- Synthesis of aromatic aldehydes by oxidative hydroxymethylation
-
A new high yield method for the synthesis of aromatic aldehydes has been developed. The procedure is based on an acid catalyzed hydroxymethylation of an arene substrate by paraformaldehyde with concurrent selective oxidation of the intermediate aromatic carbinol by 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) to the aldehyde product.
- Branytska, Oiena,Neumann, Ronny
-
-
Read Online
- Tuning the mesomorphic properties of nonisomeric chalconyl-ester bases homologous series: The effect of tail group
-
The mesomorphic properties of nonlinear chalconyl ester homologous series can be tuned in a predictable fashion with tail groups (-OC16H33) substituents on the terminal side. Novel series consisted thirteen members (C1–C8, C10, C12, C14, C16, C18). C1 to C5 homologues are nonliquid crystal, C6 to C14 homologues shows nematic mesophase enantiotropically, while C16, C18 exhibits smectic as well nematic properties. The texture of the nematic mesophase is of fan shaped, schlieren and nematic droplets type. All these compounds were characterized by elemental analyses and spectroscopic techniques such as [FTIR] and 1H Nuclear magnetic resonance [NMR] spectroscopy. The mesomorphic properties of these compoundswere observed by optical polarized light microscopy (POM) and differential scanning calorimetry (DSC).
- Sharma, Vinay S.,Patel
-
-
Read Online
- Mesomorphism dependence on molecular rigidity and flexibility
-
A novel homologous series of liquid crystalline properties is synthesized and studied with a view to understand the effect of molecular structure on its thermotropic properties. Novel homologous series consisted of thirteen homologs. All the homologs are enantiotropically smectogenic with absence of nematic property even in the monotropic condition. Textures of the homologs as observed through an optical hot stage polarizing microscopy. The mesophase temperature range vary minimum from 6.0°C to a maximum 37.0°C at the methyloxy and propyloxy derivatives of a series respectively with its thermal stability (Sm–I) 127.0°C. Transition curves of a phase diagram behaved in normal manner. Odd–even effect is observed for Sm–I transition curve.
- Ranchchh, Avani R.,Bhoya
-
-
Read Online
- Transition metal-free catalytic oxidation of aromatic alcohols with molecular oxygen in the presence of a catalytic amount of N-bromosuccinimide
-
A highly efficient N-bromosuccinimide (NBS)-mediated transition metal-free catalytic system has developed for the efficient aerobic oxidation of aromatic alcohols. Various aromatic alcohols are successfully oxidized to the corresponding aldehydes or keton
- Tong, Xinli,Sun, Yongfa,Yan, Yongtao,Luo, Xuan,Liu, Jinbiao,Wu, Zhidong
-
-
Read Online
- Mesomorphism and flexibility of alkyl chains in chalcone esters
-
A novel homologous series of chalconyl ester liquid crystals (LCs): RO?C6H4–CH:CH–COO?C6H4–CO?CH:CH?C6H4–OC10H21 (n) (para) has been synthesized and studied with a view to understanding and establishing the relationship between molecular structure and LC properties with reference to flexibility of the terminal chain. The novel series consists of eleven homologs (C1–C16). The C1 and C2 homologs are nonliquid crystals and the rest of the homologs (C3–C16) are enantiotropic nematic without exhibition of smectic mesophase. Transition and melting temperatures were determined by an optical polarizing microscope equipped with a heating stage. Textures of nematic phases are threaded or Schlieren. Cr-N/I transition curve adopts a zigzag path in a normal manner with overall descending behaviors. The N-I transition curve exhibits a sharp and shorter odd-even effect from C3 to C6 and it diminishes from and beyond C6 for higher homologs of longer n-alkyl chain (R) in more or less or negligible deviating manner from normal descending tendency. Thermal stability for the nematic is 116.4°C and mesophase length ranges from 19°C to 67°C at the C3 and C12 homolog respectively. The LC properties of present novel series are compared with structurally similar analogous series to derive group efficiency order.
- Muniya,Patel
-
-
Read Online
- A Convenient Oxidation of Benzylic Methyl, Methylene, and Methine Groups with Potassium Permanganate/Triethylamine Reagent
-
A useful and versatile procedure for benzylic oxidations with potassium permanganate/triethylamine has been developed.The methyl, methylene and methine groups are oxidized in good to excellent yields to benzylic aldehydes and ketones and to tertiary benzyl alcohols, respectively.This procedure can easily be carried out in conventional organic solvents without using any phase-transfer or supported catalysts.
- Li, Wen-Shan,Liu, Lilian Kao
-
-
Read Online
- Mesomorphism dependence of a terminal or lateral alkoxy group
-
A novel homologous series of thermotropic mesomorphs has been synthesized and studied with a view to understanding and establishing the effect of molecular structure on mesomorphic properties with reference to rigidity and flexibility of the homologues series: RO-C6H4-CH?CH-CO-C6H4-OC18H37(n). The novel homologous series comprises 13 novel homologues (C1 to C18), from which 11 homologues are enantiotropically mesogenic (C3 to C18). Smectogenic mesophase commences from C7 homologue, and nematogenic mesophase is exhibited by C3 to C18 homologues in enantiotropic manner. Thus, C7 to C18 homologues are enantiotropically smectogenic plus nematogenic. Textures of smectic phase are of the type A or C, and that of nematic phase are threaded or Schlieren as confirmed through an optical polarizing microscope equipped with a heating stage. Transition curve of a phase diagram behaved in a normal manner except N-I transition curve, which shows minor deviating trend (C12 to C18) from expected normal behavior. An odd-even effect is exhibited by N-I and Sm-N transition curves. Analytical, spectral, and thermal data confirm the molecular structures of novel homologues. Thermal stabilities for smectic and nematic are 52.7°C and 66.6°C, respectively, whose total mesophase lengths range from 12.0°C to 28.0°C. Thus, novel series of chalcones is a low melting series whose mesogenic transition temperatures vary between 38.0 and 86.0°C.
- Solanki, Ravindra,Patel
-
-
Read Online
- Mild and selective hydrozirconation of amides to aldehydes using Cp 2Zr(H)Cl: Scope and mechanistic insight
-
An investigation of the use of Cp2Zr(H)Cl (Schwartz's reagent) to reduce a variety of amides to the corresponding aldehydes under very mild reaction conditions and in high yields is reported. A range of tertiary amides, including Weinreb's amides, can be converted directly to the corresponding aldehydes with remarkable chemoselectivity. Primary and secondary amides proved to be viable substrates for reduction as well, although the yields were somewhat diminished as compared to the corresponding tertiary amides. Results from NMR experiments suggested the presence of a stable, 18-electron zirconacycle intermediate that presumably affords the aldehyde upon water or silica gel workup. A series of competition experiments revealed a preference of the reagent for substrates in which the lone pair of the nitrogen is electron releasing and thus more delocalized across the amide bond by resonance. This trend accounts for the observed excellent selectivity for tertiary amides versus esters. Experiments regarding the solvent dependence of the reaction suggested a kinetic profile similar to that postulated for the hydrozirconation of alkenes and alkynes. Addition of p-anisidine to the reaction intermediate resulted in the formation of the corresponding imine mimicking the addition of water that forms the aldehyde.
- Spletstoser, Jared T.,White, Jonathan M.,Tunoori, Ashok Rao,Georg, Gunda I.
-
-
Read Online
- N-methyl morpholine chlorochromate: An efficient reagent for oxidation of primary and secondary alcohols to carbonyl compounds
-
Instantaneous generation of N-methyl morpholine chlorochromate (NMMCC) is an efficient reagent for oxidation of primary and secondary alcohols to the corresponding carbonyl compounds. The comparison of reaction time and product yield was studied with novel NMMCC and other chlorochromate reagents and shows that the presented method requires less reaction time with good yield at laboratory temperature. The synthesis of reagent, formation of toxic and hazardous chromylchloride have been avoided, and also use of NMMCC under microwave irradiation for oxidation leads to fast reaction time and success of the strategy. Copyright Taylor & Francis Group, LLC.
- Chandrappa,Sadashiva,Rangappa
-
-
Read Online
- Mesomorphism of Novel Symmetric Dimers with Changing Alkoxy Terminal End Group
-
A novel homologous series of symmetric dimers has been synthesized. It consists of thirteen (C1 to C8, C10, C12, C14, C16 and C18) dimer ester derivatives from trans cinnamic acid with pyrocatechol. Mesomorphic property commences from C7 homologue as smectic. C1 to C6 members of the series are nonmesomorphic. C7 is monotropic smectic and the rest of the homologues from C8 to C18 are enantiotropic smectic. The nematic mesophase is totally absent. Textures and transition temperatures of the homologues are determined by an optical polarizing microscope equipped with a heating stage. IR, 1H NMR spectra, mass spectra, and differential scanning calorimetry of some members is included. The spectroscopic analyses support the molecular structures. Mesomorphic properties of the novel symmetric dimer series are compared with structurally similar series. The novel series is partly nonmesomorphic and predominantly smectogenic with textures of the A or C type, without the exhibition of the nematic phase.
