3916-44-7Relevant academic research and scientific papers
Strongly Chemiluminescent Acridinium Esters under Neutral Conditions: Synthesis, Properties, Determination, and Theoretical Study
Nakazono, Manabu,Oshikawa, Yuji,Nakamura, Mizuho,Kubota, Hidehiro,Nanbu, Shinkoh
, p. 2450 - 2461 (2017/03/11)
Various novel acridinium ester derivatives having phenyl and biphenyl moieties were synthesized, and their optimal chemiluminescence conditions were investigated. Several strongly chemiluminescent acridinium esters under neutral conditions were found, and then these derivatives were used to detect hydrogen peroxide and glucose. Acridinium esters having strong electron-withdrawing groups such as cyano, methoxycarbonyl, and nitro at the 4-position of the phenyl moiety in phenyl 10-methyl-10λ4-acridine-9-carboxylate trifluoromethanesulfonate salt showed strong chemiluminescence intensities. The chemiluminescence intensity of 3,4-dicyanophenyl 10-methyl-10λ4-acridine-9-carboxylate trifluoromethanesulfonate salt was approximately 100 times stronger than that of phenyl 10-methyl-10λ4-acridine-9-carboxylate trifluoromethanesulfonate salt at pH 7. The linear calibration ranges of hydrogen peroxide and glucose were 0.05-10 mM and 10-2000 μM using 3,4-(dimethoxycarbonyl)phenyl 10-methyl-10λ4-acridine-9-carboxylate trifluoromethanesulfonate salt at pH 7 and pH 7.5, respectively. The proposed chemiluminescence reaction mechanism of acridinium ester via a dioxetanone structure was evaluated via quantum chemical calculation on density functional theory. The proposed mechanism was composed of the nucleophilic addition reaction of hydroperoxide anion, dioxetanone ring formation, and nonadiabatic transition due to spin-orbit coupling around the transition state (TS) to the triplet state (T1) following the decomposition pathway. The TS which appeared in the thermal decomposition would be a rate-determining step for all three processes.
NOVEL HYDROXYPHENYL BORONIC ESTER, MANUFACTURING METHOD THEREFOR, AND MANUFACTURING METHOD OF HYDROXYPHENYL COMPOUND
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Paragraph 0068; 0069, (2017/04/19)
PROBLEM TO BE SOLVED: To provide a hydroxyphenyl boronic ester, a manufacturing method therefor and a biphenyl compound using the hydroxyphenyl boronic ester. SOLUTION: There are provided a manufacturing method for producing a compound of the formula (1) by reacting tertiary halogenobenzene of the formula (4) and boronic ester of the formula (3) to synthesize tertiary alkoxyphenyl boron ester of the formula (2) and reacting it with acid, and further a manufacturing method of a hydroxy biphenyl compound of the formula (7) by a Suzuki coupling reaction with an aryl halogen compound or the like. SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT
N-Doped porous carbon supported palladium nanoparticles as a highly efficient and recyclable catalyst for the Suzuki coupling reaction
Zhang, Li,Dong, Wen-Huan,Shang, Ning-Zhao,Feng, Cheng,Gao, Shu-Tao,Wang, Chun
, p. 149 - 154 (2016/01/25)
A new catalyst, Pd particles supported on the N-doped porous carbon (PC) derived from Zn-based metal-organic frameworks (zeolitic imidazolate framework: ZIF-8), was successfully prepared for the first time. The as-prepared catalyst was designated as N-doped PC-Pd, and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscope, N2 adsorption and inductively coupled plasma atomic emission spectroscopy. The N-doped PC-Pd composite exhibited high catalytic activity toward the Suzuki-Miyaura cross-coupling reactions. The yields of the products were in the range of 90%-99%. The catalyst could be readily recycled and reused at least 6 consecutive cycles without a significant loss of its catalytic activity.
