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The paper analyses the relationship between share pledging and firm performance and explores the influence of the monitoring mechanism on share pledging using the Indian dataset. The data set includes BSE Midcap firms from March 2009 to March 2019. Following Two-way Fixed Effect Model (2FE) with lagged dependent variables (LDV), we conclude that pledging activity is positively associated with stock volatility and institutional-holding serves as a monitoring mechanism for share pledging.

BACKGROUND: The first national severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serosurvey in India, done in May-June, 2020, among adults aged 18 years or older from 21 states, found a SARS-CoV-2 IgG antibody seroprevalence of 0·73% (95% CI 0·34-1·13). We aimed to assess the more recent nationwide seroprevalence in the general population in India. METHODS: We did a second household serosurvey among individuals aged 10 years or older in the same 700 villages or wards within 70 districts in India that were included in the first serosurvey. Individuals aged younger than 10 years and households that did not respond at the time of survey were excluded. Participants were interviewed to collect information on sociodemographics, symptoms suggestive of COVID-19, exposure history to laboratory-confirmed COVID-19 cases, and history of COVID-19 illness. 3-5 mL of venous blood was collected from each participant and blood samples were tested using the Abbott SARS-CoV-2 IgG assay. Seroprevalence was estimated after applying the sampling weights and adjusting for clustering and assay characteristics. We randomly selected one adult serum sample from each household to compare the seroprevalence among adults between the two serosurveys. FINDINGS: Between Aug 18 and Sept 20, 2020, we enrolled and collected serum samples from 29 082 individuals from 15 613 households. The weighted and adjusted seroprevalence of SARS-CoV-2 IgG antibodies in individuals aged 10 years or older was 6·6% (95% CI 5·8-7·4). Among 15 084 randomly selected adults (one per household), the weighted and adjusted seroprevalence was 7·1% (6·2-8·2). Seroprevalence was similar across age groups, sexes, and occupations. Seroprevalence was highest in urban slum areas followed by urban non-slum and rural areas. We estimated a cumulative 74·3 million infections in the country by Aug 18, 2020, with 26-32 infections for every reported COVID-19 case. INTERPRETATION: Approximately one in 15 individuals aged 10 years or older in India had SARS-CoV-2 infection by Aug 18, 2020. The adult seroprevalence increased approximately tenfold between May and August, 2020. Lower infection-to-case ratio in August than in May reflects a substantial increase in testing across the country. FUNDING: Indian Council of Medical Research.

This paper proposes a market mechanism for multi-interval electricity markets with generator and storage participants. Drawing ideas from supply function bidding, we introduce a novel bid structure for storage participation that allows storage units to communicate their cost to the market using energy-cycling functions that map prices to cycle depths. The resulting market-clearing process--implemented via convex programming--yields corresponding schedules and payments based on traditional energy prices for power supply and per-cycle prices for storage utilization. We illustrate the benefits of our solution by comparing the competitive equilibrium of the resulting mechanism to that of an alternative solution that uses prosumer-based bids. Our solution shows several advantages over the prosumer-based approach. It does not require a priori price estimation. It also incentivizes participants to reveal their truthful cost, thus leading to an efficient, competitive equilibrium. Numerical experiments using New York Independent System Operator (NYISO) data validate our findings.

A 1:1 stochiometric cocrystal of nicotinamide with picric acid (C12H8N5O8) has been synthesised successfully by solvent assisted grinding method and structure of the cocrystal is established by single crystal X-ray diffraction studies. The compound crystallizes in the orthorhombic space group Pbca with unit cell parameters: a = 7.7608 (11), b = 14.5110 (14), c = 24.751 (3) A and Z = 8. The crystal structure was solved by direct methods and refined to R = 0.0723 for 1755 observed reflections. Current study has primarily focused on hydrogen bonding which is the driving force for the formation of cocrystal. Hirshfeld surfaces and fingerprint plots indicate that the structures are stabilized by O⋯H, N⋯H intermolecular interactions. In order to make a better understanding supercell model of nicotinamide-picric acid cocrystal (NICPIC) is created with crystallographic data. Based on this hydrogen bonding population, radial distribution function (RDF) and bulk properties are simulated via Molecular Dynamics (MD). Furthermore, DSC/TGA analysis indicates that the NICPIC maintains its crystallinity up to 195 °C, suggesting its higher stability compared to individual components.

