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Abstract: In the past two decades, low melting mixtures have become attractive because of their interesting characteristics such as physicochemical properties, low cost of components, easiness of preparation, low toxicity, biorenewability and biodegradability. Carbohydrates the most important and widespread renewable compounds on earth, are introduced in low melting mixtures to get more cost-effective and renewable solvents. The present review mainly focuses on the properties and applications of low melting mixtures, which completely satisfy the green chemistry principles. Many physicochemical properties of low melting mixtures have been studied recently. The various studies included thermal stability, glass transition temperature, density, viscosity, acidity, surface tension, refractive index, FT-IR spectra, conductivity, etc. The application towards organic synthesis makes the low melting mixtures very important. Low melting mixtures and their use as a solvent in organic synthesis and their dual role as catalyst and solvent are discussed.

d-Sorbitol-cored PAMAM dendrimer (SOR-G1) was effectively synthesized by the ring opening polymerization of epichlorohydrin. The dendrimer was characterized using different spectroscopic and analytical techniques including IR and NMR spectroscopy, TG–DTA, and GPC. Dihydropyrano[3,2-c]chromene derivatives were synthesized using SOR-G1 as a catalyst, and it was synthesized within 30 min in ethanol/water medium and excellent yield was obtained. SOR-G1 acted as a good base catalyst on the basis of amine capacity and good thermal stability. The prepared dihydropyrano[3,2-c]chromene derivatives were characterized using GCMS, LCMS, IR, 1H NMR, and 13C NMR spectra. The catalyst could be reused up to three reaction cycles without losing its catalytic activity.

Novel isosorbide initiated polyepichlorohydrin cored PPI dendronized polymer (ISO-PECH-Amine-G1) has been prepared and its structure was determined by different spectro- analytical techniques. The catalytic activity of ISO-PECH-Amine-G1 was explored for the synthesis of polyhydroquinolines and 4-arylidene-3-methylisoxazol-5(4H)-ones. From an eco-benign perspective, the notable advantages of this protocol are as follows: (i) water as reaction medium, (ii) transition metal-free, (iii) no toxic by-products, (iv) room temperature reaction, (v) simple experimental and work-up procedure, (vi) high conversion, (vii) shorter reaction time, (viii) diverse substrate scope, (ix) no need of solvent extraction and (x) facile reusability of the catalyst. In addition, computational calculations were performed using the B3LYP/6-31G level of theory to explore various density functional theory (DFT) based descriptors such as dipole moment, hardness, chemical potential, electrophilicity index, and the nucleophilicity index of the synthesized derivatives.

Deep eutectic solvents are a class of new generation green solvents formed from two or more components, which furnish a new homogeneous liquid phase with lower melting point than the individual com...

Deep eutectic solvents are obtained by the fusion of two or more compounds: hydrogen bond donors (HBDs) and hydrogen bond acceptors (HBAs). They are formed by mixing the constituents with moderate heating (via hydrogen bond interactions). In this manuscript, the dual activities (as catalysts and reaction media) of six deep eutectic solvents were compared for the synthesis of 1,8-dioxooctahydroxanthenes at room temperature. Here DES 2, a combination of ZrOCl2·8H2O with ethylene glycol at a 1 : 2 ratio, was found to be the supreme catalyst among the six DESs and was reused for five batches. The photophysical properties of the xanthene derivatives were examined by UV-vis and fluorescence spectroscopy in THF. The synthesised molecules showed absorption maxima around 285–295 nm and emission maxima around 403–404 nm. The ground state dipole moments of all the molecules were calculated by the Debye–Guggenheim method using toluene as the non-polar solvent. All the synthesised molecules showed significant dipole moment values and are in good agreement with theoretical values.

Alternate donor–acceptor 3,4-ethylenedioxythiophene (EDOT) based copolymers with thiophene and 3-methyl thiophene were designed by employing density functional theory (DFT) in the periodic boundary condition using HSE06 exchange correlation functional and 6-31G basis set. The designed copolymers were synthesized via a simple and facile route, i.e., direct arylation and their third-order nonlinear optical properties were investigated by Z-scan technique. The resultant copolymers, P(EDOT-THP) and P(EDOT-MeTHP) were characterized by spectroscopic analysis. The photophysical and electrochemical properties of EDOT-thiophene copolymers were investigated by UV–visible spectra and cyclic voltammetry, respectively. The copolymers revealed low band gap and better electronic properties as compared to the homopolymers. The introduction of EDOT unit in the polythiophene leads to decreased HOMO-LUMO energy levels, and the absorption spectra was red shifted when compared with that of the parent compound. The nonlinear absorption and nonlinear refraction coefficient of copolymers have been investigated at 532 nm. The optical limiting properties of copolymers have also been measured. The copolymers exhibited strong optical nonlinearity owing to the presence of alternate donor-π-acceptor scheme in the polymers.

