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In this present study, biomaterials loaded/blended hybrid nanocomposites such as chitosan-blended Al2O3-TiO2 (CS-Al2O3-TiO2) and garlic-loaded Al2O3-TiO2 (G-Al2O3-TiO2) were synthesized by sol-gel method. They were characterized by various techniques such as XRD, UV-DRS, FTIR, FE-SEM, EDX and TG-DTA analysis. The photocatalytic activity of the CS-Al2O3-TiO2 and G-Al2O3-TiO2 was carried out using organic dyes such as Methylene blue (MB), Methyl orange (MO) and Rhodium B (Rh-B) under solar light. The antibacterial activity was done using the gram-negative bacteria Escherichia Coli (E. Coli). The comparison studies of photocatalytic and antibacterial activity between all the nanocomposites, such as TiO2, Al2O3-TiO2, CS-Al2O3-TiO2 and G-Al2O3-TiO2 were investigated. The order of photocatalytic and antibacterial activity was G-Al2O3-TiO2 > CS-Al2O3-TiO2 > Al2O3-TiO2> TiO2. The garlic loaded Al2O3-TiO2 nanocomposite shows a higher activity due to the presence of organic sulphur compounds. Followed by chitosan blended - Al2O3-TiO2 shows a remarkable activity due to the presence of an amine group present in chitosan composites.

We present the chemical precipitation technique for producing several quantities of sodium hexametaphosphate (SHMP) capped zinc sulphide nanoparticles doped with Ni2+ in an ambient environment. The average grain size of the nanoparticles generated was tuned by using SHMP concentration. SEM with EDAX, HRTEM, and SAED patterns was used to confirm the particle size, crystallinity, and composition. Compared to bulk ZnS, UV–Vis spectra of both capped and uncapped samples reveal a blue shift in the absorption edge. FTIR studies confirmed the capping of SHMP on the surface of Ni-doped ZnS. PL spectra of ZnS:Ni2+ nanoparticles exhibit intense and sustained visible-light emissions. The intensity of the blue emission centered at 468 nm increased with increasing SHMP concentration up to 0.75 wt percent but decreased with higher concentrations of SHMP. TG – DTA results show that SHMP – ZnS (Ni-doped) nanoparticles have excellent thermal stability due to improved shape and compactness.

2-(1-phenyl-1H-benzo[d]imidazol-2-yl)-4-(trifluoromethyl)phenol(PBITP) has been synthesised and the compound structure was confirmed by proton NMR, carbon NMR, mass spectral studies and elemental analysis. The binding interaction between PBITP and different phases of TiO2 nanoparticles were investigated. We have observed surprising result. Synthesized PBITP enhanced the fluorescence of rutile phase of TiO2 on account of the lowering of frontier orbital levels of the PBITP. But the opposite trend was observed for anatase phase of TiO2. So that, we can identify the rutile and anatase phase. The mechanism of electron transfer was discussed in detail. Emission spectroscopy has been employed to probe on the process of excited state intra-molecular proton transfer (ESIPT) in hydroxy imidazole.An abnormal Stokes – shifted emission band, at shorter and longer wavelengths has been observed in the fluorescence spectra of the sample PBITP / dioxane, which is an indication towards the existence of two different forms of intra-molecular hydrogen bonded isomers.

ABSTRACT: Cost effective precipitation and decomposition method was used for the successful synthesis of clay supported Bi-ZnO (CBZO). Synthesized CBZO was exemplified by Fourier transform infrared spectra (FT-IR), X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Diffuse Reflectance spectra (DRS), Photoluminescence spectra (PL), Energy Dispersive Spectrum (EDS), and BET measurements. The catalytic activity of CBZO was scrutinized for the detoxification of Reactive Yellow 84 (RY 84) & Trypan Blue (TB) dyes in an aqueous solution using UV-A light. The results show that CBZO is more efficient than Clay, Bi-ZnO, commercial ZnO, and bare ZnO at pH 9 for the degradation of RY 84 and TB dyes. Moreover, COD studies were proven the mineralization of dyes. Hence, thedegradation mechanism was developed for RY 84 and TB dyes degradation in the presence of UV-A light.