Effect of the functional diamine structure on the properties of a polyimide liquid crystal alignment film
Liu, Ming,Zheng, Xinguo,Gong, Shiming,Liu, Lulu,Sun, Zhen,Shao, Leishan,Wang, Yinghan
, p. 25348 - 25356 (2015/03/30)
A novel functional diamine containing triphenylamine moiety and biphenyl as well as a long alkyl chain, 4-dodecyloxy-biphenyl-4′,4′′-diaminotriphenylamine (DBDTA), was synthesized and characterized. A series of polyimides (PIs) were copolymerized from DBDTA, 3,3′-dimethyl-4,4′-methylenedianiline (DMMDA) and 4,4′-oxydiphthalic anhydride (ODPA) via a one-step method. The chemical structures of the diamine and PIs were characterized by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance spectroscopy (1H NMR). Properties such as the solubility, rubbing resistance, thermal stability and pre-tilt angle of the PIs were investigated. Furthermore, the results were compared with the PIs-BZA derived from 4-dodecyloxy-biphenyl-3′,5′-diaminobenzoate (DBPDA). The PIs-TPA derived from DBDTA exhibited better transparency and thermal stability than the PIs-BZA from DBPDA. When the content of functional diamines was only 10%, the PI1-TPA derived from DBDTA displayed better solubility than the PI1-BZA from DBPDA. In addition, all PIs could induce uniform vertical alignment of the liquid crystals (LCs) before and after the rubbing process, but PI1-BZA only induced parallel alignment of the LCs after rubbing process. It is suggested that the PI1-TPA film is more resistant to the rubbing process than PI1-BZA. This journal is
Relationship between molecular association and re-entrant phenomena in polar calamitic liquid crystals
Mandle, Richard J.,Cowling, Stephen J.,Goodby, John W.,Sage, Ian,Colclough, M. Eamon
, p. 3273 - 3280 (2015/09/02)
The relationship between molecular association and re-entrant phase behavior in polar calamitic liquid crystals has been explored in two families of materials: the 4'-alkoxy-4-cyanobiphenyls (6OCB and 8OCB) and the 4'-alkoxy-4-nitrobiphenyls. Although re-entrant nematic phase behavior has previously been observed in the phase diagram of 6OCB/8OCB, this is not observed in mixtures of the analogous nitro materials. As there is no stabilization of the smectic A phase in mixture studies, it was conjectured that the degree of association for the nitro systems is greater than that for the cyano analogues. This hypothesis was tested by using measured dielectric anisotropies and computed molecular properties to obtain a value of the Kirkwood factor, g, which describes the degree of association of dipoles in a liquid. These computed values of g confirm that the degree of association for nitro materials is greater than that for cyano and offer a useful method for quantifying molecular association in systems exhibiting a re-entrant polymorphism.
Synthesis and mesomorphic behavior of calamitic liquid crystals with a biphenyl moiety
Tandel,Patel, Nilesh K.
, p. 114 - 125 (2014/07/07)
A new mesogenic homologous series having a biphenyl moiety has been synthesized by condensing 4-hydroxy-4′-nitrobiphenyl- and methoxy-substituted 4-n-alkoxy cinnamoyl chlorides, and their liquid crystalline properties have been studied. All the members of the series are enantiotropic liquid crystals. The methyl to n-pentyl derivatives exhibit both Smectic A (SmA) and Nematic (N) phases; the higher members, starting with the n-hexyl derivative show only a SmA phase. The plot of transition temperatures versus number of carbon atoms in the alkoxy chain exhibits zig-zag pattern for Sm-N and NIsotropic (Iso) transition temperature curves. The average thermal stability is compared with other related homologous series. The introduction of polar nitro group increases significant intermolecular force of attraction which stabilizes the molecular orientation. This results into the increase in the thermal stability of the system.
Influence of N-Alkyl Substituents and Counterions on the Structural and Mesomorphic Properties of Guanidinium Salts: Experiment and Quantum Chemical Calculations
Butschies, Martin,Sauer, Sven,Kessler, Elena,Siehl, Hans-Ullrich,Claasen, Birgit,Fischer, Peter,Frey, Wolfgang,Laschat, Sabine
scheme or table, p. 3752 - 3765 (2011/09/12)
A series of N-4-(4'-alkoxybiphenyl)-N',N',N",N"-tetramethylguanidinium salts was synthesized with varying alkoxy chain lengths and additional N-alkyl substituents, each with a number of different counterions. X-ray crystal-structure analyses of 1b I, 1b PF6, 2a I, and 4a I reveal bilayer structures in the solid state and, for the 1b and 1b PF6 salts, a hydrogen-bond-type connectivity between the guanidinium N-H group and the anion is found. For the N-alkyl homologues 2a I and 4a I the anion is still oriented close to the head group, although at a larger distance. Ion pairs are present also in solution, as demonstrated by 1H NMR: the N-H chemical shift shows a good linear correlation with the radius, and hence the hardness, of the anion. The intramolecular conformational flexibility of 1b I, 2b I, 3b I, and 4b I was studied by temperature-dependent 1H NMR spectroscopy and discrete activation barriers were determined for rotations about each of the three C-N partial double bonds of the guanidinium core. The relative heights of the individual barriers change between the N-H and the N-alkylguanidinium salts. A fourth barrier is observed for the rotation about the N-biphenyl bond. DFT calculations of charge densities show that the positive charge resides primarily on the central carbon atom. Rotational barriers were calculated for N'-substituted 2-amino-1,3-dimethylimidazolidinium cations as models, and are in qualitatively good agreement with the NMR data. Mesomorphic properties were studied by differential-scanning calorimetry, polarizing optical microscopy, and X-ray diffraction (WAXS/SAXS). All liquid-crystalline guanidinium salts exhibit smectic A mesophases. Clearing temperatures show a linear correlation with the anionic radius. Substitution of the N-H group with methyl, ethyl, or propyl results in decreasing mesophase widths and a concomitant shrinkage of the layer spacings.The anion makes the difference: The synthesis of various guanidinium salts with varying alkoxy chain lengths and additional N-alkyl substituents is reported (see picture). Mesomorphic properties are studied by differential-scanning calorimetry, polarizing optical microscopy, and X-ray diffraction. All liquid-crystalline guanidinium salts exhibit smectic A mesophases.