Deep eutectic solvents formed from hydrated metal chlorides and hydrogen bond donors (Type 4) were prepared and their catalytic activity was compared for the synthesis of dihydropyrimidinones/thiones via Biginelli reaction at room temperature. The one-pot multicomponent reaction was performed between ethyl acetoacetate, various aldehydes and urea/thiourea using DESs. Among the five DESs, excellent conversion was observed using DES 2 (ZrOCl2·8H2O with ethylene glycol at 1 : 2 ratio). The higher activity of DES 2 might be due to the strong hydrogen bonding ability and low viscosity of DES 2, which favoured the reaction as a catalyst. Further, the catalyst was recycled and reused up to four consecutive cycles without significant loss in its activity. The efficiency of the present catalyst was compared with some previous reports. Various structural and quantum chemical parameters (like energy gap), dipole moment, ionization potential, electron affinity, chemical potential (μ), global hardness (η), softness (μ), electronegativity (χ), electrophilicity index (ω) of the pharmaceutically important Biginelli products were investigated using B3LYP functional at 6-31G* level, as implemented in Gaussian 09.

A porphyrin cored azide functionalised dendritic polymer was developed as a selective sensor for in vivo monitoring of mercuric ions in living (normal and cancer) cells and in an aqueous medium. The developed sensor could sense mercuric ions even at a nanomolar concentration with a limit of detection value of 0.9 nM. This probe can be used to monitor mercuric ions in living cells due to its low cytotoxicity and high cell permeability. The hydrophilic nature of the polymer makes it a promising candidate for sensing mercuric ions in real water samples. Moreover, the reversibility of this sensing strategy helps in constructing a logic gate, which is particularly useful in smart sensor design.

A porphyrin-initiated amine-functionalized polyepichlorohydrin dendritic polymer (PPECH–Amine) was effectively synthesized, and its water-soluble copper complex (PPECH–Amine–Cu) was developed by treating it with copper acetate. PPECH–Amine and PPECH–Amine–Cu were characterised by different spectroscopic and microscopic techniques. PPECH–Amine–Cu was identified as a reusable catalyst for the amination of bromo- and iodo-benzene derivatives in aqueous media. Due to the presence of residual amino groups in the PPECH–Amine–Cu catalyst, the protocol does not need any additional base additive, as ammonia itself acts as a base and a coupling partner. Due to the good water-soluble nature of this catalyst, it can be easily separated and reused up to six reaction cycles without any loss in its activity.

DESs are new and greener alternatives to ionic liquids formed by mixing components that are capable of forming hydrogen bonds between them. The strong hydrogen bond interactions between the constituents make a large depression in the melting points compared to pure constituents. They are emerging as green solvents and have loomed as adorable alternatives to conventional organic solvents and ionic liquids with unique properties. In the present article, four new CeCl3·7H2O-based DESs were developed and their physical properties were studied. Their activities were checked in the Knoevenagel condensation reaction of dimedone/malononitrile with various aldehydes. The recyclability of the catalyst/solvent was achieved up to five runs without much change in the activity.

A new polymer-supported highly functionalized dendritic polyether with peripheral NHC–Pd complex was developed by the simple anionic ring opening polymerization of glycidol on bis(3-hydroxypropyl) amine grafted Merrifield resin and its subsequent functional modification of hydroxyl group to NHC–Pd complex. The polymeric material had high stability and swelling capacity in a wide range of solvents, even in water. Similar to supported higher generation dendrimer, the newly developed system showed high palladium content with uniformly distributed and well isolated metal nanocentres. The palladium content was found to be 2.02 mmol/g which was comparatively higher than other heterogeneous NHC–Pd based catalysts and the polymer was used as heterogeneous palladium catalyst for Suzuki coupling reaction. Various factors affecting the catalyst’s performance were studied. The high availability and increased accessibility of catalytic sites, stability and dendrimer like property of the polymeric support, reusability, better resistance to metal leaching, easy synthesis etc. are the important features of this newly synthesized catalytic system.

