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The nature of metal complexes of heterocyclic thiosemicarbazones reported in the literature through 1989 have been reviewed with an emphasis on variations in stoichiometry and stereochemistry. A brief introduction is followed by a survey of the biological activity of the uncomplexed thiosemicarbazones. Next is a section on the chemical nature of thiosemicarbazones including a discussion of preparative methods, modes of coordination and isomerism. This is followed by a discussion of structural information and biological activity of the iron(III), iron(II), copper(II), cobalt(III), cobalt(II) and nickel(II) complexes of heterocyclic thiosemicarbazones. Short sections on the biological activity of other chelating thiosemicarbazones and metal complexes are also included.

Structural and physical correlations in the biological properties of transition metal heterocyclic thiosemicarbazone and S -alkyldithiocarbazate complexes

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.

Low-Temperature In Situ Amino Functionalization of TiO2 Nanoparticles Sharpens Electron Management Achieving over 21% Efficient Planar Perovskite Solar Cells.

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.

http://ir.yic.ac.cn/bitstream/133337/17510/1/Nanomaterial-based%20optical%20sensors%20for%20mercury%20ions.pdf

Nanomaterial-based optical sensors for mercury ions

Facile synthesis of Cu(II) impregnated biochar with enhanced adsorption activity for the removal of doxycycline hydrochloride from water.

A new series of mesogenic aroylhydrazone-based ligands, N-[4-(4′-alkoxy)benzoyloxybenzylidene]-N′-[4″-alkoxybenzoyl]hydrazine with either the same or different peripheral alkyl chains, and nickel(II) complexes of some of them have been synthesised They were characterised by elemental analyses, Fourier transform infrared, proton and carbon nuclear magnetic resonance and ultraviolet-visible spectroscopy The mesomorphic properties of these compounds were investigated by differential scanning calorimetry and polarising optical microscopy All the aroylhydrazones, except those with no lateral chains on either end of the molecule and where m = n = 14, 16, exhibit a monotropic or enantiotropic smectic C mesophase, which are almost insensitive to the peripheral alkoxy chain length The square planar nickel(II) complexes of the ligands show only an isotropic phase at higher temperature (>175°C) and no mesogenic nature is observed Density functional theory calculations have been performed using the GAUSSIAN-03 p

Synthesis, characterisation and mesomorphic properties of ester containing aroylhydrazones and their nickel(II) complexes

An electrical conducting and magnetic nanomaterial, [Ni(II)Hyd]-MWCNTs was synthesized via chemical modification of carboxylated MWCNTs (A-MWCNTs). The synthesized material has been studied by FTIR, UV–Visible, XPS, Raman, TGA, powder XRD, TEM and EDAX analysis. Double probe DC conductivity suggested enhanced electrical conductivity of [Ni(II)Hyd]-MWCNTs compared to A-MWCNTs. (RsQ(RctO)) is found to be best fit Randle’s equivalent circuit. The positive slope obtained from Mott-Schottky plot suggested n- type semiconducting behavior of materials. The positive shift in flat-band potential for [Ni(II)Hyd]-MWCNTs is the signature of its more conducting nature than that of A-MWCNTs. The better conductivity of [Ni(II)Hyd]-MWCNTs is also confirmed by optical and electrochemical band gap studies. The field and temperature dependent magnetization revealed intrinsic ferromagnetism in [Ni(II)Hyd]-MWCNTs with enhanced saturation magnetization, remanent magnetization and coercivity values compared to A-MWCNTs. Hence, high electrical conductivity and magnetic properties prompt the [Ni(II)Hyd]-MWCNTs for applicability in spin-based electronic devices and in other application such as EMI shielding, metamaterials, drug delivery, anticorrosion, etc.

Chemical modification of carboxylated MWCNTs for enhanced electrical conducting and magnetic properties

The present study is focused on the development of green microwave process for the synthesis of mesogenic substituted aroylhydrazones and their nickel(II) and copper(II) complexes. The compounds have been synthesised by microwave-assisted as well as thermal methods for comparison purpose. The compounds were structurally characterised by using suitable spectroscopic techniques. The mesomorphic properties were studied by differential scanning calorimetric analysis and polarising optical microscopy. The stable molecular structures of the mesogenic methylidenehydrazinato-nickel(II) complex have been obtained by density functional theoretical method to understand the structural origin responsible for the mesomorphic property.

Microwave-assisted synthesis and mesomorphic investigations of p-substituted aroylhydrazones and their nickel(II) and copper(II) complexes

In present work, we report a newly synthesized nano-inorganic hybrid magnetic material, [SBCu(II)Gd(III)]@MWCNT-COOH which is obtained by anchoring of a copper(II)–gadolinium(III) heteronuclear bimetallic complex, [triaqua(2-hydroxy-1,3-bis(3-methoxysalicylaldiminato)Cu(II)Gd(III)dinitrato)]nitrate monohydrate, [SBCu(II)Gd(III)] to carboxylated multiwalled carbon nanotubes (MWCNT-COOH) through a chemical method. MWCNT-COOH have been loaded with a number of [SBCu(II)Gd(III)] molecules on their surfaces, which generated multinuclear metal centers. [SBCu(II)Gd(III)]@MWCNT-COOH was characterized by FT-IR, UV–Vis, TGA, powder XRD, Raman spectroscopy, TEM, HRSEM, EDAX and elemental mapping. The DC electrical conductivity of materials was evaluated using two probe method suggesting that [SBCu(II)Gd(III)]@MWCNT-COOH is more conducting than [SBCu(II)Gd(III)]. The increased conductivity of [SBCu(II)Gd(III)]@MWCNT-COOH is confirmed by CV and EIS study. The capacitive and dielectric properties of the materials were investigated by Mott–Schottky electrochemical analysis. The positive value of slope signified n-type semiconducting nature of materials. The lower slope for [SBCu(II)Gd(III)] signified the strong dielectric behavior of the material. The positive shift in flat-band potential of [SBCu(II)Gd(III)]@MWCNT-COOH compared to [SBCu(II)Gd(III)] indicated its more conducting nature. Further small optical band gap obtained for [SBCu(II)Gd(III)]@MWCNT-COOH than [SBCu(II)Gd(III)] by UV–Vis studies suggested better conductivity of nano-inorganic hybrid material. Field dependent magnetization revealed enhanced saturation magnetization, remanent magnetization and coercivity of [SBCu(II)Gd(III)]@MWCNT-COOH due to generation of multinuclear metal centers on carboxylated MWCNTs. The temperature dependent magnetization measurement exhibited overlapping of field cooled and zero field cooled curves in entire temperature range (2–300 K), suggests intrinsic ferromagnetism in [SBCu(II)Gd(III)]@MWCNT-COOH. Hence, trend in variation of magnetization with magnetic field and temperature opens its utility in spin-based electronic devices.

Bachcha Singh

Papers

Synthesis, characterisation and mesomorphic properties of ester containing aroylhydrazones and their nickel(II) complexes

Chemical modification of carboxylated MWCNTs for enhanced electrical conducting and magnetic properties

Microwave-assisted synthesis and mesomorphic investigations of p-substituted aroylhydrazones and their nickel(II) and copper(II) complexes

Enhancement of electrical conductivity and magnetic properties of bimetallic Schiff base complex on grafting to MWCNTs

Synthesis, characterization and mesomorphic investigations of ester-substituted aroylhydrazones possessing a lateral hydroxyl group