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Atom probe tomography is frequently employed to characterize the elemental distribution in solids with atomic resolution. Here the potential of this technique to locally probe chemical bonds is reviewed and discussed. Two processes characterize the bond rupture in laser-assisted field emission, the probability of molecular ions (PMI), i.e., the probability that molecular ions are evaporated instead of single (atomic) ions, and the probability of multiple events (PME), i.e., the correlated field-evaporation of more than a single fragment upon laser- or voltage pulse excitation. Here it is demonstrated that one can clearly distinguish solids with metallic, covalent, and metavalent bonds based on their bond rupture, i.e., their PME and PMI values. These findings open new avenues in understanding and designing advanced materials, since they allow a quantification of bonds in solids on a nanometer scale, as will be shown for several examples. These possibilities would even justify calling the present approach bonding probe tomography (BPT)., (© 2024 The Author(s). Advanced Materials published by Wiley‐VCH GmbH.)

A hallmark of typical structural transformations is an increase in symmetry upon heating due to entropic favourability. However, local symmetry breaking upon warming is recently evidenced in rare crystalline phases. Termed as emphanisis, the phenomenon implores exploration of fascinating thermodynamic nuances that drive unusual structural evolutions. Here, synchrotron X-ray total scattering measurements are presented on a Ruddlesden-Popper mixed halide perovskite, Cs 2 PbI 2 Cl 2 , which reveal signatures of emphanisis. The genesis of symmetry lowering upon heating is traced to a lone pair-driven cooperative local structural distortion composed of thermally actuated Pb off-centring and static Cl displacement. Mapping the thermal evolution of low-lying phonon modes with inelastic neutron scattering uncovers instances of mode hardening with picosecond lifetime and an intriguing soft mode at the X-point of the Brillouin zone-features conducive to ultralow thermal transport. Together, these observations highlight the fundamental and functional implications of chemical design in engendering unconventional phenomena in crystalline materials and associated properties., (© 2024 Wiley‐VCH GmbH.)

Traditional catalyst development relies on multistep synthesis and isolation of ligand and precatalyst. Designing a catalytic system that can be assembled in situ from easily accessible starting materials can decrease the reaction complexity and enhance the synthetic utility. Herein, we report an inexpensive and commercially available CoBr 2 ·H 2 O/terpyridine-catalyzed effective and straightforward transfer hydrogenation (TH) protocol for N -heteroarenes, utilizing NH 3 ·BH 3 (AB) under ambient conditions. Synthesis of diverse substrates and bioactive molecules demonstrated a practical applicability. Control experiments and DFT studies elucidate the mechanism.

Three new hetero-metallic Cu II -Ln III complexes [(CuL)Gd(NO 3 ) 3 (CH 3 OH)] n (1), [(CuL)Tb(NO 3 ) 3 (H 2 O)]·[CuL] (2) and [(CuL)Dy(NO 3 ) 3 (H 2 O)]·[CuL] (3) have been synthesized using a mono-nuclear Cu(II) complex, [CuL], of an unsymmetrically di-condensed N 2 O 3 donor Schiff base ligand, N -(3-methoxysalicylidene)- N -(salicylidene)-1,2-ethylenediamine (H 2 L). Single crystal X-ray crystallography revealed that complex 1 is a nitrate bridged 1D chain of dinuclear Cu(II)-Gd(III) units whereas in 2 and 3, the dinuclear Cu(II)-Ln(III) units are co-crystallized with a [CuL] unit. The Ln(III) centers are nine coordinated with the geometry of a spherical capped square antiprism for Gd and spherical tricapped trigonal prism for Tb and Dy. The geometry of the Cu(II) center is distorted octahedral for complex 1 and distorted square planar for complexes 2 and 3. Temperature-dependent molar magnetic susceptibility measurements in 1-3 revealed the presence of overall ferromagnetic coupling between the Cu(II) and Ln(III) centers. Notably, field induced single-molecule magnet behavior was witnessed in the Tb(III) derivative (2). The ab initio calculations indicated that upon application of an external magnetic field, the tunneling in the ground state of complex 2 gets reduced and thereby field-induced SMM behaviour is observed. Besides, in the case of complex 1, BS-DFT calculations were carried out to gain further insights into the magnetic exchange coupling interactions between the Cu(II) and Gd(III) centers.

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.