In this paper, an efficient analytical iterative method is introduced for solving the initial value and boundary value Bratu problems. A quasilinearization method with an optimal parameter is derived and utilized to reduce the highly nonlinear Bratu equations to a sequence of linear problems. An optimal Picard iteration method is used to obtain approximate analytical solution of linearized versions of Bratu’s equations. The numerical results presented the effectiveness and high performance of the proposed method and comparisons are made with many other existing numerical solution techniques. The comparisons reveal the efficiency and applicability of the present work.

Challenge of ADHOC WSN is to maintain the stability of the network. The stability of network is directly related to energy and quality of service parameters (QoS) like time delay, throughput, etc. In case if the network is not stable then these parameters degrade and reduce the performance of ADHOC WSNs. Network stability depends upon energy as discussed above, and here we have discussed its effect on the performance of the system. In other words, ADHOC WSNs are networks comprising of tiny sensors nodes (wireless in nature) capable of transmitting data within the network via the sink. As the sensing elements are tiny devices hence the power source consists of limited energy which limits the lifetime of the network. Many techniques have been proposed and developed (as discussed in the literature review) by the researchers to efficiently utilize the limited energy available with the sensor nodes to increase the lifetime of the network. Still, the area of optimizing energy efficiency required further exploration. So, this thesis addresses the problem and tries to solve the issue by using the proposed approaches Optimization, improving residual energy and increasing throughput packet wise. In average there is 4–7% improvement in energy and 5–7% increased throughput.

Background: Repeated cross-sectional serosurveys in the same geographic area establish the trend of the evolving pandemic. We present the findings of the third round of a national serosurvey to estimate the seroprevalence of SARS-CoV-2 infection among the general population and health care workers of India. Methods: We conducted the third population-based serosurvey between Dec 18, 2020 and Jan 6, 2021 in the same 700 villages or wards from 70 districts in 21 states across India, which were selected for the first and second serosurveys. We enrolled from each district, at least 400 individuals aged ≥ 10 years from general population and 100 HCWs from sub-district level public health facilities. Serum samples from general population were tested for the presence of IgG antibodies against nucleocapsid (N) and spike protein (S1-RBD) of SARS-CoV-2 using the Abbott and Siemens assays respectively, whereas sera from HCWs were tested for anti-S1-RBD. For general population, sera positive for either of the antibodies were considered positive, while sera positive for anti-S1-RBD were considered as positive for HCW. Weighted seroprevalence estimates were adjusted for sensitivity and specificity of respective assays. Findings: Of the 28,598 sera from general population, 4585 (16%) had IgG antibodies against N, 6647 (23.2%) against S1-RBD and 7436 (26%) against either. The weighted and assay characteristic adjusted seroprevalence against either of the antibodies was 24.1 (95%CI: 23.0% to 25.3%). Seroprevalence was lower in rural areas (21.4%, 95% CI: 20.3% to 22.6%) compared to urban non-slum (29.4%, 95% CI: 26.9% - 32.1%) and slum areas (34.6%, 95% CI: 31.0% to 38.3%). Among 7385 HCWs, the seroprevalence of anti-S1-RBD IgG antibodies was 25.6% (95% CI: 23.5% to 27.8%). Interpretation: Nearly one in four individuals aged 10 years or older from general population as well as HCWs were exposed to SARS-CoV-2 by December 2020 amounting to 271 million infections in India. Funding Statement: Indian Council of Medical Research Declaration of Interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf and declare no competing interests Ethics Approval Statement: The project was approved by Institutional Human Ethics Committee at ICMR-National Institute of Epidemiology.

