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Reticular chemistry has In the post-synthetic modification (PSM) of frameworks one of the most versatile tools to adapt the systems' physicochemical properties to the specific requirements which are imposed by their application in different contexts. We can safely say that PSM methodologies in all their variants are currently one of the main resources that reticular chemists turn to when they need to diversify a framework compositionally. Practically all these modifications require the integration of functional groups appended to the organic linkers in the framework, either by direct synthesis or by post-synthetic exchange. The reactivity of these tags allows, at a subsequent stage, covalent modification of the framework under conditions that ideally respect its structural integrity. In this perspective article we introduce the use of tetrazine-based linkers as intrinsically tagged alternatives to integrate PSM with click chemistry reactivity. This strategy is ideally suited to molecular frameworks, as it combines very mild modification conditions with direct control over the organisation of built-in appendices and the acknowledged potential of click chemistry to build framework libraries. [ABSTRACT FROM AUTHOR]

The soft nature of Metal-Organic Frameworks (MOFs) sets them apart from other non-synthetic porous materials. Their flexibility allows the framework components to rearrange in response to environmental changes, leading to different states and properties. The work extends this concept to titanium frameworks, demonstrating control over charge transport in porous molecular crystals. MUV-35 is a two-fold catenated framework composed of heterometallic TiMn 2 trimers and electron donor 4,4',4″-(benzo[1,2-b:3,4-b':5,6-b″]trithiophene-2,5,8-triyl)tribenzoic acid (H 3 BTTTB) linkers, forming a rare sit-c net topology that can fold to reduce its volume by ≈40% through a single-crystal transformation controlled by linker conformation in open, intermediate, and closed states. This process, driven by a free energy difference of ≈300 kJ mol -1 , originates from the formation of a continuous network of non-covalent interactions that force the spontaneous loss of the solvent in the pores of the framework to establish charge transport pathways that afford photocurrents of 2.5 × 10 -3  S m -1 under visible light for an ON/OFF ratio (∆R) of four orders of magnitude. This photoconductivity rivals the best conductivity values described for though-transport conductive MOFs while maintaining a porosity of ≈1.000 m 2  g -1 ., (© 2025 Wiley‐VCH GmbH.)