N -heterocyclic carbene catalysis reaction protocol is disclosed for the synthesis of phthalidyl sulfonohydrazones. A broad range of N -tosyl hydrazones react effectively with phthalaldehyde derivatives under open-air conditions, enabling the formation of a new C-N bond via an oxidative path. The reaction proceeds under mild reaction conditions with broad substrate scopes, wide functional group tolerance, and good to excellent yields. The mechanistic pathway is studied successfully using control experiments, competitive reactions, ESI-MS spectral analyses of the reaction mixture, and computational study by density functional theory. The potential use of one of the phthalidyl sulfonohydrazone derivatives as the inhibitor of β-ketoacyl acyl carrier protein synthase I of Escherichia coli is investigated using molecular docking., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Achieving glass-like ultra-low thermal conductivity in crystalline solids with high electrical conductivity, a crucial requirement for high-performance thermoelectrics , continues to be a formidable challenge. A careful balance between electrical and thermal transport is essential for optimizing the thermoelectric performance. Despite this inherent trade-off, the experimental realization of an ideal thermoelectric material with a phonon-glass electron-crystal (PGEC) nature has rarely been achieved. Here, PGEC-like AgSbTe 2 is demonstrated by tuning the atomic disorder upon Yb doping, which results in an outstanding thermoelectric performance with figure of merit, zT ≈ 2.4 at 573 K. Yb-doping-induced enhanced atomic ordering decreases the overlap between the hole and phonon mean free paths and consequently leads to a PGEC-like transport behavior in AgSbTe 2 . A twofold increase in electrical mobility is observed while keeping the position of the Fermi level (E F ) nearly unchanged and corroborates the enhanced crystalline nature of the AgSbTe 2 lattice upon Yb doping for electrical transport. The cation-ordered domains, lead to the formation of nanoscale superstructures (≈2 to 4 nm) that strongly scatter heat-carrying phonons, resulting in a temperature-independent glass-like thermal conductivity. The strategy paves the way for realizing high thermoelectric performance in various disordered crystals by making them amorphous to phonons while favoring crystal-like electrical transport., (© 2023 Wiley-VCH GmbH.)

Adherent cells ensure membrane homeostasis during de-adhesion by various mechanisms, including endocytosis. Although mechano-chemical feedbacks involved in this process have been studied, the step-by-step build-up and resolution of the mechanical changes by endocytosis are poorly understood. To investigate this, we studied the de-adhesion of HeLa cells using a combination of interference reflection microscopy, optical trapping and fluorescence experiments. We found that de-adhesion enhanced membrane height fluctuations of the basal membrane in the presence of an intact cortex. A reduction in the tether force was also noted at the apical side. However, membrane fluctuations reveal phases of an initial drop in effective tension followed by saturation. The area fractions of early (Rab5-labelled) and recycling (Rab4-labelled) endosomes, as well as transferrin-labelled pits close to the basal plasma membrane, also transiently increased. On blocking dynamin-dependent scission of endocytic pits, the regulation of fluctuations was not blocked, but knocking down AP2-dependent pit formation stopped the tension recovery. Interestingly, the regulation could not be suppressed by ATP or cholesterol depletion individually but was arrested by depleting both. The data strongly supports Clathrin and AP2-dependent pit-formation to be central to the reduction in fluctuations confirmed by super-resolution microscopy. Furthermore, we propose that cholesterol-dependent pits spontaneously regulate tension under ATP-depleted conditions., (© 2024. The Author(s).)

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 AgSbTe 2 serves to partially curtail structural disorder. This strategic maneuver mitigates potential fluctuations originating from pronounced charge and size disparities between Ag + and Sb 3+ , positioned in octahedral sites within the rock salt structure. Hg doping significantly improves the phase stability of AgSbTe 2 by restricting the congenital emergence of the Ag 2 Te 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 AgSbTe 2 is 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 -1 K -1 at 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 .

Doping is usually the first step to tailor thermoelectrics. It enables precise control of the charge-carrier concentration and concomitant transport properties. Doping should also turn GeSe, which features an intrinsically a low carrier concentration, into a competitive thermoelectric. Yet, elemental doping fails to improve the carrier concentration. In contrast, alloying with Ag-V-VI 2 compounds causes a remarkable enhancement of thermoelectric performance. This advance is closely related to a transition in the bonding mechanism, as evidenced by sudden changes in the optical dielectric constant ε ∞ , the Born effective charge, the maximum of the optical absorption ε 2 (ω), and the bond-breaking behavior. These property changes are indicative of the formation of metavalent bonding (MVB), leading to an octahedral-like atomic arrangement. MVB is accompanied by a thermoelectric-favorable band structure featuring anisotropic bands with small effective masses and a large degeneracy. A quantum-mechanical map, which distinguishes different types of chemical bonding, reveals that orthorhombic GeSe employs covalent bonding, while rhombohedral and cubic GeSe utilize MVB. The transition from covalent to MVB goes along with a pronounced improvement in thermoelectric performance. The failure or success of different dopants can be explained by this concept, which redefines doping rules and provides a "treasure map" to tailor p-bonded chalcogenides., (© 2023 The Authors. Advanced Materials published by Wiley-VCH GmbH.)

