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M. M. Unterlass, H. Moura:
"Designing High-Perfomance Dyes@Zeolites by Green Hydrothermal Route: Pathways and Challenges";
Talk: 31. Deutsche Zeolith-Tagung, Technische Universität Dresden; 2019-03-06 - 2019-03-08.

The design of photoactive organic-inorganic hybrid materials (HMs) for energy conversion shows promising possibilities when high-performance dyes are hosted by molecular sieves. High-performance dyes show excellent photoelectronic properties besides their high thermal and chemical stability, light and weather fastness, durability and color strength. Incorporating such dyes into an inorganic nanoporous material has to date been largely limited to hybrid supramolecular structures.1
However, most of the techniques for the incorporation of functionality into a molecular sieve are based on post-synthetic reactions of preformed components. This usually leads to partial pore blocking and poor control of location and geometry of the active phase. Moreover, aggregation and poor dispersibility of at least one of the components in the final HMs occur as drawback. Also, the classical procedures for the preparation of the organic dyes employ multistep reactions using expensive and environmentally toxic solvents and catalysts and tedious purifications.
To overcome these challenges, we have been developed a novel and green synthetic strategy that allows the condensation of the inorganic and organic components simultaneously. Hydrothermal synthesis (HTS) is a well-established technique to generate various inorganic compounds such as zeolites. HTS is environmentally friendly as it uses nothing but water and the starting compounds and very recently2,3 we showed that organic high-performance dyes can also be prepared by the same method.
With this contribution, we discuss the achievements and drawbacks of the preparation of photoactive hybrid materials, combining the synthesis of organic dyes and inorganic zeolites in one-single step by HTS. Through a rational synthesis design, we report the synergic effects between the condensation of organic and inorganic
phases, overcoming the limit of each component and achieving enhanced properties, regarding their (i) crystallization, (ii) ordered porosity, (iii) thermal and chemical stability and (iv) dispersion of the organic dyes in the inorganic zeolite structures. The precise control over the assembly of both phases is expected to propel this field further into new realms of synthetic chemistry in which far more sophisticated dye@zeolite materials may be achieved.