Background: India witnessed a severe second wave of COVID-19 during March and June 2021. We did the fourth nationwide serosurvey to estimate prevalence of SARS-CoV-2 antibodies in the general population aged >=6 years and health care workers (HCWs). Methods: We did a cross-sectional study between 14 June and 6 July 2021 in 700 clusters in the same 70 districts across 21 states/Union Territory. From each district, a minimum of 400 individuals aged >=6 years from general population and 100 HCWs from the district public health facilities were included. The serum samples were tested for the presence of IgG antibodies against S1-RBD and nucleocapsid protein of SARS-CoV-2 using chemiluminescence immunoassay. We estimated the weighted and test adjusted seroprevalence of IgG antibodies against S1-RBD and/or nucleocapsid protein along with 95% CI. Findings: Of the 28,975 sera tested, the weighted and test adjusted prevalence of IgG antibodies against S1-RBD and/or nucleocapsid protein among the general population aged >=6 years was 67.6% (95% CI: 66.4 – 68.7). The seroprevalence increased with age and was not different in rural and urban areas. Compared to unvaccinated adults (62.3%, 95% CI: 60.9 – 63.7), seroprevalence was significantly higher among individuals who received one (81.0%, 95% CI: 79.6 - 82.3) and two doses (89.8%, 95% CI: 88.4 - 91.1). The seroprevalence of IgG antibodies among 7,252 health care workers was 85.2% (95% CI: 83.5 - 86.7). Interpretation: Nearly one third of the population is still seronegative. It is necessary to accelerate the coverage of COVID-19 vaccination among adults and continue adherence to non-pharmaceutical interventions. Funding: Indian Council of Medical Research. Declaration of Interest: None to declare. Ethical Approval: The Institutional Human Ethics Committee of the ICMR National Institute of Epidemiology, Chennai approved the study protocol.

The X-ray structure of 2-(3,4-dimethoxyphenyl)-4,5-diphenyl-1H-imidazole, has been determined. It crystallizes in orthorhombic space group Pna21, with a = 9.5018(6) A, b = 21.636(2) A, c = 19.040(1) A and Z = 8. The structure has been solved by direct methods and refined by full matrix least squares procedures to a final R value of 0.0675 for 2733 observed reflections. The asymmetric unit contains two crystallographic independent molecules. C H…O and C H…N intermolecular interactions were observed and these interactions are of paramount importance in assembling the molecules leading to packing stability. To understand pharmacological importance of the title compound, molecular docking was performed against two anti-inflammatory drug targets; Myeloperoxidase (MPO) and Cyclooxygenase (COX-2). Docking studies show binding mode of the titled molecule to be similar to the known inhibitor in their respective active site of anti-inflammatory drug targets. Thus, the title molecule also has similar mode of drug action.

Disubstituted phosphorodithioates of the type [{(2,5-CH3)2C6H3O}2PS2HNEt3] (1) and [{(3,5-CH3)2C6H3O)2(PS2)}2] (2) were synthesized and characterized by IR and NMR (1H,13C and 31P) spectroscopic studies and as single crystal X-ray analysis. The compound 1 crystallizes in monoclinic space group P21/c whereas compound 2 crystallizes in triclinic space group P¯1. The X-ray analysis reveals that in compound 1 phosphorus atom is coordinated to the two S and two O atoms to form tetrahedral geometry. The structure is stabilized by cation–anion N H⋯S hydrogen bonded interactions. In compound 2, the two phosphorus atoms have a distorted tetrahedral geometry coordinated to two (3,5-CH3)2C6H3O groups. The molecule possesses a crystallographic center of symmetry and consists of zig-zag array of S P S S P S linkages with two diphenyldithiophosphate moieties in the trans configuration. Molecular geometries, HOMO-LUMO analysis and molecular electrostatic potential of compounds 1 and 2 are investigated by theoretical calculations using B3LYP functional with the 6-311G basis combination set in the ground state and compared with the experimental values.

Comparison of first and second waves of Coronavirus disease (COVID-19) showed varied differences including the peak and time distribution. Contrary to published reports of comparing two waves in India wherein the younger age group was affected more in the second wave in India; a secondary data analysis of around 0.5 million real-time reverse transcription-polymerase chain reaction tests conducted in COVID-19 diagnostic laboratory in eastern Uttar Pradesh, India showed an increase in positivity rate in older age groups in the second wave. The positivity rate among symptomatic cases was found to be three times higher in second wave compare to the first wave. Higher positivity rates were seen across older age groups, with a shift of 11 years in the mean age of positivity in the second wave compared to the first.