This study evaluates the volumetric modulated arc therapy (VMAT) dosimetric comparison between Halcyon ring gantry and TrueBeam c-arm linear accelerators for craniospinal irradiation (CSI) of the neuro-axis. 25 patients, who received treatment for medulloblastoma and primitive neuro-ectodermal tumors between 2018 and 2021, were planned for VMAT in True Beam (TB), and Halcyon (HAL) linear accelerators using 6 MV unflattened (FFF) photon beams (HALFFF and TBFFF). Dose-volume statistics for the target and organs at risk (OARs) and the total number of monitoring units (MUs) in the treatment plans were compared which included dose received by 95% PTV volume (V95%), volume receiving ≥ 107% dose, homogeneity index (HI), conformity index (PI), MU and dose spillage (D10%, D30%, D50%, D70%, D90%). In all 26 OARs were considered of which five were serial and the remaining were parallel structures. For the former, the dose received by 0.2 cm 3 , volume = D0.2 cm 3 ) were evaluated and for the latter mean dose were evaluated. Both arms were statistically compared with paired sample t-test with a significant value of ≤ 0.05. 11 patients received treatment with the Halcyon and the rest 14 in the TrueBeam C-arm linear accelerator. Patients in the low- and intermediate-risk category (n = 13) received 23.4 Gy in 13 fractions. The remaining patients were in the high-risk category and received 35 Gy in 21 fractions or 36 Gy in 20 fractions. For HALFFF and TBFFF, PTVV95% were 97.5 ± 0.8% and 97.4 ± 0.9% respectively (p = 0.371) while the V107% were 0.6 ± 0.4% and 0.5 ± 0.5 respectively (p = 0.504). However, the number of monitoring units showed statistical significance (p < 0.001) with values of 1331.9 ± 243.4 MU and 1089 ± 206.7 MU respectively for the HAL and TB plans. The differences in spillage dose were also statistically significant, favouring HAL plans at D30% (p = 0.002), D50% (p < 0.001), D70% (p = 0.039), and D90% (p = 0.01) level except for D10% (p = 0.090). Conformity index also showed statistical significance with PI&#95;HAL = 0.9 ± 0.02 and PI&#95;TB = 0.89 ± 0.03 (p = 0.029). For 10 of the 21 parallel structures, the mean dose differences were statistically significant in favouring of HAL plans. Halcyon based VMAT CSI plans are dosimetrically superior in terms of organ dose, especially for the large organs, and offer lower spillage doses than the TrueBeam plans. Plans generated by both linear accelerators are suitable for the patients' treatments., (© 2023. The Author(s).)

Low dietary diversity significantly interplays with children’s growth failure. However, evidence of its crucial role in children’s health remains inconclusive in developing countries such as India. This study attempts to find the association between dietary diversity and growth outcomes among children aged between 6 and 23 months in India using the fourth round of the National Family Health Survey (NFHS), 2015−2016. A total of 67,278 mother-child pairs of children between the ages of 6−23 months and mothers aged 15−49 years were included in this study. Pearson’s chi-square significance test and multivariable logistic regression were used to determine the association between dietary diversity and child growth outcomes (stunted, wasted, and underweight). The study found that the prevalence of stunting and severe stunting among children aged between 6 and 23 months were 35.9% and 16.2%; 23.8% and 8.5% represented wasting, and severe wasting; and more than 32%, 10% were underweight and severely underweight respectively. This present study found that having an inadequate minimum dietary diversity (<4 food groups) significantly increases the risk of being stunted (adjusted odds ratio (AOR) = 1.29; 95% confidence interval (CI); 1.21−1.38), wasted (AOR = 1.29; 95% CI; 1.21−1.38), and underweight (AOR = 1.47; 95% CI; 1.39−1.56). Further, it was noted that children who did not intake dairy products, eggs, and other fruits and vegetables were more likely to be stunted, wasted, and underweight and more likely to be severely stunted, wasted, and underweight. Therefore, additional nutrition-specific interventions are urgently needed to strengthen and enhance existing feeding interventions aimed at improving infant and young child feeding (IYCF) practices, including complementary feeding practices among children aged between 6 and 23 months in India. The Government should focus such interventions more on states or regions where the prevalence of adequate minimum dietary diversity (MDD) and malnutrition is high.

The occurrence of overweight and obesity has increased in recent years in India. In this study, we investigate the prevalence and associated risk factors of overweight/obesity among children aged 0-59 months in India. Using data from the 2015-2016 National Family Health Survey-4 (NFHS-4), the research sample included 176,255 children aged 0 to 59 months. Bivariate and multivariate techniques were used to analyze children's risk factors for overweight/obesity. We identified that the prevalence of overweight/obesity among children aged 0-59 was 2.6% in India. The study findings reveal that factors such as child sex, age, birth weight, birth rank, maternal education, number of children, age at marriage, mother's BMI, media exposure, social group, and dietary diversity score were most significantly correlated with childhood overweight and obesity in India. Furthermore, we found that male children (ARR: 1.08) aged between 0 and 11 months (ARR: 3.77) with low birth rank (ARR: 1.24), obese (ARR: 1.81) children whose mothers married after the age of 18 (ARR: 1.15), children who belong to a scheduled tribe family (ARR: 1.46), and children who consumed 7-9 food items (ARR: 1.22) were at highest risk of being overweight and obese. However, breastfeeding (ARR: 0.85) and Muslim families (ARR: 0.87) appeared to be protective factors with respect to childhood overweight and obesity in India. Pertinent public health programs, clinical follow-up, and awareness about sedentary lifestyles can help to reduce overweight/obesity risks in children.

