title: A new nuclear magnetic resonance algorithm to determine equilibrium constants of the species in the B(III)-H2O system.
abstract: Several efforts have been attempted to study species formation by Nuclear Magnetic Resonance (NMR) in systems with several chemical equilibria present. The majority of these are qualitative and only a few have tried to relate component fractions of a distribution diagram with experimental area fractions determined from NMR spectra to obtain equilibrium constants values. In this work we present a new focus that attempts to relate the species concentration fractions in the system with area fractions beneath NMR peaks to achieve this task. 11B-NMR data of B(III)-H2O systems have been processed with the aid of formation constant values (-log *beta) obtained by potentiometry which are 9.17+/-0.01 for B(OH)3, 9.79+/-0.08 for B2O(OH)5-, 19.90+/-0.09 for B3O3(OH)4- and 38.50+/-0.04 for B5O6(OH)4-, form B(III)-H2O systems with 0.075 M< or = [B(III)]total< or = 0.700 M, in agreement with previous reports and NMR behavior. The treatment of NMR data developed in this work gives a new methodology to obtain formation constants and suggests the possibility to establish a generalization of Beer's law to NMR spectroscopy.
authors.affiliation: Facultad de Estudios Superiores Cuautitlán (UNAM), Sección Química Analítica, Campo Uno, Av. 1o de Mayo s/n, 54740, Cuautitlán-Izcalli, Mexico.
authors.forename: J C
authors.initials: JC
authors.lastname: Botello
authors.forename: E
authors.initials: E
authors.lastname: Morales-Domínguez
authors.forename: J M
authors.initials: JM
authors.lastname: Domínguez
authors.forename: A
authors.initials: A
authors.lastname: Gutiérrez
authors.forename: A
authors.initials: A
authors.lastname: Rojas-Hernández
authors.forename: M T
authors.initials: MT
authors.lastname: Ramírez
mesh_terms: D000465:Algorithms; D001895:Boron / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000706:statistics & numerical data*; D008956:Models, Chemical; D011199:Potentiometry; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D001895:Boron