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The hydrogen bonds involving sulfur in the furfuryl mercaptan monohydrate are compared with the interactions originating from the hydroxyl group in furfuryl alcohol. The dimers with water were created in a supersonic jet expansion and characterized using microwave spectroscopy and supporting molecular orbital calculations. In furfuryl alcohol-water, a single isomer is observed, in which the water molecule forms an insertion complex with two simultaneous hydrogen bonds to the alcohol (O-H⋅⋅⋅O ) and the ring oxygen (O -H⋅⋅⋅O ). When the alcohol is replaced by a thiol group in furfuryl mercaptan-water, two isomers are observed, with the thiol group preferentially behaving as proton donor to water. The first isomer is topologically equivalent to the alcohol analog but the stronger hydrogen bond is now established by water and the ring oxygen, assisted by a thiol S-H⋅⋅⋅O hydrogen bond. In the second isomer the sulfur group accepts a proton from water, forming a O -H⋅⋅⋅S hydrogen bond. Binding energies for the mercaptan-water dimer are predicted around 12 kJ mol weaker than in the alcohol hydrate (B3LYP-D3(BJ)). The non-covalent interactions in the furfuryl dimers are dominantly electrostatic according to a SAPT(0) energy decomposition, but with increasing dispersion components in the mercaptan dimers, which are larger for the isomer with the weaker O -H⋅⋅⋅S interaction.

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El desarrollo de habilidades científicas requiere de un razonamiento adecuado que debe fundamentarse en un corpus de conocimientos de contenido, procedimentales y epistémicos de la ciencia. Sin embargo, actualmente es habitual que en la práctica docente se sigan enseñando y evaluando en el aula sólo conocimientos de contenido -al margen de los otros dos mencionados-desconectados de todo contexto que permita un verdadero desarrollo de la competencia científica. Para identificar estos conocimientos y favorecer la confluencia con sus habilidades en algunos contextos es necesario que el docente disponga de recursos que faciliten su comprensión. A partir de una extensa revisión bibliográfica, se generó una base de ítems PISA que fueron caracterizados y categorizados a partir de las habilidades específicas que evalúan y los tipos de conocimientos que utilizan. En este trabajo, se presenta el análisis de algunos de los ítems PISA liberados que se corresponden con la subcompetencia Evaluar y diseñar la investigación científica, con el fin de poder ser utilizados por el docente como herramienta de reconocimiento, autoaprendizaje y retroalimentación de los conocimientos y habilidades científicas que lo orienten a una mejor comprensión de la competencia científica y que a su vez se vean reflejados en los procesos de aprendizaje de sus estudiantes. PISA items as a tool for teachers in identifying scientific knowledge and skillsThe development of scientific skills requires adequate reasoning that must be based on a body of content, procedural and epistemic science knowledge. However, it is now a common teaching practice to continue teaching and focusing only on content knowledge -apart from the two previously mentioned-disconnected from any context that allows for true development of scientific competence. To identify this knowledge and to promote the confluence of these skills it is necessary in some contexts that the educational resources be available to facilitate its understanding. From an extensive literature review, a base of PISA items that were characterized and categorized from assessing specific skills and types of knowledge used was generated. This paper presents the analysis of some of the items released by PISA that correspond to the competence Evaluate and Design Scientific Research, with the explicit goal of it being used by teachers as a tool for recognition, self-learning and feedback of knowledge and scientific skills to guide them to a better understanding of scientific compet ence and which, in turn, are reflected in the learning processes of their students.

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