23563-26-0Relevant articles and documents
Light-Promoted Nickel Catalysis: Etherification of Aryl Electrophiles with Alcohols Catalyzed by a NiII-Aryl Complex
Cao, Rui,Lai, Chu-Hui,Li, Gang,Liu, Fengyi,Lu, Huan-Huan,Wang, Chao,Xiao, Jianliang,Xue, Dong,Yang, Liu,Zhang, Wei
supporting information, p. 12714 - 12719 (2020/06/02)
A highly effective C?O coupling reaction of (hetero)aryl electrophiles with primary and secondary alcohols is reported. Catalyzed by a NiII-aryl complex under long-wave UV (390–395 nm) irradiation in the presence of a soluble amine base without any additional photosensitizer, the reaction enables the etherification of aryl bromides and aryl chlorides as well as sulfonates with a wide range of primary and secondary aliphatic alcohols, affording synthetically important ethers. Intramolecular C?O coupling is also possible. The reaction appears to proceed via a NiI–NiIII catalytic cycle.
Oxalic Diamides and tert-Butoxide: Two Types of Ligands Enabling Practical Access to Alkyl Aryl Ethers via Cu-Catalyzed Coupling Reaction
Chen, Zhixiang,Jiang, Yongwen,Zhang, Li,Guo, Yinlong,Ma, Dawei
supporting information, p. 3541 - 3549 (2019/02/26)
A robust and practical protocol for preparing alkyl aryl ethers has been developed, which relies on using two types of ligands to promote Cu-catalyzed alkoxylation of (hetero)aryl halides. The reaction scope is very general for a variety of coupling partners, particularly for challenging secondary alcohols and (hetero)aryl chlorides. In case of coupling with aryl chlorides and bromides, two oxalic diamides serve as the powerful ligands. The tert-butoxide is first demonstrated as a ligand for Cu-catalyzed coupling reaction, leading to alkoxylation of aryl iodides complete at room temperature. Additionally, a number of carbohydrate derivatives are applicable for this coupling reaction, affording the corresponding carbohydrate-aryl ethers in 29-98% yields.
Columnar self-assembly of bowl shaped fluorescent liquid crystals based on calix[4]arene with Schiff base units
Sharma, Anuj S.,Sharma, Vinay S.,Vekariya, Rajesh H.
supporting information, p. 15044 - 15051 (2018/09/29)
A new family of bowl-shaped molecules with a calix[4]arene rigid core and appended on four-sides, that display a wide range of hexagonal columnar phases, has been synthesised and well characterized. The thermal behaviours of the present compounds were established using a combination of polarising optical microscopy (POM), differential scanning calorimetry (DSC) and a high-temperature powder X-ray diffraction method (XRD). It is found that all of the synthesised materials show an enantiotropic hexagonal columnar liquid crystal phase. The structural and conformation characterization of these newly synthesised compounds was achieved by FT-IR, 1H NMR, and 13C NMR spectroscopy. All of the synthesised compounds exhibited good blue luminescence in solution under long wavelength UV light. To explore the structure property correlations, the alkoxy side chain group was varied from a lower alkyl spacer to a higher alkyl spacer on the lower rim of the calix[4]arene. The present research specified that the introduction of linking groups on the lower rim with an n-alkoxy side group is an influential approach to obtaining a supramolecular bowl shape liquid crystal which has good thermal and photophysical behaviour.
Synthesis and mesomorphic properties of 2,4-bis(4′-n-pentyloxybenzoyloxy)- benzylidine-4″- n-alkoxyaniline
Hamad, Wali M.,Azeez, Hashim J.,Al-Dujaili, Ammar H.
, p. 67 - 75 (2017/09/25)
The synthesis and mesomorphic properties of a new series of 2,4-bis(4′-npentyloxybenzoyloxy)- benzylidine-4″ -n-alkoxyaniline (DC5An) are reported. The molecular structure of compounds was confirmed by FTIR, 1H-NMR, 13C-NMR, mass spectroscopy and elemental analysis. The mesomorphic properties were studied by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM) measurements. All compounds of the series exhibit nematic (N) and smectic C (SmC) phases. The first four homologues (DC5A1-DC5A4) display a N mesophase, whereas the highest homologues (DC5A5-DC5A10) exhibit an enantiotropic dimorphism N and SmC phases. The mesomorphic properties of the present series are compared and discussed with other structurally related series.