A new series of low band gap phenylenevinylene based copolymers was designed by employing density functional theory in the periodic boundary condition using HSE06 exchange correlation functional using 6-31G basis set and synthesized via the Gilch polymerization. The theoretical band gap of the copolymers MD-CA-PPV, MD-FL-PPV, MD-PT-PPV and MD-AN-PPV were found to be 1.98, 2.07, 2.31 and 1.99 eV respectively using the DFT/HSE06/6-31G calculation and the optical band gap of 1.96, 2.03, 2.01 and 1.98 eV respectively, according to the onset edge of lower energy peak of the polymers in solution. The experimental results supported the theoretical prediction. Solvatochromic behaviour of the synthesized copolymers was studied thoroughly in toluene/acetonitrile mixtures of varying polarity at room temperature. The absorption spectrum of the PPV polymers was sensitive to solvent effects which showed bathochromic and hypsochromic shifts with increasing solvent polarity indicating that the transitions involved were π-π* and n-π*. The ground and excited state dipole moments were calculated using solvatochromic correlations. Onsager radius determined from ab initio calculation was used in the determination of dipole moments. The change in the dipole moment (Δμ) was calculated both from solvatochromic shift method and on the basis of microscopic empirical solvent polarity parameter ( E T N ) and values are compared. It was observed that the excited state dipole moment (µe) was larger than its ground state (µg) counterpart. This indicated that a substantial redistribution of the π-electron densities occurred in the more polar excited state for the selected phenylenevinylene polymers. The third-order nonlinear optical (NLO) properties of the copolymers, evaluated by Z-scan method with nanosecond laser beam at 532 nm, are reported. The nonlinear absorption coefficient of the copolymers were calculated to be 0.17 × 10−10, 2.06 × 10−10, 0.63 × 10−10 and 2.83 × 10−10 esu, respectively for MD-CA-PPV, MD-FL-PPV, MD-PT-PPV and MD-AN-PPV which certified that the polymers showed semiconductor properties.

Porphyrin cored polyepichlorohydrin (POR-PECH) dendritic polymer was identified as an efficient turn-off fluorescence probe for selective determination of cyanide ion in aqueous medium. The dendritic polymer showed strong red fluorescence at 656 and 718 nm which was quenched in the presence of cyanide ion. POR-PECH showed high selectivity towards cyanide ion over other relevant anions including Cl−, Br−, F−, I−, NO2−, NO3−, CH3COO−, SO32−, CO32−, SCN−, HCO3−, HPO42−, H2PO4− etc. The proposed sensor is highly selective, sensitive which showed quick response towards cyanide ion. The limit of detection of proposed method was found to be 1.2 μM which was admirably lower than the maximum allowed cyanide content in drinking water (1.9 μM) as recommended by WHO. Back folding of self assembled porphyrin cored PECH dendritic chains by the addition of cyanide ion caused the quenching of fluorescence. The time resolved fluorescence life time, FE-SEM image and DFT studies supported the quenching mechanism.

Polycarbosilane containing Cu(II) (Cu-PCS) was prepared. The performance of Cu-PCS as a catalyst was verified using the three-component Biginelli reaction. It was found to be a good catalyst. The product, dihydropyrimidinone, could be easily isolated from the reaction medium. The heterogeneous nature of the catalyst helped in separating the product. The reaction conditions were optimized, and the catalyst was found to be reusable. The catalytic activity of Cu-PCS was compared with that of Cu ion supported on SBA-15 and amorphous silica. Cu-PCS exhibited better catalytic activity, recyclability and was devoid of metal leaching.

