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Defect engineering, achieved by precise tuning of the atomic disorder within crystalline solids, forms a cornerstone of structural chemistry. This nuanced approach holds the potential to significantly augment thermoelectric performance by synergistically manipulating the interplay between the charge carrier and lattice dynamics. Here, the current study presents a distinctive investigation wherein the introduction of Hg doping into AgSbTe2serves to partially curtail structural disorder. This strategic maneuver mitigates potential fluctuations originating from pronounced charge and size disparities between Ag+and Sb3+, positioned in octahedral sites within the rock salt structure. Hg doping significantly improves the phase stability of AgSbTe2by restricting the congenital emergence of the Ag2Te minor secondary phase and promotes partial atomic ordering in the cation sublattice. Reduction in atomic disorder coalesced with a complementary modification of electronic structure by Hg doping results in increased carrier mobility. The formation of nanoscale superstructure with sizes (2–5 nm) of the order of phonon mean free path in AgSbTe2is further promoted by reduced partial disorder, causes enhanced scattering of heat-carrying phonons, and results in a glass-like ultralow lattice thermal conductivity (∼0.32 W m–1K–1at 297 K). Cumulatively, the multifaceted influence of Hg doping, in conjunction with the consequential reduction in disorder, allows achieving a high thermoelectric figure-of-merit, zT, of ∼2.4 at ∼570 K. This result defies conventional paradigms that prioritize increased disorder for optimizing zT.

The present work investigates TIG in terms of strength and energy consumption during joining of dissimilar metal plates between 304 Stainless Steel and AISI 1018 Mild Steel. TIG welding basically promotes a sustainable environment because it consumes less energy. Energy conservation means to reduce imbalance between demand and energy supply that is necessary to protect ecological resources and natural environment. TIG welding is a precision welding process which makes possible for joining of thinner and lighter materials. Joining of various dissimilar metals becomes great interest owing to the different challenges that are posed by deviation in the material composition as well as the characteristics of the joined metals. The main objective is to optimize energy consumption and tensile strength by taking effective process parameters that are Current, Travel Speed and Gas Flow Rate and also determination of main influential process parameters on energy consumption and tensile strength by using Taguchi method. Contour plot has also been shown in this present investigation.

India is highly vulnerable to the escalating adversities of global climate-induced disasters, with flooding among the most significant consequences incurring severe detrimental effects on traditional land-based agriculture practices due to prolonged waterlogging. In this context, floating-bed agriculture shows promise for flood-prone and wetland areas, particularly in India, where resilient farming practices are essential. This method offers a viable solution to mitigate climate-induced flooding and promote sustainable agriculture. However, challenges persist, including concerns about instability of floating beds and the risk of crop destruction. This literature review aims to comprehensively document the current global scenario of floating-bed agriculture to promote it in India. Employing the PRISMA framework, a meticulous analysis of published literature on floating agriculture was conducted using reputable search engines (Google Scholar, Web of Science, Scopus). After applying inclusion and exclusion criteria, we selected 48 research articles (published between 1997 and 2023) to include in this review paper. The analysis of 48 articles reveals significant research gaps in floating-bed agriculture, emphasizing the need for exploration by agricultural researchers and engineers. The findings underscore key benefits such as increased crop yields, while also highlighting challenges including optimal crop selection and sustainability aspects. Detailed field research and scientific investigations are essential to ascertain the viability of floating-bed agriculture as a climate-induced disasters adaptation method, fortifying the resilience of farming communities in low-lying, flood-prone, and marshy areas.