Dependence of LC state on molecular flexibility
Jadeja,Sharma, Vinay S.,Jain,Patel
, p. 144 - 153 (2016/07/14)
A novel azoester homologous series of liquid crystals (LCs) viz. RO?C6H4COOC10H6-N?N(ortho)-C6H4?OC4H9(para) has been synthesized and studied with a view to understanding and establishing the effect of molecular structure on LC properties. Homologous Series consists of thirteen members (C1 to C18). C1 to C3 members are nonliquid Crystals and the rest of the homologues are LC in an enantiotropic manner. C7 to C18 are smectogenic in addition to nematogenic whereas C4, C5, and C6 are only nematogenic. The Sm-N and N?I transition curves behave in a normal manner with the usual exhibition of an odd–even effect. The Cr-M/I curve also behaves in a normal manner. Analytical and spectral data confirm the molecular structures of homologues. The average smectic and nematic thermal stabilities are 60.31°C and 79.6°C, respectively, with total mesophase length varying minimum to maximum is 21°C to 57°C at the C6 and C14 homologue, respectively. Thus, present novel azoester homologous series is partly smectogenic and predominantly nematogenic with low ordered melting type and useful to construct LC devices workable at low temperatures or room temperature.
Study of mesomorphism dependence on molecular flexibility of an azoester series containing a napthyl unit
Jadeja,Patel
, p. 10 - 18 (2016/11/21)
A novel azoester homologous series of liquid crystalline (LC) compounds: RO?C6H4-COO?C10H6-N:N-C6H4?OC4H9(n) without lateral substitution has been synthesized and studied with a view to understanding and establishing the effects of molecular structure on thermotropic LC substances with reference to tailed-end group. The novel homologous series consists of 13 homologs (C1 to C18) whose nematogenic and smectogenic mesomorphism commences enantiotropically from C6 and C12 members of the series, respectively. The C12–C18 homologs are smectogenic and C6–C18 are nematogenic, of which C12–C18 homologs are smectogenic plus nematogenic. The C1–C5 homologs are nonmesogenic. Transition temperatures and the textures of the homologs were determined and identified by an optical polarizing microscope (POM) equipped with a heating stage. Textures of a nematic phase are threaded or Schlieren and that of the smectic phase are of the type A or C. Transition curves Cr-M/I, Sm-N and N-I of a phase diagram behaved in normal manner except N-I transition temperature of C10 homolog which deviated by 9°C–10°C from normal behavior. N-I transition curve exhibited odd-even effect. Analytical, spectral, and thermal data confirms the molecular structures of homologs. Thermal stability for smectic and nematic are 115.5°C and 138.5°C, respectively whose corresponding mesophaselengths are varied from 10.0°C to 16.0°C and 13.0°C to 24.0°C, respectively. Group efficiency order for smectic and nematic are derived from comparative study of structurally similar analogous series; as smectic: ?OC4H9 (n) > ?CH3 > ?H; Nematic: ?H > ?OC4H9 (n) > ?CH3
The effect of molecular rigidity and flexibility on the mesomorphism of azoesters
Jadeja,Patel
, p. 28 - 36 (2016/11/21)
ASBTRACT: An Azoester novel homologous series RO-C6H4-COO-C6H4-N?N-C6H4-OC4H9(n) (para) of liquid crystalline (LC) materials are synthesized and studied with a view to understanding and establishing the effects of molecular structure on liquid crystal behavior with reference to lateral, terminal, or central group or groups on the basis of molecular rigidity and/or flexibility. The novel homologous series consists of thirteen (C1 to C18) homologues. C1 to C5 homologues are nonmesogenic and the rest of the homologues are enantiotropically mesogenic. C8 to C18 homologues are smectogenic plus nematogenic and the remaining two C6 and C7 homologues are only nematogenic without exhibition of smectic property. Analytical, thermal and spectral data confirms the molecular structures. Textures and transition temperatures of homologues were determined by an optical polarizing microscope (POM) equipped with a heating stage. Textures of a nematic phases are threaded or Schlieren and that of a smectic phase are of the type of A or C. The average thermal stabilities for smectic and nematic are 111.3°C and 124.7°C, respectively. The smectic and nematicmesophase lengths from 10.0°C to 28.0°C and 7.0°C to 16.0°C, respectively. The transition temperatures are compared with known series.
