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Hybrid organic-inorganic perovskites (HOIPs) occupy a prominent position in the field of materials chemistry due to their attractive optoelectronic properties. While extensive work has been done on the crystalline materials over the past decades, the newly reported glasses formed from HOIPs open up a new avenue for perovskite research with their unique structures and functionalities. Melt-quenching is the predominant route to glass formation; however, the absence of a stable liquid state prior to thermal decomposition precludes this method for most HOIPs. In this work, we describe the first mechanochemically-induced crystal-glass transformation of HOIPs as a rapid, green and efficient approach for producing glasses. The amorphous phase was formed from the crystalline phase within 10 minutes of ball-milling, and exhibited glass transition behaviour as evidenced by thermal analysis techniques. Time-resolved in situ ball-milling with synchrotron powder diffraction was employed to study the microstructural evolution of amorphisation, which showed that the crystallite size reaches a comminution limit before the amorphisation process is complete, indicating that energy may be further accumulated as crystal defects. Total scattering experiments revealed the limited short-range order of amorphous HOIPs, and their optical properties were studied by ultraviolet-visible (UV-vis) spectroscopy and photoluminescence (PL) spectroscopy., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The structure of a new ZIF-8 polymorph with quartz topology (qtz) is reported. This qtz-[Zn(mIm)2] phase was obtained by mechanically amorphising crystalline ZIF-8, before heating the resultant amorphous phase to between 282 and 316 °C. The high-temperature phase structure was obtained from powder X-ray diffraction, and its thermal behaviour, CO 2 gas sorption properties and dye adsorption ability were investigated.

Here we present efficient and scalable mechanochemical formation of hybrid organic-inorganic perovskites of the form [TPrA][M(dca) 3 ] (M = Mn 2+ , Co 2+ ) and the subsequent formation of their bulk melt-quenched glasses. In situ X-ray diffraction reveals direct, facile, and almost instantaneouos formation of both crystalline materials, while slow cooling limits recrystallisation in glasses. The glasses show good stability to acidic and basic aqueous solutions and display higher carbon dioxide uptakes than their crystalline precursors.

Four novel dicyanamide-containing hybrid organic-inorganic ABX 3 structures are reported, and the thermal behaviour of a series of nine perovskite and non-perovskite [AB(N(CN) 2 ) 3 ] (A = (C 3 H 7 ) 4 N, (C 4 H 9 ) 4 N, (C 5 H 11 ) 4 N; B = Co, Fe, Mn) is analyzed. Structure-property relationships are investigated by varying both A-site organic and B-site transition metal cations. In particular, increasing the size of the A-site cation from (C 3 H 7 ) 4 N → (C 4 H 9 ) 4 N → (C 5 H 11 ) 4 N was observed to result in a decrease in T m through an increase in Δ S f . Consistent trends in T m with metal replacement are observed with each A-site cation, with Co < Fe < Mn. The majority of the melts formed were found to recrystallise partially upon cooling, though glasses could be formed through a small degree of organic linker decomposition. Total scattering methods are used to provide a greater understanding of the melting mechanism., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Zeolitic imidazolate frameworks (ZIFs) can be melt-quenched to form glasses. Here, we present an alternative route to glassy ZIFs via mechanically induced amorphisation. This approach allows various glassy ZIFs to be produced in under 30 minutes at room temperature, without the need for melt-quenching.