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Sachin Kumar Singh

Bio: Sachin Kumar Singh is an academic researcher from Banaras Hindu University. The author has contributed to research in topics: Mesophase & Liquid crystal. The author has an hindex of 11, co-authored 26 publications receiving 274 citations. Previous affiliations of Sachin Kumar Singh include Indian Institute of Technology Guwahati & Schiller International University.

Papers
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TL;DR: The Raman, IR and DFT study confirm that Cu metal has good binding affinity to the isolated adenine base.

9 citations

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TL;DR: In this paper, two new liquid crystalline series of disubstituted aroylhydrazones with (ABB(OH)H-n) and without lateral hydroxyl group were synthesized by microwave-assisted methods.
Abstract: The present study is focused on the development of green microwave process for the synthesis of mesogenic substituted aroylhydrazones and their structure–mesophase relationship study. Two new liquid crystalline series of disubstituted aroylhydrazones with (ABB(OH)H-n) and without lateral hydroxyl group (ABBH-n) (n = 6–16) have been synthesised by microwave-assisted methods. The compounds were structurally characterised by using suitable spectroscopic techniques. The mesomorphic properties of the series of aroylhydrazones were examined using differential scanning calorimetric analysis and polarising optical microscopy. The relationship between structure and mesogenic properties was analysed by comparison of the present series and earlier reports on homostructural series of aroylhydrazones. Thus, the effects of substitution of phenyl rings with ester and ether linking group at both terminals and introduction of hydroxyl group at lateral position on stability of mesophase and their width were investigated. I...

9 citations

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TL;DR: In this article, the authors used a surface enhanced Raman scattering (SERS) method to monitor the decyclization of creatinine at basic pH using a silver island film.
Abstract: Creatinine → creatine decyclization is an important reaction wherein we obtain a beneficial compound from a toxic substance. Decyclization of creatinine at basic pH has been monitored in vitro by time series surface enhanced Raman scattering (SERS) using a silver island film. NH2 scissoring, CN and CO stretching modes of creatinine serve as Raman markers for monitoring the decyclization reaction. Transition state calculations using DFT have revealed the path of the formation of creatine by the cleavage of the endocyclic CN bond of creatinine. The Raman signatures of ring opening are clearly observed after 120 min at pH 8, and further increasing the pH increases the reaction rate even more, as the signatures are observed after 60 and 30 min at pH 10 and 12, respectively; however, the reversibility of the reaction is more prominent at higher pH. Therefore, pH 8 is the most favorable among the three pH values for the decyclization reaction to be stable at room temperature. The proper understanding of this reaction where a toxic substance is converted to a beneficial compound is expected to open the scope for further extensive research.

9 citations

Journal ArticleDOI
TL;DR: In this article, a homologous series of N-[4]-nalkoxy)benzoyloxy-2-hydroxybenzylidene)-4-carbethoxy anilines and their copper(II) complexes have been synthesized.
Abstract: A novel homologous series of N-[4-[4′-n-alkoxy)benzoyloxy-2-hydroxybenzylidene)-4-carbethoxy anilines, H2n+1CnOC6H4C(O)OC6H3(OH)C(H)˭NC6H4COOC2H5 (n = 6, 8, 10, 12, 14, 16) and their copper(II) complexes have been synthesized. All these compounds have been characterized by suitable spectroscopic techniques. The mesomorphic properties of these compounds were investigated by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). The ligands exhibit wide range of enantiotropic smectic A and nematic phases as confirmed by their typical optical texture under polarizing microscope. The square planar copper(II) complexes of the ligands show only an isotropic phase at higher temperature and no mesogenic nature is observed. DFT calculations have been performed using GAUSSIAN-03 program at B3LYP level to obtain the stable electronic structure of the ligand with decyloxy chain length and its copper(II) complex.

