Reactions between copper(I) iodide and triphenylphosphine have been explored in solution and in the solid state and six luminescent coordination complexes have been obtained and characterized by X-ray diffraction and UV-vis spectroscopy and photophysics. Solid-state reactions of CuI with PPh₃ in different conditions (kneading, vapour digestion) and stoichiometries resulted in the formation of high ratio ligand : metal compounds while tetrameric structures could be obtained only by solution reactions. Crystal structures were determined by single crystal X-ray diffraction while purity of the bulk product was checked by powder diffraction (XRPD). Three different tetrameric structures with 1 : 1 stoichiometry have been synthesized: two closed cubane-type polymorphs [CuI(PPh₃)]₄ (form 1a) and [CuI(PPh₃)]₄ (form 1b) and an open step-like isomer [CuI(PPh₃)]₄ (form 2). The conversions between the polymorphs and isomers have been studied and characterized by XRPD. The most stable form [CuI(PPh₃)]₄ (form 1b) can convert into the open step-like isomer [CuI(PPh₃)]₄ (form 2) in a slurry experiment with EtOH or CH₂Cl₂ or AcCN and converts back into [CuI(PPh₃)]₄1b when exposed to vapors of toluene. At room temperature all the tetrameric compounds exhibit luminescence in the solid state and, notably, the two polymorphs show a dissimilar dual emission at low temperature. The luminescence features in the solid state seem to be peculiarly related to the presence of the aromatic phosphine ligand and depend on the Cu–Cu distance in the cluster.

Channel expansion of flexible molecular architectures endowed with porosity has been proved to be responsive to gas stimuli, such as pressurized CO₂, CH₄, Xe and hydrocarbons.

Time resolved in situ (TRIS) monitoring has revolutionised the study of mechanochemical transformations but has been limited by available data quality. Here we report how a combination of miniaturised grinding jars together with innovations in X-ray powder diffraction data collection and state-of-the-art analysis strategies transform the power of TRIS synchrotron mechanochemical experiments. Accurate phase compositions, comparable to those obtained by ex situ measurements, can be obtained with small sample loadings. Moreover, microstructural parameters (crystal size and microstrain) can be also determined with high confidence. This strategy applies to all chemistries, is readily implemented, and yields high-quality diffraction data even using a low energy synchrotron source. This offers a direct avenue towards the mechanochemical investigation of reactions comprising scarce, expensive, or toxic compounds. Our strategy is applied to model systems, including inorganic, metal-organic, and organic mechanosyntheses, resolves previously misinterpreted mechanisms in mechanochemical syntheses, and promises broad, new directions for mechanochemical research.

Solid-state reactions of copper(I) iodide with 1,4-diazabicyclo[2.2.2]octane (DABCO) and piperazine in different conditions (kneading, vapour digestion, thermal treatment) resulted in the formation of four new luminescent systems, which have been characterized viaX-ray diffraction and photo-luminescence spectroscopy. At room temperature all compounds exhibit a bright emission in the solid state that markedly shifts bathochromically on cooling to 77 K. The luminescence of the almost isostructural 2D-coordination polymers [Cu₂I₂(L)₂]_∞ (L = DABCO, piperazine) exhibits an unusually long lifetime (125 and 53 μs, respectively), which becomes even longer (609 and 420 μs, respectively) at 77 K.