- Bhola,Maheta,Bhoya
-
-
Read Online
- Solvent-free Williamson synthesis: An efficient, simple, and convenient method for chemoselective etherification of phenols and bisphenols
-
Etherification of phenols with dimethyl- and diethylsulfates and benzyl chloride was performed efficiently in the presence of a suitable solid base, NaHCO3 or K2CO3, under solvent-free conditions. The reaction proceeded rapidly at low temperature, and the corresponding ethers were obtained with high purity and excellent yield. Selective etherification of electron-poor phenols in the presence of electron-rich ones and also selective mono-etherification of bisphenols are the noteworthy advantages of this method. This method is environmentally friendly. Copyright Taylor & Francis Group, LLC.
- Massah, Ahmad R.,Mosharafian, Masumeh,Momeni, Ahamad R.,Aliyan, Hamid,Naghash, H. Javaherian,Adibnejad, Mohamad
-
-
Read Online
- Mesomorphism dependence on heterocyclic end group
-
An ester homologous series containing a heterocyclic end group was synthesized and studied with a view to understanding and establishing the effect of molecular structure on liquid crystal behavior. The novel series consists of 13 homologues. All members of the series are enantiotropically smectogenic without exhibition of nematogenic character. The textures of smectogenic homologues are of the type smectic A or C. The transition temperatures were determined by an optical polarizing microscope equipped with a heating stage. The Sm-I transition curve in a phase diagram behaves partly in an abnormal manner with the exhibition of an odd-even effect. The average thermal stability for smectic is 141.45°C and the mesomorphic phase length ranges from 8.1°C to 30.3°C. Analytical and spectral data confirm the molecular structures. The liquid crystal properties of present series are compared with the structurally similar known homologous series.
- Bhola,Bhoya
-
-
Read Online
- Mesomorphic study of novel chalconyl-ester-based nonisomeric series: Synthesis and characterization
-
A newly designed homologues series: 3-(3-(4-(Dimethylamino) phenyl) acrylonyl) phenyl 3-(4-n-alkoxyphenyl) acrylate has been synthesized and studied through chalconyl ester linking group at (meta) position. The series consists of 13 compounds, in which C1 to C4 homologue are nonliquid crystal, while C5 to C18 exhibit nematic phase, and C12 to C18 shows smectic and nematic phase with enantiotropically manner. Mesophase image of present compounds are rod like, needle and threaded type textures investigated by POM. All this compounds were characterized by elemental analysis, FT-IR and 1H NMR. The mesomorphism is measured by POM, DSC, and molecular packing is determined by XRD technique. The following synthesized chalconyl ester-based compounds C5 to C12 shows antibacterial as well as antifungal activity compared with corresponding standard drugs. Analytical and spectral data confirmed the molecular structures of homologous series.
- Sharma, Vinay S.,Patel
-
-
Read Online
- Mesomorphism dependence on halogenated chalconyl esters in terms of molecular flexibility/rigidity
-
Vinyl carboxy central group containing a novel chalconyl ester homologous series: RO.C6H4.CH ? CH.COO.C6H4.CH ? CH.CO.C6H4.I (para) have been synthesized and studied with a view to understand and establish the relation between thermotropic liquid crystalline (LC) behaviors and the molecular structure. Novel chalconyl ester homologous series consists of thirteen homologs (C1–C18). C1–C3 homologs are nonmesogenic, C4 homolog is enantiotropic nematogenic and the rest of the homologs (C5–C18) are enantiotropically smectogenic plus nematogenic. Phase transition temperatures and textures of LC phase were determined by an optical polarizing microscopy (POM) equipped with a heating stage. Cr-M/I, Sm-N, N-I transition curves in a phase diagram behaved in normal manner. Sm-N and N-I transition curves exhibited odd-even effect from C4–C10 or nearby C10 homolog. Textures of nematic phase are threaded or Schlieren and that of the smectic phase are of the type smectic A or C. Analytical and spectral data confirms the molecular structure of homologs. Thermal stabilities for smectic and nematic mesophases are 155.0 and 180.7, respectively, and their corresponding mesophaselengths are varied from minimum to maximum at 17.0°C–39.0°C as well as 15.0°C–30.0°C. Thus, it is middle ordered melting type series. The group efficiency orders derived on the basis of smectic and nematic thermal stabilities are as under: Sm: -C6H4.I > -C6H4.Cl > -C4H3S and N:- C6H4.I > -C6H4.Cl > -C4H3S from comparative study of structurally similar analogous series
- Sharma, Vinay S.,Patel
-
-
Read Online
- Intermolecular C–O Coupling Using Hemicucurbituril Supported Ionic Liquid Phase Catalyst
-
Abstract: Hemicucurbituril supported ionic liquid phase catalyst (HmCucSILP) has been synthesized by anchoring multilayer of ionic liquid ([Bmim]Cl) containing Pd(OAc)2 and X-phos on the surface of hemicucurbit[6]uril. The HmCucSILP was effectively employed in intermolecular C–O coupling of aryl halides with sodium alkoxides for the synthesis of alkyl aryl ethers. Graphical Abstract: [Figure not available: see fulltext.]
- Kurane, Rajanikant,Bansode, Prakash,Khanapure, Sharanabasappa,Kale, Dolly,Salunkhe, Rajashri,Rashinkar, Gajanan
-
-
Read Online
- Mesomorphism behaviour and photoluminescent properties of new asymmetrical 1,2-di(4-alkoxybenzylidene) hydrazines
-
{1-[4-(n-Alkoxy)]-2-(4’-decyloxy)benzylidene}hydrazines (n-alkoxy = O(CH2)nH, n = 1–9, 12, 16 or 18), an asymmetrical series of 1,2-disubstituted hydrazines, were prepared in a simple two-step procedure as a part of our continuing work in evaluating hydrophobic azine compounds as photoluminescent liquid crystalline materials. The compounds were characterized spectroscopically and their liquid crystalline behaviour and luminescent properties were evaluated using polarized light optical microscopy, differential scanning calorimetry and X-ray powder diffraction techniques. The studies revealed that all of these compounds are liquid crystalline materials exhibiting photoluminescent properties in the crystalline and liquid crystal states.
- Awad, Adil A.,Omarali, Al-Ameen Bariz,Al-Karawi, Ahmed Jasim M.,Al-Qaisi, Zyad Hussein J.,Majeed, Samer Ghanim
-
-
Read Online
- Study the effects of terminal side chain and –nitro group on mesomorphic behaviour of cinnamate-chalconyl based liquid crystal
-
The influence of the terminal side chain and lateral nitro on mesomorphism due to the flexibility and polarity of lateral group is investigated. A new homologues series is synthesized to accomplish this aim. The C1 to C3 homologue are nonmesomorphic, while the rest of the homologues exhibit enantiotropic nematic and smectic properties. The texture of the nematic mesophase is of threaded, Schlieren and droplets type. All these compounds were characterized by elemental analyses and spectroscopic techniques of FTIR and 1H Nuclear magnetic resonance (NMR). The phase behaviour was studied by polarizing optical microscopy (POM), differential scanning calorimetry (DSC), and X-ray diffraction techniques.
- Sharma, Vinay S.,Patel
-
-
Read Online
- Synthesis and mesomorphic properties of new chalconyl-ester based liquid crystals: The effect of tail group
-
A new homologous series viz. 4-(3-(3, 4-dioctadecyloxy) phenyl)-3- oxoprop-1-en-1-yl) phenyl-3-(4-n-alkoxy phenyl) cinnamate) based on two linking groups have been synthesized and characterized. The mesomorphic properties of these compounds were observed by optical polarized light microscopy (POM) and confirmed by differential scanning calorimetry (DSC). All synthesized compounds exhibited LC behaviour except compound C1. Thermal stability of smectic and nematic phase of present series are 79.0°C and 120.0°C whose temperature range is vary from 14 to 20°C and 24 to 56°C respectively. The mesomorphic properties of present series were compared with other structurally related mesogenic homologous series to evaluate the effects of tail group on mesomorphism.
- Sharma, Vinay S.,Vekariya, Rajesh H.,Sharma, Anuj S.,Patel
-
-
Read Online
- Synthesis, characterization, and mesomorphic investigation of vinyl ester-substituted chalcones and effect of lateral ?NO2 and ?OCH3 group
-
A novel homologous series of α-4-(4′-n-alkoxy cinnamoyloxy) phenyl β-2″-nitro, 3″–4″ di methoxy benzoyl ethylenes, H2n + 1CnO?C6H4?CH?CH?COO?C6H4?CO?CH?CH?C6H2(NO2) (OCH3)2 (n = 1–8, 10, 12, 14, 16, 18) has been synthesized. All these compounds have been characterized by suitable spectroscopic techniques. C1 homologue is nonmesogenic, while C2 homologue shows enantiotropic nematogenic property and the rest of the homologous (C3?C18) displayed enantiotropically smectogenic plus nematogenic phase. Phase transition temperatures and textures of the LC phase were determined by an optical polarizing microscopy (POM) equipped with a heating stage. The mesomorphic properties of these compounds were confirmed by differential scanning calorimetry (DSC) analysis.
