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This paper examines whether laws requiring oil and gas firms to disclose the chemicals used in their fracking operations affect the mortgage lending activity for properties located in nearby areas. I hypothesize and find that the disclosure mandate reduces uncertainty about the value of housing collateral and subsequently increases (1) the probability of obtaining a mortgage by 2.5 percentage points (pp), and (2) loan-to-value by 2.2 pp. My main analyses exploit the variation in the location of properties relative to fracking wells. Cross-sectional tests that exploit heterogeneity in drinking water sources and the content of firm disclosures further substantiate my inferences and mitigate endogeneity concerns. These findings suggest that disclosure regulation for oil and gas firms affects housing collateral values, thereby impacting the mortgage market. JEL Classifications: G14; G21; G32; G38; K22; L71; M41; M48. [ABSTRACT FROM AUTHOR]

The aim of this study was to understand the role of the intermolecular hydrogen bond interactions present in paracetamol hydrochloride monohydrated salt. Paracetamol hydrochloride monohydrate salt (PRA-HCl) and paracetamol (form I) were investigated via vibrational (FT-IR and FT-Raman) spectroscopy and density functional theory (DFT) to gain insight into the hydrogen bond patterns present in these crystalline materials. Two different density functionals, wB97X-D and M062X, were used for the comparison of the results. The geometrical parameters of PRA-HCl and form I obtained using these functional were compared with the crystallographic data, which proved the existence of intra-molecular and intermolecular hydrogen bonds. The C10=O2 group of form I forms an intramolecular hydrogen bond, while the O1–H18 group of PRA-HCl forms an intermolecular hydrogen bond with a chloride ion (Cl−), resulting in the elongation of the bond length and shift to a lower wavenumber for the O1–H18 group. To examine the potency of hydrogen bonding, quantum theory of atoms in molecules (QTAIM) calculations were performed and the results suggested that O1–H18…Cl22 is a strong intermolecular hydrogen bond. The chemical reactivity parameters reveal that the PRA-HCl and PRA-OXA cocrystals are more reactive and softer (low HOMO–LUMO energy gap) in comparison to paracetamol (form I). [ABSTRACT FROM AUTHOR]

Investigations of structural reactivity, molecular interactions and vibrational characterization of pharmaceutical drugs are helpful in understanding their behaviour. The aim of this study is to determine the molecular, electronic and chemical properties of the antibiotic drug nitrofurantoin (NF), after cocrystallisation with 3-aminobenzoic acid (3ABA) and to understand how those changes lead to variation of properties in the cocrystal NF–3ABA. NF–3ABA formation is explained by stabilization via the hydrogen-bond network between NF and 3ABA molecules. It is thoroughly characterized by IR, Raman and CP-MAS solid-state 13C NMR techniques, along with quantum chemical calculations. The results of IR, Raman, and 13C NMR analyses showed that imide N–H23 and C12=O of NF interact with the acid C=O and –OH groups in 3-ABA, respectively. Therefore the IR, Raman, and 13C NMR spectra verified the formation of N–H…O and O–H…O hydrogen bonds. To study hydrogen bonding interactions theoretically in NF–3ABA, two functionals B3LYP and wB97X-D have been used. A comparison is made between the results obtained by B3LYP and those predicted at the wB97X-D level. It is found that wB97X-D is best applied density functional theory (DFT) functional to describe the hydrogen bonding interactions. The strength and nature of hydrogen bonding in NF–3ABA have been analysed by quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) analysis. To validate the results obtained by QTAIM theory and to study the long-range forces, such as van der Waals interactions, the steric effects in NF–3ABA, the reduced density gradient (RDG) and the isosurface have been plotted using Multiwfn software. QTAIM and isosurface analysis suggested that the hydrogen bonding interactions present in NF–3ABA are moderate in nature. The calculated HOMO–LUMO energy gap shows that NF–3ABA is more active than NF and 3ABA. Chemical reactivity descriptors are calculated to understand the various aspects of pharmacological sciences. Chemical reactivity parameters show that NF–3ABA is softer and chemically more reactive than NF. The results suggest that cocrystals can be a feasible alternative for positively changing the targeted physicochemical properties of an active pharmaceutical ingredient (API). [ABSTRACT FROM AUTHOR]

