Mechanics, Ionics, and Optics of Metal–Organic Framework and Coordination Polymer Glasses

Abstract

Melt and glassy states of coordination polymers (CPs)/metal−organic frameworks (MOFs) have gained attention as a new class of amorphous materials. Many bridging ligands such as azolate, nitrile, thiocyanide, thiolate, pyridine, sulfonate, and amide are available to construct crystals with melting temperatures in the range of 60−593 °C. Here, we discuss the mechanism of crystal melting, glass structures, and mechanical properties by considering both experimental and theoretical studies. High and exclusive H + or Li + conductivities in moldable CP glasses have been proven in the all-solid-state devices such as fuel cells or secondary batteries. Transparent glasses with wide composition and available dopants are also attractive for nonlinear optics, photoconductivity, emission, and light-harvesting. The ongoing challenge in the field is to develop the design principles of CP/MOF melts and glasses, corresponding functions of mass (ion, electron, photon, phonon, and so forth). transport and conversion, and the integration of devices with the use of their tunable mechanical properties.

Assembling metal–organic cages as porous materials

“…These requirements apply to porous materials, which are used in a myriad of applications such as sensing, optics, fine molecular separations, catalysis, and energy storage and conversion. [2][3][4] As well as classical porous materials including zeolites and activated carbons, metal-organic frameworks (MOFs) are of great importance. The pore size and shape found in the two-or threedimensional extended structures of MOFs are tunable through the use of modular building blocks (metal clusters and organic linkers).…”

Exploration of glassy state in Prussian blue analogues

“…The recent emergence of a new direction toward glass and liquid metal-organic framework/coordination polymers (MOF/ CPs) has opened up a new opportunity for discovering unique properties that deviate from the crystalline norm and as a pathway to developing new materials [17][18][19] . Thus far, only a few CPs and MOFs have shown the capability to undergo the glass transformation process.…”

Photoluminescent coordination polymer bulk glasses and laser-induced crystallization

“…Glassy coordination polymers (CPs) and metal-organic frameworks (MOFs) have been of interest as a new class of amorphous materials. [1][2][3][4] Their structure and properties are distinct from conventional glasses and are controlled by the combination of metal ions and bridging molecular ligands. In addition, the non-crystalline, high processability, and adhesive characteristics have gained research interest in both fundamental behaviors as well as applications such as ion conductive solid electrolytes, gas separation membranes, and electrochemical catalysis.…”