- Sharma, Vinay S.,Patel
-
-
Read Online
- Stepwise degradation of hydroxyl compounds to aldehydes: Via successive C-C bond cleavage
-
Stepwise degradation of hydroxyl compounds to aldehydes via successive cleavage of C-C bonds was achieved by using a bimetallic catalytic system (PdCl2 + CuCl) without any ligands and additives. The broad applicability is expanded to a diverse range of aromatic, aliphatic, primary and secondary alcohols, as well as lignin model compounds.
- Liu, Mingyang,Zhang, Zhanrong,Shen, Xiaojun,Liu, Huizhen,Zhang, Pei,Chen, Bingfeng,Han, Buxing
-
-
Read Online
- Synthesis, characterization and study of liquid crystal properties of new homologous chalcone series
-
Onenewmesogenic homologous series of chalconyl derivativewith two ring (3/-(4/- (decyloxy) phenyl-1-(4-(alkoxy) phenyl) prop-2-en-1-one) has been synthesized and characterized by a combination of elemental analysis and standard spectroscopic methods. In the series, the lower members (C4 and C5) exhibit only enantiotropic nematic mesophase but middle and higher members exhibit enantiotropic nematic as well as smecticmesophase. The nematicmesophase commence from C4 homologue and smectic mesophase (smectic-A type texture) commence from C6 homologue as enantiotropic and persists up to the lastmember synthesized. The mesomorphic properties of present serieswere compared with other two structurally similar series to study the effects of change of meta and para position on the mesomorphism.
- Jain,Patel
-
-
Read Online
- Mesomorphism and molecular flexibility in novel chalconyl derivatives with two phenyl rings
-
A novel chalconyl liquid crystalline (LC) homologous series with two phenyl rings and one central bridge RO?C6H4?CH=CH–CO?C6H4(O?C18H37) (meta) has been synthesized and studied with a view to understanding and establishing the effects of molecular structure on thermotropic LC behaviors or properties. Homologous series of present investigation (C1–C18) consists of thirteen homologues, and thermotropic mesomorphism for nematic and smectic commences from C3 and C6 homologues respectively. The C3, C4, and C5 homologues are enantiotropically nematic, whereas, the homologues from C6 to C18 are monotropically smectic plus nematic. Melting points and transition temperatures were determined using a polarizing optical microscope (POM) equipped with a heating stage. The textures of the nematic phase are threaded or Schlieren and that of a smectic phase are fan shaped of smectic-A or smectic-C type. The Cr?I/M, N?I/I?N, and N-Sm transition curves behave in the normal manner, and the Cr-I/M exhibits an odd-even effect. Analytical, thermal, and spectral data confirm the molecular structures. Thermal stabilities of smectic and nematic are low. Mesophase lengths are very short, ranging between 1–8°C and 14°C. The novel compounds are compared with a known series.
- Sharma, Vinay S.,Jain,Patel
-
-
Read Online
- Synthesis and study of new homologous series of ester-chalcone exhibiting nematic phases
-
A novel homologous series of ester-chalcone have been synthesized and their liquid crystals (LCs) properties are studied. All the homologue shows nematic phase except C1-C4 homologue. Classical nematic textures are observed in this homologous series with the help of polarizing optical microscope (POM) equipped with hot stage. The role of flexible methylene group spaces, degree of polymerization and central linkage on the exhibition of all the homologue is discussed. The novel homologous series has been characterized by the standard methods (1HNMR, IR, and elemental analysis).
- Jain,Patel
-
-
Read Online
- Gadolinium Complex of 1,4,7,10-Tetraazacyclododecane-1,4,7-Trisacetic Acid (DO3A)-Ethoxybenzyl (EOB) Conjugate as a New Macrocyclic Hepatobiliary MRI Contrast Agent
-
We report the synthesis of a macrocyclic Gd chelate based on a 1,4,7,10-Tetraazacyclododecane-1,4,7-Trisacetic acid (DO3A) coordinationn cage bearing an ethoxybenzyl (EOB) moiety and discuss its use as a T1 hepatobiliary magnetic resonance imaging (MRI) contrast agent. The new macrocyclic liver agent shows high chelation stability and high r1 relaxivity compared with linear-Type Gd chelates, which are the current clinically approved liver agents. Our macrocyclic, liver-specific Gd chelate was evaluated in vivo through biodistribution analysis and liver MRI, which demonstrated its high tumor detection sensitivity and suggested that the new Gd complex is a promising contrast agent for liver cancer imaging.
- Baek, Ah Rum,Kim, Hee-Kyung,Park, Subin,Lee, Gang Ho,Kang, Hyo Jeung,Jung, Jae-Chang,Park, Joon-Suk,Ryeom, Hun-Kyu,Kim, Tae-Jeong,Chang, Yongmin
-
-
Read Online
- The effect of geometrical shape and molecular rigidity on mesomorphism
-
A novel nonlinear homologous series RO?C6H4?CH?CH?COO?C6H4 (meta) ?CO?CH?CH?C6H4?OC12H25(n) (para) consisting of three phenyl rings, two central bridges ?CH?CH?COO? and ?CO?CH?CH? as well as ?OR and ?OC12H25(n) as flexible and constant terminal end groups respectively. The object in view is aimed to understand and establish the effect of molecular structure on LC properties of nonlinear inverted “V” shaped molecules. Novel homologous series consists of thirteen homologues. Transition temperatures and textures were determined by polarizing optical microscopy (POM) equipped with a heating stage. Textures of nematic phases are threaded or schlieren and that of a smectic phases are of the type-A or C. Transition curves of a phase diagram behaved in a normal manner. Sm-N and N-I transition curves exhibited odd-even effect. Analytical, Thermal and Spectral data confirms the molecular structure of homologues.
- Patel, Priya K.,Shah
-
-
Read Online
- Mesomorphism Dependence on Molecular Flexibility and Molecular Rigidity
-
A novel liquid crystal (LC) homologues series of ethylene derivatives was synthesized and evaluated for mesomorphic properties. Mesomorphism commences from sixth member of the series. Textures of the nematic phase are threaded or Schlieren and those of the smectic phase are of the focal conic fan type. The N-I and Sm-N transition curves of the phase diagram exhibit odd-even effects and behave in a normal manner. The average thermal stabilities of the smectic and nematic are 113.4°C and 123.2°C with mesogenic phase lengths varying between 3.3°C and 8.1°C and 4.5°C to 13.5°C, respectively. The LC behavior of the novel series is compared with a structurally similar known series.
- Bhola,Bhoya
-
-
Read Online
- Synthesis and mesomorphic properties of coumarin derivatives with chalcone and imine linkages
-
We report here design and synthesis of two new mesogenic homologous series of coumarin derivatives consisting of chalcone and imine central linkages along with terminal n-alkoxy chain. All the compounds were synthesized and characterized by combination of elemental analysis and standard spectroscopic methods. All compounds were screened under polarising optical microscope (POM) for liquid crystalline properties, thermogram of all compounds were studied using differential scanning calorimetry (DSC) to get phase transition temperatures, enthalpy and entropy. X-ray single crystal study of n-octyloxy coumarin derivative 16 g was resolved with imine central linkage, which showed linear rod like geometry.
- Durgapal, Sunil Dutt,Soni, Rina,Soman, Shubhangi S.,Prajapati
-
-
Read Online
- Room temperature aerobic oxidation of alcohols using CuBr2 with TEMPO and a tetradentate polymer based pyridyl-imine ligand
-
A series of tetradentate pyridyl-imine terminated Schiff-base ligands has been investigated for their ability in the catalytic oxidation of alcohols when combined with copper bromide (CuBr2) and 2,2,6,6- tetramethylpiperidyl-1-oxy (TEMPO). Analogous bidentate ligands showed poorer catalytic activity and the ratio of Cu:ligand was of crucial importance in maintaining high yields. The polydimethylsiloxane (PDMS) derived pyridyl-imine terminated ligand combined with copper(II) ions affords an effective and selective catalyst for aerobic oxidations of primary and secondary alcohols under aqueous conditions. Preliminary mechanistic studies suggest that bimetallic complexes may be playing a role in the catalytic transformation.
- Hu, Zhenzhong,Kerton, Francesca M.
-
-
Read Online
- Role of n-alkoxy terminal end groups on mesomorphism
-
A homologous series RO-C6H4-CH:CH-COO-C6H4-CO-CH:CH-C6H4-OC6H13 (n) of novel liquid crystals (LC) has been synthesized and studied with a view to understanding and establishing the relation between molecular structure of a substance and the LC properties or behavior of thermotropic LC materials. Novel series consist of 11 homologues. C1 and C2 homologue derivatives are non-LCs and the rest of homologues (C3 to C16) are nematogenic without exhibition of smectic property. Transition temperatures were determined by an optical polarizing microscopy equipped with a heating stage. Transition curve Cr-N/I of a phase diagram behaved in normal manner. N/I transition curve partly deviated at C6 and C10 homologues from normal descending behavior, and exhibited very narrow and sharp odd-even effects. Textures of nematic phase are threaded or Schlieren. Thermal, analytical, and spectral data confirmed the molecular structures of novel chalconyl ester derivatives. Thermal stability for nematic is 95.77°C and the upper and lower mesophase lengths vary from 35 to 16°C at C5 and C8 homologues respectively. Group efficiency order derived for nematic on the basis thermal stability is -OC10H21 (n) > -OC8H17(n) > -OC6H13(n).
