3905-64-4Relevant articles and documents
Enthalpy of Steric Inhibition to Solvation due to tert-Butyl Groups on an Anion Radical
Stevenson, Gerald R.,Kokosinski, Jeanette D.,Chang, Yoh-Tz
, p. 6558 - 6562 (1981)
Electro-spin resonance technique have been utilized to measure the enthalpy of electron transfer from the anion radical of naphthalene (N -. , K + ) to 2-tert-butylnaphthalene (TBN) and from the anion radical of TBN (TBN -. , K + ) to 2,6-di-tert-butylnaphthalene (DTBN) in dimethoxyethane (DME).These endothermic enthalpies of electron transfer were combined with the heat of solvation of the gas-phase anion radical of naphthalene plus the gas-phase potassium cation in DME, the heats of solvation of the neutral hydrocarbons in DME, and the heats of vaporization of the hydrocarbons in a thermochemical cycle to yield the enthalpy of solvation of (DTBN -. ) g + (K + ) g in DME.This enthalpy of solvation is about 17 kcal/mol less exothermic than that for (N -. ) g + (K + ) g and is attributed to the steric inhibition to solvation by the tert-butyl groups on DTBN -. .The enthalpy of solvation of (N -. ) g + (K + ) g (-162 kcal/mol) was determined by combining the enthalpy of the reaction of the DME solvated anion radical with water with a series of well-known constants in a thermochemical cycle.Thus, by utilizing a combination of calorimetric and ESR techniques a complete picture of the thermodynamic parameters controlling the stabilities of the solvated and gas-phase anion radicals of N and DTBN has been generated.
Synthesis and Properties of Perylene-Bridge-Anchor Chromophoric Compounds
Avenoso, Joseph,Doble, Samantha,Fan, Hao,Galoppini, Elena,Gundlach, Lars,Harmer, Ryan,Lloyd, Katherine,Rego, Luis G. C.,Yan, Han
, p. 6330 - 6343 (2020/09/18)
The quest to control chromophore/semiconductor properties to enable new technologies in energy and information science requires detailed understanding of charge carrier dynamics at the atomistic level, which can often be attained through the use of model systems. Perylene-bridge-anchor compounds are successful models for studying fundamental charge transfer processes on TiO2, which remains among the most commonly investigated and technologically important interfaces, mostly because of perylene's advantageous electronic and optical properties. Nonetheless, the ability to fully exploit synthetically the substitution pattern of perylene with linker (= bridge-anchor) units remains little explored. Here we developed 2,5-di-tert-butylperylene (DtBuPe)-bridge-anchor compounds with t-Bu group substituents to prevent π-stacking and one or two linker units in both the peri and ortho positions, by employing a combination of Friedel-Crafts alkylations, bromination, iridium-catalyzed borylation, and palladium-catalyzed cross-coupling reactions. Photophysical characterization and computational analysis by density functional theory (DFT) and time-dependent DFT (TD-DFT) were carried out on four DtBuPe acrylic acid derivatives with a single or a double linker in peri (12b), ortho (15b), peri,peri (18b), and ortho,ortho (21b). The energies of the unoccupied orbitals {LUMO, LUMO + 1, LUMO + 2} are strongly affected by the presence of a π-conjugated linker, resulting in a stabilization of these states and a red shift of their absorption and emission spectra, as well as the loss of vibronic structure in the spectrum of the peri,peri compound, consistent with the strong bonding character of this substitution pattern.
Microwave-assisted regioselective alkylation of naphthalene compounds using alcohols and zeolite catalysts
Yamashita, Hiroshi,Mitsukura, Yumi,Kobashi, Hiroko,Hiroki, Kazuaki,Sugiyama, Jun-ichi,Onishi, Kiyotaka,Sakamoto, Tetsuo
experimental part, p. 145 - 149 (2010/08/20)
Regioselective alkylation of naphthalene compounds with alcohols smoothly proceeded in the presence of zeolite catalysts under microwave irradiation. A H-mordenite (H-M) zeolite catalyst (SiO2/Al2O3 ratio = 240) showed the highest efficiency. In the microwave reactions, high reaction rates and high selectivities for 2,6-dialkylnaphthalenes were achieved. In the best case for the reaction of 2-isopropylnaphthalene with isopropyl alcohol, the conversion and the selectivity were 43.5% and 66.4%, respectively. In di-tert-butylation of naphthalene with tert-butyl alcohol, the conversion and the selectivity reached 86.5% and 70.4%, respectively. The conversions and the selectivities were generally higher than those obtained by conventional oil bath heating.
