A Simple, Quick, and Precise Procedure for the Determination of Water in Organic Solvents

A procedure for the UV/VIS-spectroscopic determination of water by the use of a solvatochromic pyridiniumphenolate betaine is given. The water content of organic solvents is calculated by a two parameter equation from λmax of the dye. A typical, detection limit is of the order of 1 mg in 1 ml solvent for routine spectrometers. The parameters for the determination of water are given for a number of commonly used solvents

MOLECULAR INTERACTION BETWEEN BENZONITRILEAND HEXAMETHYLPHOSPHORIC TRIAMIDEBY 13CNMR T1RELAXATIONTIME STUDIES ANDAS INITIOQM CALCULATIONS: EXTENDED INVESTIGATION

ABSTRACT It has been obtained the anisotropy ratio a = Tdortho-,meta-13C)/Tdpara-13Co)f dilute solutions of bn change from 1.7 in fa solution and 1.5 in neat bn to 1.0 in HMPT. Thus the anisotropyratio comes out to be a = 1. In HMPT, obviously, solvent molecules cluster around Ph-C=N in such a way, that non-covalent interactions lead to isotropic reorientational motion like a spherical molecule. To conform with the T1times, a layer arrangement with at least two HMPT molecules per Ph-C=N seems to be likely. From computational quantum calculations of non-covalent intermolecular interactions and Mie potential analysis, the solute-solventmolecularpairs in bn.. .HMPThave almost equal interaction energies for the ortho, meta, and para configuration and the layered configurations are energeticallypermitted Keywords: 13CT1spin-lattice relaxation times, ab initio quantum chemistry calculations, intermolecular interactions, isotropic and anisotropic rotational motio