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Tuning the SOCT-ISC of bodipy based photosentizers by introducing different electron donating groups and its application in triplet-triplet-annihilation upconversion
To study the effect of electron-donating ability on spin orbit charge transfer intersystem crossing (SOCT-ISC) efficiency, a series of bodipy derivatives (BDP-O, BDP-2-MN, BDP-2-EN) linked with electron-donating groups with different electron-donor abilities were synthesized. For BDP-2-MN and BDP-2-EN, both compounds show a sharp charge transfer emission band at 630 nm, and the local excited (LE) emission in both compounds were completely quenched due to photo-induced electron transfer (PET). By femtosecond transient absorption measurement, the triplet state population in both compounds was confirmed to occur through charge recombination (1996 ps ~2307 ps) process after the photo-induced electron transfer upon photoexcitation of bodipy moiety. A long-lived triplet excited state was observed for both compounds (lifetimes: 37 ~ 42 μs) via nanosecond transient absorption. The BDP-2-MN and BDP-2-EN can act as the triplet photosensitizers without heavy elements for the application of triplet-triplet-annihilation upconversion (TTA-UC, ΦUC can reach 4.88%). In case of BDP-O molecule, no triplet signal was observed for this compound because of poor electronic coupling between donor and acceptor. Therefore, the triplet excited state properties of bodipy chromophore was successfully regulated by adjusting electronic strength of donor moiety and implement these photosensitizers in the application of TTA-UC.
Liang, Hui,Sun, Shanshan,Zafar, Mahmood,Yuan, Zhanxiang,Dong, Yuye,Ji, Shaomin,Huo, Yanping,Li, Ming-De,Zhao, Jianzhang
(2020)
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Electrochemical Aerobic Oxidative Cleavage of (sp3)C-C(sp3)/H Bonds in Alkylarenes
An electrochemistry-promoted oxidative cleavage of (sp3)C-C(sp3)/H bonds in alkylarenes was developed. Various aryl alkanes can be smoothly converted into ketones/aldehydes under aerobic conditions using a user-friendly undivided cell setup. The features of air as oxidant, scalability, and mild conditions make them attractive in synthetic organic chemistry.
Liu, Shuai,Liu, Zhong-Quan,Shen, Tong,Shen, Xu,Wang, Nengyong,Wu, Jintao,Yang, Le,Zhao, Jianyou
p. 3286 - 3295
(2022/03/14)

Novel N-heterocyclic carbene cyclic palladium compound as well as preparation method and application thereof
The invention discloses a novel N-heterocyclic carbene cyclic palladium compound as well as a preparation method and application thereof, and belongs to the technical field of organic catalysis. The novel N-heterocyclic carbene cyclic palladium compound is prepared by the following steps: heating, stirring and mixing N-(4-butoxybenzyl)-N-ethylethylamine, palladium chloride and an organic solvent in an inert gas atmosphere, then adding potassium carbonate, performing stirring and mixing, and finally adding 1-(2,6-diisopropyl phenyl)-3-butyl-brominated imidazole for reflux reaction; and after the reaction is finished, performing quenching with an acid solution, performing extracting to obtain a crude product, and performing column chromatography separation and purification to obtain the novel N-heterocyclic carbene cyclic palladium compound. The N-heterocyclic carbene cyclic palladium compound provided by the invention has high catalytic activity, can catalyze cross-coupling reactions between aryl chloride and aryl phenylboronic acid and between aryl chloride and secondary amine in a catalytic amount of 1 mol%, and can be used as a high-efficiency catalyst for the coupling reactions.
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Paragraph 0027; 0031; 0034

(2021/06/26)

