Electronic substituent effects in the electron impact mass spectrometry of 2-(arylazo)-4-phenylphenols.
A mass spectrometric study of a set of six novel 2-(arylazo)-4-phenylphenols 1-6 was performed. The electron impact spectra were acquired and analyzed for five of the compounds in order to establish a fragmentation pattern. The suggested pathways were investigated and confirmed by means of tandem mass spectrometry (MS/MS) experiments together with high-resolution accurate mass data. However, the sixth molecule, a sodium sulfonate salt, was studied using fast atom bombardment (FAB) ionization in positive and negative modes. In addition, some electronic substituent effects were investigated by analyzing Hammett-McLafferty linear free energy correlations for some peaks derived from the corresponding molecular ions. Also, the role of the O-H...N hydrogen bond present in the target compounds was analyzed. The roles of these H-bonds were consistent with the corresponding acidity constant values obtained experimentally as well as by theoretical quantum chemistry calculations using HF/6-31 + G(d,p) and B3LYP/6-31G(d,p). Some spectrometric data were correlated with topological properties derived from the atoms-in-molecules (AIM) theory.
Pérez-Caballero
Guadalupe
G
Facultad de Estudios Superiores Cuautitlán, Campo 1, Universidad Nacional Autónoma de México, Av. 1ro de Mayo s/n, Col. Santa María de las Torres, Cuautitlán Izcalli, Estado de México CP 54740. perezcg@servidor.unam.mx
Jiménez-Cruz
Federico
F
Matamoros
Pablo Hernández
PH
García
José Guadalupe
JG
Cortés-Guzmán
Fernando
F
Miranda
René
R