- Muniya,Patel
-
-
Read Online
- “Dependence of Mesomorphism in Combination with Fluoro and Chloro Groups”
-
A novel azoester homologous series with chloro lateral group and a fluoro terminal end group was synthesized and characterized for mesomorphic properties. It consists of thirteen azo ester derivatives from trans-4-n-alkoxy cinnamic acid with 4-hydroxy-3-chloro phenyl azo-3-chloro-4-fluoro benzene. Mesomorphic property commences from C4homologue as smectic.C1 to C3 member of the series are non-mesomorphic. C4 to C18 homologous are enantiotropic smectic A phase. The nematic mesophase is totally absent. Texture and transition temperatures of the homologues are determined by an optical polarizing microscopy equipped with heating stage. 1H NMR, IR spectra, mass spectra, of some member is included. The spectroscopic analysis supports the molecular structure. A phase diagram is used to illustrate the mesomorphic behaviour across the series. Mesophaselength for smectic is varying from18.0°C to 69.00C. Mesomorphic properties of the novel azoester series are compared with structurally similar series.
- Ranchchh, Avani R.,Tharesha, Bhavna R.,Bhoya
-
-
Read Online
- Magnetic nanoparticle supported ionic liquid phase catalyst for oxidation of alcohols
-
Anew magnetic nanoparticle supported ionic liquid phase (SILP) catalyst containing perruthenate anions was prepared by a multistep procedure. The various analytical techniques such as FT-IR spectroscopy, X-ray photoelectron spectroscopy, transmission elec
- Naikwade, Altafhusen,Jagadale, Megha,Kale, Dolly,Rashinkar, Gajanan
-
-
Read Online
- Dependence of mesomorphism on molecular rigidity of chalconyl liquid crystals with two phenyl rings
-
A novel homologues series: RO-C6H4?CH=CH?CO?C6H4?OC16H33(n) (meta) of chalcones with two phenyl rings is synthesized and studied with a view to understanding and establishing the relationship between molecular structure and mesogenic behavior. The series consists of 13 homologues (C1 to C18). Mesomorphism commences from the second member of the series. C2 to C6 homologues are enantiotropicnematic and the rest of the homologues (C7 to C8) are monotropicnematic plus monotropicsmectic. C1 homologue is nonmesogenic. Transition temperatures were determined by an optical polarizing microscope (POM) equipped with a heating stage. Textures of nematic and smectic phases are threaded, Schlieren or smectic-A, respectively, as judged directly from the heating top of microscopic observations. Thermal, analytical and spectral data confirms the molecular structures. Thermal stabilities for smectic and nematic are few (1 or 2°C) degrees and 72.6°C, respectively. The mesophase lengths are relatively shorter with low mesomorphic transition temperatures (44.0°C to 85.0°C).
- Sharma, Vinay S.,Patel
-
-
Read Online
- Synthesis and mesomorphic properties of new chalconyl-linkage-based liquid crystal compounds: The effect of flexibility
-
A new series of liquid crystals involving chalconyl-based mesogenic units interlinked between two benzene cores were designed and synthesized. The target chalconyl compounds were obtained by the reaction of 4-n-alkoxy benzaldehyde with 4-n-hexadecyloxy (–OC16H33) acetophenone in presence of base. The liquid crystalline properties of synthesized compounds were observed by polarizing optical microscope study. The molecular structures of the compounds were confirmed by Fourier transform infrared, 1H, and 13C nuclear magnetic resonance spectra. The compounds of the series C3 to C8, C10, C12, C14, C16, and C18 exhibited mesophase in enantiotropically manner. The transition temperature reduced as alkyl spacer of left side group increased. The observed texture images are droplets, broken fan, and threaded like. Thermal stability of current homologous series for (N-I/I-N) is 69.8°C and for smectic phase (Sm + N) is 58.0°C.
- Sharma, Vinay S.,Patel
-
-
Read Online
- Nighttime tropospheric chemistry: Kinetics and product studies in the reaction of 4-Alkyl- and 4-Alkoxytoluenes with NO3 in gas phase
-
Alkylbenzenes are important constituents of gasoline and industrial solvents and contribute to the formation of tropospheric ozone. The removal of these compounds from the troposphere is due to reaction with OH during the day and with NO3 during the night. Five para-substituted toluenes are reacted with the nitrate radical in gas phase. Samples to be used for product analysis were preconcentrated and analyzed by GC-MSD analysis with the use of a reference curve. The yields of methanol, ethanol, and formaldehyde were determined by FTIR analysis of the reaction mixture in the chamber. Carbonyl compounds, benzyl alcohols, and nitroderivatives were formed. In the case of the alkoxytoluenes, products were also an alkanol, benzyl alcohols, and nitrophenols. Indirect rate constants measurements were performed by comparing by FTIR measurements the decay of the aromatic compound under investigation to that of a reference compound, with a known rate constant for the reaction with NO3 added to the gas mixture. Wall loss constants were evaluated by FTIR. A Hammett correlation with ρ = - 4.3 ± 0.6; r2-= 0.87 was obtained. This and the kinetic isotope effect of 1.5-1.8 suggest a reaction mechanism occurring via an addition-elimination pathway.
- Bolzacchini, Ezio,Meinardi, Simone,Orlandi, Marco,Rindone, Bruno,Hjorth, Jens,Restelli, Gianbattista
-
-
Read Online
- Mesomorphism dependence on central bridges and the efficiency order of the tail group
-
A novel homologous series: RO-C6H4?CH?CH?COO?C6H4?CH?N-C6H3 (CH3)2 of ortho-meta Schiff's bases has been synthesized and studied with a view to understanding and establishing the effects of molecular structure on mesomorphic properties and to provide a source of novel liquid crystalline (LC) materials. The series consists of 13 homologues (C1 to C8, C10, C12, C14, C16 & C18). C1 and C3 homologues are nonmesomorphic, C2 and C4monotropicnematic, C6 and C7monotropicsmectic in addition to enantiotropicnematic, C5 is only enantiotropicnematic, C8, C10, C12 are enantiotropically smectogenic plus nematogenic and C14, C16, C18 homologues are enantiotropically smectic only. Textures and transition temperatures were determined using an optical polarizing microscope equipped with a heating stage. Analytical and spectral data confirm the molecular structures. Average smectic and nematic thermal stabilities are 100.16°C and 110.83°C, respectively. Mesomorphic properties of present novel series are compared with structurally similar homologous series.
- Bhola,Bhoya
-
-
Read Online
- Dependence of mesomorphism on flexibility of lateral and terminal groups of chalconyl esters
-
A novel liquid crystalline homologous series of chalconyl vinyl esters with a lateral bromo substituent RO─C6H4─CH═CH─COO─C6H3─(Br)─CO-CH═CH─C6H4─C12H25(n) has been synthesized and studied with a view to understanding and establishing the relation between the molecular structure and liquid crystal (LC) behavior in terms of molecular flexibility of the lateral and terminal groups. The novel homologous series consists of thirteen (C1–C18) homologues, whose enantiotropic nematic and smectic mesomorphism commences from the C4, (C4–C18) and the C5, (C5–C18) homologue, respectively. The rest of the homologues (C1, C2, C3) are nonliquid crystals (NLC). Mesomorphism and transition temperatures were examined using an optical polarising microscope (POM) equipped with a heating stage. Textures of nematic phase are threaded or Schlieren and those of the Smectic-A or Smectic-C are focal conic. Analytical, thermal and spectral data supported molecular structures of the novel homologues. Thermal for smectic and nematic are 87.5°C and 101.1°C, respectively, whose, total mesophase length ranges from 17°C to 30°C at C14 and C7 homologue, respectively. The mesomorphic transition temperature ranges are between 70°C and 113°C.
- Patel, Priya K.,Shah
-
-
Read Online
- Highly efficient and selective aerobic oxidation of alcohols in aqueous media by TEMPO-containing catalytic systems
-
The use of molecular oxygen as the oxidant and water as reaction medium is a charming research orientation in the oxidation of alcohols. In this communication, the efficient aerobic oxidation of alcohols to the corresponding carbonyl compounds in aqueous media has been achieved with TEMPO-containing catalytic systems. In the absence of base/acid, a 99% conversion and 94% selectivity for benzaldehyde were obtained for the oxidation of benzyl alcohol by TEMPO-Ce(IV)-NaNO2 in water. Moreover, the effects of quaternary ammonium salts and anionic surfactants were investigated. The aerobic selective oxidation of different non-heterocyclic alcohols in aqueous media was further investigated, and the moderate to high yields (45.5-98.0%) of products were obtained.
