Dimethylselenide (Me2Se), a simple and small organochalcogen, has been used as a ligand to synthesize complexes [PdII(Me2Se)2Cl2] (1) and [RuII(p-cymene)(Me2Se)2Cl](PF6) (2). Complexes 1 and 2 have been characterized by multi-nuclear...

Mercury (Hg2⁺) contamination in water poses severe environmental and health risks due to its extreme toxicity and bioaccumulation potential. Herein, we report a sulfur doped activated carbon derived from banana stem (BS-AC (400)), synthesized via H₂SO₄ activation and low-temperature annealing under N₂, as a low-cost yet highly efficient fluorescent probe for Hg2⁺ detection. Comprehensive characterization (XPS, FTIR, XRD, HR-TEM/SAED) confirmed successful heteroatom incorporation, high porosity, and graphitic domains. BS-AC (400) exhibited intense photoluminescence with a maximum emission at 335 nm upon 230 nm excitation, which was selectively and efficiently quenched by Hg2⁺ even in the presence of 14 competing metal ions. The sensor achieved a detection limit of 9.73 µM and demonstrated excellent reproducibility, photostability, and applicability in real water samples, achieving 94–103

This study highlights selective Pd 2+ detection using metal complex- and MOF-based optical sensors, addressing key innovations, challenges, and future directions.

A 2-(methylthio)aniline based palladacycle [PdII(L)Cl] (1) {where HL = 2-(methylthio)-N-(naphthalen-1-ylmethylene)benzenamine} has been synthesized and characterized by 1H, 13C{1H} NMR, UV-Vis, FT-IR and ESI-MS techniques. The coordination mode of HL in 1 was determined using single-crystal X-ray crystallography. The molecular structural elucidation revealed the orthometallation of Pd(II) with naphthalene moiety in 1. Ligand HL coordinated to Pd(II) via thioaniline-S and imine-N atoms, leading to a distorted square planar geometry around the Pd metal centre. The Pd-N and Pd-S bond distances were depicted as 2.001(8) & Aring; and 2.374(3) & Aring;, respectively. Complex 1 was found to be a highly efficient catalyst for Sonogashira (copper and amine free) and Suzuki-Miyaura cross coupling reactions of various aryl halides under aerobic conditions. The required amount of catalyst to achieve a good to excellent catalytic conversion was 0.01-0.05 mol%. During the course of coupling using 1 as catalyst, unexpected formation of Pd(0) nanoparticles PdNPs1 has been observed. These in-situ generated NPs have been characterized using transmission electron microscopy (TEM), EDAX, EDS mapping, UV-Vis, FT-IR and powder X-ray diffraction (PXRD) studies.

Chemical nucleases have seen gradual growth in the field of chemistry and biomedical science. So far, a diverse range of small organic molecules as well as coordination complexes have been developed as chemical nucleases to cleave DNA mainly via three major pathways i.e., photoinduced, oxidative or hydrolytic pathways. However, most of such nucleases suffer from their practical applications in real-life samples because they require an external redox agent for functioning. In this context, small organic/inorganic compounds acting as the ‗selfactivating‘ chemical nucleases have emerged as viable alternatives as therapeutic agents for DNA cleavage activity with no exogeneous agent. The aim of this chapter is to highlight the self-activated DNA cleavage shown by mononuclear copper complexes with specific emphasis on their recent development and challenges

Two closely related coumarin-based chemosensors, L1 with a -NO2 group and L2 with an -I group, have been designed as the fluorescent sensors. Chemosensors L1 and L2 have been utilized for the selective detection of Mg2+ and Zn2+ ions, respectively. The non-fluorescent L1 and L2 exhibit 'turn-on' fluorescence response with Mg2+ and Zn2+ ions, respectively. The absorption spectrum of L1 in presence of Mg2+ ion exhibits a 12 nm blueshift while L2 shows a 5 nm red-shift with Zn2+ ion. Chemosensors L1 and L2 show noteworthy detection limits of 0.10 and 0.35 mu M and binding constants (Kb; x104 M-1) of 0.45 and 1.14 for Mg2+ and Zn2+, respectively. The chemosensor-metal binding was studied by mass and proton NMR spectra while a 2:1 stoichiometry was confirmed by Job's plot. The crystal structure of [(L2)2Zn] complex further confirms a 2:1 stoichiometry as well as binding mode of the chemosensors. Both chemosensors further worked as the colorimetric sensors for the detection of Mg2+ and Zn2+ ions. For both chemosensors, reversibility was achieved by using ATP while logic gates were also generated. Chemosensor L2 was found to be AIEE active in MeOH-H2O and EtOH-H2O solvent systems. Water promoted H-type aggregation by hindering the - C--N bond rotation which enhanced the emission. The formation of aggregates was confirmed by the dynamic light scattering and florescence lifetime measurements.

