1711-46-2Relevant articles and documents
Metal ion-catalyzed Diels-Alder and hydride transfer reactions. Catalysis of metal ions in the electron-transfer step
Fukuzumi, Shunichi,Ohkubo, Kei,Okamoto, Toshihiko
, p. 14147 - 14155 (2002)
Rates of Diels - Alder cycloaddition of anthracenes with p-benzoquinone and its derivatives as well as rates of hydride-transfer reactions from 10-methyl-9,10-dihydroacridine to the same series of p-benzoquinones are accelerated significantly in the presence of metal ions in acetonitrile. An extensive comparison of the catalytic effects of metal ions in electron transfer from one-electron reductants (cobalt tetraphenylporphyrin and decamethyrferrocene) to p-benzoquinones with those in the Diels - Alder reactions of the quinones as well as the hydride-transfer reactions has revealed that the catalysis of metal ions in each case is ascribed to the 1:1 and 1:2 complexes formed between the corresponding semiquinone radical anions and metal ions. The transient absorption and ESR spectra of the semiquinone radical anion-metal ion complexes are detected directly in the electron-transfer reduction of p-benzoquinone derivatives in the presence of metal ions. The catalytic reactivities of a variety of metal ions in each reaction are well correlated with the energy splitting values of πg levels because of the complex formation between O2.- andMn+, which are derived from the gzz values of the ESR spectra of the O2.--Mn+ complex.
Hybrid Molecular Container Based on Glycoluril and Triptycene: Synthesis, Binding Properties, and Triggered Release
Liu, Wenjin,Lu, Xiaoyong,Xue, Weijian,Samanta, Soumen K.,Zavalij, Peter Y.,Meng, Zihui,Isaacs, Lyle
, p. 14101 - 14110 (2018)
We designed and synthesized a “hybrid” molecular container 1, which is structurally related to both cucurbit[n]uril (CB[n]) and pillar[n]arene type receptors. Receptor 1 was fully characterized by 1H NMR, 13C NMR, IR, MS and X-ray single crystal diffraction. The self-association behavior, host–guest recognition properties of 1, and the [salt] dependence of Ka were investigated in detail by 1H NMR and isothermal titration calorimetry (ITC). Optical transmittance and TEM measurements provide strong evidence that receptor 1 undergoes co-assemble with amphiphilic guest C10 in water to form supramolecular bilayer vesicles (diameter 25.6±2.7 nm, wall thickness ≈3.5 nm) that can encapsulate the hydrophilic anticancer drug doxorubicin (DOX) and the hydrophobic dye Nile red (NR). The release of encapsulated DOX or NR from the vesicles can be triggered by hexamethonium (8 c) or spermine (10) which leads to the disruption of the supramolecular vesicles.
Melt-phase synthesis and properties of triptycene-containing copolyesters
Liu, Yanchun,Turner, S. Richard,Wilkes, Garth
, p. 4049 - 4056 (2011)
A new triptycene diol (TD), triptycene-1,4-hydroquinone-bis(2-hydroxyethyl) ether, was synthesized and was used to prepare a series of copolyesters with dimethyl 1,4-cyclohexanedicarboxylate (1,4-DMCD) by melt polycondensation. Straight chain aliphatic spacers, including ethylene glycol (EG), 1,4-butanediol (BD), and 1,6-hexanediol (HD), were used as codiols with TD to explore the effects of straight chain flexible spacers on copolyester properties. A concomitant series of non-triptycene copolyesters based on hydroquinone bis(2-hydroxyethyl) ether (HBE), bis[4-(2-hydroxyethoxy)phenyl] sulfone (BHPS), 1,1-bis[4-(2-hydroxyethoxy)phenyl]cyclohexane (BHPC), or 1,1-bis(2- hydroxyethoxy)phenyl-3,3,5-trimethylcyclohexane (BHPT) were prepared for comparison. The results demonstrated that the triptycene-containing polyesters in this study have higher thermal stability and higher glass transition temperatures (Tg's) than the corresponding non-triptycene analogues. For triptycene-containing copolyesters, the mechanical properties were found to be dependent on the types and compositions of comonomer diols. A 1,4-butanediol-based triptycene copolyester was observed to have a significant increase in Tg and modulus while maintaining high elongation at ambient temperature (23 °C). However, all the studied 1,4-butanediol-based copolyesters were brittle and had comparable modulus values at low temperatures (-25 or -40 °C).
Preparation and gas transport properties of triptycene-containing polybenzoxazole (PBO)-based polymers derived from thermal rearrangement (TR) and thermal cyclodehydration (TC) processes
Luo, Shuangjiang,Liu, Junyi,Lin, Haiqing,Kazanowska, Barbara A.,Hunckler, Michael D.,Roeder, Ryan K.,Guo, Ruilan
, p. 17050 - 17062 (2016/11/11)
Polybenzoxazoles (PBOs), such as thermally rearranged (TR) polymers, have been shown to have excellent gas separation performance. Herein we report the preparation and transport properties of two new series of PBO-based polymers that were thermally derived from triptycene-containing o-hydroxy polyimide and polyamide precursors via a thermal rearrangement (TR) process and a thermal cyclodehydration (TC) process, respectively. Incorporation of triptycene units into poly(hydroxyimide) precursor structures led to a significant increase of fractional free volume and created ultrafine microporosity in the converted PBO-based TR polymers, which enabled both high gas permeabilities and high selectivities. Although the TC process of the poly(hydroxyamide) precursor led to moderate improvement in the separation performance of the resulting triptycene-containing PBO polymers as compared to the TR process, the PBO films converted via the TC process exhibited excellent mechanical properties superior to many other TR polymers previously reported in the literature as well as the triptycene-containing TR polymers in this study. In particular, the PBO film thermally rearranged at 450 °C showed a H2 pure gas permeability of 810 barrer, a CO2 permeability of 270 barrer, and CO2/CH4 and H2/CH4 selectivities of 67 and 200, respectively, at 35 °C and 11 atm, which are far beyond the upper bound limits.
