Abstract A theoretical analysis of free Gibbs Energy and NMR 1H 13C chemical shifts of the effect of introduce methyl groups on diphenyl rings, to produce different isomers of (E)-1-(α,Ꞵ-dimethylbenzylidene)-2,2-diphenylhydrazine, is presented. IR vibrational frequencies, Mulliken charges, molecular electrostatic potential (MEP), Gibbs free energy (G) and 1H- and 13C-NMR chemical shifts were obtained by theoretical calculations. In this analysis it was found that the position of the methyl group affects the values of the 1H- and 13C-NMR chemical shifts and the ∆G and ∆H thermodynamic properties of formation and reaction, these properties vary with the same trend, for the isomers studied. Gibbs free energy calculations show that the theoretical (E)-1-(3,4-Dimethylbenzylidene)-2,2-diphenylhydrazine isomer is the most stable, which explains the success of the experimental synthesis of this compound among the other isomers. For this molecule, the C of the HC=N group is the most nucleophilic and the H is the least acidic. The 1H-NMR chemical shifts of protons show a strong correlation with the C=N distance. It was also observed that methyl affects the ν(C=N) frequencies, the C=N distance increases when the inductive effect of the methyl groups is in the structure.

Résumé. Cet article, fondé sur les données d’une enquête de terrain réalisée de 2015 à 2017, propose de s’interroger sur les modalités de participation du Mexique à l’ensemble des processus nécessaires à la naissance d’un enfant quand elle se déroule avec plusieurs acteurs dans différents lieux. Il fait l’hypothèse que, pour comprendre le fonctionnement de ce marché mondial, il convient de considérer les conditions et les conjonctures politicosociales locales qui rendent possible le développement de l’offre tout comme sa régulation ou son interdiction, et en propose une analyse.

Abstract. Based on data ethnography carried out from 2015 to 2017, this article proposes to question the modalities of Mexico’s participation in all the processes necessary for the procreation of a child when it takes place with several actors in different places. He supports the hypothesizes that, in order to understand the functioning of this global market, it is necessary to consider the local politico-social conditions and conjunctures which make possible the development of the offer as well as its regulation or its prohibition, and proposes a interpretive analysis.

Resumen. Con base en una investigación de campo realizada entre 2015 y 2017, este artículo se pregunta sobre las modalidades de participación de México en el conjunto de procesos necesarios para la procreación de un niño cuando este involucra numerosos actores y diferentes países. Sostiene la hipótesis de que, para comprender el funcionamiento de ese mercado mundial, es importante considerar las condiciones y coyunturas político-sociales que hacen posible tanto el desarrollo de la oferta de gestación subrogada como su regulación o prohibición. Asimismo, propone un análisis interpretativo.