Abstract Herein, the work addresses the synthesis of biomaterials (chitosan and garlic) loaded CdO–TiO2 hybrid nanocomposites for photocatalytic water treatment and photodynamic cancer therapeutic applications that were reported the first time. CdO–TiO2 (CT) nanocomposites were synthesized and loaded with the biomaterials such as chitosan and garlic by simple sol–gel method. The nanomaterials were characterized and the photodegradation of three model pollutants, Methylene blue (MB), Methyl orange (MO) and Rhodamine B (Rh-B) was opted to investigate the efficiency of the synthesized photocatalyst under the solar light. From the results, the garlic-loaded CdO–TiO2 (AS-CT) hybrid nanocomposites exhibit a superior photocatalytic activity than the chitosan-loaded CdO–TiO2 (CS-CT) and CdO–TiO2 (CT) nanocomposites under the irradiation of solar light. Additionally, the cell viability of the synthesized nanocomposites was carried out in HeLa cell lines under different concentrations, light doses and incubation periods using an LED light source. Compared to the CS-CT and CT nanocomposites, an efficient photodynamic activity was achieved in the case of AS-CT hybrid nanocomposites. Actually, the end-use properties required for both processes in AS-CT nanocomposites appear similar due to the presence of organo sulphurus compounds.

In this article the potential variation in biochemical constituents of peanut plant leaves affect by presoaking peanut seeds in copper oxide nanoparticles suspension has been studied and compared with its bulk counterpart. The synthesized nanoparticles were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) studies. The Fourier transform infrared (FTIR) analysis shows the most prominent peaks at ∼2923 cm−1, ∼1636 cm−1 and ∼1033 cm−1, which correspond to lipids, protein and carbohydrate content in leaf samples respectively. The calculated mean ratio of the peak intensities for various frequency regions and total band area calculation for various band regions explain the variation in lipid, protein and carbohydrate content of leaf samples. Further the FTIR spectra were processed by de-convolution and curve fitting to quantitatively examine the chemical contents and structure changing of the secondary structure of protein. The calculated integrated band area of β – sheet, β – turn and α – helix secondary structure of protein varies to greater extent in all samples compared to control. Principal component analysis (PCA) has been carried out to explain the total variance in secondary structure of protein content in peanut plant leaves. Principal component 1 (PC1) accounts for 63.50% variation in secondary structure of protein whereas principal component 2 (PC2) accounts for 29.56%. The application of nanoparticles via presoaking method implies potential variation in biochemical constituents but doesn't affect the growth of plants considerably.

Epoxy resin modified with nano scale fillers offers excellent combination of properties such as enhanced dimensional stability, mechanical and electrical properties, which make them ideally suitable for a wide range of applications. However, the studies about functionalized nano-hybrid for coating applications still require better insight. In the present work we have developed silane treated nanoparticles and to reinforce it with diglycidyl epoxy resin to fabricate surface functionalized nano-hybrid epoxy coatings. The effect of inorganic nano particles on the corrosion and fouling resistance properties was studied by various (1, 3, 5 and 7 wt%) filler loading concentrations. Diglycidyl epoxy resin (DGEBA) commonly was used for coating. 3-Aminopropyltriethoxysilane (APTES) was used as a coupling agent to surface treats the TiO2 nanoparticles. The corrosion and fouling resistant properties of these coatings were evaluated by electrochemical impedance and static immersion tests, respectively. Nano-hybrid coating (3 wt% of APTES–TiO2) showed corrosion resistance up to 108 Ω cm2 after 30 days immersion in 3.5% NaCl solution indicating an excellent corrosion resistance. Static immersion test was carried out in Bay of Bengal (Muttukadu) which has reflected good antifouling efficiency of the 3 wt% APTES–TiO2 loaded nano-hybrid coating up to 6 months.