- Yan, Yongtao,Tong, Xinli,Wang, Kaixuan,Bai, Xueqin
-
-
Read Online
- Reductant-directed formation of PS-PAMAM-supported gold nanoparticles for use as highly active and recyclable catalysts for the aerobic oxidation of alcohols and the homocoupling of phenylboronic acids
-
Polystyrene-polyamidoamine-supported gold nanoparticles were prepared using a reductant-directed formation strategy. The resulting catalysts exhibited excellent activities in the aerobic oxidation of benzyl alcohols and the homocoupling of phenylboronic acids under mild conditions and can be recycled at least 14 times without significant loss of activity. The Royal Society of Chemistry 2012.
- Zheng, Jie,Lin, Shengyue,Zhu, Xianhao,Jiang, Biwang,Yang, Zhen,Pan, Zhengying
-
-
Read Online
- Molecular flexibility dependence on mesogenic behaviors of isomeric and nonisomeric series
-
A novel homologous series containing vinyl ester and azomethane central bridges and n-alkoxy as well as 3″,4″-dimethyl groups as flexible terminal/lateral groups viz. RO?C6H4?CH = CH?COO?C6H4?N?CH?C6H3-(CH3)2 have been synthesized and studied with a view to establishing the relation between molecular structure and thermotropic liquid crystal (LC) properties with reference to molecular flexibility within the series. The series consists of twelve homologues (C1 to C16). C6 and C7 homologues are smectogenic plus nematogenic and C8 to C16 homologues are only smectogenic, and the rest of the homologues (C1 to C5) are nonmesomorphic. Transition temperatures and the textures of the homologues were determined using an optical polarizing microscope equipped with a heating stage (POM). The textures of a nematic phase are threaded or Schlieren and that of a smectic phase are of the A or C type. Analytical, thermal and spectral data support the molecular structures. Smectic and nematic thermal stabilities are 116.85°C and 147.5°C, respectively. Whose Sm?N/I and N-I mesophase lengths are varied between 15°C to 21°C and 25°C to 62°C, respectively. The novel compounds are compared with structurally-similar series.
- Rakhasia,Ranchchh, Avani R.,Bhoya
-
-
Read Online
- Synthesis and study of mesomorphic properties in rod-like chalconyl compounds
-
In order to investigate the influence of the central linking group and effect on flexibility on mesophase behavior of liquid crystal we have synthesized newly homologous series viz. 3-(4-Octyloxyphenyl)-1-(4′-n-alkoxy phenyl) prop-2-en-1-one (Series-l) consists of thirteen homologues (C1 to C8, C10, C12, C14, C16, C18). Textures of a nematic phases are threaded or Schlieren type. The textures of smectic and nematic phase are directly judged from the heating and cooling condition. Group efficiency order for mesophases is derived on the basis of thermal stabilities from the comparative study of thermometric data determined from structurally analogous series. A transition curve as depicted in a phase diagram behaves in normal manner. Structural and conformational characterization of these new compounds had achieved by 1H NMR, 13C NMR, IR, and elemental analysis.
- Sharma, Vinay S.,Patel
-
-
Read Online
- Study of mesomorphism and its relation to molecular structure through molecular rigidity and flexibility
-
Novel liquid Crystalline (LC) substances of chalconyl ester derivatives from Vinyl aromatic carboxylic acids are synthesized and studied with a view to understanding and establishing the relation between molecular structure, RO-C6H4-CH=CH-COO-C6H4-CH=CH-CO-C6H4-F (para) and LC properties of the thermotropic variety. Homologous series consists of eleven members (C1 to C16). C1 and C2 members of novel series are nonliquid crystals (NLC) and the rest of the homologues (C3 to C16) are enantiotropic nematic with absence of smectic property throughout. Transition temperatures and textures of homologues were determined by an optical polarizing microscope (POM) equipped with a heating stage. Textures of nematic phase are threaded or Schlieren. The transition temperatures of novel homologues are relatively lower than the corresponding dimeric trans n-Alkoxy Cinnamic acids from which, novel homologues are synthesized. Thermal, analytical, spectral data confirmed molecular structures of novel homologues. Cr-N/I and N-I transition curves behaved in normal manner except C8 to C14 homologues which deviated from normal descending tendency in N-I transition curve. N-I transition curve exhibited odd-even effect up to C6 homologue and odd member's N-I transition curve occupied lower position than even member's N-I transition curve. Thermal stability for nematic is 118.2°C; with its total mesophase length ranging from 12.0 to 50.0°C. Thus, it is a middle ordered melting type series with absence of smectic property. Group efficiency order derived on the basis of thermal stability using comparative study of present novel series with structurally similar analogous series as mentioned below. Smectic: Series-Y > Series- X = Series-1 and Nematic: Series-X > Series- 1 > Series-Y
- Muniya,Patel
-
-
Read Online
- Mesomorphism dependence on central bridge and tail ended polar group
-
A novel azoester homologous series of laterally and terminally substituted viz, RO–C6H4–CH=CH–COO–C6H3–(CH3) –N=N–C6H4–Cl is synthesized, characterized and studied with a view to understand and establish the relation between molecular structure and thermotropic liquid crystalline property of its homologs. Series consists of twelve homologs. LC properties commence from very first member of a series and continue up to last homolog as enantiotropic nematic with absence of smectic property even in the monotropic condition. Transition temperatures of homologs were determined by polarizing optical microscopy equipped with a heating stage. The transition curves Cr?N and N?I behaved in normal manner. Thermal stability for nematic is 196.7?C whose mesophaselength ranges from 35°C to 131°C.
- Ranchchh, Avani R.,Chavda, Kavita,Bhanderi, Roshani,Patel, Suman,Bhoya
-
-
Read Online
- Dependence of mesomorphism on molecular rigidity of nonlinear and linear isomeric and nonisomeric chalconyl esters
-
The novel thermotropic liquid crystalline (LC) materials have been synthesized and studied through chalconyl ester nonlinear (meta substituted) homologous series RO-C6H4?CH?CH?COO?C6H4-CO?CH?CH?C6H4-OC14H29(n) with a view to understand the effect of molecular structure on LC behavior with reference to determine the difference between linear and nonlinear shaped molecules. Novel series consisted of thirteen members, whose nematogenic enantiotropic mesomorphism commences from C6 homologue and continued up to C18 homologue with the absence of smectogenic character. C1 to C5 homologues are nonliquid crystals as determined through an optical polarising microscope (POM) equipped with a heating stage. Transition temperatures of LC homologues alternate and are lower than the corresponding n-alkoxy cinnamic acids. Cr-N/I and N-I transition curve behaved in normal manner. N-I transition curve exhibited odd-even effect in a phase diagram. Textures of nematic phase are threaded or Schlieren or determined by miscibility method and from observing mesophase on the top of the POM. Thermal stability for nematic is 92.5 and mesophase length minimum to maximum is 19.0 to 32.0°C at the C10/18and C6 homologue. Group efficiency order on the basis of thermal stability is (Formula presented.) Thus, novel series is nematogenic and low melting type. Analytical and spectral data confirmed the molecular structures of homologues.
- Jain,Patel
-
-
Read Online
- Mesomorphism dependence on heterocyclic tail
-
A novel homologous series of liquid crystal materials containing a heterocyclic ring was synthesized with a view to understanding and establishing the relation between liquid crystal (LC) properties and a molecular structure; and with a view to curing skin-related diseases following biological activity studies. The series consist of 13 (C1 to C18) members. All the members are liquid crystals. The C4 to C18 members are smectogenic of which C4 and C5 are monotropic and remaining members (C6 to C18) are enantiotropic in nature; whereas all C1 to C18 members are enantiotropically nematogenic. Hence the C1, C2, C3 members are only nematogenic and the rest of the homologues are smectogenic in addition to nematogenic. Transition temperatures were determined by an polarizing optical microscope equipped with heating stage. Analytical and spectral data confirmed the molecular structures of homologues. It is a middle ordered melting type series. LC properties of a series are compared with the structurally known series.
- Bhola,Bhoya
-
-
Read Online
- Highly efficient BODIPY-doped upconversion nanoparticles for deep-red luminescence bioimagingin vivo
-
We demonstrate a 3,5-di(p-oxethyl)styryl conjugated BODIPY showing deep-red upconversion luminescence with a high efficiency of 16.6%. Furthermore, water-soluble BODIPY-doped upconversion nanoparticles with efficiency up to 6.9% under low excitation power
- Jia, Ti,Wang, Qiuhong,Xu, Ming,Yuan, Wei,Feng, Wei,Li, Fuyou
-
supporting information
p. 1518 - 1521
(2021/02/21)
-
- Dibenzazepine-linked isoxazoles: New and potent class of α-glucosidase inhibitors
-
α-Glucosidase inhibition is a valid approach for controlling hyperglycemia in diabetes. In the current study, new molecules as a hybrid of isoxazole and dibenzazepine scaffolds were designed, based on their literature as antidiabetic agents. For this, a series of dibenzazepine-linked isoxazoles (33–54) was prepared using Nitrile oxide-Alkyne cycloaddition (NOAC) reaction, and evaluated for their α-glucosidase inhibitory activities to explore new hits for treatment of diabetes. Most of the compounds showed potent inhibitory potency against α-glucosidase (EC 3.2.1.20) enzyme (IC50 = 35.62 ± 1.48 to 333.30 ± 1.67 μM) using acarbose as a reference drug (IC50 = 875.75 ± 2.08 μM). Structure-activity relationship, kinetics and molecular docking studies of active isoxazoles were also determined to study enzyme-inhibitor interactions. Compounds 33, 40, 41, 46, 48–50, and 54 showed binding interactions with critical amino acid residues of α-glucosidase enzyme, such as Lys156, Ser157, Asp242, and Gln353.