The reaction of the mononuclear Ni(II) building block [NiL] of an asymmetrically dicondensed N2O3donor Schiff base ligand, N-salicylidene-N′-3-methoxysalicylidene-1,3-propanediamine (H2L), with LnCl3·6H2O (Ln = Gd, Tb, Dy) in a 2:1 molar ratio leads to the formation of three hexanuclear carbonato-bridged Ni4Ln2complexes formulated as [Ni4Ln2(CO3)2Cl2(L)2(L′)2(CH3CN)2]·4CH3CN·2H2O (Ln = Tb (2), Dy (3)), where H2L′ = N,N′-bis(salicylidene)-1,3-propanediamine. In complex 1, the unsymmetrical nature of the Schiff base remains intact; however, in 2and 3, between the two metalloligands coordinated to each Ln, one is the precursor [NiL] of the unsymmetrical ligand whereas the other [NiL′] of the symmetrical ligand, formed by an in situaldehyde-exchange reaction during complex formation with Ln salts. The Ln(III) centers are octacoordinated with a biaugmented-trigonal-prismatic geometry in all three complexes. In complex 1, half of the Ni(II) centers possess a distorted octahedral geometry while the other half has a square-pyramidal geometry; all of the Ni(II) centers in complexes 2and 3have a distorted-octahedral geometry. A magnetic study clarifies that the Ni–Ln magnetic exchange couplings are ferromagnetic. Though the complexes consist of a hexanuclear [Ln2Ni4] system, the magnetic properties have been analyzed on a trinuclear Ni–Ln–Ni basis. The exchange parameter 2JGd–Ni/kBin 1was estimated to be +0.61 to +0.84 K across the double-oxide bridges. Complexes 2and 3exhibited an indication of single-molecule magnets in an ac susceptibility study.

Efficient manipulation of thermal conductivity and fundamental understanding of the microscopic mechanisms of phonon scattering in crystalline solids are crucial to achieve high thermoelectric performance. Thermoelectric energy conversion directly and reversibly converts between heat and electricity and is a promising renewable technology to generate electricity by recovering waste heat and improve solid-state refrigeration. However, a unique challenge in thermal transport needs to be addressed to achieve high thermoelectric performance: the requirement of crystalline materials with ultralow lattice thermal conductivity (κL). A plethora of strategies have been developed to lower κLin crystalline solids by means of nanostructural modifications, introduction of intrinsic or extrinsic phonon scattering centers with tailored shape and dimension, and manipulation of defects and disorder. Recently, intrinsic local lattice distortion and lattice anharmonicity originating from various mechanisms such as rattling, bonding heterogeneity, and ferroelectric instability have found popularity. In this Perspective, we outline the role of manipulation of chemical bonding and structural chemistry on thermal transport in various high-performance thermoelectric materials. We first briefly outline the fundamental aspects of κLand discuss the current status of the popular phonon scattering mechanisms in brief. Then we discuss emerging new ideas with examples of crystal structure and lattice dynamics in exemplary materials. Finally, we present an outlook for focus areas of experimental and theoretical challenges, possible new directions, and integrations of novel techniques to achieve low κLin order to realize high-performance thermoelectric materials.

Fundamental understanding of the relationship between chemical bonding, lattice dynamics, and thermal transport is not only crucial for thermoelectrics but also essential in photovoltaics and optoelectronics. This leads to a widespread search for low thermally conductive crystalline metal halide perovskites with improved electrical transport and stability. Pb-free all-inorganic Sn-based halide perovskites are particularly compelling because of their degenerate hole doping capability, which generally results in p-type conduction. Herein, we demonstrate an n-type thermoelectric conduction in concurrence with an ultralow lattice thermal conductivity (κlat∼0.29–0.22 W/m·K) in an air-stable vacancy-ordered double perovskite Cs2SnI6. Phonon dispersion calculated by density functional theory indicates the presence of low-frequency localized optical modes at 8 and 32 cm–1due to the dynamical rotation of SnI6octahedra and anharmonic rattling of Cs-atoms, respectively, which are experimentally verified by temperature-dependent Raman spectroscopy and low-temperature heat capacity measurement. Cs2SnI6exhibits a soft elastic lattice with chemical bonding hierarchy that causes low bulk and shear moduli, which in turn results in a low measured sound velocity of ∼1158 m/s. Low-energy anharmonic optical modes strongly couple with heat-carrying acoustic phonons and, consequently, limit phonon group velocity and phonon lifetime to an ultrashort value, leading to an intrinsically ultralow κlatin n-type Cs2SnI6.