The interaction of metal oxide nanoparticles with plants has not been extensively studied. An attempt has been made to examine the potential variation in peanut plant leaves due to the application of Fe2O3 nanoparticle by pre-sowing technique and to compare with its bulk counterpart. Fe2O3 nanoparticle was synthesized by chemical route and characterized using X-ray diffraction, atomic force and scanning electron microscopy. The Fe2O3 nanoparticle and its bulk counterpart are applied to the peanut seeds by pre-soaking method at two different concentrations: 500 and 4000 ppm. A total of three replicates were chosen for each morphological and physiological measurement (at an average of three plants per replica). The Fourier transform infrared spectral analysis shows the most prominent peaks at 2923 and 1636 cm−1, and other peaks vary due to Fe2O3 stress, which was confirmed by the calculated mean ratio of the peak intensities for various frequency regions. All leaf samples show considerable increase in glycoprotein, with 500 ppm bulk and 4000 ppm nano-Fe2O3 samples exhibiting a maximum increase of 73.86% and 71.45%, respectively. The total amide I and II protein content of leaf sample soaked in 500 ppm bulk Fe2O3 suspension decreased to a greater extent compared with other leaf samples. The leaf samples soaked in 500 ppm concentration of both bulk and nano-Fe2O3 suspension exhibited lower lipid content with total band area of 76.97 ± 0.832 and 76.31 ± 0.468, respectively. The cumulative percentage of explained variance in secondary structure of protein of all leaf samples is 83.888% in which factor 1 accounts for 51.870% and factor 2 accounts for 32.018% of the total data variance. The principal component (PC) loadings plot for the spectral range 1600–1700 cm−1 clearly shows that the PC1 factor might establish the maximum variation of the secondary structure of protein in leaf samples.

In the title compound, C20H16N2, the benzimidazole ring system forms dihedral angles of 28.50 (7) and 72.44 (7)° with the tolyl and phenyl rings, respectively. In the crystal, molecules are linked into chains along the a-axis direction by weak C—H...N interactions. The crystal structure also features C—H...π interactions.

In the title compound, C20H16N2O, the 1H-benzimidazole ring forms dihedral angles of 48.00 (6) and 64.48 (6)°, respectively with the benzene and phenyl rings, which are inclined to one another by 58.51 (7)°. In the crystal, weak C—H...π interactions are the only intermolecular interactions present.

In the title molecule, C20H13F3N2, the benzimidazole unit is close to being planar [maximum deviation = 0.012 (1) Å] and forms dihedral angles of 31.43 (7) and 61.45 (9)° with the 4-(trifluoromethyl)phenyl and 1-phenyl rings, respectively; the dihedral angle between these rings is 60.94 (10)°. In the crystal, C—H...F hydrogen bonds link the molecules into chains along the c-axis direction. The CF3 group is rotationally disordered with an occupancy ratio of 0.557 (8):0.443 (8) for the F atoms.

In the title molecule, C19H14N2O, the benzimidazole unit is close to being planar [maximum deviation = 0.0253 (11) Å] and forms dihedral angles of 68.98 (6) and 20.38 (7)° with the adjacent phenyl and benzene rings; the dihedral angle between the latter two planes is 64.30 (7)°. An intramolecular O—H...N hydrogen bond generates an S(6) ring motif. In the crystal, molecules are linked by C—H...N and C—H...O hydrogen bonds, and consolidated into a three-dimensional architecture by π–π stacking interactions, with a centroid–centroid distance of 3.8428 (12) Å.

In the title molecule, C19H14N2, the benzimidazole unit is close to being planar [maximum deviation = 0.0102 (6) Å] and forms dihedral angles of 55.80 (2) and 40.67 (3)° with the adjacent phenyl rings; the dihedral angle between the phenyl rings is 62.37 (3)°. In the crystal, one C—H...N hydrogen bond and three weak C—H...π interactions involving the fused benzene ring and the imidazole ring are observed, leading to a three-dimensional architecture.

In the title molecule, C19H13FN2, the benzimidazole unit is close to planar [maximum deviation = 0.0342 (9) Å] and forms dihedral angles of 58.94 (3) and 51.43 (3)° with the phenyl and fluorobenzene rings, respectively; the dihedral angle between the phenyl and fluorobenzene rings is 60.17 (6)°. In the crystal, three C—H...F hydrogen bonds and two weak C—H...π interactions involving the fused benzene ring lead to a three-dimensional architecture.

