title: Push-pull 1,3-thiazolium-5-thiolates. Formation via concerted and stepwise pathways, and theoretical evaluation of NLO properties.
abstract: The transformation of münchnones (mesoionic rings featuring the 1,3-oxazolium-5-olate core) into their sulfur counterparts (1,3-thiazolium-5-thiolates) by reaction with CS(2), pioneered by Huisgen and his group in the early 1970s, has been re-investigated in detail by means of both experimental and theoretical methods. The synthetic strategy can be tuned to incorporate donor and acceptor groups in appropriate positions. Calculations of molecular hyperpolarizabilities together with orbital topologies evidence that these sulfur-containing heterocycles exhibit nonlinear optical responses, thereby pointing to potential applications of mesoionic structures in the NLO field. From a mechanistic viewpoint, modeling of the whole systems at the B3LYP/6-31G(d) level reveals that concerted and stepwise pathways are operative depending on the substitution pattern of the parent münchnone, which also account for the experimental results.
authors.affiliation: Departamento de Química Orgánica e Inorgánica, QUOREX Research Group, Facultad de Ciencias, Universidad de Extremadura, E-06006, Badajoz, Spain. dcannie@unex.es
authors.forename: David
authors.initials: D
authors.lastname: Cantillo
authors.forename: Martín
authors.initials: M
authors.lastname: Avalos
authors.forename: Reyes
authors.initials: R
authors.lastname: Babiano
authors.forename: Pedro
authors.initials: P
authors.lastname: Cintas
authors.forename: José L
authors.initials: JL
authors.lastname: Jiménez
authors.forename: Mark E
authors.initials: ME
authors.lastname: Light
authors.forename: Juan C
authors.initials: JC
authors.lastname: Palacios
authors.forename: Valentín
authors.initials: V
authors.lastname: Rodríguez