Diels-Alder approach to biaryls (DAB): Importance of the ortho-nitro moiety in the [4 + 2] cycloaddition
Ashburn, Bradley O.,Carter, Rich G.
, p. 255 - 257 (2008/10/09)
A series of nitrophenyl acetylenes were evaluated for their utility in a cycloaddition-cycloreversion approach to polysubstituted biaryls. ortho-Nitrophenyl acetylene consistently provided the target biaryls in superior yields as compared to the meta and para nitro substituted variants. This journal is The Royal Society of Chemistry.
Heterogeneous Pd/C-catalyzed ligand-free Suzuki-Miyaura coupling reaction using aryl boronic esters
Kitamura, Yoshiaki,Sakurai, Ai,Udzu, Takahiro,Maegawa, Tomohiro,Monguchi, Yasunari,Sajiki, Hironao
, p. 10596 - 10602 (2008/02/12)
Heterogeneous Pd/C-catalyzed Suzuki-Miyaura cross-coupling reaction of aryl boronic esters with aryl bromides was successfully carried out in aqueous media at room temperature without the use of a ligand such as phosphine derivatives.
4′-substituted-4-biphenylyloxenium ions: Reactivity and selectivity in aqueous solution
Novak, Michael,Poturalski, Matthew J.,Johnson, Whitney L.,Jones, Matthew P.,Wang, Yueting,Glover, Stephen A.
, p. 3778 - 3785 (2007/10/03)
Azide trapping shows that the 4′-substituted-4-biphenylyloxenium ions 1b-d are generated during hydrolysis of 4-aryl-4-acetoxy-2,5-cyclohexadienones, 2c and 2d, and O-(4-aryl)phenyl-N-methanesulfonylhydroxylamines, 3b and 3c. In addition, the 4′-bromo-substituted ester, 2d, undergoes a kinetically second-order reaction with N3 that accounts for a fraction of the azide adduct, 5d. Since both first-order and second-order azide trapping occurs simultaneously in 2d, the second-order reaction is not enforced by the short lifetime of 1d, which has similar azide/solvent selectivity to the unsubstituted ion, 1a. In contrast the 4′-CN and 4′-NO2 ions 1e and 1f cannot be detected by azide trapping during the hydrolysis of the dichloroacetic acid esters 2e′ and 2f′ even though 18O labeling experiments show that a fraction of the hydrolysis of both esters occurs through Calkyl-O bond cleavage. These esters exhibit only second-order trapping by azide. Correlations of the azide/solvent selectivities of 1a-d with the calculated relative driving force for hydration of the ions (ΔE of eq 4) determined at the pBP/DN*//HF/6-31G* and BP/6-31G*//HF/6-31G* levels of theory suggest that 1e and 1f have lifetimes in the 1-100 ps range. Ions with these short lifetimes are not in diffusional equilibrium with nonsolvent nucleophiles, and must be trapped by such nucleophiles via a preassociation mechanism. The second-order trapping that is observed in these two cases is enforced by the short lifetime of the cations, and may occur by a concerted SN2′ mechanism or by internal azide trapping of an ion sandwich produced by azide-assisted ionization. Comparison of azide/solvent selectivities of the oxenium ions 1a-c with the corresponding biphenylylnitrenium ions 8a-c shows that 4′-substituent effects on reactivity in both sets of ions are similar in magnitude, although the nitrenium ions are ca. 30-fold more stable in an aqueous environment than the corresponding oxenium ions. The magnitude of the 4′-substituent effects for electron-donating substituents suggest that both sets of ions are more accurately described as 4-aryl-1-imino-2,5- cyclohexadienyl or 4-aryl-1-oxo-2,5-cyclohexadienyl carbocations. Calculated structures of the oxenium ions are also consistent I with this interpretation.