The increasing demand for microelectronics has significantly driven the advancement of thin film energy storage devices, specifically lithium-ion batteries. In this current work, binder-free lithium cobalt oxide (LCO) has been synthesized by Radio Frequency (RF) magnetron sputtering on aluminium foil substrate in an argon atmosphere. The investigation focused on optimizing the cathode on aluminium foil by varying parameters, such as RF source power, working pressure, and temperature of the substrate. The deposited layers were analyzed for their structural and surface properties to confirm the formation of LCO. The surface of LCO obtained from this binder-free approach helps us create an excellent interface between cathode-electrolyte with a low contact angle (18.1 degrees). An electrochemical analysis of the optimized sample (480 nm thick) was carried out by using 1 M lithium hexa-fluoro-phosphate. The initial charge capacity in the 2 - 4.2 V voltage range was obtained to be 624 mAh/cm(3) at the C-rate of 0.05C, which is closer to the theoretical capacity (690 mAh/cm(3)). Signifying, over 90 % of total lithium is contributed during the charge storage mechanism. As a result, it can be interpreted that the binder-free sputtering technology can be implemented to fabricate efficient electrodes for lithium-ion batteries.

This study explores the spatial patterns of particulate matter (PM) in the megacity of Delhi. A GRIMM aerosol spectrometer is used to analyze different aerodynamic diameters (PM10, PM2.5, PM1.0), inhalable, thoracic, and alveolic particles, and black carbon (BC) at six prominent locations in Delhi during summer and winter. Additionally, metals (Pb, Fe, Ca, Al, Zn), along with silicon and sulfur, are analyzed using an ED-XRF spectrometer over the sampling locations during the summer season. The sampling site data are interpolated using the Kriging method to generate spatial maps to explore the air pollution problem in Delhi. East Delhi is observed to be the most polluted site, while Guru Gobind Singh Indraprastha University (GGSIPU) is the least polluted site. We further observe a high correlation between Al-Fe, Al-Ca, Zn-Pb, Ca-Fe, and S-Zn, indicating their common source of emission. Aerosols are also found to be highly enriched with metals like Al, S, Fe, Zn, and Pb, suggesting strong anthropogenic sources of these metals. Construction activities, resuspended dust, an increased number of vehicles, faulty agricultural practices, and soil could be recognized as major sources of the particulate concentration in an urban area like Delhi.

In this study, an easily synthesizable Schiff base probe TQSB having a quinoline fluorophore is demonstrated as a fluorescent and colorimetric turn-on sensor for Al3+ ions in a semi-aqueous medium (CH3CN/water; 4 : 1; v/v). Absorption, emission and colorimetric studies clearly indicated that TQSB exhibited a high selectivity toward Al3+, as observed from its excellent binding constant (Kb = 3.8 × 106 M-1) and detection limit (7.0 nM) values. TQSB alone was almost non-fluorescent in nature; however, addition of Al3+ induced intense fluorescence at 414 nm most probably due to combined CHEF (chelation-enhanced fluorescence) and restricted PET effects. The sensing mechanism was established via Job's plot, NMR spectroscopy, ESI-mass spectrometry, and density functional theory (DFT) analyses. Furthermore, to evaluate the applied potential of probe TQSB, its sensing ability was studied in real samples such as soil samples and Al3+-containing Digene gastric tablets as well as on low-cost filter paper strips. Fluorescence microscopy imaging experiments further revealed that TQSB can be used as an effective probe to detect intracellular Al3+ in live cells with no cytotoxicity.

The present review discusses selected compounds based on polycyclic aromatic hydrocarbons (PAHs); mainly those containing naphthalene, anthracene, fluorene, pyrene, triphenylene and perylene rings. The focus has been placed to highlight both properties and applications of such PAH-containing compounds in gelation, aggregation-induced enhanced emission (AIEE) and mechanochromism as well as in fluorescence sensing of assorted analytes.