AZOBENZENE COMPOUND AND HEAT PUMP SYSTEM USING THE SAME
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Paragraph 0074; 0076, (2016/10/10)
PROBLEM TO BE SOLVED: To provide an azobenzene compound capable of repeated structural changes without heating, and a heat pump system using the same. SOLUTION: An azobenzene compound represented by the general formula (1) and undergoing cis-trans isomerization reaction upon light irradiation is used as a heat medium of a heat pump system. In the formula, at least one of R1 to R3 is (CH2CH2O)n-R10; R4 is R11, O-R11, NH-R11, or COO-R11; X- is Cl-, Br-, I-, BF4-, PF6-, CH3(CH2)nSO3-, TsO-, (YSO2)2 N-, or (NC)2 N-; n is an integer between 0 and 2; and Y is F, CF3, or C2F5. COPYRIGHT: (C)2015,JPO&INPIT
Photoliquefiable ionic crystals: A phase crossover approach for photon energy storage materials with functional multiplicity
Ishiba, Keita,Morikawa, Masa-Aki,Chikara, Chie,Yamada, Teppei,Iwase, Katsunori,Kawakita, Mika,Kimizuka, Nobuo
supporting information, p. 1532 - 1536 (2015/02/05)
Ionic crystals (ICs) of the azobenzene derivatives show photoinduced IC-ionic liquid (IL) phase transition (photoliquefaction) upon UV-irradiation, and the resulting cis-azobenzene ILs are reversibly photocrystallized by illumination with visible light. The photoliquefaction of ICs is accompanied by a significant increase in ionic conductivity at ambient temperature. The photoliquefaction also brings the azobenzene ICs further significance as photon energy storage materials. The cis-IL shows thermally induced crystallization to the trans-IC phase. This transition is accompanied by exothermic peaks with a total ΔH of 97.1 kJmol-1, which is almost double the conformational energy stored in cisazobenzene chromophores. Thus, the integration of photoresponsive ILs and self-assembly pushes the limit of solar thermal batteries.
A molecular insight on the supramolecular assembly of thiophene polymers
Suryanarayanan, Chandrasekaran,Ravindran, Ezhakudiyan,Ananthakrishnan, Soundaram Jeevarathinam,Somanathan, Narayanasastri,Mandal, Asit Baran
, p. 18975 - 18982 (2012/10/29)
Herein, the relationship between supramolecularly self-assembled microstructures and the chemical structures of photoluminescent molecules is discussed. A series of non-amphiphilic molecules with different length alkyl chains (4-14), central mesogenic groups, and chemical linkers were designed and synthesized. Intricate analysis shows that the supramolecular assembly varies with change in torsion angle of the thiophene linking group on elongation of the alkyl chain. Small angle X-ray scattering measurement shows long range molecular interaction for lower alkyl chain length, AFM reveals circular domains for octyl and decyl alkyl group polymers. UV-Visible and photoluminescence studies in solution and thin-film show that the J-aggregate patterns for the circular domain of the polymer backbone has a major effect on the polymer absorbance, and produces a larger shift for the photoluminescence signals at higher wavelengths. Excitation polarisation studies show a change in molecular ordering in various colour regions with change in aggregation by means of maximum dichroic ratio for the circular domain assembly. Charge carrier mobility and cyclic voltammetry studies show higher mobility and reduced band gap for these circular domain polymers. Dynamic light scattering studies of octyl alkyl chain polymers show a bimodal distribution, which shows the apparent nature of anisotropy in solution. The Royal Society of Chemistry.