6 citations


Cited by
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TL;DR: A facile one-step, low-temperature, nonhydrolytic approach to in situ synthesizing amino-functionalized TiO2 nanoparticles (abbreviated as NH2 -TiO2 NPs) is developed by chemical bonding of amino (-NH2 ) groups, via TiN bonds, onto the surface of TiO1 NPs.
Abstract: Titanium oxide (TiO2 ) has been commonly used as an electron transport layer (ETL) of regular-structure perovskite solar cells (PSCs), and so far the reported PSC devices with power conversion efficiencies (PCEs) over 21% are mostly based on mesoporous structures containing an indispensable mesoporous TiO2 layer. However, a high temperature annealing (over 450 °C) treatment is mandatory, which is incompatible with low-cost fabrication and flexible devices. Herein, a facile one-step, low-temperature, nonhydrolytic approach to in situ synthesizing amino-functionalized TiO2 nanoparticles (abbreviated as NH2 -TiO2 NPs) is developed by chemical bonding of amino (-NH2 ) groups, via TiN bonds, onto the surface of TiO2 NPs. NH2 -TiO2 NPs are then incorporated as an efficient ETL in n-i-p planar heterojunction (PHJ) PSCs, affording PCE over 21%. Cs0.05 FA0.83 MA0.12 PbI2.55 Br0.45 (abbreviated as CsFAMA) PHJ PSC devices based on NH2 -TiO2 ETL exhibit the best PCE of 21.33%, which is significantly higher than that of the devices based on the pristine TiO2 ETL (19.82%) and is close to the record PCE for devices with similar structures and fabrication procedures. Besides, due to the passivation of the surface trap states of perovskite film, the hysteresis of current-voltage response is significantly suppressed, and the ambient stability of devices is improved upon amino functionalization.

197 citations

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TL;DR: In this article, the authors summarized the published innovations in nanomaterial-based optical sensors for the detection of Hg 2+ according to different sensing strategies, including colorimetric, fluorescent and surface enhanced Raman scattering detection.
Abstract: As one of the most toxic heavy metals, mercury ion (Hg 2+ ) has become a concern focus for its severe threats to environment and human health. As a result, it is of great importance to develop novel methods to realize the recognition and quantification of Hg 2+ . The past decades witness the development of nanomaterial-based optical sensors for Hg 2+ detection, showing the benefits of simplicity, rapidity, high sensitivity and selectivity, and cost-effectiveness. The reported methods have allowed the detectability down to nanomolar concentrations or much lower levels, and proved their practical applications for detecting and quantifying Hg 2+ in synthetic solutions or natural water samples. In this review, we summarize the published innovations in nanomaterial-based optical sensors for the detection of Hg 2+ according to different sensing strategies, including colorimetric, fluorescent and surface enhanced Raman scattering detection. Moreover, some challenges and significant attempts related to these methods are also discussed.

191 citations

Journal ArticleDOI
TL;DR: The experimental results suggest that the adsorption efficiency of DOX is dominated by the strong complexation, electrostatic interactions between DOX molecules and the Cu-BC samples, which hold the significant potential for enhancing the effectiveness to remove DOX from water.

146 citations

Journal ArticleDOI
TL;DR: In this paper, the basic principles involved in the design of chemosensors for the selective analysis of palladium, problems and challenges in the field as well as possible future research directions are presented.

77 citations

Journal ArticleDOI
TL;DR: In this article, the authors focus on the portable and smart devices integrated with nanomaterials for monitoring heavy metal ions (HMIs) and summarize the miniaturization, portability, and commercialization of HMIs detection devices.
Abstract: With increasing concerns of ecological environment, safe drinkable water and healthy food, the detection for heavy metal ions (HMIs) becomes an attractive research field. On the basis of optical, electrical and other signals from nanomaterials, many interesting methods and portable devices for detection of HMIs are growing flourishingly. In this review, we focus on the portable and smart devices integrated with nanomaterials for monitoring HMIs. The interesting design of the miniaturization, portability, and commercialization of HMIs detection devices are summarized and introduced comprehensively.

64 citations