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Introduction: In this reported work, we have used 80 % aqueous dimethyl sulphoxide (DMSO) for density and viscosity measurement of pyrimidine-5-carbonitrile at 298.15 K. The obtained experimental results show that as concentration increases density and viscosity increases. From the results of density and viscosity, we have found apparent molar volume, limiting apparent molar volume, semi-empirical parameters, Falkenhagen coefficients and Jones Dole coefficients. Method: The apparent molar volume and limiting apparent molar volume having negative values indicated electostrictive solvation of ions and weak or absence of ion solvent interactions respectively. Result & Discussion : Falkenhagen coefficients are independent of concentration and possess positive values that shows strong solute-solute interactions. Jones-Dole coefficient with negative value shows weak solute-solvent interactions. The strong solute-solute interactions were present in A-1 as compared to A-2 compound because of the high electronegativity of oxygen atom. These parameters provides information about the type of the molecular interactions such as solute-solute, solute-solvent and solvent-solvent. Conclusion: We have reported density and viscosity study of 4-amino-2-hydroxy-6- phenylpyrimidine-5-carbonitrile and 4-amino-2-mercapto-6-phenylpyrimidine-5-carbonitrile in 80 % aqueous DMSO solution at 298.15 K. A stronger molecular association is observed in A-2 than A-1 shown by negative values of Øv.

In present work, the concentration and temperature dependence of the thermodynamic properties of 3-substituted Schiff base of 4-piperidyl N-(4-chlorophenyl)maleimide compound in 80% DMSO was estimated. Concentration (0.002-0.01 M) and temperature (298-313 K) dependent densitometric and viscometric measurement were employed to evaluate limiting molar volume (φv 0), semi-empirical parameter (Sv), Falkenhagen (A) and Jones-Dole (B) viscosity coefficient. The obtained results suggest the presence of weaker solute-solvent interactions and stronger solute-solute interactions. It was observed that these interactions strongly depend on the temperature of the system. Furthermore, the Gibbs free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) of the system were also evaluated. The negative values of ΔG and ΔH and positive values of ΔS indicating reaction was spontaneous and exothermic in nature.

Background: The Novel coronavirus (COVID-19), which started in Wuhan (China) during December 2019, has spread to the rest of the world until now (July 2020). COVID-19 infections are more prevalent in developed countries rather than in the fast-developing, and underdeveloped countries. Now novel COVID-19 infection is a global health problem. In a fast-developing country like India, the incidence of coronavirus infections is increasing day by day. The fifth phase of lockdown has started in India to reduce the incidence of infection.Purpose: The purpose of this study of the impact of lockdown on the India’s environment, according to the literature survey from various research papers, news, social networking, government data (websites), etc., indicates that the lockdown helping to reduce transit in India and at the same time has a great impact on reduced pollution such as air pollution, water pollution, land pollution, etc., thus improving the balance of the environment after March 2020 onwards.Methods: In this work, we have used an online method using various online sources, which has mainly surveyed some important cities in India, have also studied the factors such as air pollution, river pollution, land pollution, etc. and its impact on Indian environment.Results: According to an online survey, lockdown has had a significant impact on the Indian environment, reducing the number of vehicles on the road that improving air quality, reducing river pollution, and having a positive impact on various fields. Lockdown has been very beneficial to the environment.Conclusions: The observations from various parts of the sources show that reduced pollution has also reduced the number of patients in hospitals, mainly jaundice (yellow fever), chikungunya, typhoid, respiratory diseases, etc. This review article explains the brief analysis of the impact of COVID-19 lockdown on India’s environment.

Pyrimidine-5-carbonitrile and pyrimidine-5-carboxamide were synthesized from the various substituted benzaldehyde, malononitrile and cyanoacetamide, urea/thiourea in the presence of ammonium chloride followed by characterization using IR, $$^{1}\hbox {H NMR}$$ spectroscopic technique. Pyrimidine-5-carbonitrile and pyrimidine-5-carboxamide were synthesized from the various substituted benzaldehyde, malononitrile and cyanoacetamide, urea/thiourea in the presence of ammonium chloride.

A set of new Schiff bases of N-aryl 3- and 4-substituted maleimides has been prepared via condensation of N-aryl 3- and 4- substituted maleimides with p-toluene sulfonyl hydrazide in acidic medium at room temperature. The structures of synthesized compounds were characterized by IR, 1H NMR, 13C NMR, MS spectral data, and further confirmed by single-crystal x-ray crystallography for 5c. The computational study was carried out using Gaussian 09 software by using the B3LYP/6-311+G(d,p) basis set. Single-crystal study results showed much closeness with computational study results. These novel compounds were screened for their antimicrobial activity against two pathogenic bacteria such as Escherichia coli (ATCC 8739) and Staphylococcus aureus (ATCC25923) and two pathogenic fungi such as Aspergillus niger (MCIM10231) and Candida albicans (MTCC6275). The investigation of antimicrobial screening data showed that the most of tested compounds are moderate to good microbial inhibitors.

Viscosities of ammonium sulfate, potassium sulfate, and aluminum sulfate in water and water + (5 %, 10 %, 15 %, and 20 %) N,N-dimethylformamide mixed solvent have been measured at T = (298.15 and 308.15) K and at atmospheric pressure. A molality range has been studied between (0.0081 and 0.1000) mol·kg−1. The viscosity data have been analyzed with the Jones−Dole equation, and B coefficients have been calculated. The results have been interpreted in terms of structure making/breaking behavior of these salts in water and water + DMF mixed solvents.

Densities of (NH 4 ) 2 SO 4 , K 2 SO 4 and Al 2 (SO 4 ) 3 have been measured in dimethylsulphoxide(DMSO) + water, containing 0,5,10,15 and 20 mass % of DMSO, at different concentrations and at 298.15, 303.15, 308.15 and 313.15 K. From these densities, apparent molar volumes have been derived. The apparent molar volume data have been analyzed using Masson equation. The limiting apparent molar volume, Vφ0, and slope, S*v, are interpreted in terms of solute-solvent and solute-solute interactions, respectively. The Vφ0 values vary with temperature as a power series of temperature. Finally, the Structure making/breaking capacities of salts have been inferred from the Hepler's criterion.