This article presents the photophysical and photoconductive properties of a newly synthesized low band gap Donor-Acceptor conjugated poly (benzothiadiazole-triphenylamine) co-polymer labelled as P(BTZ-TPA) in which 2,1,3 benzothiadiazole (BTZ) act as the electron deficient moiety and triphenylamine (TPA) is used as donor moiety. Photophysical properties of this synthesized polymer were analyzed by recording steady state absorption and emission spectra of dilute solution and thin films respectively. In addition to this, solvatochromic experiments were carried out using a binary mixture consisting of toluene and acetonitrile to understand the solvent dependence on the ground state and excited states of this polymer. The optical characterization revealed high degree of intramolecular charge transfer through the polymer backbone. The P(BTZ-TPA) thin films exhibit good fluorescence emission with emission peak around 615 nm. Quantum yield of the fluorescence emission is measured in relative method. Also, fluorescence decay parameters were examined using time correlated single-photon counting (TCSPC) technique. Carrier generation and transport of the generated carriers upon photo excitation is studied in pristine polymer films as well as in P(BTZ-TPA):PCBM blend films, by performing photoconductivity studies using broad spectral source and lasers of wavelengths 488 nm and 632 nm. P(BTZ-TPA) thin films exhibited good photoresponse over the entire visible region, with promising internal photocurrent efficiency. Quenching of fluorescence is observed in PCBM blend films. This drastic quenching of fluorescence emission is assigned to the charge transfer interaction between co-polymer and PCBM, and is confirmed by substantial increment in photoconductivity of the blend films. An internal photocurrent efficiency of 17.4% was obtained in the blend films for a biasing field of 10 V / μ m .

The limited absorption range of photopolymers in the visible region was always a matter of concern due to their wide-spread application in the field of holography. The present work has investigated the possibility of extending the limited absorption range towards the entire visible range by simple modifications in the photopolymer composition so that panchromaticity can be invoked in the material. Here modification was done on already developed photopolymer material by adding another photosensitizer. Studies showed that holographic performance was improved to a great extent. It was possible to record gratings with blue, green and red wavelengths in 130 µm thick films with more than 80% diffraction efficiency (DE) creating a refractive index modulation of ∼1.7 × 10−3 at exposure energy of 50 mJ/cm2. This material will be a good candidate for data storage and color holographic applications. One of the remarkable findings was that the storage and shelf life of the material could be extended compared to other photopolymer materials. This material could be used to write gratings with 70% DE even after 12 months of storage. Thus, addition of a second photosensitizer not only extended the absorption range, but also the shelf life of the photopolymer.

Deep eutectic solvents (DESs) are fluids composed of different Lewis or Bronsted acids and bases, generally acknowledged as new analogues to ionic liquids (ILs), because of their similar characteristics, but with more advantages related to preparation cost, environmental impact etc. Their preparation involve the simple mixing of two components generally with moderate heating that are inexpensive, non-toxic, biodegradable and the resulting mixture is capable to overcome the drawbacks of conventional organic solvents and ILs. Chemical reactions with these materials are significantly less hazardous and they can act as catalysts as well as reaction media. Here, three new DESs based on ZrOCl2·8H2O in combination with urea, ethylene glycol and glycerol are introduced. Physicochemical properties like phase behaviour, Freezing point, density, viscosity, thermal stability and miscibility properties in common solvents are determined. In addition, a new method for the determination of acidity of DESs having both Bronsted and Lewis sites is also introduced in this work. A convenient synthesis of pyrrole through Paal–Knorr reaction is reported using a variety of amines which are used to establish the importance of this catalyst in organic reactions. The products are analysed by GC–MS, 1H NMR and 13C NMR. By comparing the three DESs, DES 1 (formed from ZrOCl2·8H2O with urea) has the lowest density, viscosity, highest acidity and thermal stability. It was shown to be an excellent green catalyst for Paal–Knorr reaction. Reusability of the catalyst was also achieved up to 4 runs, without significant loss in its catalytic activity.

Soluble conjugated donor-acceptor phenothiazine-N-piperidine substituted triazine copolymer (P(PZ-TN)) has been designed and synthesized via Suzuki coupling reaction. To investigate the variation in band structure of the copolymer, quantum-chemical calculation using DFT theory was carried out in the periodic boundary condition (PBC) formalism at HSE06 and B3LYP correlation function using 6–31 G basis set. The insertion of triazine unit as an alternating monomer in the copolymer of phenothiazine and triazine lowers the HOMO and LUMO energy levels. The optical band gap of the copolymer was calculated to be 2.5 and 2.3 eV in THF solution and as thin film, respectively from the onset of low energy optical transition. In thin film, the energy gap tends to narrow and the absorption and emission peaks are red shifted owing to the better interaction and increase in planarity of the copolymer in thin film. Theoretical studies along with photophysical and electrochemical studies confirmed that the copolymer exhibited relatively low band gap than that of homopolymer. The absorption and emission spectra of the copolymer, in solvents of varying polarity showed positive solvatochromism. The third-order nonlinear optical properties of copolymer, P(PZ-TN) were investigated by Z-scan technique at 532 nm. The copolymer showed strong third-order nonlinear optical susceptibility and low optical limiting threshold values of 1.27 × 10−11 esu and 0.22 GW/cm2, respectively.