In this paper, an effective analytical method is introduced for solving a class of two-point nonlinear doubly singular boundary value problems (SBVPs) arising in various physical models. The method is the combination of Newton’s quasilinearization and Picard iteration method in which quasilinearization is utilized to reduce the nonlinear doubly SBVPs to a sequence of linear problems and then the Picard iteration method is used to obtain the approximate analytical solutions of linearized equations arising from quasilinearization method. The convergence analysis of the method is also discussed. To demonstrate the efficiency of the method, we consider various numerical examples arising in physical models including real-life problems. The numerical simulations justify the superiority and high performance of the method and the obtained results are compared with some other existing schemes. The comparisons reveal the applicability and effectiveness of the present work. The method also works quite efficiently for other nonlinear boundary value problems of any order. The method is successfully applied on second and third–order regular boundary value problems and the results are compared with the existing methods.

Today the fundamental aspect of the researchers is to explore maximum physical properties of the material for device fabrication. In the present article, single crystal X-ray diffraction has been carried out to verify the formation of the synthesized compound. In addition to that, powder X-ray diffraction has been performed to obtain diffraction pattern of l -Prolinium Picrate single crystal. The strain present inside the single crystal was measured using Hall-Williamson equation from PXRD measurements. The dark current and photon current was obtained from photoconductivity technique whose plot depicted that the sample was negative photoconducting material. Optical homogeneity of the single crystal was analyzed using birefringence technique. Its resistance towards Nd: YAG laser was scrutinized for l -Prolinium Picrate single crystal by applying 1 pulse per second. Different thermal parameters like thermal conductivity, thermal diffusivity, thermal effusivity and specific heat were computed using photo-pyroelectric technique. Solid state parameters were calculated from Clausius Mossotti relation by taking structural information of the title compound. Also, optical parameters like refractive index, reflectance etc were calculated through UV–Vis–NIR analysis.

The title compound (6bR,14bR,15R,15aR)-ethyl 5-bromo-14b-phenyl-1,6b,8,9,14,14b,15,15a- octahydrochromeno [3′,4′:2,3] indolizino [8,7-b] indole-15-carboxylate belongs to an indole derivative. The compound crystallizes in the triclinic crystal system with the space group P1. The asymmetric unit cell consists of two molecules. In the crystal, hydrogen bond interactions of the type N–H⋅⋅⋅O, C–H⋅⋅⋅O and C–H⋅⋅⋅N are present. Further, the molecular structure is stabilized by C–H⋅⋅⋅π interactions. Intermolecular interactions were analyzed using Hirshfeld surface analysis.

A new series of adducts of bis(O-butylxanthato)nickel(II) with substituted pyridines have been synthesized by treating bis(O-butylxanthato)nickel(II) with substituted pyridines in acetone. The complexes have been characterized by elemental analysis, conductivity measurements, magnetic susceptibility measurements, TGA/DTA studies, infrared and electronic spectral studies. X-ray studies of one of the adduct bis(O-butylxanthato)bis(3-chloropyridine)nickel(II) shows that the central metal is octahedrally coordinated within a trans-N2S4 donor set, with the Ni atom located on a centre of inversion. The complex crystallizes in the monoclinic space group P21/c with unit cell parameters a = 11.8088(8) A, b = 12.2042(7) A, c = 9.0252(5) A, β = 93.789(6), Z = 2. Crystal structure was solved by direct methods and refined by full matrix least squares procedures to a final R-value of 0.0380 (wR2 = 0.0885) for 2083 observed reflections. The butyl chain is disordered over two set of sites, with occupancy ratios of 0.741:0.259. These studies suggest a distorted octahedral structure and paramagnetic nature of the adducts.