- Umm-E-Farwa,Ullah, Saeed,Khan, Maria Aqeel,Zafar, Humaira,Atia-tul-Wahab,Younus, Munisaa,Choudhary, M. Iqbal,Basha, Fatima Z.
-
supporting information
(2021/05/10)
-
- 1,3-Oxazine-2-one derived dual-targeted molecules against replicating and non-replicating forms of Mycobacterium tuberculosis
-
The high mortality rate and increasing prevalence of resistant Mtb are the major concerns for the Tuberculosis (TB) treatment in this century. To curtail the prevalence of resistant Mtb, we have prepared 1,3-oxazine-2-one based dual targeted molecules. Compound 67 and 68 were found to be equally active against replicating and non-replicatiing form of Mtb (MICMABA 3.48 and 2.97 μg/ml; MICLORA 2.94 and 2.15 μg/ml respectively). They had found to suppress the biosynthesis of alfa, methoxy and keto-mycolate completely, as well as inhibit enzymatic activity of MenG (IC50 = 9.11 and 6.25 μg/ml respectively for H37Ra; IC50 = 11.76 and 10.88 μg/ml respectively for M smegmatis).
- Velappan, Anand Babu,Kesamsetty, Dhanunjaya,Datta, Dhrubajyoti,Ma, Rui,Hari, Natarajan,Franzblau, Scott G.,Debnath, Joy
-
supporting information
(2020/10/02)
-
- Anticancer, antimicrobial activities of quinoline based hydrazone analogues: Synthesis, characterization and molecular docking
-
Based on the biologically active heterocycle quinoline, a series (18a-p) of quinoline hydrazone analogues were prepared, starting from 6-bromo/6-chloro-2-methyl-quinolin-4-yl-hydrazines. For all the newly synthesized compounds cytotoxic activities were carried out at the National Cancer Institute (NCI), USA, against full NCI 60 human cancer cell lines. Amongst all the tested compounds, nine compounds (18b, 18d, 18e, 18f, 18g, 18h, 18i, 18j, 18l) exhibited important anti-proliferative activity at 10 μM concentration and were further screened at 10-fold dilutions of five different concentrations (0.01, 0.1, 1, 10 and 100 μM) with GI50 values ranging from 0.33 to 4.87 μM and LC50 values ranging from 4.67 μM to >100j μM. Further, the mean values of GI50, TGI and LC50 of the most potent compound 18j were compared with the clinically used anticancer agents bendamustine and chlorambucil, revealed that the quinolyl hydrazones holds promise as a potential anticancer agents. Further all the newly prepared compounds were screened for their antimicrobial activity. All the quinolyl hydrazones displayed good to excellent antimicrobial activity with MIC values ranging from 6.25 to 100 μg/mL against the tested pathogenic strains. Molecular docking of the synthesized compounds into the active binding site of human DNA topoisomerase I (htopoI) was carried out to predict the binding mode to the DNA topoisomerase I inhibitors. Hopefully in future, compounds based on quinoline core could be used as a lead compounds for designing new anticancer agents.
- Katariya, Kanubhai D,Shah, Shailesh R.,Reddy, Dushyanth
-
supporting information
(2019/11/26)
-
- Contribution of stilbene-imine additives on the structural, ionic conductivity performance and theoretical evaluation on CMC-based biopolymer electrolytes
-
New solid biopolymer electrolytes (SBEs) were prepared by integrating stilbene-imine derivatives bearing vinylene (–CH[dbnd]CH–) and azomethine (–CH[dbnd]N–) as additives in carboxymethyl cellulose (CMC) based electrolyte. The investigation on their spectroscopic and theoretical assessments were conducted to alter the energy level in improving the structural and ionic conductivity performance. The simulated results from frontier molecular orbitals (FMO) and Mulliken-charge analysis revealed that -CF3 and -NO2 substituents significantly reduce the HOMO-LUMO gap up to 0.68 eV. The highest ionic conductivity of SBEs achieved at ambient temperature was ~8 × 10?3 Scm-1 upon the addition of additive, obeying an Arrhenius model with reciprocal of temperature (303 K–373 K). The coordination interaction of C–O bond and CH[dbnd]N band facilitated the dissociation of more cation (H+) of NH4Cl which permits alternative route for H+ to hop into coordinating site in CMC. The outcomes are ideal in the development of electrochemical devices.
- Isa, M. I. N,Khairul, Wan M.,Rahamathullah, Rafizah
-
-
- In vitro study and structure-activity relationship analysis of stilbenoid derivatives as powerful vasorelaxants: Discovery of new lead compound
-
The development of vasorelaxant as the antihypertensive drug is important as it produces a rapid and direct relaxation effect on the blood vessel muscles. Resveratrol (RV), as the most widely studied stilbenoid and the lead compound, inducing the excellent vasorelaxation effect through the multiple signalling pathways. In this study, the in vitro vascular response of the synthesized trans-stilbenoid derivatives, SB 1-8e were primarily evaluated by employing the phenylephrine (PE)-precontracted endothelium-intact isolated aortic rings. Herein we report trans-3,4,4′-trihydroxystilbene (SB 8b) exhibited surprisingly more than 2-fold improvement to the maximal relaxation (Rmax) of RV. This article also highlights the characterization of the aromatic protons in terms of their unique splitting patterns in 1H NMR.
- Chan, Sock Ying,Loh, Yean Chun,Oo, Chuan Wei,Yam, Mun Fei
-
-
- 2-Aryl benzazole derived new class of anti-tubercular compounds: Endowed to eradicate mycobacterium tuberculosis in replicating and non-replicating forms
-
The high mortality rate and the increasing prevalence of Mtb resistance are the major concerns for the Tuberculosis (TB) treatment in this century. To counteract the prevalence of Mtb resistance, we have synthesized 2-aryl benzazole based dual targeted molecules. Compound 9m and 9n were found to be equally active against replicating and non-replicating form of Mtb (MIC(MABA) 1.98 and 1.66 μg/ml; MIC(LORA) 2.06 and 1.59 μg/ml respectively). They arrested the cell division (replicating Mtb) by inhibiting the GTPase activity of FtsZ with IC50 values 45 and 64 μM respectively. They were also capable of kill Mtb in non-replicating form by inhibiting the biosynthesis of menaquinone which was substantiated by the MenG inhibition (IC50 = 11.62 and 7.49 μM respectively) followed by the Vit-K2 rescue study and ATP production assay.
- Datta, Dhrubajyoti,Debnath, Joy,Franzblau, Scott G.,Ghosh, Kalyan Sundar,Hari, Natarajan,Ma, Rui,Rana, Shiwani,Velappan, Anand Babu
-
-
- Encapsulation of Flavin Cofactor within a Manganese Porphyrin-Based Metal-Organic Polyhedron for Reductive Dioxygen Activation
-
Encapsulation of flavin mononucleotide (FMN) in a porphyrinatomanganese(III)-based cubic cage allowed the fast reduction of manganese(III) porphyrin in the presence of nicotinamide adenine dinucleotide (NADH). This supramolecular system was capable of efficiently activating dioxygen and catalyzing the oxidation of benzyl alcohol. Control experiments suggested that the close proximity between FMN and manganese(III) porphyrins forced by the host-guest interaction might benefit the electron-transfer process from the FMN cofactor to the metal centers.
- Guo, Huimin,He, Cheng,Li, LiLi,Li, Xuezhao,Wang, Hailing,Yang, Linlin
-
supporting information
p. 2636 - 2640
(2020/03/19)
-
- “Effect of the linking unit on the calamitic-shaped liquid crystal: a comparative study of two homologous series of benzoate and cinnamate linked compounds”
-
Two homologous series based on three linking groups have been synthesized and well characterized by elemental analyses and spectroscopic techniques such as Fourier transform infrared [FT-IR] and proton magnetic resonance magnetic resonance [1H NMR] spectroscopy. The mesomorphic properties of these compounds were observed by using optical polarized microscopy (POM) and confirmed by differential scanning calorimetry (DSC) analysis. In this present investigation, we have synthesized two homologous series viz. (E)-4-(3-(4-(tetra decanoyloxy) phenyl) acryloyl) phenyl-4-n-alkoxy benzoate (Series-1) and 4-((E)-3-(4-(((E)-3-(4-n-alkoxy phenyl) acryloyl) oxy) phenyl)-3-oxo prop-1-en-1-yl) phenyl tetradecanoate (Series-2). Both of the series are differing with respect to the first linking group. All the homologous in following series displays LC properties on heating as well as cooling condition except first four homologous (C1 to C4) in series-1 and six homologous (C1 to C6) in series-2. To get more insights, the HOMO, LUMO studies are carried out which supports intramolecular charge transfer interactions in this class of mesogens.