The title compound, C22H20N2, crystallizes with two independent molecules (A and B) in the asymmetric unit. The benzimidazole units are almost planar [maximum deviations = 0.0161 (8) Å for A and 0.0276 (8) Å for B]. The dihedral angles between the benzimidazole unit and the benzene rings of the 4-methylbenzyl and 4-methylphenyl groups are 76.64 (3) and 46.87 (4)°, respectively, in molecule A. The corresponding values in molecule B are 86.31 (2) and 39.14 (4)°. The dihedral angles between the planes of the two benzene rings are 73.73 (3) and 80.69 (4)° in molecules A and B, respectively. Pairs of weak intermolecular C—H...N hydrogen bonds link B molecules, forming centrosymmetric dimers with R22(8) ring motifs. There are no significant corresponding interactions involving the A molecules.

Gold loaded TiO2 nanoparticles was synthesized and characterized by powder XRD, HR-TEM, and EDX analysis. The binding interaction of 5-amino-2-mercaptobenzimidazole (fluorochrome) with TiO2 and gold loaded TiO2 nanoparticles was discussed herein. The interaction of fluorochrome with TiO2 and Au-TiO2 nanoparticles has been studied by UV-visible, fluorescence, and FT-IR spectral techniques. Fluorescence emission occurs at 421 nm and this has been selectively enhanced by TiO2 nano semiconductor. This technique is sensitive to detect and estimate TiO2 nano semiconductor at a micromolar level. This switch-on fluorescence is obtained when fluorochrome is binds with TiO2 nanoparticles. This increase in fluorescence is suppressed when TiO2 nanoparticles is loaded with gold. This is because of chemo sensing nature of the gold. The strong adsorption of fluorochrome over the surface of nano semiconductor results in the electron transfer between fluorochrome and semiconductor. Further, the binding site of semiconductor with fluorochrome has been studied theoretically by molecular electrostatic potential diagram. [ABSTRACT FROM AUTHOR]

The antibacterial and antifungal effects of non-functionalized and surface-functionalized Mn 3 O 4 nanoparticles were comparatively analyzed to reason out the potential changes in antimicrobial activities due to functionalization with 5-amino-2-mercapto benzimidazole (AMB) molecule. The surface functionalization of Mn 3 O 4 nanoparticles with AMB molecule was confirmed by the XRD result, which shows the shift in 2 θ values with noticeable peaks. The surface morphology and functionalization of Mn 3 O 4 nanoparticles were additionally confirmed by HR-SEM and EDAX studies. Antimicrobial activities were investigated by an agar-well-diffusion method using the bacteria Staphylococcus aureus and Pseudomonas aeruginosa and fungi Aspergillus niger . The functionalized Mn 3 O 4 nanoparticles possess remarkable antibacterial and antifungal effect than the non-functionalized Mn 3 O 4 nanoparticles and AMB molecule. The coating of low energy surface layer over metal oxide nanoparticles such as Mn 3 O 4 offers an active surface toward both transfer of electron and the adsorption or desorption of water, inorganic ions, and other molecules, which leads to the increased antimicrobial activity of f-Mn 3 O 4 nanoparticles.Communicated by Ramaswamy H. Sarma.

The utilization of photodynamic therapy (PDT) has been rapidly increasing due to its advantage as an effective treatment modality for cancer. The organic photosensitizers employed for PDT have some disadvantages, including high toxicity, non-selectivity toward tumors and poor absorption of light. The low light penetration into the tumor sites resulting from low wavelength of absorption and long-term skin photosensitivity. Hence, the attention toward non-toxic inorganic photosensitizers like noble metal nanoparticles (NPs) has been increasing nowadays. In bioscience, NPs are replacing organic dyes since they have photostability and non-toxicity. Generally, nanomaterials can easily form compounds with other substances as well as organic materials and the modified NPs surface enhances the chemical activity. Among the metal NPs, noble metals, especially gold and silver are attractive because of their size and shape-dependent unique optoelectronic properties. The coating of inorganic/organic materials on top of the noble metal makes the NPs bio-compatible and less toxic. Furthermore, Ag- and Au-based inorganic/organic complex NPs could offer a new possibility because of their unique structures. Meanwhile, the coating of inorganic/organic complex NPs protects the noble metals and stabilizes them against chemical corrosion and enhances the production of reactive oxygen species. Thus, in this review, we have highlighted the role of Ag- and Au-based inorganic/organic hybrid nano-photosensitizers in photodynamic therapy.Communicated by Ramaswamy H. Sarma.