Being crucial part of plant-based novel discovery of drug from natural resources, a study was done to explore the antibacterial potential of curcumin mimics in combination with antibiotics against multidrug resistant isolates of Pseudomonas aeruginosa. The best candidate Van D, a curcumin mimics reduced the MIC of tetracycline (TET) up to 16 folds against multidrug resistant clinical isolates. VanD further inhibited the efflux pumps as evident by ethidium bromide efflux and by in-silico docking studies. In another experiment, it was also found that Van D inhibits biofilm synthesis. This derivative kills the KG-P2, an isolate of P. aeruginosa in a time dependent manner, the post-antibiotic effect (PAE) of tetracycline was extended as well as mutant prevention concentration (MPC) of TET was also decreased. In Swiss albino mice, Van D reduced the proinflammatory cytokines concentration. In acute oral toxicity study, this derivative was well tolerated and found to be safe up to 1000 mg/kg dose. To the best of our knowledge, this is the first report on curcumin mimics as synergistic agent via inhibition of efflux pump.

Four novel pregnane-NSAIDs prodrugs 3β-(2-(6-methoxynaphthalene-2yl) propionoxy)-16α-methoxy-pregn-5-ene-20-one (3), 16α-methoxy-pregn-5-ene-20-one-3yl-2(4-iso butyl phenyl) propanoate (4), 3β-(2-(6-methoxynaphthalene-2yl) propionoxy) 20-hydroxy-16α-methoxy-pregn-5-ene (5) and 20-hydroxy-16α-methoxy-pregn-5-ene-20-one-3yl-2(4-iso butyl phenyl) propanoate (6) have been synthesized. They were analyzed experimentally by spectroscopic techniques like 1H, 13C NMR, FT-IR, UV–visible spectroscopy, mass spectrometry and correlated by theoretical calculations. The structure and conformations of 3 was established by single crystal X-ray diffraction, which crystallized in orthorhombic form having P212121 space group. Absolute configuration of C-20 hydroxy derivatives 5 and 6 was established by circular dichroism (CD) analysis. Conformational analysis of 5 was carried out to determine the most stable conformation. The electronic properties, such as frontier orbitals, band gap energies, oscillator strength and wavelength have been calculated using time dependent density functional theory (TD-DFT). The vibrational wavenumbers have been calculated using DFT method and assigned with the help of potential energy distribution (PED). Global and local reactivity descriptors have been computed to predict reactivity and reactive sites in the molecule. First hyperpolarizability (β0) of synthesized compounds has been computed to evaluate non-linear optical (NLO) response. Molecular electrostatic potential (MEP) for synthesized compounds have also been determined to check their electrophilic or nucleophilic reactivity as well as reaction path.

Ultrasonic-assisted, catalyst-free reactions of ninhydrin with ethyl cyanoacetate and diethyl malonate led to the unprecedented formation of an indenopyran and a spiroindenofuran viz. diethyl 4-cyano-2-hydroxy-5-oxo-4,5-dihydroindeno[1,2-b]pyran-3,4-dicarboxylate 1 and diethyl 3a′,8b′-dihydroxy-1,3,4′-trioxo-1,3,3a′,4′-tetrahydrospiro[indene-2,2′-indeno[1,2-b]furan]-3′,3′(8b′H)-dicarboxylate 3, respectively. In addition to these unprecedented results, reactions of ninhydrin with dimedone, ethyl acetoacetate and ethyl nitroacetate yielded 4b,9b-dihydroxy-7,7-dimethyl-7,8-dihydro-4bH-indeno[1,2-b]benzofuran-9,10(6H,9bH)-dione 5, ethyl 3a,8b-dihydroxy-2-methyl-4-oxo-4,8b-dihydro-3aH-indeno[1,2-b]furan-3-carboxylate 6 and 2-hydroxy-2-(nitromethyl)-1H-indene-1,3(2H)-dione 7, respectively. The structures of 1, 3, 5, 6 and 7 were determined by X-ray crystallography and attempts have been made to propose the mechanism of their formation.