- Kashyap, Dinesh,Patel, Sunil,Prajapat, Varsha,Sharma, Vinay,Vasava, Dilip
-
-
- Liquid Crystalline Properties of 4,4'-methylenebis(N-(4-Alkanoxybenzylidene)aniline): Synthesis, Characterization, and Theoretical study
-
The paper presents six homologues series of Schiff bases ether compounds distinguished by the length of terminal alkoxy groups which substituted on a side benzene nucleus. The above structures were demonstrated through the use of spectroscopic techniques, like FT- IR and1H-NMR. Polarized hot stage optical microscopy was used to study both mesomorphic properties and phase transitions. The results showed that out of the six compounds only three (B2, B3 and B4) were pure (marble) nematic mesophase, while no liquid crystal properties for (B5, B6 and B7) compounds. The theoretical study for the electronic structures was intended to study the effects of alkyl chain length on the electronic structure by using Gaussian program, DFT and 6-31G as basis set. The theoretical results indicate that there is no effect to the terminal substituted alkoxy groups on the HOMO energies but there is an effect on LUMO energies through decreasing energy for the prepared compounds.
- Yaseen, Mohammed Taha,Kshash, Abdullah Hussein
-
p. 1107 - 1114
(2020/01/08)
-
- Basic Anion-Exchange Resin-Catalyzed Aldol Condensation of Aromatic Ketones with Aldehydes in Continuous Flow
-
A general method for the aldol condensation of aromatic ketones with aldehydes was developed under continuous-flow conditions using a commercially available, strongly basic anion-exchange resin (A26) as catalyst. This procedure, in addition to exhibiting a wide substrate scope, promoted carbon-carbon bond formation under mild conditions using a quasi-stoichiometric ratio of starting reagents with good to excellent yields, thereby forming a limited amount of waste and allowing the process to be applied to sequential-flow systems. A proof of concept was developed in the first fully heterogeneously catalyzed two-step flow synthesis of donepezil, which is a blockbuster commercial anti-Alzheimer's drug.
- Laroche, Benjamin,Saito, Yuki,Ishitani, Haruro,Kobayashi, Shū
-
supporting information
p. 961 - 967
(2019/05/02)
-
- Preparation method of sugar-reducing medicine dapagliflozin
-
The invention discloses a preparation method for hypoglycemic drugdapagliflozin. The method comprises the steps that 4-hydroxybenzaldehyde is adopted as a starting raw material, alkylation, carbonyl reduction, chlorination and alkylation reaction with asepsin, diazotization and chlorination are performed to obtain a dapagliflozinmidbody 5-bromo-2-chloro-4'-ethyoxyl diphenylmethane, then, the midbody and 2,3,4,6-tetra-O-trimethyl silicone-D-glucolactone are subjected to condensation, etherification and methoxyl removal to obtain the hypoglycemic drugdapagliflozin. The raw materials adopted by the technological path are low in price and easy to obtain, the technology can achieve industrialization easily, and the final product is high in purity; the technological path is novel, the syntheticroute is short, no risky or complex technology exists in the reactions, equipment is simple, operation is easy and convenient, and the method is suitable for industrial production.
- -
-
Paragraph 0050-0053
(2019/10/01)
-
- Peripheral Substitution of Tetraphenyl Porphyrins: Fine-Tuning Self-Assembly for Enhanced Electroluminescence
-
This study reports the synthesis of two novel zinc porphyrin families bearing four or eight alkoxy chains at their peripheral phenyl rings, with the length of the alkoxy chains ranging from 2, to 6, and to 12 carbon atoms. All zinc porphyrin derivatives were fully characterized with respect to their photophysical and electrochemical features. The zinc porphyrins could be processed into thin films which, depending on the length of the alkoxy chains on the aryl substituents, were found to be either of an ordered or a disordered nature, as it is revealed by spectroscopic and microscopic techniques. The films containing ordered self-assemblies displayed significantly enhanced electrical conductivity compared to the disordered films. This led to remarkable differences regarding their electroluminescence response that occurs at lower bias. Furthermore, their luminous efficiency was of almost one order of magnitude higher than that of disordered films.
- Charisiadis, Asterios,Bagaki, Anthi,Fresta, Elisa,Weber, Katharina T.,Charalambidis, Georgios,Stangel, Christina,Hatzidimitriou, Antonios G.,Angaridis, Panagiotis A.,Coutsolelos, Athanassios G.,Costa, Rubén D.
-
p. 254 - 265
(2018/04/24)
-
- Preparation method of 5-bromine-2-chlorine-4'-ethyoxyl diphenylmethane
-
The invention provides a preparation method of 5-bromine-2-chlorine-4'-ethyoxyl diphenylmethane. The preparation method comprises the following steps: (1) using 4-hydroxybenzaldehyde and bromoethane as raw materials, a polar solvent as a reaction solvent and inorganic base as a catalyst to react so as to prepare 4-ethoxy-benzaldehyde; (2) using hydroxylamine hydrochloride and 4-hydroxybenzaldehyde as raw materials and a hydroxyl-containing solvent as a reaction solvent to react so as to obtain oxime, and then reacting under the effect of a dehydrating agent so as to generate 4-ethoxyl benzonitrile; (3) using 4-bromaniline and 4-ethoxyl benzonitrile as raw materials, using lewis acid as a catalyst, and performing a Hoesch reaction to generate 5-bromine-2-amino-4'-ethyoxyl benzophenone; (4) performing a diazo-reaction on 5-bromine-2-amino-4'-ethyoxyl benzophenone, and then reacting with cuprous chloride to synthesize 5-bromine-2-chlorine-4'-ethyoxyl benzophenone; and (5) performing a reduction reaction on 5-bromine-2-chlorine-4'-ethyoxyl benzophenone to obtain 5-bromine-2-chlorine-4'-ethyoxyl diphenylmethane. The method is low in cost, low in environment stress and short in synthetic route.
- -
-
Paragraph 0024-0027
(2017/11/18)
-
- Efficient and practical method for the synthesis of hydrophobic azines as liquid crystalline materials
-
A series of hydrophobic symmetrical azines: 1,2-bis[4-(n-alkoxy)benzylidene]hydrazine (where, n-alkoxy: O(CH2)nH, n = 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 16, or 18) have been prepared following an efficient and practical method. These compounds have been synthesized via the condensation reaction of hydrazine hydrate and appropriately 4-(n-alkoxy) benzaldehydes in acidic medium under ambient conditions. The prepared organic compounds have been characterized and their structures were elucidated depending upon micro-elemental analysis and spectral data (IR, UV-Vis, 1HNMR, 13C{1H}NMR, 2D 1H-1H-cozy, 2D 1H-13C-HSQC, and mass spectra). Liquid crystalline behavior of the prepared compounds was studied using polarized light optical microscopy and differential scanning calorimetry techniques. This study revealed that all the compounds displayed enantiotropic liquid crystal properties, exhibiting smectic and nematic mesophases.
- Hammood, Ali Jasim,Kased, Ahmed Fadhel H.,Al-Karawi, Ahmed Jasim M.,Raseen, Sameem R.,Tomi, Ivan Hameed R.,Omar Ali, Al-Ameen Bariz
-
p. 114 - 129
(2017/07/04)
-
- Mesogenic naphthyl derivatives
-
Two new mesogenic homologous series of liquid crystalline naphthalene derivatives with different central linkages: 2- Naphthyl-4-n-alkoxybenzoates (I) and trans-2-Naphthyl -4-n –alkoxycinnamates(II), have been synthesized and characterized by a combination of elemental analysis and standard spectroscopic methods. Twelve compounds have been synthesized in both the series I and II. In series I, methoxy to n-pentyloxy derivatives are non mesogenic, n-hexyloxy to n-hexadecyloxy derivatives exhibit monotropic nematic mesophase. Smectic A mesophase commences from n-decyloxy derivatives as a monotropy and persist up to the last member synthesized. All the 12 compounds of series II exhibit mesomorphism. Methoxy to n-propyloxy derivatives exhibit monotropic nematic mesophse, and n-butyloxy to n-tetradecyloxy derivatives exhibit enantiotropic nematic mesophase. n-Hexayloxy to n-hexadecyloxy derivatives also exhibit enantiotropic smectic A mesophase. The mesomorphic properties of present series were compared with each other and with a structurally related mesogenic homologous series to evaluate the effects of central linkage on mesomorphism.
