No abstract

To understand the influence of the methyl group in the stability and conformational behavior of the piperidine ring, the standard (p 0 ) 0.1 MPa) molar enthalpies of formation of 1-methylpiperidine, 3-methylpiperidine, 4-methylpiperidine, 2,6-dimethylpiperidine, and 3,5-dimethylpiperidine, both in the liquid and in the gaseous states, were determined at the temperature of 298.15 K. The numerical values of the enthalpies of formation in the liquid and in the gaseous state are, respectively, -(95.9 ( 1.6) and -(59.1 ( 1.7) kJ‚mol -1 for 1-methylpiperidine; -(123.6 ( 1.4) and -(79.2 ( 1.6) kJ‚mol -1 for 3-methylpiperidine; -(123.5 ( 1.5) and -(82.9 ( 1.7) kJ‚mol -1 for 4-methylpiperidine; -(153.6 ( 2.1) and -(111.2 ( 2.2) kJ‚mol -1 for 2,6-dimethylpiperidine; and -(155.0 ( 1.7) and -(105.9 ( 1.8) kJ‚mol -1 for 3,5-dimethylpiperidine. In addition, and to be compared with the experimental results, theoretical calculations were carried out considering different ab initio and density functional theory based methods. The standard molar enthalpies of formation of the four isomers of methylpiperidine and of the 12 isomers of dimethylpiperidine have been computed. The G3MP2B3-derived numbers are in excellent agreement with experimental data, except in the case of 2,6-dimethylpiperidine for which a deviation of 9 kJ‚mol -1 was found. Surprisingly, the DFT methods fail in the prediction of these properties with the exception of the most approximated SVWN functional.

Static bomb calorimetry, Calvet microcalorimetry and the Knudsen effusion technique were used to determine the standard molar enthalpy of formation in the gas phase, at T = 298.15 K, of the indole and indoline heterocyclic compounds. The values obtained were 164.3 +/- 1.3 kJ x mol(-1) and 120.0 +/- 2.9 kJ x mol(-1), respectively. Several different computational approaches and different working reactions were used to estimate the gas-phase enthalpies of formation for indole and indoline. The computational approaches support the experimental results reported. The calculations were further extended to the determination of other properties such as bond dissociation enthalpies, gas-phase acidities, proton and electron affinities and ionization energies. The agreement between theoretical and experimental data for indole is very good supporting the data calculated for indoline.

Although the quality of parent-adolescent emotional bonds has consistently been proposed as a major influence on young adult's psycho-emotional functioning, the precise means by which these bonds either facilitate or impede adaptive coping are not well-understood. In an effort to advance this inquiry, the present study examined interrelationships among measures of parental attachment, emotion regulation processes, and preferred coping strategies within a sample of 942 college freshmen. Structural Equation Modelling was used to test whether the link between attachment to parents and the use of particular coping strategies is mediated by differences in emotion regulation mechanisms. As hypothesized, differences in attachment to parents predicted differences in the use of emotion regulation mechanisms and coping strategies. More specifically, having a close emotional bond, feeling supported in autonomy processes and having (moderately) low levels of separation anxiety toward parents predict more constructive emotion regulation mechanisms and coping strategies. Additionally emotion regulation was found to (partly or totally) mediate the association between attachment and coping. Keywords: attachment to parents, coping, emotion regulation, emerging adults, structural equations modelling.Aunque la calidad de los lazos emocionales entre padres y adolescentes siempre ha sido propuesta como una importante influencia en el funcionamiento psico-emocional del adulto joven, los mecanismos precisos por los cuales estos lazos facilitan o impiden el afrontamiento adaptativo no son bien conocidos. En un esfuerzo por avanzar en esta indagación, el presente estudio examinó las interrelaciones entre las medidas de apego parental, los procesos de regulación emocional, y las estrategias preferidas de afrontamiento en una muestra de 942 estudiantes de primer año de universidad. Para probar si la relación entre el apego a los padres y el uso de determinadas estrategias de afrontamiento está mediada por las diferencias en los mecanismos de regulación emocional, se utilizaran Modelos de Ecuaciones Estructurales. Como fue hipotetizado, las diferencias en el apego a los progenitores se demostraron predictivas de diferencias en el uso de los mecanismos de regulación emocional y estrategias de afrontamiento. Más específicamente, tener un vínculo afectivo cercano con los padres, sentir su apoyo en los procesos de autonomía y sentir niveles (moderadamente) bajos de ansiedad de separación hacia los progenitores, son condiciones predictivas de mecanismos de regulación emocional y estrategias de afrontamiento más constructivos. Además, se encontró en la regulación emocional un mediador (total o parcial) para la asociación entre el apego y el afrontamiento. Palabras clave: apego a los padres, afrontamiento, regulación emocional, adultos emergentes, modelos de ecuaciones estructurales.