Electricity Driven 1,3-Oxohydroxylation of Donor-Acceptor Cyclopropanes: a Mild and Straightforward Access to β-Hydroxy Ketones
An unprecedented external oxidant-free electrochemical protocol for 1, 3-oxohydroxylation of donor-acceptor cyclopropane is disclosed. The strategy encompasses the activation of the labile π-electron cloud of the aryl ring to cleave the strained Csp3?Csp3 bond of cyclopropane to afford the β-hydroxy ketones via insertion of molecular oxygen. More significantly, based on the detailed mechanistic investigations and cyclic voltammetry experiments, a plausible mechanism is proposed.
Banerjee, Prabal,Maajid Taily, Irshad,Saha, Debarshi
supporting information
p. 5053 - 5057
(2021/09/30)

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)

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
(2019/11/26)

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)

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
(2020/09/04)

Light-Promoted Nickel Catalysis: Etherification of Aryl Electrophiles with Alcohols Catalyzed by a NiII-Aryl Complex
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.
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)

Porphyrin molecule for fluorenyl Friedel-Crafts reaction modification, post-modification material, preparation method and application thereof
The invention discloses a porphyrin molecule for fluorenyl Friedel-Crafts reaction modification, a post-modification material, a preparation method and application thereof. The method for functional modification of porphyrin molecule by Friedel-Crafts reaction introduces porphyrin ring into a conjugate interrupted steric hindrance group molecule, advantageously destroys the pi-pi effect between faces, effectively regulates the energy level structure and realizes functional modification. The synthetic strategy of Friedel-Crafts reaction provided by the invention is green and environment-friendly, has low loss and high yield, is simple in operation and low in cost, and is a new porphyrin functional modification method that can be popularized and applied. The porphyrin Friedel-Crafts post-modified structural molecule designed and synthesized by the invention is a functional photoelectric information material, can be applied to a memristor active layer for functional simulation of an artificial neural network, and is expected to provide new possibility for application of organic memristor materials.
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Paragraph 0059; 0061; 0062

(2019/11/19)

Side chain modified porphyrin molecules and application thereof
The invention discloses side chain modified porphyrin molecules and application thereof. According to the side chain modified porphyrin molecules, porphyrin molecules with electron enriching functionsare adopted as a core of capturing charges, an alkoxy chain segment is adopted as an inhibition part of a charge transfer process, and the molecules are ensured to be applied to flexible structures for solution processing. Molecule structures are reasonably designed from the view of film morphologies, preparation processes and performance regulation and control, and properties of organic field effect transistor storage devices are compared. The invention provides a material and device preparation method which is feasible in commercial popularization, low in cost and simple in process while properties of storage devices are regulated.
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Paragraph 0061; 0065-0066

(2019/12/25)

Highly frustrated liquid crystal phases in optically active dimers: Synthesis and rich phase transitional behavior
Herein we report on the synthesis and characterization of four new series of optically active, nonsymmetric dimers in which cholesterol is covalently linked to a Schiff base core through an ω-oxyalkanoyl spacer. While the Schiff base core is substituted with n-butyloxy, n-hexyloxy, n-octyloxy, n-decyloxy and n-dodecyloxy tails, three even-parity spacers, namely, 4-oxybutanoyl, 6-oxyhexanoyl, 8-oxyoctanoyl, and an odd-parity spacer, namely, 5-oxypentanoyl, have been used to join the two cores. The experimental results show that the length and parity of the spacer and the length of the terminal tail play a vital role in deciding the phase sequences of the dimers. In general, the dimers possessing an even-parity spacer display enantiotropic LC phases such as chiral nematic (N?), twist grain boundary (TGB), smectic A (SmA), chiral smectic C (SmC?) and twist grain boundary phase with SmC? slabs (TGBC?). Some of these dimers display TGBC? over a wide temperature range. The dimers with an odd-parity (5-oxypentanoyl) spacer display, unlike their even-membered counterparts, blue phases (BPIII/II/I); besides, they stabilize N? and/or unknown smectic (SmX) phases. The circular dichroism (CD) measurements were carried out as a function of temperature on the planar texture formed by three even-membered dimers and an odd-membered dimer. The occurrence of a strong negative CD band in the N? phase of the even-membered dimers suggests a left-handed screw sense of the macroscopic helical structure, and the scenario is opposite in the case of an odd-membered dimer.
Nayak, Rashmi Ashwathama,Bhat, Sachin A.,Shanker,Rao, D. S. Shankar,Yelamaggad
supporting information
p. 2148 - 2162
(2019/02/05)

