Synthetic Amino Acids for Programming Adaptive Response in Pyrazolate Peptide Frameworks

Achieving chemical stability and conformational flexibility within adaptive porous materials built from peptide bonds and amino acid chemistry remains a significant challenge in framework design. Here, we introduce an alternative synthetic platform that employs bispyrazolate amino acid dipeptides, enabling the integration of short, conformationally flexible peptides into pyrazolate frameworks built from rigid rod-type [Zn(μ₂-Pz)₂] secondary building units. The nature of the amino acid side chain dictates both the dimensionality and adaptive response of the resulting networks, allowing the controlled assembly of either three-dimensional (MUV-A) or layered two-dimensional (MUV-F and MUV-Y) architectures. Solvent-induced transformations reveal a continuum of dynamic responses, ranging from highly flexible reopening in MUV-A to solvent-selective switching in MUV-Y, governed by the interplay between backbone conformational freedom and host–guest interactions. This work establishes a general synthetic platform to program the dynamic behavior of chemically robust peptide-based frameworks, bridging reticular design with programmable adaptive porosity.