As the periodic atomic arrangement of a crystal is made to a disorder or glassy-amorphous system by destroying the long-range order, lattice thermal conductivity, κ L , decreases, and its fundamental characteristics changes. The realization of ultralow and unusual glass-like κ L in a crystalline material is challenging but crucial to many applications like thermoelectrics and thermal barrier coatings. Herein, we demonstrate an ultralow (~0.20 W/m·K at room temperature) and glass-like temperature dependence (2-400 K) of κ L in a single crystal of layered halide perovskite, Cs 3 Bi 2 I 6 Cl 3 . Acoustic phonons with low cut-off frequency (20 cm -1 ) are responsible for the low sound velocity in Cs 3 Bi 2 I 6 Cl 3 and make the structure elastically soft. While a strong anharmonicity originates from the low energy and localized rattling-like vibration of Cs atoms, synchrotron X-ray pair-distribution function evidence a local structural distortion in the Bi-halide octahedra and Cl vacancy. The hierarchical chemical bonding and soft vibrations from selective sublattice leading to low κ L is intriguing from lattice dynamical perspective as well as have potential applications., (© 2022. The Author(s).)

Aim: This study aims​ to report preclinical validation, and the first clinical treatment of total bone marrow irradiation (TMI) and total bone marrow and lymph nodal irradiation (TMLI) using Volumetric modulated arc therapy in Halcyon-E ring gantry linear accelerator. Preclinical validation includes simulation, planning, patient-specific QA, and dry run., Material and Method: Four patients, two female and two male, with body weights of 116 kg, 52 kg, 64 kg, and 62 kg; with two with chronic myeloid leukemia, one each with acute lymphoblastic leukemia and acute myeloid leukemia (AML) were simulated and planned for TMI/TMLI. Patients were immobilized with a full-body vacuum bag. Head first supine (HFS) and Feet first supine (FFS) CT scans were acquired from head to knee and knee to toe. Planning target volume (PTV) was created with a uniform margin of 6 mm over the total bone marrow/bone marrow + lymph nodes. HFS and FFS PTVs were optimized independently using 6MV unflatten energy for 12 Gy in 6 fractions. Plans were merged to create the resultant dose distribution using a junction bias dose matching technique. The total number of isocenters was ≤ 10 per CT set, and two to four full arcs were used for each isocenter. A junction dose gradient technique was used for dose feathering between arcs between adjacent isocenters., Result: Only one female patient diagnosed as AML received the TMLI treatment, while the other three patients dropped out due to clinical complications and comorbidities that developed in the time between simulation and treatment. The result presented has been averaged over all four patients. For PTV, 95% dose was normalised to 95% volume, PTV&#95;V107% receiving 3.3 ± 3.1%. Total lung mean and V12Gy were 1048.6 ± 107.1 cGy and 19.5 ± 12.1%. Maximum lens doses were 489.5 ± 35.5 cGy (left: L) and 497 ± 69.2 cGy (right: R). The mean cardiac and bilateral kidney doses were 921.75 ± 89.2 cGy, 917.9 ± 63.2 cGy (L), and 805.9 ± 9.7 cGy (R). Average Monitor Unit was 7738.25 ± 1056.6. The median number of isocenters was 17(HFS+FFS), average MU/Dose (cGy) ratio per isocenter was 2.28 ± 0.3., Conclusion: Halcyon-E ring gantry linear accelerator capable of planning and delivering TMI/TMLI.​​., (© 2022. The Author(s).)

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 (κ L ). A plethora of strategies have been developed to lower κ L in 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 κ L and 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 κ L in order to realize high-performance thermoelectric materials.

Background: The Covid-19 pandemic has a significant impact on education and mental health outcomes. This study attempts to analyze the factors associated with academic satisfaction level, psychological stress/anxiety, and future academic risk among Indian students of higher education in the wake of the Covid-19 pandemic., Methods: An online survey was conducted through a structured questionnaire among students of higher education. Multivariate ordered logistic regression models were performed to find out the predictors of perceived academic satisfaction level, psychological stress, and academic risk among the participants., Results: Among the 630 participants, the majority of the students (73%) had low to moderate levels of academic satisfaction. Over two-thirds of participants (68%) had a high level of stress and nearly two-fifths (38%) of the participants felt very high risk in their academic career. The multivariate logistic regression models show that the likelihood of psychological stress and academic risk was significantly higher among students aged above 25 years, researchers, and those who belong to broken families. Besides, the higher probability of satisfaction level is associated with female students, undergraduates, belonging to economically well-off families, and rural residents., Conclusion: Our study suggests that the Covid-19 pandemic leads to a range of psychological health problems. Therefore, increase students' satisfaction with online classes and it is essential to preserve the mental health of individuals and to develop psychological interventions that can improve the mental health of students during the Covid-19 pandemic., Competing Interests: The authors declare no conflict of interest., (© 2022 Published by Elsevier Ltd.)