Herein, the work addresses the synthesis of biomaterials (chitosan and garlic) loaded CdO-TiO 2 hybrid nanocomposites for photocatalytic water treatment and photodynamic cancer therapeutic applications that were reported the first time. CdO-TiO 2 (CT) nanocomposites were synthesized and loaded with the biomaterials such as chitosan and garlic by simple sol-gel method. The nanomaterials were characterized and the photodegradation of three model pollutants, Methylene blue (MB), Methyl orange (MO) and Rhodamine B (Rh-B) was opted to investigate the efficiency of the synthesized photocatalyst under the solar light. From the results, the garlic-loaded CdO-TiO 2 (AS-CT) hybrid nanocomposites exhibit a superior photocatalytic activity than the chitosan-loaded CdO-TiO 2 (CS-CT) and CdO-TiO 2 (CT) nanocomposites under the irradiation of solar light. Additionally, the cell viability of the synthesized nanocomposites was carried out in HeLa cell lines under different concentrations, light doses and incubation periods using an LED light source. Compared to the CS-CT and CT nanocomposites, an efficient photodynamic activity was achieved in the case of AS-CT hybrid nanocomposites. Actually, the end-use properties required for both processes in AS-CT nanocomposites appear similar due to the presence of organo sulphurus compounds., (© 2021. The Author(s).)

With recent scientific developments, Photodynamic therapy (PDT) offers the promisie to become incorporated into the mainstream of cancer therapy. Noble metal based nano-PDT is increasing due to its advantages in the field of biomedicine. In this study, noble metal based Ag@SiO 2 core-shell nanoparticles were synthesized and to confirm the core-shell structure they were characterized by UV-vis, XRD, FTIR, TEM, and EDX. Our data confirm that core-shell type Ag@SiO 2 nanoparticles maintain its ability to kill cancer cells upon light irradiation. This shows that SiO 2 shell may not only prevent aggregation but it also may enhance the photodynamic activity of Ag nanoparticles., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Metal-semiconductor core-shell type Pd@SiO 2 nanoparticles (NPs) were successfully synthesized by Stober's method and the product was characterized by UV-vis, XRD, FT-IR, SEM, HR-TEM and EDX techniques. In vitro Photodynamic activity and DNA binding studies of Pd@SiO 2 core shell nanoparticles were studied. Cell viability of the core-shell nanoparticles against HeLa cell line was screened by MTT assay after exposing at different light doses. The outcome of the present study indicates that the core-shell Pd@SiO 2 NPs are highly stable and exhibited strong photodynamic efficiency under LED light illumination in HeLa cells. The results indicated that SiO 2 supported on the surface of Pd NPs not only prevented the aggregation in addition exhibited remarkable photodynamic activity., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In this article a series of epoxy nanocomposites film were developed using amine functionalized (ZnO-APTES) core shell nanoparticles as the dispersed phase and a commercially available epoxy resin as the matrix phase. The functional group of the samples was characterized using FT-IR spectra. The most prominent peaks of epoxy resin were found in bare epoxy and in all the functionalized ZnO dispersed epoxy nanocomposites (ZnO-APTES-DGEBA). The XRD analysis of all the samples exhibits considerable shift in 2θ, intensity and d-spacing values but the best and optimum concentration is found to be 3% ZnO-APTES core shell nanoparticles loaded epoxy nanocomposites supported by FT-IR results. From TGA measurements, 100wt% residue is obtained in bare ZnO nanoparticles whereas in ZnO core shell nanoparticles grafted DGEBA residue percentages are 37, 41, 45, 46 and 52% for 0, 1, 3, 5 and 7% ZnO-APTES-DGEBA respectively, which is confirmed with ICP-OES analysis. From antimicrobial activity test, it was notable that antimicrobial activity of 7% ZnO-APTES core shell nanoparticles loaded epoxy nanocomposite film has best inhibition zone effect against all pathogens under study., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Metal-semiconductor core-shell type Au@SiO2 nanoparticles were prepared by Stober's method. They were characterized by absorption, XRD, HR-TEM and EDAX techniques. The resulting modified core-shell nanoparticles shows that the formation of singlet oxygen, which was confirmed by ESR technique. The photohemolysis studies were carried out under two different experimental conditions. It is observed that the photohemolysis increases with concentration as well as light dose. Cell viability of the core-shell nanoparticles against HeLa cell lines were studied by MTT assay method. The outcomes of the present study indicate that, the Au@SiO2 core-shell nanoparticles are extremely stable with a very high photodynamic efficiency under visible light illumination., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Multicomponent, highly efficient, catalytic synthesis of some polysubstituted imidazole under solvent-free condition is reported. Characterization of polysubstituted imidazole have been carried out by X-ray diffraction (XRD) and spectral techniques. Electronic spectral studies reveal that their solvatochromic behavior depends not only on the polarity of the medium but also on the hydrogen bonding properties of the solvents. Specific hydrogen bonding interaction in polar solvents modulated the order of the two close lying lowest singlet states. The solvent effect on both the absorption and emission spectral results have been analyzed by multiple parametric regression analysis. Solvatochromic effects on the emission spectral position indicate the charge transfer (CT) character of the emitting singlet states both in a polar and a non polar environment. The fluorescence decays for the imidazole fit satisfactorily to a single exponential kinetics. The prototropic studies of N,N-dimethyl-4-(1,4,5-triphenyl-1H-imidazol-2-yl)naphthalen-1-amine (DTINA) reveal that two monocations [imidazole nitrogen protanated (MC1) and dimethylamino nitrogen protanated (MC2)] and a dication [both imidazole nitrogen and dimethylamino nitrogen protanated (DC)] are formed by protonation in both ground and excited states. These observations are in consistent with quantum chemical calculations.