- Patel,Prajapati
-
p. 106 - 115
(2017/03/08)
-
- Mesomorphism dependence on molecular rigidity and substitution of same functional group on lateral or terminal position of tailed phenyl ring
-
Novel liquid crystal materials (LCs) of low temperature range (53°C to 75°C) have been synthesized through a series of chalconyl derivatives consisting of two phenyl rings bonded through a –CH?CH?CO? central bridge to study the effect of molecular structure on LC properties in general and with a focus on molecular rigidity. The novel homologues series (C1 to C18) consists of thirteen homologues with general formula RO?C6H4?CH?CH?CO?C6H4?OC10H21(n) (meta). The C1, C2, C3 homologues are nonliquid crystals (NLC) and the rest of the homologues (C4 to C18) are either monotropic or enantiotropic liquid crystals. C4 to C6 homologues are enantiotropicnematic and the rest of the mesomorphic homologues are (C7 to C18) monotropicsmectic in addition to monotropicnematic character. Transition and melting temperatures including textures of homologues were determined by an optical polarizing (POM) microscopy equipped with a heating stage. Textures of a nematic phase are threaded or Schlieren, and that of the smectic phase are of the type Smectic A or C as judged directly from the heating top of the microscope. Thermal stability for smectic is very poor and of the nematic is (N-I) 69.3°C whose, total mesophase length ranges between 07.0 to 14.0°C at C8 and C4 homologues respectively.
- Sharma, Vinay S.,Patel
-
p. 178 - 187
(2017/03/08)
-
- The effect of position of octadecyloxy tail on the formation of liquid crystal with chalconyl-ester and chalconyl-vinyl ester series: Comparison with corresponding linkage group
-
Two series of chalconyl-based liquid crystals which differ from each other in the position of the first linking group have been synthesized and characterized by elemental analyses and spectroscopic techniques such as Fourier transform infrared and proton magnetic resonance magnetic resonance [1H NMR] spectroscopy. The mesomorphic properties of these compounds were observed by optical polarized light microscopy (POM) and differential scanning calorimetry (DSC). We have synthesized two homologous series viz. 3-(3-(4-(Octadecyloxy) phenyl) acrylonyl) phenyl 3-(4-n-alkoxyphenyl) acrylate (series-1) and 3-(3-(4-(Octadecyloxy) phenyl) acryloyl) phenyl 4-n-alkoxy benzoate (series-2). Series-1 has chalconyl-ester central linkage group while in series-2 chalconyl-vinyl ester group is present and tail octadecyloxy side chain is common in both homologous series. All the homologous in present series display LC property in enantiotropical manner except first three homologous in both series.
- Solanki,Sharma, Vinay. S.,Patel
-
p. 216 - 232
(2017/03/08)
-
- Synthesis and mesomorphic properties of quinoline-8-yl-4-((4-n-alkoxy benzylidene) amino) benzoate: The effect of linkage group
-
A new homologous series viz. quinoline-8-yl-4-((4-n-alkoxy benzylidene) amino) benzoate based on two central linking groups have been designed and characterised by elemental analyses and spectroscopic techniques such as Fourier transform infrared [FT-IR] and protonmagnetic resonance magnetic resonance [1H NMR] spectroscopy. The mesomorphic properties of these compounds were observed by polarizing optical light microscopy (POM) and confirmed by differential scanning calorimetry (DSC). All synthesized compounds displayed LC property except first two homologue. The lower homologues (n = 4 to 8) display SmA and SmC phase while, in higher homologues (n = 10 to 18) SmC and nematic phasewere seen in heating and cooling condition.
- Sharma, Vinay. S.,Vekariya, Rajesh H.,Sharma, Anuj. S.,Patel
-
-
- Synthetic pathway for a new calamitic series of liquid crystal: Comparison with corresponding linkage group
-
Reduction-responsive cystamine-incorporated gelatin microspheres were prepared by an emulsification method. On SEM micrograph, the microsphere, prepared at pH 9.0 and at the carboxyl/amino group molar ratio of 1:1, was sphere-like and its diameter was a few to 100 μm. The gelatin to cystamine ratio of the microsphere was about 1:0.2 (w/w), determined by energy dispersive X-ray spectroscopy. Two endothermic peaks were observed around 92°C and 126°C, which were thought to be the melting point of gelatin-rich phase and that of cystamine-rich phase, respectively. The microsphere released its payload (FITC-dextran) in dithiothreitol (a reducing agent) concentration-dependent manner.
- Sharma, Vinay S.,Vekariya, Rajesh H.,Sharma, Anuj S.,Patel
-
p. 143 - 157
(2017/10/27)
-
- New hockey stick shaped amino allylidene (?N?CH?CH?CH) based compounds: Effect of linkage group on mesomorphic properties
-
Two nonlinear hockey stick shaped homologous series based on three linking groups have been synthesized and characterized by elemental analyses and spectroscopic techniques. The mesomorphic properties of these compounds were observed by polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). In this present investigation, we have synthesized two homologous series viz. 2-((3-phenyl allylidene) amino) phenyl 4-((4-n-alkoxy benzylidene) amino) benzoate (series-1) and 4-((2-((3-phenyl allylidene) amino) phenoxy) carbonyl) phenyl-4-n-alkoxy benzoate (series-2). Both the series are differing with respect to first linking group. In series-1, comp.C4-C18 shows nematic as well as smectic phase while in series-2, comp.C10-C16 shows smectic and nematic phase while comp.C4-C18 shows only nematic phase.
- Sharma, Vinay. S.,Vekariya, Rajesh. H.,Sharma, Anuj. S.,Patel
-
-
- The effect of position of tert-butyl tail group on the formation of liquid crystal in Schiff base ester based homologous series
-
We report a newly rod like calamatic liquid crystalline materials, which are constructed by the self-organization of a rod-like carboxylic acid derivative based on Schiff base ester as the linking group with tert butyl tail group. A newly series of 4-(tert-butyl) phenyl 4-((4-alkoxybenzylidene) amino) benzoate with different alkyl chain spacer (n = 1 to 8, 10, 12, 14, 16, and 18) were synthesized and their mesomorphic properties were investigated by differential scanning calorimetry and polarized optical microscopy. All homologous in present series displays mesophase in enantiotropically manner. Thermal stability of SmC-SmA is 137.5 °C. All the compounds were characterized by spectroscopic and elemental analysis. The effects of varying left alkyl side spacer on mesomorphism with its structurally related compounds in series have been discussed.
- Sharma,Patel
-
-
- Synthesis and investigation of novel benzimidazole derivatives as antifungal agents
-
The rise and emergence of resistance to antifungal drugs by diverse pathogenic fungal strains have resulted in an increase in demand for new antifungal agents. Various heterocyclic scaffolds with different mechanisms of action against fungi have been investigated in the past. Herein, we report the synthesis and antifungal activities of 18 alkylated mono-, bis-, and trisbenzimidazole derivatives, their toxicities against mammalian cells, as well as their ability to induce reactive oxygen species (ROS) in yeast cells. Many of our bisbenzimidazole compounds exhibited moderate to excellent antifungal activities against all tested fungal strains, with MIC values ranging from 15.6 to 0.975?μg/mL. The fungal activity profiles of our bisbenzimidazoles were found to be dependent on alkyl chain length. Our most potent compounds were found to display equal or superior antifungal activity when compared to the currently used agents amphotericin B, fluconazole, itraconazole, posaconazole, and voriconazole against many of the strains tested.
- Chandrika, Nishad Thamban,Shrestha, Sanjib K.,Ngo, Huy X.,Garneau-Tsodikova, Sylvie
-
supporting information
p. 3680 - 3686
(2016/07/20)
-
- Syntheses and characterization of aryl-substituted pyrogallol[4]arenes and resorcin[4]arenes
-
Seven aryl-substituted pyrogallol[4]arenes and six aryl-substituted resorcin[4]arenes were synthesized through the acid catalyzed reaction of either pyrogallol or resorcinol with a specific alkoxybenzaldehyde. Single crystal X-ray data was obtained for all thirteen compounds. In order to determine the effect of the different pendent -R groups, four properties were investigated: π-π distance, inward tilt, twist angle, and the angle between the planes containing the pendent -R groups. Positioning of the -R groups, the carbon atom chain length of the -R groups, the number of upper-rim hydroxyl groups (resorcin[4]arene vs. pyrogallol[4]arene), and the number of substituted phenyl groups all influenced these four properties. The trends that develop are investigated and discussed.
- Pfeiffer, Constance R.,Feaster, Kyle A.,Dalgarno, Scott J.,Atwood, Jerry L.
-
p. 222 - 229
(2015/12/31)
-
- Homoserine lactone derivatives, preparation method thereof and pharmaceutical composition for prevention or treatment of the periodontal diseases containing the same as an active ingredient
-
The present invention relates to homoserine lactone derivatives, optical isomers of the same, or pharmaceutically acceptable salts of the same. The homoserine lactone derivatives in the present invention have excellent properties as a quorum sensing antagonist which hinders communications among bacteria. According to the present invention, the homoserine lactone derivatives can hinder gene expressions of bacteria while effectively blocking formation of biofilm which is known to raise resistance against antibiotics, and suppress propagation of bacteria, thereby being useful as a pharmaceutical composition for preventing or treating periodontal diseases.
- -
-
Paragraph 0225-0228
(2017/04/14)
-