A mononuclear uranyl complex, [UO 2 L] ( 1 ), has been synthesized with the ligand N , N '-bis(3-methoxy-2-hydroxybenzylidene)-1,6-diamino-3-azahexane (H 2 L). 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 + , Ca 2+ , Sr 2+ , and Ba 2+ ) 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 [UO 2 LLi(NO 3 )] ( 2 ), [UO 2 LNa(BF 4 )] 2 ( 3 ), [UO 2 LK(PF 6 )] 2 ( 4 ), [(UO 2 L) 2 Ca]·(ClO 4 ) 2 ·CH 3 CN ( 5 ), [(UO 2 L) 2 Sr(H 2 O) 2 ]·(ClO 4 ) 2 ·CH 3 CN ( 6 ), and [(UO 2 L) 2 Ba(ClO 4 )]·(ClO 4 ) ( 7 ) have also been isolated in the solid state by reacting complex 1 with the corresponding metal ions and characterized by single-crystal X-ray diffraction. Density functional theory calculations of the optimized [UO 2 LM] 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.

Orthorhombic GeSe is a promising thermoelectric material. However, large band gap and strong covalent bonding result in a low thermoelectric figure of merit, zT≈0.2. Here, we demonstrate a maximum zT≈1.35 at 627 K in p-type polycrystalline rhombohedral (GeSe) 0.9 (AgBiTe 2 ) 0.1  , which is the highest value reported among GeSe based materials. The rhombohedral phase is stable in ambient conditions for x=0.8-0.29 in (GeSe) 1-x (AgBiTe 2 ) x  . The structural transformation accompanies change from covalent bonding in orthorhombic GeSe to metavalent bonding in rhombohedral (GeSe) 1-x (AgBiTe 2 ) x  . (GeSe) 0.9 (AgBiTe 2 ) 0.1 has closely lying primary and secondary valence bands (within 0.25-0.30 eV), which results in high power factor 12.8 μW cm -1  K -2 at 627 K. It also exhibits intrinsically low lattice thermal conductivity (0.38 Wm -1  K -1 at 578 K). Theoretical phonon dispersion calculations reveal vicinity of a ferroelectric instability, with large anomalous Born effective charges and high optical dielectric constant, which, in concurrence with high effective coordination number, low band gap and moderate electrical conductivity, corroborate metavalent bonding in (GeSe) 0.9 (AgBiTe 2 ) 0.1 . We confirmed the presence of low energy phonon modes and local ferroelectric domains using heat capacity measurement (3-30 K) and switching spectroscopy in piezoresponse force microscopy, respectively., (© 2021 Wiley-VCH GmbH.)

A new Ni(ii) complex [NiL] (complex 1) of an asymmetrically di-condensed N 2 O 3 donor Schiff base ligand, N-salicylidene-N'-3-methoxysalicylidene-1,3-propanediamine (H 2 L), has been synthesized and utilized for the synthesis of three heterometallic complexes, [(NiL) 2 Mn(NCS) 2 (CH 3 OH) 2 ]·CH 3 OH (2) [(NiL) 2 Mn(N(CN) 2 ) 2 (CH 3 OH) 2 ]·CH 3 OH (3) and [(NiL) 2 Mn 2 (N 3 ) 2 (μ 1,1 -N 3 ) 2 (CH 3 OH) 2 ] (4). Single crystal X-ray diffraction analyses show that complexes 2 and 3 have linear trinuclear structures where two tridentate O 3 donor (NiL) units are coordinated to the central octahedral Mn(ii) centre, whereas complex 4 has a centrosymmetric tetranuclear structure where two binuclear (NiL)Mn units are linked via two phenoxido and two μ 1,1 -N 3 bridges. Among the heterometallic complexes (2-4), only 4 is active towards the catalytic oxidation of 3,5-di-tert-butylcatechol to the corresponding quinone. The turnover number for the aerobic oxidation of 3,5-DTBC is 935 h -1 . ESI-mass spectra have been recorded to scrutinize the mechanistic pathway of this catalytic reaction. Variable temperature magnetic susceptibility measurements suggest that complexes 2-4 are antiferromagnetically coupled with coupling constants (J) of -4.84 and -5.23 cm -1 for complexes 2 and 3, respectively and J 1 = -2.20 cm -1 , J 2 = 1.13 cm -1 and J 3 = -1.12 cm -1 for complex 4. DFT calculations have been used to rationalize the magnetic super-exchange in complexes 2-4, by computing the theoretical coupling constants and analyzing the spin density plots.

N-Heterocyclic carbene-catalyzed tandem Stetter-aldol reaction of phthalaldehyde and α,β-unsaturated ketimines has been developed to afford functionalized naphthalen-1(2 H )-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.

Here, we present lattice dynamics associated with the local chemical bonding hierarchy in Zintl compound TlInTe 2 , which cause intriguing phonon excitations and strongly suppress the lattice thermal conductivity to an ultralow value (0.46-0.31 W m -1  K -1 ) in the 300-673 K. We established an intrinsic rattling nature in TlInTe 2 by studying the local structure and phonon vibrations using synchrotron X-ray pair distribution function (PDF) (100-503 K) and inelastic neutron scattering (INS) (5-450 K), respectively. We showed that while 1D chain of covalently bonded I n T e 2 n - n transport heat with Debye type phonon excitation, ionically bonded Tl rattles with a frequency ca. 30 cm -1 inside distorted Thompson cage formed by I n T e 2 n - n . This highly anharmonic Tl rattling causes strong phonon scattering and consequently phonon lifetime reduces to ultralow value of ca. 0.66(6) ps, resulting in ultralow thermal conductivity in TlInTe 2 ., (© 2020 Wiley-VCH GmbH.)