This study reports the development and evaluation of self-healing hydrogel composed of carboxymethyl chitosan (CmCh) and oxidized alginate, with a focus on wound healing applications. Oxidized alginate was synthesized via metaperiodate oxidation and characterised. The hydrogels were formulated using Schiff base reactions with two weight ratios of oxidized alginate and CmCh, and their cross-linking mechanism was proposed. The developed hydrogels were characterised for their gelation, pH, self-healing capability, conductivity, and injectability. The optimized hydrogel was further evaluated for antibacterial activity, cytotoxicity, haemocompatibility, and in vitrowound healing studies. Results revealed that hydrogels with the lowest ratio of oxidized alginate to CmCh exhibited superior gelation, tensile strength, and injectability without needle clogging. Additionally, rapid self-healing of hydrogels was confirmed via Scanning Electron Microscope (SEM) analysis. The optimized hydrogel displayed good antibacterial activity against Staphylococcus aureusand Escherichia coli, alongside haemocompatibility. Additionally, in vivostudies demonstrated comparable wound healing efficacy to marketed formulations and significant improvement over control groups. These findings indicates the potential of self-healing hydrogels made up of oxidized alginate and CmCh for tissue engineering applications.

The strategic design and synthesis of two isomeric CuIIcomplexes, [CuLA] and [CuLB], of asymmetrically dicondensed N2O3-donor Schiff-base ligands (where H2LAand H2LBare N-salicylidene-N′-3-methoxysalicylidenepropane-1,2-diamine and N-3-methoxysalicylidene-N′-salicylidenepropane-1,2-diamine, respectively) have been accomplished via a convenient CuIItemplate method. These two complexes have been used as metalloligands for the synthesis of three pairs of Cu–Ln isomeric complexes [CuL(μ-NO3)Ln(NO3)2(H2O)]·CH3CN (for complexes 1A–3A, L = LA, and for complexes 1B–3B, L = LBand Ln = Gd, Tb, and Dy, respectively), all of which have been characterized structurally. In all six isomorphous and isostructural complexes, the decacoordinated LnIIIcenters and pentacoordinated CuIIcenters possess sphenocorona and square-pyramidal geometries, respectively. The isomeric pair of Cu–Gd compounds shows field-induced slow relaxation of magnetization, although they present the typical isotropic behavior of GdIIIcomplexes, indicating that slow relaxation is not due to the usual energy barrier originating from the magnetic anisotropy. The isostructural derivatives with the ion-anisotropic lanthanides TbIIIand DyIIIdo not show slow magnetic relaxation with or without a direct-current bias field, demonstrating that the magnetic response of the isotropic system CuII–GdIIIoccurs through different mechanisms than the rest of the Ln cations.

A mononuclear Ni(II) complex, [NiL2]·2H2O, was prepared by the reaction of a N2O2donor monocondensed Schiff base ligand, 2-((3-aminopropylimino)methyl)-6-methoxyphenol (HL), with NiCl2·6H2O. The reaction of this complex with NiCl2·6H2O and LnCl3·6H2O (Ln = Gd, Tb, Dy, Ho) in a 1:1:1 molar ratio leads to four hexanuclear Ni4Ln2complexes formulated as [{(NiL)2Gd}2(μ2-Cl)2(μ3-OH)4(OH2)4]Cl4·CH3CN·H2O (1), [{(NiL)2Tb}2(μ2-Cl)2Cl2(μ3-OH)4(OH2)2]Cl2·12H2O (2), [{(NiL)2Dy}2(μ2-Cl)2Cl2(μ3-OH)4(OH2)2]Cl2·16H2O (3), and [{(NiL)2Ho}2(μ2-Cl)2(μ3-OH)4(OH2)4]Cl4·CH3CN·1.8H2O (4). The Ln(III) centers are octacoordinated with a triangular-dodecahedral geometry, and the geometries around the Ni(II) centers are distorted octahedral in all four complexes. The temperature-dependent DC magnetic measurements reveal the existence of ferromagnetic interactions in all four complexes (1–4). The AC susceptibility measurements performed with and without an applied DC field show SMM behavior in complexes 2–4with a single slow relaxation process in 2(SR) but slow (SR) and fast (FR) relaxation processes in 3and 4. The energy barriers of the relaxation times for the SR processes are ca. 13, 20, and 19 K in 2–4, respectively.