A newly synthesized four-ring bent-core liquid crystal (BCLC) has been studied using experimental and quantum chemical approach. Differential scanning calorimetry (DSC), polarised optical microscopy (POM), and X-ray investigations were carried out to identify the phase transitions and associated phases. DSC along with POM revealed four phase transitions i.e. Cr → SmX → SmC → NcybC→ Iso in the temperature range from 30 °C to 180 °C. The existence of smectic C like fluctuations also known as cybotactic groups in the broad temperature range of the nematic phase was confirmed by small angle X-ray diffraction. Conformational and vibrational analyses have been performed using density functional theory (DFT), to identify the most stable conformer having a bent shape. Analysis of the potential energy surface (PES) for different torsional angles revealed the most probable conformational states for the BCLC. Temperature dependent Fourier transform infrared (TD-FTIR) spectroscopy is used to study phase transitions and revealed marked changes in the spectral line shape especially the vibrations of OH, CH2, CH3, C=O, and HC=N groups during the SmC → NcybC phase transition above ∼95 °C. A good agreement between the calculated and observed infrared spectra validates the structure of this conformer that has been used for further studies. [ABSTRACT FROM AUTHOR]

Ampicillin 6[D (−) α-amino-phenyl-acetamido] penicillanic acid (AMP) is a β-lactam antibiotic that is active against both gram-positive and gram-negative. Due to industrial and biological importance of β-lactam antibiotics, an extensive quantum chemical study on AMP was carried out. The theoretical ground-state geometry and electronic structure of AMP are optimised by the DFT/B3LYP/6-311++G(d,p) method and compared with those of the crystal data. Four conformers have been found by potential energy surface scan. Among them, the geometry of the conformer-IV matches well with the experimental value, so we proceed with it. Natural bond orbital analysis has been used to analyse the stability of the molecule arising from hyperconjugative interactions and charge delocalisation. HOMO and LUMO have been plotted and analysed in order to describe the chemical reactivity of the molecule. MEP for these conformers shows that the negative potential is visualised over the O41 atom of C=O group of the molecule. Molecular docking studies show that the title molecule exhibits an antibacterial activity. The interpretation of diverse aspects of chemical bonding has been done by computing global and local reactivity descriptors. The variation of thermodynamic properties (such as C°p, m, S°m, H°m) with temperature has been studied theoretically. The present work will be helpful to systematically understand the structures and the electronic properties of AMP for studying the structure–activity relationship and to develop new drugs and their analytical methods. [ABSTRACT FROM PUBLISHER]

Abstract: Thin films of a-Se80Te20− x Cu x (where x=2, 6, 8 and 10) were deposited on glass substrates by vacuum evaporation technique. The absorbance, reflectance and transmittance of as-deposited thin films were measured in the wavelength region 400–1000nm. The optical band gap and optical constants of amorphous thin films have been studied as a function of photon energy. The optical band gap increases on incorporation of copper in Se80Te20− x Cu x system. The value of refractive index (n) decreases while the value of the extinction coefficient (k) increases with increasing photon energy. The results are interpreted in terms of concentration of localized states. [Copyright &y& Elsevier]

Abstract: The crystallization kinetics of Se80Te20−x Zn x with x =0.5, 1.0, 1.5, 2.0 and 2.5 chalcogenide glasses were investigated using non-isothermal crystallization approach. The glass transition temperature (T g ) and crystallization temperature (T c ) of these glasses were determined using the differential scanning calorimeter at different heating rates. The dependence of T g and T c on the heating rate (β) has been used for the determination of the activation energy of crystallization (E c), the activation energy of structural relaxation (E t), crystallization enthalpy (ΔH c) and the Avrami exponent (n). It was found that the enthalpy released is minimum at 2.5% of Zn, hence, the glass with 2.5% of Zn is most stable in the Se80Te20−x Zn x system. The crystallization kinetics for the glasses was studied by using the modified Kissinger and Ozawa equations. [Copyright &y& Elsevier]

Abstract: Results of differential scanning calorimetric (DSC) under non-isothermal condition of bulk amorphous semiconducting alloys of Se80Te20− x Cu x (x=2, 4, 6, 8 and 10) glasses with different heating rates are reported and discussed. The glass transition temperature, crystallization temperature at different heating rates and structural change during glass transition have been determined from an empirical relation. The dependence of the glass transition temperature (T g), crystallization temperature (T c), the activation energy for structural relaxation (ΔE t), the activation energy of crystallization (ΔE c) and the order parameter (n) are calculated at different heating rates. On the basis of the obtained experimental data, the temperature difference T c−T g is found to be maximum for Se80Te16Cu4 glass, which indicates that this glass is the thermally most stable in the composition range of investigation. [Copyright &y& Elsevier]