We engineered a dynamic hydrogen-bonded “molecular straitjacket” in the zero-dimensional antimony chloride (H2cpp)(Hfa)SbCl6 via a mixed-cation strategy. In-situ variable-temperature single-crystal diffraction directly reveals that this network contracts within a specific thermal window, forcing a structural rigidification of the luminescent octahedron. This simultaneously suppresses non-radiative loss (leading to emission enhancement, ATQ) and attenuates exciton-lattice coupling (causing a spectral blueshift). This work provides atomistic insights and a design blueprint for rationally engineering stimuli-responsive luminescent materials through dynamic supramolecular interfaces .

In this work, we designed and synthesized two new 3-D pillared metal–organic frameworks (MOFs) [Cd2(adc)2(bpp)3∙4H2O]n (1) and [Cd2(adc)2(bpp)3]n (1b) with a 2-D breathing mode of reversible dehydration–rehydration. The dynamic behavior between 1 and 1b was detected by in situ single-crystal XRD analysis, which demonstrated that this 3-D pillared MOF contracted and expanded in two dimensions accompanied by dehydration–rehydration. Additionally, 1b exhibited faster water vapor response compared to commercial silica gel desiccant at normal temperature (21 °C) and humidity (RH% 50), which was detected by in situ IR. Therefore, the results suggests that this kind of flexible 3-D pillared metal–organic framework of 1 and 1b would be a reliable sensor for monitoring water vapor. (H2adc = 4,4’-azodibenzoic acid, bpp = 1,3-di(4-pyridyl)propane)