In the present work, four new heterometallic coordination complexes, {[(CuL)2Mn(nic)(H2O)2](ClO4)(0.5H2O)}n(1), {[(CuL)2Cd(nic)(H2O)2](ClO4)(H2O)}n(2), [(CuL)2Mn(nic)2]·2CH3OH (3), and [(CuL)2Cd(nic)2]·2CH3OH (4) (where H2L = N,N′-bis(α-methylsalicylidene)-1,3-propanediamine and nic = nicotinate ion), have been synthesized and characterized by single-crystal X-ray crystallography. In complexes 1and 2, the nicotinate ion acts as a bifunctional linker (N,O donor) and joins the linear trinuclear nodes to form 1D polymeric chains. However, in complexes 3and 4, the nicotinate ion uses only the oxygen atoms of the carboxylic acid (O donor) to bind to the metal centers, forming discrete linear trinuclear units, while the pyridyl nitrogen (N donor atom) remains free. The dc magnetic susceptibility measurements show that the CuIIand MnIIions are antiferromagnetically coupled in both 1and 3, with exchange coupling constants (JMn–Cu) of −20.57 ± 0.08 and −9.38 ± 0.08 cm–1, respectively. Among the four complexes, 1and 3show catechol oxidase and phenoxazinone synthase like catalytic activities. The turnover numbers (kcat) of complexes 1and 3for catecholase activity are 1121 and 720 h–1, respectively, at an optimum pH of 8.0 and for phenoxazinone synthase activity are 429 and 398 h–1, respectively, at an optimum pH of 9.7. The higher kcatvalues of 1for both reactions are attributable to a water molecule coordinated to the central MnIIatom that facilitates the substrate–catalyst binding. An ESI-mass spectral analysis indicates that trinuclear heterometallic species, e.g., [(CuL)2Mn(nic)(H2O)]+for 1and [(CuL)2Mn(nic)]+for 3, are the active species that bind to the substrate, and on that basis, probable mechanisms through the formation of radical intermediates have been proposed.

Fundamental understanding of the correlation between chemical bonding and lattice dynamics in intrinsically low thermal conductive crystalline solids is important to thermoelectrics, thermal barrier coating, and more recently to photovoltaics. Two-dimensional (2D) layered halide perovskites have recently attracted widespread attention in optoelectronics and solar cells. Here, we discover intrinsically ultralow lattice thermal conductivity (κL) in the single crystal of all-inorganic layered Ruddlesden–Popper (RP) perovskite, Cs2PbI2Cl2, synthesized by the Bridgman method. We have measured the anisotropic κLvalue of the Cs2PbI2Cl2single crystal and observed an ultralow κLvalue of ∼0.37–0.28 W/mK in the temperature range of 295–523 K when measured along the crystallographic c-axis. First-principles density functional theory (DFT) analysis of the phonon spectrum uncovers the presence of soft (frequency ∼18–55 cm–1) optical phonon modes that constitute relatively flat bands due to localized vibrations of Cs and I atoms. A further low energy optical mode exists at ∼12 cm–1that originates from dynamic octahedral rotation around Pb caused by anharmonic vibration of Cl atoms induced by a 3s2lone pair. We provide experimental evidence for such low energy optical phonon modes with low-temperature heat capacity and temperature-dependent Raman spectroscopic measurements. The strong anharmonic coupling of the low energy optical modes with acoustic modes causes damping of heat carrying acoustic phonons to ultrasoft frequency (maximum ∼37 cm–1). The combined effect of soft elastic layered structure, abundance of low energy optical phonons, and strong acoustic–optical phonon coupling results in an intrinsically ultralow κLvalue in the all-inorganic layered RP perovskite Cs2PbI2Cl2.