High thermoelectric performance is generally achieved through either electronic structure modulations or phonon scattering enhancements, which often counteract each other. A leap in performance requires innovative strategies that simultaneously optimize electronic and phonon transports. We demonstrate high thermoelectric performance with a near room-temperature figure of merit, ZT ~ 1.5, and a maximum ZT ~ 2.6 at 573 kelvin, by optimizing atomic disorder in cadmium-doped polycrystalline silver antimony telluride (AgSbTe 2 ). Cadmium doping in AgSbTe 2 enhances cationic ordering, which simultaneously improves electronic properties by tuning disorder-induced localization of electronic states and reduces lattice thermal conductivity through spontaneous formation of nanoscale (~2 to 4 nanometers) superstructures and coupling of soft vibrations localized within ~1 nanometer around cadmium sites with local strain modulation. The strategy is applicable to most other thermoelectric materials that exhibit inherent atomic disorder., (Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

The strategic design and synthesis of two isomeric Cu II complexes, [CuL A ] and [CuL B ], of asymmetrically dicondensed N 2 O 3 -donor Schiff-base ligands (where H 2 L A and H 2 L B are N -salicylidene- N '-3-methoxysalicylidenepropane-1,2-diamine and N -3-methoxysalicylidene- N '-salicylidenepropane-1,2-diamine, respectively) have been accomplished via a convenient Cu II template method. These two complexes have been used as metalloligands for the synthesis of three pairs of Cu-Ln isomeric complexes [CuL(μ-NO 3 )Ln(NO 3 ) 2 (H 2 O)]·CH 3 CN (for complexes 1A - 3A , L = L A , and for complexes 1B - 3B , L = L B and Ln = Gd, Tb, and Dy, respectively), all of which have been characterized structurally. In all six isomorphous and isostructural complexes, the decacoordinated Ln III centers and pentacoordinated Cu II centers 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 Gd III complexes, 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 Tb III and Dy III do not show slow magnetic relaxation with or without a direct-current bias field, demonstrating that the magnetic response of the isotropic system Cu II -Gd III occurs through different mechanisms than the rest of the Ln cations.

Organic fluorescent semiconducting nanomaterials have gained widespread research interest owing to their potential applications in the arena of high-tech devices. We designed two pyrazaacene-based compounds, their stacked system, and the role of gluing interactions to fabricate nanomaterials, and determined the prospective band gaps utilizing the density functional theory calculation. The two pyrazaacene derivatives containing complementary amide linkages (-CONH and -NHCO) were efficiently synthesized. The synthesized compounds are highly soluble in common organic solvents as well as highly fluorescent and photostable. The heterocycles and their mixture displayed efficient solvent dependent fluorescence in the visible region of the solar spectrum. Notably, the compounds were associated through complementary NH•••O = C type hydrogen bonding, π-π stacking, and hydrophobic interactions, and thereby afforded nanomaterials with a low band gap. Fascinatingly, the fabricated stacked nanomaterial system exhibited resistive switching behavior, leading to the fabrication of an efficient write-once-read-many-times memory device of crossbar structure.

In the present work, four new heterometallic coordination complexes, {[(CuL) 2 Mn(nic)(H 2 O) 2 ](ClO 4 )(0.5H 2 O)} n ( 1 ), {[(CuL) 2 Cd(nic)(H 2 O) 2 ](ClO 4 )(H 2 O)} n ( 2 ), [(CuL) 2 Mn(nic) 2 ]·2CH 3 OH ( 3 ), and [(CuL) 2 Cd(nic) 2 ]·2CH 3 OH ( 4 ) (where H 2 L = 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 1 and 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 3 and 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 Cu II and Mn II ions are antiferromagnetically coupled in both 1 and 3 , with exchange coupling constants ( J Mn-Cu ) of -20.57 ± 0.08 and -9.38 ± 0.08 cm -1 , respectively. Among the four complexes, 1 and 3 show catechol oxidase and phenoxazinone synthase like catalytic activities. The turnover numbers ( k cat ) of complexes 1 and 3 for 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 k cat values of 1 for both reactions are attributable to a water molecule coordinated to the central Mn II atom that facilitates the substrate-catalyst binding. An ESI-mass spectral analysis indicates that trinuclear heterometallic species, e.g., [(CuL) 2 Mn(nic)(H 2 O)] + for 1 and [(CuL) 2 Mn(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 (κ L ) in the single crystal of all-inorganic layered Ruddlesden-Popper (RP) perovskite, Cs 2 PbI 2 Cl 2 , synthesized by the Bridgman method. We have measured the anisotropic κ L value of the Cs 2 PbI 2 Cl 2 single crystal and observed an ultralow κ L value 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 -1 that originates from dynamic octahedral rotation around Pb caused by anharmonic vibration of Cl atoms induced by a 3s 2 lone 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 κ L value in the all-inorganic layered RP perovskite Cs 2 PbI 2 Cl 2 .