In this paper, we report the study of a novel p-aminoazobenzene based non-conjugated, benzoxazine polymer, poly([4-(6-tert-butyl-4H-benzo[e][1,3]oxazin-3-yl)phenyl]-phenyldiazene) (AZO-PBZ) synthesized using solvent free, thermally activated cationic ring opening polymerization. The thermal, photophysical, electrochemical, and photoconducting properties of the polymer were investigated. The optical absorption band edges of AZO-PBZ thin film was observed at 555 nm. Photoinduced charge transfer nature of AZO-PBZ was studied by analyzing the fluorescence spectra and performing photoconductivity experiments. Incorporation of [6, 6]-phenyl-C61-butyric acid methyl ester denoted as PCBM into the polymer leads to quenching of the fluorescent intensity and exhibits significant photoconductivity. The photocurrent through the PCBM blend films was measured as a function of electric field to recognize the field dependence on carrier generation. Internal photocurrent efficiency of the polymer:PCBM blend samples was found to be in the order of 10−5 and photoconductive sensitivity was of the order of 10−11 S W−1cm, which is adequate for photorefractivity.

Three novel multifunctional polyether grafted dendritic solid supports for organic synthesis were developed via single step, grafting from and hypergrafting strategies. In order to improve both the swelling capacity and loading capacity of conventional resins simultaneously, the hybrid supports were developed by grafting either multivalent linear polymers or dendritic architectures to the conventional resin. The ring opening polymerization of strained cyclic monomers was explored for the development of multivalent polymer grafts on the solid support. The physico-chemical properties of the dendritic solid supports were studied by various characterization techniques and analytical methods. Among the hybrid supports, Het-PG was found to be a novel solvent like high loading solid support. High functional group capacity of 7 mmol g−1 which was introduced via single step approach, increased accessibility of functional sites even at high loading etc. make Het-PG a versatile solid support for organic synthesis. The applicability of dendritic solid support (Het-PG) as a high loading hybrid support for multistep solid phase organic synthesis of small peptides was investigated. The high functional group capacity and increased accessibility of functional sites in Het-PG were exploited for addressing the poor industrial scalability issue of solid phase organic synthesis. A novel approach to solid phase peptide synthesis using solvent like high loading hybrid solid support is presented.

The photoinduced charge transfer properties of low band gap donor-acceptor π-conjugated copolymer poly(2,5-(3,4-ethylenedioxythiophene)-alt-2,7-(9,9-dioctylfluorene)) labelled as P(EDOT-FL) has been investigated through solvatochromic and photoconductivity studies. The effect of strong acceptor, Phenyl-C61-butyric acid methyl ester (PCBM) on the photogeneration of free carriers is studied by comparing the fluorescence spectra and photoconductive properties of the polymer-PCBM blend [P(EDOT-FL):PCBM] films with the pristine polymer films. The positive solvatochromism exhibited by the P(EDOT-FL) revealed its photoinduced charge transfer nature of the absorption and emission bands. The blend films exhibited quenching of the fluorescence intensity and showed increased photoconductivity. Internal photocurrent efficiency and photoconductive sensitivity of the pristine P(EDOT-FL) films and P(EDOT-FL):PCBM blend films were calculated as a function of electric field, by measuring the photocurrent generated in the sample. Blend films exhibited higher internal photocurrent efficiency of 86% and photoconductive sensitivity of 5.44 × 10−7 SW−1cm at 70 V/μm. The obtained photoconductive sensitivity at low electric field (

Merrifield resin supported dendronized polymer and its copper complex having ethylene glycol initiated polyepichlorohydrin as core (EG-Gn-Cu, n = 0,1,2) have been synthesised for the first time and characterized. They were found to be highly selective heterogeneous catalysts for the synthesis of tetra-substituted imidazole derivatives under mild reaction conditions. Higher generation dendronized polymer showed increased catalytic activity due to extension and rigidification of the linear polymeric core. Dendronized EG-G2-Cu catalyst was found to be better over dendrigraft GLR-G2-Cu catalyst. No leaching of the metal from the catalyst was observed. Reusability of the catalyst was tested for five cycles without loss of significant catalytic activity.

