S. Okouchi et al., HYDRATION OF AMINES, DIAMINES, POLYAMINES AND AMIDES STUDIED BY NMR, Journal of the Chemical Society. Faraday transactions, 92(11), 1996, pp. 1853-1857
Citations number
22
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
The spin-lattice relaxation times, T-1, of natural abundance (H2O)-O-1
7 have been measured for aqueous solutions of nine amines, five diamin
es, two polyamines and five amides, as a function of the concentration
at 25 degrees C. The water-accessible surface areas of the solute mol
ecules were calculated. The coordination number, n(h), and the rotatio
nal correlation times, tau(c)(0), of water molecules around the solute
molecules were estimated and compared with that of pure water tau(c)(
0). The value of tau(c)(h)/tau(c)(0) = 2.02 for tert-butylamine is the
largest and that of tau(c)(h)/tau(c)(0) = 0.97 for urea the smallest
obtained. The value of n(h) (tau(c)(h)/tau(c)(0)-1) was defined as the
dynamic hydration number (DHN). The partial molar volumes and the par
tial molar heat capacities for these homologues at infinite dilution a
re linearly dependent on their DHN.