“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
p. 58 - 70
(2019/08/28)

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
p. 67 - 77
(2019/06/21)

Studies on some thiazolidinones as antioxidants for local base oil
In this work, 5 thiazolidinone derivatives of the type 5-benzylidene -2-(1-piperidinyl)-4-oxo-1,3-thiazolidine (101), 5-(4-butoxybenzylidene)-2-(1-piperidinyl)-4-oxo-1,3-thiazolidine (102), 5-(4-hexyloxybenzylidene)-2-(1-piperidinyl)-4-oxo-1,3-thiazolidine (103), 5-(4-octyloxybenzylidene)-2-(1-piperidinyl)-4-oxo-1,3-thiazolidine (104) and 5-(4-decyloxybenzylidene)-2-(1-piperidinyl)-4-oxo-1,3-thiazolidine (105) are synthesized and characterized using conventional tools analyses. They are tested as antioxidants for local base stock and the efficiency of these compounds, as antioxidants, was monitored through studying the change in total acid number and viscosity, the results reveal that the efficiency order is ranked as follows 105 > 104 > 103 >102 > 101. The quantum chemical parameters such as the lowest unoccupied molecular orbital (LUMO), the highest occupied molecular orbital (HOMO) energy levels and the energy gap (EHOMO-ELUMO) were calculated. The experimental results were on the same line with the quantum chemical calculations.
Mohammed, Hoda A.,Attia, Sayed K.,Nessim, Maher I.,Shaaban, Mohamed E.,El-Bassoussi, Ali A. M.
p. 1619 - 1634
(2019/09/09)

Bowl-shaped fluorescent liquid crystals derived from 4-: Tert butyl calix[4]arene and trans cinnamic acid derivatives
A new family of bowl-shaped molecules with a calix[4]arene rigid core appended by four-side and two-side substitution with trans 4-n-alkoxy cinnamic acid has been synthesized and well characterized. The LC behaviours of the novel materials were studied by using optical polarising microscopy, differential scanning calorimetry and high-temperature powder X-ray diffraction methods to confirm the smectic organization. It is found that all of the prepared materials display enantiotropic LC phases in the present series-1 (1d4-1, 1d5-l, 1d8-1, 1d10-l, 1d12-l, 1d14-l) and series-2 (1d4-1l, 1d5-ll, 1d8-1l, 1d10-ll, 1d12-ll, 1d14-ll). The electrochemical behaviour shows the higher reactivity of the proposed derivatives, which is in good agreement with the DFT values. The relationship between the structure and the mesomorphic behaviour of the compounds in both series is discussed. These synthesized supramolecular compounds show blue luminescence in solution as well as in solid thin films under long wavelength UV light. To get more insights, HOMO and LUMO studies were carried out, which support intramolecular charge transfer interactions in this class of mesogens.
Sharma, Vinay S.,Singh, Hemant Kumar,Sharma, Anuj S.,Shah, Akshara P.,Shah, Priyanka A.
supporting information
p. 15575 - 15584
(2019/10/19)

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)

Triplet state photosensitizer and preparation method thereof and up-conversion system
The invention provides a photosensitizer having a structure shown as a formula (BDP-1) to a formula (BDP-3). The photosensitizer provided by the invention is a triplet state photosensitizer; the photosensitizer has a high mole extinction coefficient at visible light, and emits high-strength light in TTA up-conversion, i.e., efficient up-conversion is realized under the condition of a low-power (5.0mw) excitation light source; in addition, strong absorption on the visible light can be realized, up-conversion from green light to blue light and that from red light to the green light are realizedby a triplet state-triplet state annihilation process, and the photosensitizer having the property can be widely applied to fields such as photocatalytic organic synthesis, photodynamic treatment, bioimaging and solar cells.
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Paragraph 0076-0079

