Crystal and molecular structure of dimeric bis[N,N-di-n-propyldithiocarbamato]zinc(II) and the study of exchange-coupled copper(II)-copper(II) pairs in its lattice

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Erratum to "Crystal and molecular structure of dimeric bis[N,N-di-n-propyldithiocarbamato]zinc(II) and the study of exchange-coupled copper(II)-copper(II) pairs in its lattice"

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Experimental and Theoretical Studies of Ultrasonic Velocity in Binary Liquid Mixtures of Ethyl benzoate

Ultrasonic velocity is measured at 2MHz frequency in the binary mixtures of Ethyl Benzoate with 1-Propanol, 1-Butanol, 1-Pentanol and theoretical values of ultrasonic velocity have been evaluated at 303K using Nomoto's relation, Impedance relation, Ideal mixture relation, Junjie's method and free length theory. Theoretical values are compared with the experimental values and the validity of the theories is checked by applying the chi-square test for goodness of fit and by calculating the average percentage error (APE). A good agreement has been found between experimental and Nomoto’s ultrasonic velocity

Study of excess dielectric and thermodynamic parameters of hydrogen bonded system: Isobutanol and ethyl benzoate

597-611The complex dielectric permittivity of polar systems of isobutanol and ethyl benzoate for various mole fractions at different temperatures has been studied by using the open-ended coaxial probe technique method in the microwave frequency range from 20 MHz to 20 GHz. The dipole moment, excess dipole moment, Bruggeman parameter, excess Helmholtz energy, excess permittivity, excess inverse relaxation time, excess thermodynamic values are calculated using experimental results. The optimized geometry, harmonic vibrational wave numbers and dipole moments of pure and equimolar binary mixtures have been calculated theoretically from HF, B3LYP with 6-311G and 6-311G+ basis sets by using Gaussian-03 software. Conformational analysis of the formation of hydrogen bond between isobutanol and ethyl benzoate is supported by the FT-IR, 1NMR and molecular polarizability calculations. The calculated wave numbers and dipole moments agree well with the experimental values. Further, the correlations among the parameters have been discussed in detail

Experimental and Theoretical Studies of Ultrasonic Velocity in Binary Liquid Mixtures of Ethyl Benzoate

Abstract: Ultrasonic velocity is measured at 2MHz frequency in the binary mixtures of Ethyl Benzoate with 1-Propanol, 1-Butanol, 1-Pentanol and theoretical values of ultrasonic velocity have been evaluated at 303K using Nomoto's relation, Impedance relation, Ideal mixture relation, Junjie's method and free length theory. Theoretical values are compared with the experimental values and the validity of the theories is checked by applying the chi-square test for goodness of fit and by calculating the average percentage error (APE). A good agreement has been found between experimental and Nomoto's ultrasonic velocity

Co-Amorphous Formation of High-Dose Zwitterionic Compounds with Amino Acids To Improve Solubility and Enable Parenteral Delivery

Solubilization of parenteral drugs is a high unmet need in both preclinical and clinical drug development. Recently, co-amorphous drug formulation has emerged as a new strategy to solubilize orally dosed drugs. The aim of the present study is to explore the feasibility of using the co-amorphous strategy to enable the dosing of parenteral zwitterionic drugs at a high concentration. A new screening procedure was established with solubility as the indicator for co-amorphous co-former selection, and lyophilization was established as the method for co-amorphous formulation preparation. Various amino acids were screened, and tryptophan was found to be the most powerful in improving the solubility of ofloxacin when lyophilized with ofloxacin at a 1:1 weight ratio, with more than 10 times solubility increase. X-ray powder diffraction showed complete amorphization of both components, and an elevated <i>T</i>_g compared with the theoretical value was observed in differential scanning calorimetry. Fourier transform infrared spectroscopy revealed that hydrogen bonding and π–π stacking were possibly involved in the formation of a co-amorphous system in the solid state. Further solution-state characterization revealed the involvement of ionic interactions and π–π stacking in maintaining a high concentration of ofloxacin in solution. Furthermore, co-amorphous ofloxacin/tryptophan at 1:1 weight ratio was both physically and chemically stable for at least 2 months at 40 °C/75% RH. Lastly, the same screening procedure was validated with two more zwitterionic compounds, showing its promise as a routine screening methodology to solubilize and enable the parenteral delivery of zwitterionic compounds

