Characterization, phase-solubility, and molecular modeling of inclusion complex of 5-nitroindazole derivative with cyclodextrins.
The slightly water-soluble 5-nitroindazole derivative (5-NI) and its inclusion with either beta-cyclodextrin (betaCD) or Heptakis (2,6-di-O-methyl)-beta-cyclodextrin (DMbetaCD) were investigated. The stoichiometric ratios and stability constants describing the extent of formation of the complexes were determined by phase-solubility measurements obtaining type-A(L) diagrams in both cases. According to the continuous variation method (Job's plot) a 1:1 stoichiometry has been proposed for the complexes. Also electrochemical studies were carried out on both CDs complexes, where the observed change in the E(PC) value for DMbetaCD indicated a lower feasibility of the nitro group reduction. The detailed spatial configuration is proposed based on two-dimensional NMR methods. These results are further interpreted using molecular modeling studies. The latter results are in good agreement with the experimental data.
Jullian
Carolina
C
Departamento de Química Orgánica y Fisicoquímica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Casilla 233, Santiago 1, Chile. cjullian@uchile.cl
Morales-Montecinos
Javier
J
Zapata-Torres
Gerald
G
Aguilera
Benjamín
B
Rodriguez
Jorge
J
Arán
Vicente
V
Olea-Azar
Claudio
C
D003198:Computer Simulation; D003505:Cyclodextrins / Q000737:chemistry*; D007191:Indazoles / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods / Q000592:standards; D008958:Models, Molecular; D015394:Molecular Structure; D044367:Phase Transition; D012015:Reference Standards; D012995:Solubility; D014867:Water / Q000737:chemistry
D003505:Cyclodextrins; D007191:Indazoles; D014867:Water; C530840:5-nitroindazole