Imidazolium-based chiral ionic liquid containing a ,a-diaryl-(S)-prolinol trimethylsilyl ether acts as an efficient and reusable organocatalyst for the enantioselective Friedel-Crafts reaction between indoles and a , b-unsaturated aldehydes. 3-Alkylated indoles were obtained in 62-89 % yields with 47-88 % enan-tiomeric excesses using a ,a-diphenyl-(S)-prolinol trimethylsilyl ether having hexafluorophosphate anion [PF6]- (20 mol%) and triethylamine (40 mol%) as a base additive in 1,4 dioxane at 25 degrees C. The a ,a-diphenyl-(S)-prolinol trimethylsilyl ether having hexafluorophosphate anion [PF6]- was recycled and reused for FC reaction up to seven recycles with consistent enantioselectivity, but a considerable loss in yield of the product was observed after the third recycling. The energies of possible conformers (iminium intermedi-ates) were calculated by DFT.(c) 2023 Elsevier Ltd. All rights reserved.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Group 10 metals including Ni, Pd and Pt have been extensively applied in various essential aspects of human social life, material science, industrial manufactures, medicines and biology. The ionic forms of these metals are involved in several biologically important processes due to their strong binding capability towards different biomolecules. However, the mishandling or overuse of such metals has been linked to serious contamination of our ecological system, more specifically in soil and water bodies with acute consequences. Therefore, the detection of group 10 metal ions in biological as well as environmental samples is of huge significance from the human health point of view. Related to this, considerable efforts are underway to develop adequately efficient and facile methods to achieve their selective detection. Optical sensing of metal ions has gained increasing attention of researchers, particularly in the environmental and biological settings. Innovatively designed optical probes (fluorescent or colorimetric) are usually comprised of three basic components: an explicitly tailored receptor unit, a signalling unit and a clearly defined reporter unit. This review deals with the recent progress in the design and fabrication of fluorescent or colorimetric organic sensors for the detection of group 10 metal ions (Ni(II), Pd(II) and Pt(II)), with attention to the general aspects for design of such sensors.

Chemical nucleases have found potential applications in the research fields of chemistry, biotechnology and medicine. A variety of metal complexes have been explored as good to outstanding therapeutic agents for DNA cleavage activity most likely via hydrolytic, oxidative or photoinduced cleavage pathways. However, most of these DNA cleaving agents lack their utility in in vivo applications due to their dependence on exogenous oxidants or reductants to achieve successful DNA damage. In view of addressing these issues, the development of metal complexes/organic molecules serving as self-activating chemical nucleases has received growing attention from researchers. In only the last decade, this field has dramatically expanded for the usage of chemical nucleases as therapeutic agents for DNA damage. The present study provides an overview of the opportunities and challenges in the design and development of self-activating chemical nucleases as improved DNA therapeutic candidates in the absence of an external redox agent. The reports on DNA nuclease activity via self-activation, especially with copper, zinc and iron complexes, and their mechanistic investigation have been discussed in this review article.

The reaction of Pd(OAc)2 with N,N'-di(4-tolyl)thiourea and N,N'-bis(2-anisyl)thiourea were explored to understand the influence of subtle steric/electronic properties of the substituents on the aryl rings of thiourea upon the structure of the resulting compounds. Pd(OAc)2 upon reaction with two equivalents of N,N & PRIME;-di(4-tolyl) thiourea and N,N'-bis(2-anisyl)thiourea separately in toluene at 60 degrees C afforded bis-chelated complexes [Pd{& kappa;2(N, S)-(C(NAr)(S)(ArNH)}2] [Ar = C6H4Me-4 (1), C6H4(OMe)-2 (2)] in 78 and 86% yields, respectively. Complexes 1 and 2 were characterized by microanalytical, FT-IR, 1H NMR spectroscopic data and single crystal X-ray diffraction analyses. Both the complexes were studied for their potential catalytic efficacy towards SuzukiMiyaura (i.e., C-C coupling) reactions. They exhibited fair to excellent catalytic ability towards such catalytic reactions at very low catalyst loading (Cat. load. 0.01 mol%) allowing the use of various aryl bromides as substrates. Complex 2 showed relatively higher catalytic activity as compared to complex 1.

An efficient dual functional naphthalene-derived Schiff base NpSb probe has been synthesised and evaluated for its fluorescence and chromogenic response towards metal ions. The NpSb probe was capable of selectively recognising Al3+ and Zn2+ ions when they were excited at the same wavelength in an aqueous organic solvent system. Almost non-fluorescent NpSb displayed a 'turn-on' fluorescence response when treated with Zn2+ (λem = 416 nm) and Al3+ (λem = 469 nm) ions due to the chelation-enhanced fluorescence (CHEF) effect. The limit of detection (LoD) values for Al3+ and Zn2+ have been determined to be 38.0 nM and 43.0 nM, respectively. The binding constants for Al3+ and Zn2+ were found to be 1.18 × 106 M-1 and 3.5 × 105 M-1, respectively. The NpSb also acted as a colorimetric sensor for Al3+ as the colour of the probe's solution turned to pale green from colourless upon Al3+ addition. The binding mechanism between NpSb and Zn2+/Al3+ was supported by the ESI-MS, Job's plot, NMR, and DFT studies. The reversibility experiments were carried out with an F- ion and EDTA with the development of corresponding logic gates. Moreover, NpSb could be applied to detect Al3+ ions in real samples such as tap water, distilled water and soil samples.

