title: Supramolecular phosphate transfer catalysis by pillar[5]arene.
abstract: A kinetic study on dinitrophenylphosphate monoester hydrolysis in the presence of a cationic pillararene, P5A, has been carried out. Formation of the supramolecular complex between phosphate ester and P5A has been studied by NMR showing complexation-induced upfield proton shifts indicative of aromatic ring inclusion in the pillararene cavity. Molecular dynamic calculations allow structure characterization for the 1 : 1 and 1 : 2 complexes. As a result of the supramolecular interaction both the acidity of DNPP and its hydrolysis rate constants are increased. Catalysis results from combination of both electrostatic stabilization reducing the negative electron density on the PO3(=) oxygens and monoester dianion destabilization by the steric effects of close NMe3(+) groups hindering the hydrogen-bonding with water and destabilising the monoester dianion.
authors.affiliation: Departamento de Química, Universidade Federal de Santa Catarina, Florianópolis, SC 88040-900, Brazil.
authors.forename: Daiane G
authors.initials: DG
authors.lastname: Liz
authors.affiliation: Departamento de Química, Universidade Federal de Santa Catarina, Florianópolis, SC 88040-900, Brazil.
authors.forename: Alex M
authors.initials: AM
authors.lastname: Manfredi
authors.affiliation: Departamento de Química, Universidade Federal de Santa Catarina, Florianópolis, SC 88040-900, Brazil.
authors.forename: Michelle
authors.initials: M
authors.lastname: Medeiros
authors.affiliation: Facultad de Química, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Santiago, Chile.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Montecinos
authors.affiliation: Departamento de Química Física, Centro de Investigaciónen Química Biológica y Materiales Moleculares (CIQUS), Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
authors.forename: Borja
authors.initials: B
authors.lastname: Gómez-González
authors.affiliation: Departamento de Química Física, Centro de Investigaciónen Química Biológica y Materiales Moleculares (CIQUS), Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Garcia-Rio
authors.affiliation: Departamento de Química, Universidade Federal de Santa Catarina, Florianópolis, SC 88040-900, Brazil.
authors.forename: Faruk
authors.initials: F
authors.lastname: Nome