introduction of multiple β-lactoside modules onto the 6C-position of cellulose was achieved through regioselective bromination/azidation of cellulose and the following Cu+-catalyzed chemoselective coupling with a
Kinetics of (porphyrin)manganese(III)-catalyzed olefin epoxidation with a soluble iodosylbenzene derivative
Collman, James P.,Zeng, Li,Wang, Hong J. H.,Lei, Aiwen,Brauman, John I.
, p. 2707 - 2714 (2007/10/03)
We examined the kinetics of a well-behaved system for homogeneous porphyrin-catalyzed olefin epoxidation with a soluble iodosylbenzene derivative 1 as the terminal oxidant and Mn(TPFPP)Cl (2) as the catalyst. The epoxidation rates were measured by using the initial rate method, and the epoxidation products were determined by gas chromatography. The epoxidation rate was found to be first order with respect to the porphyrin catalyst and zero order on the terminal oxidant. In addition, we found the rate law to be sensitive to the nature and concentration of olefin substrates. Saturation kinetics were observed with all olefin substrates at high olefin concentrations, and the kinetic data are consistent with a Michaelis-Menten kinetic model. According to the observed saturation kinetic results, we propose that there is a complexation between the active oxidant and the substrate, and the rate-determining step is thought to be the breakdown of this putative substrate-oxidant complex that generates the epoxidation products and the resting state porphyrin catalyst. Competitive epoxidations further indicate a reversible complexation of the active oxidant and the olefin substrate. The activation parameters ΔH? and ΔS? for the oxygen-transfer process (k2) in the cis-cyclooctene epoxidation were determined to be 12.3±0.9 k cal mol-1 and -15.6±3.2 cal mol-1 K-1, respectively. In addition, the Hammett constant ρ+ was measured for the epoxidation of para-substituted styrenes, and the value of -0.27±0.04 is too low to be consistent with the involvement of a discrete carbocation in the transition state. We also prepared a (porphyrin)-manganese catalyst immobilized on silica support, and found the epoxidation of cis-cyclooctene catalyzed by this heterogeneous catalyst proceeds at virtually the same turnover frequency as by the homogeneous porphyrin catalyst. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
