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Luminescent metal–organic frameworks (LMOFs) are one of the most promising materials for being implemented as active layers in the fabrication of photonic devices such as luminescent sensors of harmful chemicals. It is highly desirable that these materials undergo quantifiable spectroscopic (absorption or emission) changes in the presence of vapors of those analytes, as in many industrial processes, these toxic compounds are in the gas phase. Although great progresses have been achieved in the field, in most of the examples reported hitherto, the detection of chemicals by LMOFs is attained in solution. Herein, we present a novel approach consisting of the encapsulation of proton transfer dyes (8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt, HPTS, and 3-hydroxyflavone, 3-HF) within the pores of two distinct MOFs. The trapped proton transfer dyes (PT-dyes) may exist as different structures (enol, anion, or zwitterion), each of these exhibiting unique optical properties. Indeed, our findings reveal that the dyes can be encapsulated as anionic or enol species. Remarkably, the PT-dye@MOF composites exhibit a high luminescence quantum yield (up to 30%), which is sensitive (showing shifting in the emission wavelengths with a concomitant quenching/enhancement of the intensity) in the presence of vapors of an acid (HCl) and a base (triethylamine). These results open a novel avenue for the development of smarter vapoluminescent MOF-based materials.

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El presente trabajo tiene tres partes claramente diferenciadas. En la primera de ellas, se contempla la evolución histórica del seguro hasta nuestros días. La segunda parte recoge el surgimiento del régimen de previsión social obligatoria, su nacimiento en el siglo XVII en el reino Unido, su evolución en Europa y en algunos países del resto del mundo. Existen dos corrientes del sistema de previsión social: Atlántico o universalista y el continental o individualista. La tercera parte se centra en el surgimiento de la Seguridad Social en España y la aparición del sistema de previsión social complementaria o Planes y Fondos de pensiones, haciendo especial reseña a su incidencia en variables biométricas, actuariales, sociales y financieras.<br /><br />The present paper is clearly divided in three main differentiated parts. The first one deals with the historical evolution of insurance up to the present times. The second part is about the appearance of the compulsory social security, its birth in the United Kingdom in 17th Century, its evolution in Europe and in some other countries of the world. There are two streams for the social security system: The Atlantic or universal and the continental or individualist. The third part is focused on the appearance of the health service in Spain and the appearance of a complementary social security system or pension funds and it emphasizes their impact on biometric, actuarial, social and financial variables