(2018/04/01)

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
p. 33 - 42
(2019/02/24)

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
p. 43 - 51
(2019/02/24)

“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
p. 49 - 58
(2019/07/03)

Synthesis and Structure–Activity Relationships of Novel Benzylamine-Type Antifungals as Butenafine-Related Antimycotics
Benzylamine-type antimycotics like naftifine, butenafine, or terbinafine are a well-known class of antimycotics since the 1980s. The following paper describes the synthesis and biological evaluation of a series of novel benzylamine-type antimycotics characterized by an isooctyl side chain and various substituents at the benzylamine moiety. The compounds were prepared from benzaldehyde derivatives and 2-amino-6-methylheptane by reductive amination with sodium triacetoxyborohydride and subsequent precipitation with hydrogen chloride. The antimycotic activity of the resulting compounds was evaluated in an agar diffusion assay against the yeasts C. glabrata and Yarrowia lipolytica, the mold Aspergillus niger and the dermatophyte H. burtonii. The compounds were also tested in a microdilution assay against the yeast Candida glabrata and the dermatophyte H. burtonii to determine the minimal inhibitory concentrations (MIC). Compounds with an aromatic ether side chain or a short alkyl ether side chain showed significant antimycotic activity against C. glabrata, comparable to terbinafine or clotrimazole.
Krauss, Jürgen,Stadler, Martina,Bracher, Franz
(2017/05/05)

Natural α-methylenelactam analogues: Design, synthesis and evaluation of α-alkenyl-γ and δ-lactams as potential antifungal agents against Colletotrichum orbiculare
In our continued efforts to improve the potential utility of the α-methylene-γ-lactone scaffold, 62 new and 59 known natural α-methylenelactam analogues including α-methylene-γ-lactams, α-arylidene-γ and δ-lactams, and 3-arylideneindolin-2-ones were synthesized as the bioisosteric analogues of the α-methylenelactone scaffold. The results of antifungal and cytotoxic activity indicated that among these derivatives compound (E)-1-(2, 6-dichlorobenzyl)-3-(2-fluorobenzylidene) pyrrolidin-2-one (Py51) possessed good selectivity with the highest antifungal activity against Colletotrichum orbiculare with IC50?=?10.4?μM but less cytotoxic activity with IC50?=?141.2?μM (against HepG2 cell line) and 161.2?μM (against human hepatic L02?cell line). Ultrastructural change studies performed by transmission electron microscope showed that Py51 could cause important cell morphological changes in C.?orbiculare, such as plasma membrane detached from cell wall, cell wall thickening, mitochondria disruption, a dramatic increase in vacuolation, and eventually a complete loss in the integrity of organelles. Significantly, mitochondria appeared one of the primary targets, as confirmed by their remarkably aberrant morphological changes. Analysis of structure–activity relationships revealed that incorporation of the aryl group into the α-exo-methylene and the N-benzyl substitution increased the activity. Meanwhile, the α-arylidene-γ-lactams have superiority in selectivity over the 3-arylideneindolin-2-ones. Based on the results, the N-benzyl substituted α-(2-fluorophenyl)-γ-lactam was identified as the most promising natural-based scaffold for further discovering and developing improved crop-protection agents.
Delong, Wang,Lanying, Wang,Yongling, Wu,Shuang, Song,Juntao, Feng,Xing, Zhang
p. 286 - 307
(2017/03/09)

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)

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
p. 1 - 12
(2017/03/08)

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
p. 13 - 27
(2017/03/08)

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
p. 40 - 51
(2017/03/08)

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
p. 52 - 61
(2017/03/08)

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
p. 129 - 140
(2017/03/08)

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
p. 159 - 167
(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, 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
p. 241 - 251
(2017/03/08)

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
p. 10 - 22
(2017/10/27)