Adsorption of organic pollutants, toxic metal ions, and removal of harmful bacteria can give us clean and pure drinkable water from wastewater resources. Respective magnetite nanoparticles (MNPs) were synthesized using a cheaper and greener way in an open-air environment with the use of crude latex of Jatropha curcas (JC) and leaf extract of Cinnamomum tamala (CT). Characterization of MNPs had been performed by dynamic light scattering (DLS), Ultraviolet-visible (UV-vis) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, powdered X-ray diffraction (XRD), and field emission scanning electron microscope (FE-SEM). The size ranges of the synthesized MNPs were observed in between 20-42 nm for JC-Fe 3 O 4 and within 26-35 nm for CT-Fe 3 O 4 by FE-SEM images. The effect of synthesized magnetic nanoparticles in wastewater treatment (bacterial portion), dye adsorption, toxic metal removal as well as antibacterial, antioxidant, and cytotoxic activities were studied. This purification will lead to an increase in the resources of pure drinking water in the future.

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: R 3 m ), 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 % AgBiSe 2 . We show ultralow lattice thermal conductivity (κ L ) 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 (AgBiSe 2 ) 0.1 crystals 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 (AgBiSe 2 ) 0.1 are directly evident in the low temperature heat capacity ( C p ) 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 κ L and enhances the thermoelectric performance in rhombohedral (GeSe) 0.9 (AgBiSe 2 ) 0.1 crystals.

A two-step optimization strategy is used to improve the thermoelectric performance of SnTe via modulating the electronic structure and phonon transport. The electrical transport of self-compensated SnTe (that is, Sn 1.03 Te) was first optimized by Ag doping, which resulted in an optimized carrier concentration. Subsequently, Mn doping in Sn 1.03-x Ag x Te resulted in highly converged valence bands, which improved the Seebeck coefficient. The energy gap between the light and heavy hole bands, i.e. ΔE v decreases to 0.10 eV in Sn 0.83 Ag 0.03 Mn 0.17 Te compared to the value of 0.35 eV in pristine SnTe. As a result, a high power factor of ca. 24.8 μW cm -1  K -2 at 816 K in Sn 0.83 Ag 0.03 Mn 0.17 Te was attained. The lattice thermal conductivity of Sn 0.83 Ag 0.03 Mn 0.17 Te reached to an ultralow value (ca. 0.3 W m -1  K -1 ) at 865 K, owing to the formation of Ag 7 Te 4 nanoprecipitates in SnTe matrix. A high thermoelectric figure of merit (z T≈1.45 at 865 K) was obtained in Sn 0.83 Ag 0.03 Mn 0.17 Te., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Two mononuclear uranyl complexes, [UO 2 L 1 ] (1) and [UO 2 L 2 ]⋅0.5 CH 3 CN⋅0.25 CH 3 OH (2), have been synthesized from two multidentate N 3 O 4 donor ligands, N,N'-bis(5-methoxysalicylidene)diethylenetriamine (H 2 L 1 ) and N,N'-bis(3-methoxysalicylidene)diethylenetriamine (H 2 L 2 ), respectively, and have been structurally characterized. Both complexes 1 and 2 showed a reversible U VI /U V couple at -1.571 and -1.519 V, respectively, in cyclic voltammetry. The reduction potential of the U VI /U V couple shifted towards more positive potential on addition of Li + , Na + , K + , and Ag + metal ions to acetonitrile solutions of complex 2, and the resulting potential was correlated with the Lewis acidity of the metal ions and was also justified by theoretical DFT calculations. No such shift in reduction potential was observed for complex 1. All four bimetallic products, [UO 2 L 2 Li 0.5 ](ClO 4 ) 0.5 (3), [UO 2 L 2 Na(ClO 4 )] 2 (4), [UO 2 L 2 Ag(NO 3 )(H 2 O)] (5), and [(UO 2 L 2 ) 2 K(H 2 O) 2 ]PF 6 (6), formed on addition of the Li + , Na + , Ag + , and K + metal ions, respectively, to acetonitrile solutions of complex 2, were isolated in the solid state and structurally characterized by single-crystal X-ray diffraction. In all the species, the inner N 3 O 2 donor set of the ligand encompasses the equatorial plane of the uranyl ion and the outer open compartment with O 2 O' 2 donor sites hosts the second metal ion., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

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., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

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 AgBiSe 2 with 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 (AgBiSe 2 ) x for 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 AgBiSe 2 concentration arises due to increasing contribution of Bi p orbitals in the conduction band edge of (GeTe) 100- x (AgBiSe 2 ) 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 (AgBiSe 2 ) x has 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 (AgBiSe 2 ) 20 at 467 K and ∼0.6 in n-type (GeTe) 50 (AgBiSe 2 ) 50 at 500 K.