We report for the first time a simple, highly efficient and ecofriendly approach for the preparation of pyrrole derivatives in the presence of dendritic amine grafted on mesoporous silica under solvent free condition. We have synthesized and characterized the three generations of dendritic amine grafted on mesoporous silica (G0–G2) through a stepwise growth technique. The maximum yield was observed with third generation (G2) and the catalyst was easily separated from the reaction mixture. Studies showed that dendritic effect of amino groups on the catalyst was the driving force of the reaction pathway, which has led to the formation of pyrrole derivatives. The green aspect of the present method are use of metal free catalyst, low catalyst loading, shorter reaction times, organic solvents are not needed, facile work-up, purification of the products by non-chromatographic methods, the excellent yield of the products, room temperature and the reusability of the catalyst.

Alternate reaction media have become very important due to the problems created by the highly volatile nature of the solvents. The deep eutectic mixture is a kind of an alternate reaction medium which has emerged in recent years. Low melting mixtures were introduced by making the deep eutectic mixture more cost-effective and renewable by introducing carbohydrates into it. The properties of low melting mixtures include easiness to prepare, usage of low-cost components, biodegradability, solubility in water, easy separation from organic compounds, etc. The low melting mixtures such as glucose:urea:NH4Cl, glucose:ChCl, glucose:urea:ChCl, glycerol:urea:NH4Cl, and ethylene glycol:urea:NH4Cl were used in different ratios for the reactions. The properties such as viscosity, density, acidity, glass transition temperature, and thermal stability were studied. An unusual method for the synthesis of symmetrical azines is introduced wherein benzaldehyde and hydroxylamine are reacted in the presence of glucose:urea:NH4Cl. The method of synthesis needs only less reaction time, temperature and the product was easily separated. The products were confirmed using GC-MS and NMR techniques. The recyclability of glucose:urea:NH4Cl was studied.

The present work reports dendronized polymer based catalysis in which the dendritic cavity and surface functional groups are the reactive centers due to the formation of dendritic unimolecular micelle in aqueous medium. First generation amine functionalized tris(hydroxymethyl)propane initiated polyepichlorohydrin cored dendronized polymer (TMP-PECH-Amine-G1) was synthesized and was properly characterized with different analysis techniques. High functional group capacity, thermal stability and good water solubility are the eye-catching features of the TMP-PECH-Amine-G1 catalyst. The catalytic activity of TMP-PECH-Amine-G1 was studied by synthesizing 4-aryl-1H-1,2,3-triazoles by one pot condensation reaction of aromatic aldehydes, nitromethane and sodium azide. The synthesized catalyst offered high yield of products with low catalyst loading in green reaction media without the presence of any external additives. The catalyst was regenerated for six cycles of reaction without substantial loss in activity. This is the first reported method where homogeneous amine functionalized dendronized polymer was used as an organo catalyst for the synthesis of 4-substituted triazoles.

Owing to the importance of pyranopyrazole scaffolds, several methods for their synthesis were developed. The previous reports on the synthesis of pyranopyrazole derivatives suffered many drawbacks which included difficulty in the workup, longer reaction time, high cost of catalyst and use of organic solvents. The present article reports the use of low melting mixture as a catalyst and solvent for the synthesis of pyranopyrazole derivatives. A study on the physical properties of the new Lactic Acid: Urea: NH4Cl low melting mixture such as density, viscosity, acidity, refractive index, surface tension is reported. IR spectra, 1H NMR spectra, emission spectra, polarity and cytotoxicity were also studied. The application in the synthesis of pyranopyrazole derivatives was established. The present method of synthesis of pyranopyrazole derivatives followed a simple procedure and easy workup protocol. The reaction was performed without the use of organic solvents. The components used in the mixture were easily available. The reaction required only less time and reactions were done at 28 ​°C.

Holographic performance of an economically cheap metal ion doped photopolymer material is presented. We investigated the effect of incorporation of nickel ion into the methylene blue sensitized poly (vinyl alcohol)/acrylamide (MBPVA/AA) photopolymer system. The composition and preliminary characterization of the developed photopolymer material is reported. The presence of nickel ion improves the diffraction efficiency, stability of the material and it operates in a wide range of spatial frequencies (550–2000 lines/mm) at exposure energy of 100 mJ/cm 2 . When nickel ion concentration was 0.01 mM, maximum diffraction efficiency of 84% at exposure energy of 100 mJ/cm 2 with spatial frequency 1335 lines/mm could be achieved for gratings recorded using wavelength of 632.8 nm. The material showed panchromaticity with more than 70% diffraction efficiency in both blue and green regions. Effects of humidity and temperature on the stored gratings were studied by keeping films in different environmental conditions. Suitability of recording large area holograms was also explored.