Background: Many topical agents are available in the market, which interfere with the pigmentation process at different levels. They are often known to cause side effects ranging from irritation to tumor over chronic use. Objective: The present study was designed to develop and characterize an anti blemish cream containing herbal oils. Methods: A herbal cream was formulated using dill, nagarmotha and black cumin oil and subjected to evaluation of its anti blemish potential against stress augmented UV-B rays-induced hyperpigmentation. Topical oil in water type of creams containing 2%, 4% and 6% of each oil was formulated using herbal oils. The formulated cream was characterized for solubility, pH, particle size, grittiness, viscosity, stability, phase separation, shelf life and spreadability, and found to be stable. Acute dermal toxicity was carried out individually for dill, nagarmotha and black cumin oil according to the OECD guidelines 402. Hyperpigmentation was induced in all the experimental animals by stress-augmented UV-B irradiation method. The animals were treated for 30 days (twice daily) with standard and test formulations by topical administration, whereas the disease group was left untreated. The skin of the animals was subjected to photographical study as well as grading for pigmentation and irritation before and after treatment. After the treatment period, the serum antioxidant levels were estimated and histopathology, histochemical studies of skin were performed. Results: The animals treated with test formulations containing 2%, 4%, and 6% of herbal oil showed significant improvement in pigmentation compared to disease control as it is evident in photographic biochemical, histopathological and histochemical studies. Conclusion: Thus, it was concluded that the developed anti-blemish cream containing herbal oils possesses significant anti-blemish potential. This study necessitates further evaluations in human subjects as it could have a high positive therapeutic value in the treatment of hyperpigmentation.

The orthorhombic phase of GeSe, a structural analogue of layered SnSe (space group: Pnma), has recently attracted attention after a theoretical prediction of high thermoelectric figure of merit, zT > 2. The experimental realization of such high performance in orthorhombic GeSe, however, is still elusive (zT ≈ 0.2). The rhombohedral phase of GeSe, a structural analogue of GeTe (space group: R3m), previously stabilized at high pressure (2 GPa) and high temperature (1600 K), is promising due to its theoretically predicted ferroelectric instability and the higher earth abundance of Se compared to Te. Here, we demonstrate high thermoelectric performance in the rhombohedral crystals of GeSe, which is stabilized at ambient conditions by alloying with 10 mol % AgBiSe2. We show ultralow lattice thermal conductivity (κL) of 0.74–0.47 W/mK in the 300–723 K range and high zT ≈ 1.25 at 723 K in the p-type rhombohedral (GeSe)0.9(AgBiSe2)0.1crystals grown using Bridgman method. First-principles density functional theoretical analysis reveals its vicinity to a ferroelectric instability which generates large anomalous Born effective charges and strong coupling of low energy polar optical phonons with acoustic phonons. The presence of soft optical phonons and incipient ferroelectric instability in (GeSe)0.9(AgBiSe2)0.1are directly evident in the low temperature heat capacity (Cp) and switching spectroscopy piezoresponse force microscopy (SS-PFM) experiments, respectively. Effective scattering of heat carrying acoustic phonons by ferroelectric instability induced soft transverse optical phonons significantly reduces the κLand enhances the thermoelectric performance in rhombohedral (GeSe)0.9(AgBiSe2)0.1crystals.