For circumventing the cumbersome and expensive multifunctional and multipolymer adsorbents for high-performance removals of hazardous water-contaminant(s), chitosan-g-[2-acrylamido-2-methyl-1-propanoic acid (AMPS)-co-2-(3-acrylamidopropanamido)-2-methylpropane-1-sulfonic acid (APAMPS)-co-2-(N-(3-amino-3-oxopropyl)acrylamido)-2-methylpropane-1-sulfonic acid (NAOPAMPS)-co-acrylamide (AM)] (i.e., chitosan-g-tetrapolymer), a multifunctional scalable and reusable hydrogel, was synthesized by grafting of chitosan and in situ attachments of N-H functionalized NAOPAMPS and APAMPS hydrophilic acrylamido-monomers during free-radical solution-polymerization of the two ex situ added AMPS and AM monomers in water. The response surface methodology was employed to synthesize one hydrogel envisaging the optimum balance between swelling and stability for the superadsorption of Cu(II), Cd(II), Pb(II), Cr 2 O 7 2- , and HPO 4 2- . The in situ attachments of NAOPAMPS and APAMPS, grafting of chitosan into tetrapolymer, structures and properties, pH-responsive abilities, superadsorption mechanism, and reusability were understood via in depth microstructural analyses of adsorbed and/or unadsorbed chitosan-g-tetrapolymer(s) through 1 H/ 13 C NMR, FTIR, XPS, TGA, XRD, DLS, and pH PZC . The maximum adsorption capacities of Cd(II), Cu(II), Pb(II), Cr 2 O 7 2- , and HPO 4 2- were 1374.41, 1521.08, 1554.08, 47.76, and 32.76 mg g -1 , respectively., (Copyright © 2019 Elsevier Inc. All rights reserved.)

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 Bi 2 O 2 Se 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 Bi 2 O 2 Se 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.

Cu2Te is a superionic conductor that belongs to the Phonon Liquid Electron Crystal class of thermoelectric (TE) materials. Despite the simple chemical formula, the crystal structures and phases in the Cu2Te system have not been understood properly. In this work, we study the structural and TE properties of Cu2Te (CT2), Cu1.6Te (CT1.6) and Cu1.25Te (CT1.25). The samples were synthesized via a solid-state reaction method. Powder X-ray diffraction analysis revealed that the samples have different crystal structures depending upon the Cu : Te stoichiometry. The elemental compositional analysis showed that all the samples are copper deficient. This is due to the precipitation of metallic copper on the surface of the ingot arising from the thermal dissociation of Cu2Te. The transport properties were measured in the temperature range 300 K-600 K. The electrical conductivity (σ) decreases with an increase in temperature indicating a metal-like behaviour for all the samples. The positive Seebeck coefficients (S) for all the samples indicates that majority charge carriers are holes. The sample CT2 has a higher S (29.5 μV K-1 at 573 K) and a lower σ (2513 S cm-1 at 573 K) due to a lower carrier (hole) concentration compared to the other two samples. With the increase in Cu deficiency, the hole concentration increases, and this leads to higher electronic thermal conductivity in the samples CT1.6 and CT1.25. The maximum thermoelectric figure of merit of 0.03 at 524 K is achieved for the sample CT2 owing to its higher power factor (0.24 mW m-1 K-2) and lower thermal conductivity (3.8 W m-1 K-1). The present study bridges the gap between the theoretical predictions and experimental observations involving the various possible structures in this system. Furthermore, we have shown that the Cu vacancies are detrimental to the thermoelectric performance of Cu2Te.

Three Zn(II) complexes, [Zn 2 (HL) 2 (NO 3 ) 2 ]·H 2 O (1), [(Zn 4 L 2 )(μ 3 -OH) 2 ](NO 3 ) 2 ·0.5H 2 O (2), and [(Zn 6 L 2 )( o-van) 2 (μ 3 -OCH 3 ) 2 (μ 3 -OH) 2 ](NO 3 ) 2 (3), have been synthesized by exploiting the flexidentate nature of a multidentate Schiff base ligand, H 2 L ( 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, [Zn 2 (HL) 2 (H 2 O) 2 ][C 6 H 2 N 3 O 7 ] 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.

The realization of n-type Ge chalcogenides is elusive owing to intrinsic Ge vacancies that make them p-type semiconductors. GeSe crystallizes into a layered orthorhombic structure similar to SnSe at ambient conditions. The high-symmetry cubic phase of GeSe is predicted to be stabilized by applying 7 GPa external pressure or by enhancing the entropy by increasing to temperature to 920 K. Stabilization of the n-type cubic phase of GeSe at ambient conditions was achieved by alloying with AgBiSe 2 (30-50 mol %), enhancing the entropy through solid solution mixing. The interplay of positive and negative chemical pressure anomalously changes the band gap of GeSe with increasing the AgBiSe 2 concentration. The band gap of n-type cubic (GeSe) 1-x (AgBiSe 2 ) x (0.30≤x≤0.50) has a value in the 0.3-0.4 eV range, which is significantly lower than orthorhombic GeSe (1.1 eV). Cubic (GeSe) 1-x (AgBiSe 2 ) x exhibits an ultralow lattice thermal conductivity (κ L ≈0.43 W m -1  K -1 ) in the 300-723 K range. The low κ L is attributed to significant phonon scattering by entropy-driven enhanced solid-solution point defects., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)