Studies carried out to gauge the potential of a metal-ion doped panchromatic photopolymer recording material for application in real-time holographic data storage is presented. The photopolymer films are spin coated on glass plates to ensure better surface uniformity. Volume holographic transmission gratings with peak diffraction efficiency of 80% could be stored in the photopolymer films of 100 μm thickness. An efficiency of 70% is achievable even for gratings recorded with exposure energy as low as 10 mJ/cm 2 . A checkerboard pattern data page recorded in the photopolymer film using a defocused 4- f recording geometry could be reconstructed with good image quality. The experimental results illustrate the competency of the developed photopolymer for holographic data storage applications.

The synthesis of multi-arm star dendrigraft amidoamine polymer with pentaerythritol initiated polyepichlorohydrin as the core, PEN-G2, on a solid resin support has been demonstrated. We have functionalized a Merrifield resin support with polyepichlorohydrin, and dendrons are grown on it up to second generation using a “graft from” approach. The estimation of amine functionality was done and found to be 25 mmol g−1 which was 70% of the theoretical value. Photolytic cleavage of the dendrigraft polymer from the support resulted in a brown water-soluble viscous liquid. The molecular weight of 3966 shows that out of the 9 G1 dendritic substituents, 5 of them were converted to generation G2. The TEM image of the G2 polymer shows an inhomogeneous polygon-like appearance. The chiral modification of the dendrigraft polymer, PEN-G2, has been done. The copper complex of chiral modified PEN-G2 dendrigraft polymer was synthesized and characterized. The copper complex of PEN-G2 dendrigraft polymer was found to be an excellent catalyst for the synthesis of isoquinuclidines via aza Diels–Alder reaction between cyclohexenone and imines. The catalyst exhibited superior enantioselectivity. The reusability of the catalyst was studied for five reaction cycles.

The synthesis of dendrigraft amidoamine polymers with glycerol initiated polyepichlorohydrin cores has been demonstrated on a Merrifield resin support to achieve heterogenosity for catalytic applications. In earlier studies of supported dendritic systems, no effort has been initiated to synthesize a dendritic polymer with high functionality at a low generation. The copper complexes of the Gn (n = 0, 1, 2) dendrigraft polymers were found to be excellent catalysts for the synthesis of benzimidazole derivatives via reactions between o-phenylenediamine and aldehydes. Aliphatic and cyclic ketones also showed excellent conjugation with o-phenylenediamine. A detailed study of the synthesis of 2-substituted benzimidazoles and 2,2-disubstituted benzimidazoles was performed with dendrigraft G2 copper catalyst. The reusability of the catalyst was examined for five consecutive steps, and no significant loss of catalytic activity was observed. The catalyst possessed the following green attributes: the final oxidation step was conducted using air, only a small amount of catalyst was needed to drive the reaction, and ethanol was used as the solvent under room temperature conditions.

This paper reports the synthesis of two new supramolecules, Phenyl(octacyanomethoxy)calix[4]resorcinarene (3a) and 4-Cyanomethoxyphenyl(octacyanomethoxy)calix[4]resorcinarene (3b) by alkylating the hydroxyl groups present in Phenylcalix[4]resorcinarene and 4-Hydroxyphenylcalix[4]resorcinarene respectively. Full O-alkylation was done at room temperature by simple stirring. The X-ray diffraction studies, were done to get the crystal-packing arrangements of alkylated resorcinarene derivatives. Absorption and emission spectra of the compounds were recorded in different organic solvents and both exhibited negative solvatochromism with the polarity of solvents. Molecular geometry optimization, vibrational wave numbers and frontier molecular orbitals were calculated by dispersion corrected DFT-D method using hybrid density functional ωB97X-D and the split-valence double-zeta basis set 6-31G(d). DFT-D studies revealed that the synthesised supramolecules existed in two different conformers, chair (C2h) and Boat (C2V). Boat (C2v) conformer had more stability than the chair (C2h) conformer. HOMO-LUMO energies were calculated to explain the kinetic stability of the compounds, found that Phenyl(octacyanomethoxy)calix [4]resorcinarene has more kinetic stability.