Materials with ultrahigh dielectric constants and a low value of dielectric loss are important for energy storage and electronic devices. Traditionally, high dielectric constant is found in ferroelectric complex oxides, but they exhibit high dielectric loss as well. Herein, a broadband colossal dielectric constant in a superionic halide, RbAg4I5, with a low dielectric loss is presented. The real part of the dielectric constant, ε′, increases by 102orders of magnitude as RbAg4I5goes through a superionic transition at 121 K. At room temperature, ε′ > 106in the frequency range 10–1to 104Hz with a low dielectric loss, which ranges between 2.03 and 0.53. The maximum of ε′ reaches a colossal value of 6.4 × 108at 0.1 Hz at 300 K. The molecular dynamics simulation reveals the presence of Ag+clusters with a broad size distribution. The intercluster diffusion of Ag+causes significant instantaneous charge separation and a consequent large fluctuation in the dipole moments. The fluctuating dipoles, in turn, result in the colossal dielectric constant in RbAg4I5.

Successful applications of a thermoelectric material require simultaneous development of compatible n- and p-type counterparts. While the thermoelectric performance of p-type GeTe has been improved tremendously in recent years, it has been a challenge to find a compatible n-type GeTe counterpart due to the prevalence of intrinsic Ge vacancies. Herein, we have shown that alloying of AgBiSe2with GeTe results in an intriguing evolution in its crystal and electronic structures, resulting in n-type thermoelectric properties. We have demonstrated that the ambient rhombohedral structure of pristine GeTe transforms into cubic phase in (GeTe)100–x(AgBiSe2)xfor x≥ 25, with concurrent change from its p-type electronic character to n-type character in electronic transport properties. Such change in structural and electronic properties is confirmed from the nonmonotonic variation of band gap, unit cell volume, electrical conductivity, and Seebeck coefficient, all of which show an inflection point around x∼ 20, as well as from the temperature variations of synchrotron powder X-ray diffractions and differential scanning calorimetry. First-principles density functional theoretical (DFT) calculations explain that the shift toward n-type electronic character with increasing AgBiSe2concentration arises due to increasing contribution of Bi p orbitals in the conduction band edge of (GeTe)100–x(AgBiSe2)x. This cubic n-type phase has promising thermoelectric properties with a band gap of ∼0.25 eV and ultralow lattice thermal conductivity that ranges between 0.3 and 0.6 W/mK. Further, we have shown that (GeTe)100–x(AgBiSe2)xhas promising thermoelectric performance in the mid-temperature range (400–500 K) with maximum thermoelectric figure of merit, zT, reaching ∼1.3 in p-type (GeTe)80(AgBiSe2)20at 467 K and ∼0.6 in n-type (GeTe)50(AgBiSe2)50at 500 K.

GeTe and its derivatives have recently attracted wide attention as promising thermoelectric materials. The principle challenge in optimizing the thermoelectric figure of merit, zT, is the low Seebeck coefficient (S) and high thermal conductivity of GeTe. Here, we report a high zTof ∼2.1 at 723 K in In and Bi co-doped GeTe along with an extremely high TE conversion efficiency of ∼12.3% in a single-leg thermoelectric generator for the temperature difference of 445 K. In and Bi play a distinct but complementary role. In doping significantly enhances the Sthrough the formation of resonance level, which is confirmed with first-principles density functional theory calculations and Pisarenko plot considering two valance band model. However, Bi doping markedly reduces the lattice thermal conductivity due to the formation of extensive solid solution point defects and domain variants. Moreover, a high value of Vickers microhardness (∼200 Hv, Hv = kgf/mm2) reveals excellent mechanical stability.