A series of novel and highly efficient Lewis acids covalently grafted over sulfonic acid functionalized carbon@titania composites were successfully synthesized via sulfonation of carbon@titania composites followed by treatment with different Lewis acids like AlCl3, FeCl3, SbCl3, SnCl2, Cu(OAc)2 and Bi(NO3)3. The utility of the developed catalysts was explored for the synthesis of a diverse range of 4H-pyrimido[2,1-b]benzothiazoles and benzoxanthenones, and among various catalysts, C/TiO2–SO3–SbCl2 was found to be the most active. We report here the synthesis of five novel compounds and the structure of one of the compounds has also been confirmed by single-crystal X-ray diffraction. All the five prepared composites were characterized by FTIR and ICP-AES analysis, whereas the most active one, C/TiO2–SO3–SbCl2 was further characterized by XRD, EDX, CHNS, SEM, TEM, HRTEM and TGA. The catalyst can be recovered and reused for atleast five runs without any significant impact on catalytic activity and selectivity. The high catalytic activity, thermal stability, simple recovery and reusability, and eco-friendly nature of the catalyst makes the present method to be particularly attractive from the view point of green chemistry.

Thiosalicylato complexes of Zn(II) and Hg(II), [Zn(SC6H4CO2)(TMEDA)]2 (1) and [TMEDA-H2][Hg(SC6H4CO2)2] (2) where (TMEDA = N,N,N',N'-tetramethylethylenediamine) have been synthesized and characterized by spectral and single crystal X-ray analyses. Thiosalicylate opted different binding modes; in 1 all three binding sites are used whereas in 2 bonding of the ligands are mainly through S atoms, however, Hg-O distances indicate the existence of significant Hg…O interactions. Bonding features have been explained on the basis of DFT calculations. Electronic absorption and emission spectral properties of both complexes have been studied. Electronic transitions have been calculated by TDDFT method and the results are consistent with the experimental spectra. We further have evaluated anti-bacterial, anti-biofilm and anti-tumour activities of 1 in addition to its cytotoxicity profile. It has been found to be highly effective against Escherichia coli, Klebsiella pneumoniae, Methicillin sensitive Staphylococcus aureus, Methicillin resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa clinical as well as reference strains. Interestingly, complex 1 has been found to be more potent than earlier reported Au(III) as well as Pt(II) thiosalicylate complexes. The effect of complex 1 on 72 h old biofilms of S. Aureus (MDR isolate 3) has been investigated by confocal laser scanning microscopy which revealed its bactericidal activities at the concentration as low as 0.125 µg/mL possibly by membrane alterations as evident by clear propidium iodide (PI) uptake. However, its antibiofilm activity is possibly due to interactions with biofilm matrix constituents.

The molecular structure and detailed spectroscopic analysis of some novel newly synthesized pregnane derivatives have been performed using experimental techniques like 1H, 13C NMR, NOESY, FT-IR, UV–visible spectroscopy, mass spectrometry, crystallography, as well as theoretical calculations. The structure and stereochemistry of 3β-benzoyloxy 16α-methoxy pregn-5-ene-20-one (3) has been confirmed by single crystal X-ray diffraction, which crystallized in orthorhombic form having P212121 space group with unit cell parameters a = 6.395(5) A, b = 19.872(17) A, c = 19.898(16) A and Z = 4. Quantum chemical calculations have been performed by density functional theory (DFT) using B3LYP functional and 6-31G (d,p) basis set. The electronic properties such as frontier orbitals and band gap energies have been calculated using time dependent density functional theory (TD-DFT). The strength and nature of weak intramolecular interactions have been studied by AIM approach. The vibrational wavenumbers have been calculated using DFT method and assigned with the help of potential energy distribution (PED). Global and local reactivity descriptors have been computed to predict reactivity and reactive sites in the molecule. First hyperpolarizability values have been calculated to describe the nonlinear optical (NLO) property of the synthesized compounds. Molecular electrostatic potential (MEP) analysis has also been carried out.

A new and efficient method has been developed for the conversion of α,β-unsaturated ketones to 1,5-diketones via tandem retro-Aldol and Michael addition in the presence of Co(acac)2 covalently anchored amine functionalized silica [AS-Co(acac)2]. The single crystal X-ray crystallography confirms the formation of 1,5-diketones. This method has been proved to be an attractive alternative to existing methodologies under conventional homogeneous catalysis with the frequent troublesome manipulation and work-up. The AS-Co(acac)2 was found to be highly active and could be recycled for four consecutive runs with slight decrease in activity.