Pyrene linked-coumarin based fluorescent chemosensors L1 and L2 are utilized for the selective detection of Cu2+ and Zn2+ ions, respectively. Both chemosensors differed by a methylene spacer that connects the coumarin and pyrene rings through an imine group. The inclusion of methylene spacer dramatically changed the detection profiles of two chemosensors. While L1 showed fluorescence "turn-off" response towards the Cu2+ ion; L2 showed "turn-on" emission enhancement with the Zn2+ ion. Both chemosensors illustrated nano-molar detection limits and were selective even in the presence of other competing metal ions. The 1 : 1 stoichiometry between a chemosensor and Cu2+/Zn2+ ion was supported by the binding studies, Job's plot, NMR spectral titrations, mass spectra and density functional theory (DFT) studies. The detection ability of both chemosensors was utilized by fabricating the filter paper test-strips as well as polystyrene films for quick and visual monitoring of these ions in different water samples. Chemosensor L2 was further utilized for the "turn-on" detection of Zn2+ ion in HepG2 cells whereas solution generated L2-Zn species functioned as a secondary chemosensor for the detection of cystine, an important amino acid.

Biorelevant metal ions such as Cu2+ and Fe2+/Fe3+ participate in various biological events which include electron transfer reactions, delivery and uptake of oxygen, DNA and RNA syntheses, and enzymatic catalysis to maintain fundamental physiological processes in living organisms. So far, several analytical techniques have been investigated for their precise detection; however, luminescence-based sensing is often superior due to its high sensitivity, selectivity, fast and easy operation and convenient cellular imaging. Owing to their immense photophysical and photochemical properties stemming from large Stokes shift, absorption in visible region, good photostability and long excited state lifetimes, Ru(II)-polypyridyl-based complexes have gained increasing interest as luminophores. Over past few decades, several Ru(II)-polypyridyl based chemosensors have rapidly been developed for detection of different biorelevant and other metal ions. The main object of this book chapter is to cover a majority of Ru(II)-polypyridyl based chemosensors showing a selective and sensitive detection of bio-relevant Cu2+ and Fe2+/Fe3+ ions. The photophysical properties of Ru(II) complexes, detection of metal ions, sensing mechanism and applications of these sensors are discussed at a length.

Novel Coronavirus disease (COVID-19), after being identified in late December 2019 in Wuhan city of China, spread very fast and has affected all the countries in the world. The impact of lockdowns on particulate matter during the lockdown period needs attention to explore the correlation between anthropogenic and natural emissions. The current study has demonstrated the changes in fine particulate matter PM 2.5 , PM 10 and their effect on air quality during the lockdown. The air quality before the lockdown was low in New Delhi (India) and Riyadh (Saudi Arabia), among major cities worldwide. The air quality of India is influenced by dust and sand from the desert and surrounding areas. Thus, the current study becomes important to analyse changes in the air quality of the Indian sub-continent as impacted by dust storms from long distances. The result indicated a significant reduction of PM 2.5 and PM 10 from 93.24 to 37.89 μg/m 3 and from 176.55 to 98.87 μg/m 3 during the lockdown period as compared to pre lockdown period, respectively. The study shows that average concentrations of PM 10 and PM 2.5 have declined by -44% and -59% during the lockdown period in Delhi. The average value of median PM 10 was calculated at 33.71 μg/m 3 for Riyadh, which was lower than that value for New Delhi during the same period. The values of PM 10 were different for pre and during the lockdown periods in Riyadh, indicating the considerable influence on air quality, especially the concentration of PM 10 , from both the natural (sand and dust storms) and the anthropogenic sources during the lockdown periods. However, relatively smaller gains in the improvement of air quality in Riyadh were correlated to the imposition of milder lockdown and the predominance of natural factors over the anthropogenic factors there. The Air Quality Index (AQI) data for Delhi showed the air quality to be ‘satisfactory’ and in the green category during the lockdown period. This study attempts to better understand the impact of particulate matter on the short- and long-term air quality in Delhi during the lockdown. This study has the scope of being scaled up nationwide, and this might be helpful in formulation air pollution reduction and sustainable management policies in the future.