Ultrathin ferroelectric semiconductors with high charge carrier mobility are much coveted systems for the advancement of various electronic and optoelectronic devices. However, in traditional oxide ferroelectric insulators, the ferroelectric transition temperature decreases drastically with decreasing material thickness and ceases to exist below certain critical thickness owing to depolarizing fields. Herein, we show the emergence of an ordered ferroelectric ground state in ultrathin (∼2 nm) single crystalline nanosheets of Bi2O2Se at room temperature. Free-standing ferroelectric nanosheets, in which oppositely charged alternating layers are self-assembled together by electrostatic interactions, are synthesized by a simple, rapid, and scalable wet chemical procedure at room temperature. The existence of ferroelectricity in Bi2O2Se nanosheets is confirmed by dielectric measurements and piezoresponse force spectroscopy. The spontaneous orthorhombic distortion in the ultrathin nanosheets breaks the local inversion symmetry, thereby resulting in ferroelectricity. The local structural distortion and the formation of spontaneous dipole moment were directly probed by atomic resolution scanning transmission electron microscopy and density functional theory calculations.

Oxazine-6-one and 4-pyrimidinol are two important frameworks in pharmaceutical production. Herein, we disclosed a simple, efficient, inexpensive organic base-promoted and additive-stimulated protocol for the syntheses of variably functionalized oxazine-6-ones and 4-pyrimidinols employing acetonitrile solvent under conventional heating conditions using an oil bath through C–N and C–O coupled domino steps. This simple practicable productive protocol utilizes easily producible cheap precursors, namely, benzimidates or benzamidines, with differently substituted dicyano-olefins, and it comprises step economy, robustness, and moisture insensitive conditions affording high yield that avoids the use of transition-metal catalysts, multistep with multicomponent strategy, and harsh reaction conditions involving hazardous chemicals. This method is scalable into gram-scale production with good yield.

Traditional catalyst development relies on multistep synthesis and isolation of ligand and precatalyst. Designing a catalytic system that can be assembled in situfrom easily accessible starting materials can decrease the reaction complexity and enhance the synthetic utility. Herein, we report an inexpensive and commercially available CoBr2·H2O/terpyridine-catalyzed effective and straightforward transfer hydrogenation (TH) protocol for N-heteroarenes, utilizing NH3·BH3(AB) under ambient conditions. Synthesis of diverse substrates and bioactive molecules demonstrated a practical applicability. Control experiments and DFT studies elucidate the mechanism.

Three Zn(II) complexes, [Zn2(HL)2(NO3)2]·H2O (1), [(Zn4L2)(μ3-OH)2](NO3)2·0.5H2O (2), and [(Zn6L2)(o-van)2(μ3-OCH3)2(μ3-OH)2](NO3)2(3), have been synthesized by exploiting the flexidentate nature of a multidentate Schiff base ligand, H2L (N,N′-bis(3-methoxysalicylidene)diethylenetriamine), by changing the reaction conditions and stoichiometry of the reactants. All three complexes are highly fluorescent in solution as well as in solid and have been used as luminescence sensors toward nitrophenol explosives in both the media. In aqueous/methanol medium, these complexes show very high selectivity and sensitivity with detection limit in ppb (2.03) or nM level (8.89 nM) for picric acid. The yellow color of all three Zn(II) complexes changes to red on mixing with small amount (∼5%) of picric acid in solid state, revealing the potential of these complexes for practical use in naked eye detection of 2,4,6-trinitrophenol (TNP) or picric acid in ambient light. In order to identify the host–guest interactions between Zn(II) complex and TNP, single crystals of the adduct of TNP with Zn(II) complex, [Zn2(HL)2(H2O)2][C6H2N3O7]2(4), were grown. Its X-ray crystal structure reveals that two picrate ions are attached to a dinuclear host with the help of H-bonding and π···π interactions, throwing light into the quenching mechanism and selectivity of detection.