A set of π-expanded imidazole derivatives employing excited state intramolecular proton transfer (ESIPT) was designed and synthesized. The relationship between the structure and photophysical properties were thoroughly elucidated by comparing with the analogue blocked with ESIPT functionality. The compound possessing an acidic NH function as part of an intramolecular hydrogen bond system has much higher fluorescence quantum yield and Stokes shift and the π-expansion strongly influences the optical properties. The occurrence of ESIPT for imidazole tosylamide derivatives were less affected by the hydrogen-bonding ability of the solvents compared to the unprotected amine. The low pKa values for the monocation ⇌ neutral equilibrium indicate the presence of intramolecular hydrogen bonding between the amino proton and tertiary nitrogen atom.

Photophysical and electrochemical studies of cyclometalated cationic heteroleptic iridium(III) complex salts have been carried out. For these complex salts the intense absorption bands appeared around 263 nm and are assigned to spin-allowed π-π* transitions of phenanthroline ligands. Moderately intense and weak absorption bands observed around 341 and 440 nm, respectively. These bands are assigned to spin-allowed metal to ligand charge transfer (1)MLCT and (3)MLCT transitions, respectively. The influence of anions and proton on the photophysical and electrochemical studies were also carried out. The emission wavelength was red shifted and emission color changed from yellow to red by the addition of CF3CO2H. The solution color changed from green to brown and the emission was quenched by the addition anions such as of F(-), CH3COO(-) and H2PO4(-).

