GRATITUDE ET BIEN-ÊTRE SOCIAL : MÉCANISMES EXPLICATIFS DES EFFETS DE LA GRATITUDE SUR LE BIEN-ÊTRE INDIVIDUEL ET COLLECTIF

La gratitude a été définie comme une émotion sociale agréable qui génère de nombreuses conséquences positives sur la santé physique, mentale et sociale par le biais d’une augmentation de la capacité à apprécier les expériences, à percevoir des bénéfices même en cas d’adversité, et à développer, maintenir et améliorer les relations sociales. Toutefois, loin d’être un état dont les effets ne bénéficieraient qu’à l’individu, la gratitude engendre également des effets bénéfiques pour autrui, notamment par le biais de son expression : l’expression de gratitude génère un sentiment d’utilité et de valeur sociale chez l’interlocuteur, augmentant par-là le bien-être psychologique. Au-delà du simple effet de contagion émotionnelle, la gratitude entraîne une amélioration réciproque des relations, ce qui favorise le maintien ou l’amélioration des relations sociales constructives, auxquelles le bien-être est étroitement lié. Les mécanismes explicatifs des liens entre gratitude et bien-être individuel et collectif sont présentés, ainsi que des perspectives de recherche et d’applications pratiques.Gratitude has been defined as a social emotion which generates numerous positive consequences on physical, mental and social well-being through the development of the ability to savor experiences, to find benefits even when facing adversity, and to develop, maintain, and increase positive relationships. However, far from leading to a state in which the effects would only benefit the individual, gratitude generates beneficial effects for others as well. Expressing gratitude generates feelings of social utility and social worth which positively impact psychological well-being of the receiving party. Beyond emotional contagion, through which relatives benefit from others’ positive emotions, gratitude opens a pathway that nurtures mutual positive relationships, thereby ensuring maintenance or increased well-being. The present article explains the mechanisms through which gratitude positively impacts individual and collective well-being, and presents further research and practical avenues

Suppressing Cyclic Polymerization for Isoselective Synthesis of High-Molecular-Weight Linear Polylactide Catalyzed by Sodium/Potassium Sulfonamidate Complexes

A new sodium/potassium crown ether complex system with a series of bichelating sulfonamides as ligands was developed for the ring-opening polymerization (ROP) of <i>rac</i>-lactide. In this system, the side reaction of cyclic polymerization can be suppressed very well because of very different ROP rates initiated by BnOH and sulfonamide anion. The synthesis of high molecular weight linear polylactide with molecular weight high up to 107 kg/mol was successful. The best isoselectivity also can reach to a high value of <i>P</i>_m = 0.84. The NMR analysis of the reaction mixture of <i>rac</i>-lactide and complex <b>3</b> together with kinetic studies suggests the mechanism of ROP in the absence of alcohol is a coordination–insertion mechanism. After addition of BnOH, the ROP rate can increase remarkably due to the cooperation interaction of alcohol and complex <b>3</b>

Suppressing Cyclic Polymerization for Isoselective Synthesis of High-Molecular-Weight Linear Polylactide Catalyzed by Sodium/Potassium Sulfonamidate Complexes

A new sodium/potassium crown ether complex system with a series of bichelating sulfonamides as ligands was developed for the ring-opening polymerization (ROP) of <i>rac</i>-lactide. In this system, the side reaction of cyclic polymerization can be suppressed very well because of very different ROP rates initiated by BnOH and sulfonamide anion. The synthesis of high molecular weight linear polylactide with molecular weight high up to 107 kg/mol was successful. The best isoselectivity also can reach to a high value of <i>P</i>_m = 0.84. The NMR analysis of the reaction mixture of <i>rac</i>-lactide and complex <b>3</b> together with kinetic studies suggests the mechanism of ROP in the absence of alcohol is a coordination–insertion mechanism. After addition of BnOH, the ROP rate can increase remarkably due to the cooperation interaction of alcohol and complex <b>3</b>

Suppressing Cyclic Polymerization for Isoselective Synthesis of High-Molecular-Weight Linear Polylactide Catalyzed by Sodium/Potassium Sulfonamidate Complexes

A new sodium/potassium crown ether complex system with a series of bichelating sulfonamides as ligands was developed for the ring-opening polymerization (ROP) of <i>rac</i>-lactide. In this system, the side reaction of cyclic polymerization can be suppressed very well because of very different ROP rates initiated by BnOH and sulfonamide anion. The synthesis of high molecular weight linear polylactide with molecular weight high up to 107 kg/mol was successful. The best isoselectivity also can reach to a high value of <i>P</i>_m = 0.84. The NMR analysis of the reaction mixture of <i>rac</i>-lactide and complex <b>3</b> together with kinetic studies suggests the mechanism of ROP in the absence of alcohol is a coordination–insertion mechanism. After addition of BnOH, the ROP rate can increase remarkably due to the cooperation interaction of alcohol and complex <b>3</b>

Alternating Sequence Controlled Copolymer Synthesis of α‑Hydroxy Acids via Syndioselective Ring-Opening Polymerization of <i>O</i>‑Carboxyanhydrides Using Zirconium/Hafnium Alkoxide Initiators

The ring-opening polymerization (ROP) of <i>O</i>-carboxyanhydrides (OCAs) can give diverse poly­(α-hydroxy acid)­s (PAHAs) with different functional groups because of easy modification of the side group of OCAs, which can extend applications of PAHAs widely. The stereoselective polymerization of <i>O</i>-carboxyanhydrides and further sequence controlled alternating copolymerization of OCAs were still big challenges until now for lack of suitable catalysts/initiators. In this work, a highly syndioselective ROP of OCAs system as the first stereoselective example in this area is reported using zirconium/hafnium alkoxides as initiators with the highest <i>P</i>_r value up to 0.95. Furthermore, these initiators were successfully applied in the precisely alternating sequence controlled copolymerization of PheOCA and Tyr­(Bn)­OCA, and alternating copolymerization of LacOCA and PheOCA was also achieved