This paper deals with the fabrication and characterization of polymeric crosslinked films based on N,O-carboxymethyl chitosan (CMCh) and poly (vinyl alcohol) (PVA) using vanillin as crosslinking agent. The prepared film was characterised by FTIR, DSC, swelling index, hydrolytic degradation study, water vapour transmission study, tensile strength, and anti-bacterial study. Additionally, cytotoxicity and cell viability studies were also carried out using L929 mouse fibroblast cell lines. Further, an in-vitro wound healing scratch assay, and in-vivostudy using an excision wound model were used to explore the potential of the optimised films. The mechanism of crosslinking was the formation of Schiff bases between vanillin and the amino group of CMCh and on the other side, hydrogen bond formation between the hydroxyl groups of vanillin and PVA. Furthermore, the presence of hydrogen bonding as well as the formation of new polymeric entity was detected by FTIR and DSC studies. Swelling study indicated that an increased concentration of CMCh improved the swelling index, reflecting its hydrophilic behavior. The hydrolytic degradation study showed that the films containing higher concentrations of CMCh had greater structural integrity. The film was found to encourage cellular proliferation at a concentration of 10 mg/mL. Further scratch assay results were found to encourage the migration of cells. In-vivo wound healing studies indicated comparable healing potential of the optimised crosslinked film in comparison to the marketed formulation and much better healing when compared to control, CMCh and PVA films. Thus, the developed crosslinked CMCH-PVA film demonstrated several unique properties and can be further explored as a material for biomedical applications.

A mononuclear uranyl complex, [UO2L] (1), has been synthesized with the ligand N,N′-bis(3-methoxy-2-hydroxybenzylidene)-1,6-diamino-3-azahexane (H2L). The complex showed a reversible U(VI)/U(V) redox couple in cyclic voltammetric measurements. The reduction potential of this couple showed a positive shift upon the addition of redox-inactive alkali- and alkaline-earth Lewis acidic metal ions (Li+, Na+, K+, Ca2+, Sr2+, and Ba2+) to an acetonitrile solution of complex 1. The positive shift of the reduction potential has been explained on the basis of the Lewis acidity and internal electric-field effect of the respective metal ions. The bimetallic complexes [UO2LLi(NO3)] (2), [UO2LNa(BF4)]2(3), [UO2LK(PF6)]2(4), [(UO2L)2Ca]·(ClO4)2·CH3CN (5), [(UO2L)2Sr(H2O)2]·(ClO4)2·CH3CN (6), and [(UO2L)2Ba(ClO4)]·(ClO4) (7) have also been isolated in the solid state by reacting complex 1with the corresponding metal ions and characterized by single-crystal X-ray diffraction. Density functional theory calculations of the optimized [UO2LM]n+complexes have been used to rationalize the experimental reduction and electric-field potentials imposed by the non-redox-active cations.

SnSe has emerged as one of the most promising materials for thermoelectric energy conversion due to its extraordinary performance in its single-crystal form and its low-cost constituent elements. However, to achieve an economic impact, the polycrystalline counterpart needs to replicate the performance of the single crystal. Herein, we optimize the thermoelectric performance of polycrystalline SnSe produced by consolidating solution-processed and surface-engineered SnSe particles. In particular, the SnSe particles are coated with CdSe molecular complexes that crystallize during the sintering process, forming CdSe nanoparticles. The presence of CdSe nanoparticles inhibits SnSe grain growth during the consolidation step due to Zener pinning, yielding a material with a high density of grain boundaries. Moreover, the resulting SnSe–CdSe nanocomposites present a large number of defects at different length scales, which significantly reduce the thermal conductivity. The produced SnSe–CdSe nanocomposites exhibit thermoelectric figures of merit up to 2.2 at 786 K, which is among the highest reported for solution-processed SnSe.

N-Heterocyclic carbene-catalyzed tandem Stetter-aldol reaction of phthalaldehyde and α,β-unsaturated ketimines has been developed to afford functionalized naphthalen-1(2H)-one derivatives as the formal [4+2] annulation product. Interestingly, the reaction of aldimines led to the formation of isoquinoline derivatives instead of the expected indanone derivatives as a [4+1] annulation product.