Alkoxy substituted D-π-A dimethyl-4-pyrone derivatives: Aggregation induced emission enhancement, mechanochromic and solvatochromic properties
Three series of D-π-A 2,6-dimethyl-4-pyrone-cored derivatives were designed and synthesized. Evaluation by spectroscopic methods indicated that all the compounds exhibited aggregation-induced emission enhancement (AIEE) effect and solvatochromism. The experimental results revealed that the restriction of intramolecular rotation is the key element for showcasing the AIEE phenomenon. Moreover, all of the compounds presented red-shifted mechanochromic behavior, the extent of the red-shift was mainly dependent on the position and length of alkoxyl group. The PXRD and DSC profiles demonstrated a transformation from crystalline to amorphous state upon grinding. The D-A strategy introduced in this work could facilitate the development and application of ingenious mechanochromic materials.
Cao, YuQi,Xi, Ye,Teng, XinYu,Li, Yang,Yan, Xilong,Chen, Ligong
p. 75 - 83
(2016/10/25)

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
p. 99 - 110
(2017/09/25)

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
p. 84 - 98
(2017/09/25)

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
p. 53 - 65
(2017/07/04)

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)

Highly efficient reduction of carbonyls, azides, and benzyl halides by NaBH4 in water catalyzed by PANF-immobilized quaternary ammonium salts
A series of polyacrylonitrile fiber-supported quaternary ammonium salts (PANF-QAS) were prepared and applied to the catalytic reduction of aldehydes, ketones, azides, and benzyl halides in water using NaBH4 as the reducing reagent in a highly efficient, economic, and environmentally benign way. The structure-activity relationships were investigated, which showed that the catalysts made up of quaternary ammonium salts with longer alkyl chains, larger cationic radii and better lipophilicity speed up the reduction reaction to afford the products in excellent yield. Moreover, the optimized catalyst can be applied to the reduction of 1-naphthaldehyde in a continuous flow process with outstanding reactivity and recyclability.
Du, Jianguo,Xu, Gang,Lin, Huikun,Wang, Guangwei,Tao, Minli,Zhang, Wenqin
supporting information
p. 2726 - 2735
(2016/05/24)

Synthesis, spectroscopic and computational characterization of the tautomerism of pyrazoline derivatives from chalcones
In the present study a series of novel pyrazolines derivatives has been synthesized, and their structures assigned on the basis of FT-Raman, 1H and 13C NMR spectral data and computational DFT calculations. A joint computational study using B3LYP/6-311G(2d,2p) density functional theory and FT-Raman investigation on the tautomerism of 3-(4-substituted-phenyl)-4,5-dihydro-5-(4-substituted-phenyl)pyrazole-1-carbothioamide and 3-(4-substituted-phenyl)-4,5-dihydro-5-(4-substituted-phenyl)pyrazole-1-carboxamide are presented. The structures were characterized as a minimum in the potential energy surface using DFT. The calculated Raman and NMR spectra were of such remarkable agreement to the experimental results that the equilibrium between tautomeric forms has been discussed in detail. Our study suggests the existence of tautomers, the carboxamide/carbothioamide group may tautomerize, in the solid state or in solution. Thermodynamic data calculated suggests that the R(CS)NH2 and R(CO)NH2 species are more stable than the R(CNH)SH and R(CNH)OH species. Additionally, results found for the 1H NMR shifting, pointed out to which structure is present.
Miguel, Fbio Balbino,Dantas, Juliana Arantes,Amorim, Stefany,Andrade, Gustavo F.S.,Costa, Luiz Antnio Sodr,Couri, Mara Rubia Costa
p. 318 - 326
(2015/08/06)

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
p. 11 - 19
(2016/03/01)

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
p. 54 - 62
(2016/09/04)

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
p. 80 - 90
(2016/09/04)

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
p. 50 - 57
(2016/10/04)

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
p. 19 - 27
(2016/11/21)

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
p. 27 - 34
(2016/11/22)

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
p. 35 - 43
(2016/11/22)