Excess thermodynamic and acoustic properties for the binary mixtures of Methyl Benzoate at T = (303, 308, 313, 318 and 323) K

<div><p>Density and speed of sound data for (Methyl Benzoate + 1-Propanol), (Methyl Benzoate + 1-Butanol) and (Methyl Benzoate + 1-Pentanol) have been determined at temperatures = (303, 308, 313, 318 and 323) K. From this data, excess parameters like excess volume, V^E, excess isentropic compressibility, , and excess intermolecular free length, , have been computed. The variations of these parameters with composition and temperature of the mixtures are discussed in terms of molecular interactions in these mixtures. The values of and for all the systems under study are negative.</p></div

Structure, Properties and Applications of Two-Dimensional Hexagonal Boron Nitride

Hexagonal boron nitride (h-BN) has emerged as a strong candidate for two-dimensional (2D) material owing to its exciting optoelectrical properties combined with mechanical robustness, thermal stability, and chemical inertness. Super-thin h-BN layers have gained significant attention from the scientific community for many applications, including nanoelectronics, photonics, biomedical, anti-corrosion, and catalysis, among others. This review provides a systematic elaboration of the structural, electrical, mechanical, optical, and thermal properties of h-BN followed by a comprehensive account of state-of-the-art synthesis strategies for 2D h-BN, including chemical exfoliation, chemical, and physical vapor deposition, and other methods that have been successfully developed in recent years. It further elaborates a wide variety of processing routes developed for doping, substitution, functionalization, and combination with other materials to form heterostructures. Based on the extraordinary properties and thermal-mechanical-chemical stability of 2D h-BN, various potential applications of these structures are described

A Cyclic Phosphoramidate Prodrug of 2'-deoxy-2'-fluoro-2'-C-methylguanosine for the Treatment of Dengue Infection

Monophosphate prodrug analogs of 2'-deoxy-2'-fluoro-2'-C-methylguanosine have been reported as potent inhibitors of hepatitis C virus (HCV) RNA-dependent RNA polymerase. These prodrugs also display potent anti-dengue activities in cellular assays although their prodrug moieties were designed to produce high levels of triphosphate in the liver. Since peripheral blood mononuclear cells (PBMCs) are one of the major targets of dengue virus, different prodrug moieties were designed to effectively deliver 2'-deoxy-2'-fluoro-2'-C-methylguanosine monophosphate prodrugs and their corresponding triphosphates into PBMCs after oral administration. We identified a cyclic phosphoramidate prodrug 17 demonstrating a well-balanced anti-dengue cellular activity and in vitro stability profiles. We further determined the PBMCs concentration of active triphosphate needed to inhibit 50% virus replication (TP50). Compound 17 was assessed in AG129 mouse model and demonstrated 1.6- and 2.2-log viremia reduction at 100 and 300 mg/kg BID, respectively. At 100 mg/kg BID, the terminal triphosphate concentration in PBMCs reached above TP50, demonstrating TP50 as the target exposure for efficacy. In dogs, oral administration of 17 resulted in high PBMCs triphosphate level, exceeding TP50 at 10 mg/kg. Unfortunately, two-week dog toxicity studies at 30, 100, and 300 mg/kg/day showed that No Observed Adverse Effect Level (NOAEL) could not be achieved due to pulmonary inflammation and hemorrhage. The preclinical safety results suspended further development of 17 Nevertheless, present work has proven the concept that an efficacious monophosphate nucleoside prodrug could be developed for the potential treatment of dengue infection