The thiopyrazole gave many new polycyclic thiopyranopyrazole-heterocycles when it was assembled with a variety of O-alkenylated/alkynylated salicylaldehydes and naphthaldehydes in Bronsted acidic ionic liquid, [Hmim]HSO4, via domino/Knoevenagel–hetero-Diels–Alder (DKHDA) reaction. The reaction is highly stereoselective and the work-up procedure required no chromatography of products in many cases.

Planar (N-benzyl-N-furfuryldithiocarbamato-S,S')(thiocyanato-N)(triphenylphospine)nickel(II), [Ni(bfdtc)(NCS)(PPh3)], (1) was prepared from bis(N-benzyl-N-furfuryldithiocarbamato-S,S')nickel(II), [Ni(bfdtc)2], (2) and characterized by elemental analysis, cyclic voltammetry, electronic, IR and variable temperature (1)H and (13)C NMR spectra. For complex 1, the thioureide vCN value is shifted to higher wavenumber compared to 2 and N(13)CS2 carbon signal observed for 1 is additionally shielded compared to the parent complex 2, suggesting increased strength of the thioureide bond due to the presence of the π-accepting phosphine. In the room temperature (13)C NMR spectrum of 1, two pseudo doublets are observed in the aliphatic region. Variable temperature (13)C NMR spectral studies suggest that the fast thiocyanate exchange appears to be responsible for the appearance of pseudo doublets. Single crystal X-ray structural analysis of 1 and 2 confirm the presence of four coordinated nickel in a distorted square planar arrangement with the NiS2PN and NiS4 chromophores, respectively. The NiS bonds are symmetric in 2 (2.1914(14) and 2.2073(13)Å). But significant asymmetry in NiS bond distances was observed in 1 (2.2202(8)Å and 2.1841Å). This observation clearly supports the less effective trans effect of SCN(-) over PPh3. Cyclic voltammetric studies revealed easier reduction of nickel(II) to nickel(I) in complex 1 compared to 2.

Five novel nickel(II) complexes of disubstituted diphenyldithiophosphates, [{(ArO) 2 PS 2 } 2 Ni] [Ar = 2,4-(CH 3 ) 2 C 6 H 3 ( 1 ), 2,5-(CH 3 ) 2 C 6 H 3 ( 2 ), 3,4-(CH 3 ) 2 C 6 H 3 ( 3 ), 3,5-(CH 3 ) 2 C 6 H 3 ( 4 ) and 4-Cl-3-CH 3 C 6 H 3 ( 5 )], have been synthesized in aqueous medium and structurally characterized by IR, heteronuclear NMR ( 1 H, 13 C and 31 P) spectroscopic and single crystal X-ray analyses. Complexes 1 and 5 crystallize in the triclinic space group P 1 ¯ , whereas complex 4 crystallizes in the monoclinic space group P 2 1 /n . In these complexes, the ligands are coordinated to the nickel ion as a bidentate chelating agent via the two thiolate sulfur atoms, leading to a spirocyclic system. Crystal structure determination of complexes 1 , 4 and 5 reveals that the complexes consist of mononuclear units with the nickel(II) ion coordinated in a bis-bidentate fashion with a distorted square planar coordination environment. A cyclic voltammetry experiment was used to probe the redox capabilities of complex 4 . The investigated complexes, along with the ligands, have been screened for in vitro antifungal activities against the fungus Penicillium chrysogenum .

An improved microwave assisted one-pot method for the synthesis of twelve new aryldiazenylchromeno [4,3-b] pyrrolidines via intramolecular azomethine ylide cycloaddition route is described. The method is efficient and advantageous over conventional and solvent-free thermal methods. The stereochemistry of the compounds was confirmed on the basis of various NMR experiments, and finally by single crystal X-ray diffraction data. N-Methyl or ethyl pyrrolidine based heterocycles gave good biological activities.

A new lignan rhamnoside identified as 2,6-di(4′,5′-dihydroxyphenyl)-3,7-dioxabicyclo[3.3.0]octane-1-hydroxy-5- O -rhamnopyranoside ( 1 ) has been isolated from the ethanolic extract of seed pods of Bauhinia retusa . Its structure was established by extensive spectroscopic techniques (UV, IR, 1D NMR, 2D NMR, HRESIMS).