A fluorophore 2-(naphthalen-1-yl)-1,4,5-triphenyl-1H-imidazole [NTI] has been designed, synthesized and characterized by (1)H NMR, (13)C NMR, mass and single crystal XRD. Absorption, emission, lifetime and cyclic voltammetry have been made to deduce the interaction between NTI and ZnO and Bi2O3 nanocrystals. NTI act as a new host for ZnO and Bi2O3 nanocrystals that enhance its luminescence. The apparent binding constant has been obtained. Adsorption of the NTI on ZnO and Bi2O3 nanocrystals lowers the HOMO energy level of the NTI. The strong adsorption of the NTI on the surface of ZnO and Bi2O3 nanocrystals is likely due to the chemical affinity of the nitrogen atom of the NTI to the zinc ion on the surface of nanocrystals. SEM and EDS spectra confirmed the adsorption of NTI on the surface of nanocrystals., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Multicomponent, one-pot, highly efficient, indium trifluoride (InF3) catalytic synthesis of 2-(naphthalen-1-yl)-4,5-diphenyl-1H-imidazole under solvent-free condition is reported. Characterization of imidazole has been carried out by spectral techniques. The synthesized phosphated imidazole (PI) and phosphated imidazole bound magnetic nanoparticles (PIBMN) were characterized using Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and powder X-ray diffraction (XRD). The photophysical characteristics of the synthesized phosphated imidazole and phosphated imidazole bound magnetic nanoparticles were investigated by steady-state absorption and emission spectroscopy as well as time resolved fluorometry. From these experiments, the position of the spectral maxima (λabs, λexc and λemi), and lifetime (τ) of the synthesized phosphated imidazole and phosphated imidazole bound magnetic nanoparticle have been determined., (Copyright © 2013 Elsevier B.V. All rights reserved.)

This article presents optical, electrochemical, and thermal properties of novel class of green fluorescent 1-(4,5-diphenyl-1-p-tolyl-1H-imidazol-2-yl)naphthalen-2-ol. Detailed photo physical and quantum chemical studies have been performed to elucidate the excited state intramolecular proton transfer (ESIPT) reaction leading a large stokes shifted fluorescence emission from the phototautomer. The results of quantum chemical investigations confirmed the intramolecular charge transfer characteristics of the ESIPT tautomers. The high photoluminescence quantum yield is ascribed to twisted chromophores due to phenyl substituents at 1,2-position of the imidazole ring which restricted intramolecular motion, leading to an optically allowed lowest optical transition without self quenching., (Copyright © 2013 Elsevier B.V. All rights reserved.)

A new fluorophore 2-(4-fluorophenyl)-1-phenyl-1H-phenanthro [9,10-d]imidazole has been synthesized and characterized by spectroscopic techniques. Nanoparticulate ZnO enhances the fluorescence of the synthesised fluorophore. The absorption, fluorescence, lifetime, cyclic voltammetry and infrared studies reveal that fluorophore is attached to the surface of ZnO semiconductor. Photo-induced electron transfer (PET) explains the enhancement of fluorescence by nanoparticulate ZnO and the apparent binding constant has been obtained. Adsorption of the fluorophore on ZnO nanoparticle lowers the HOMO and LUMO energy levels of the fluorophore. The strong adsorption of the phenanthrimidazole derivative on the surface of ZnO nanocrystals is likely due to the chemical affinity of the nitrogen atom of the organic molecule to the zinc ion on the surface of nanocrystal., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Some novel 1,2-diaryl benzimidazole derivatives have been designed, synthesized and characterized by mass, (1)H, (13)C-NMR spectral studies and single crystal XRD. The charge distribution has been calculated from the atomic charges by non-linear optical (NLO) and natural bond orbital (NBO) analyses have been calculated by abinitio method. Synthesized 1,2-diaryl benzimidazole derivatives have the largest μgβ0 value and can be used as potential NLO materials. Analysis of the molecular electrostatic potential (MEP) energy surface exploited the region for non-covalent interactions in the molecule. Calculated bond lengths, bond angles and dihedral angles are found to be slightly higher than that of X-ray diffraction values of its experimental datas., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Some fluorescent benzimidazole derivatives have been designed and synthesized using cobalt(ii) hydroxide as highly efficient catalyst. Synthesized compounds have been characterized by (1)H and (13)C-NMR and mass spectral analysis. The solvent effect on the absorption and fluorescence bands has been analyzed and supplemented by computational studies. Solvatochromic effects on the spectral position and profile of the stationary fluorescence spectra clearly indicate the charge transfer (CT) character of the emitting singlet states of all of the compounds studied in both polar and non-polar environments. The fluorescence decays for the benzimidazoles fit satisfactorily to a single exponential kinetics. HOMO and LUMO orbital pictures [DFT/B3LYP/6-31G(d,p)] evidence the existence of excited state intramolecular proton transfer (ESIPT) in benzimidazole derivatives containing a hydroxy group.