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We synthesized a (1‐propylpyridinium)2[ReN(CN)4]‐type organic–inorganic hybrid exhibiting water‐vapor‐induced drastic structural changes of the [ReN(CN)4]2− assemblies. Specifically, upon exposure to water vapor, dehydrated nitrido‐bridged chains were converted to hydrated cyanido‐bridged tetranuclear clusters via rearrangements of large molecular building units in the crystals. These switchable assembly forms display substantially different photo‐physical properties, although in both cases the emission is caused by a metal‐centered d–d transition. The nitrido‐bridged chain exhibited a near‐infrared (749 nm) emission, which blue‐shifted as the temperature increased, while a visible (561 nm) emission and its red shift was demonstrated by the cyanido‐bridged cluster. [ABSTRACT FROM AUTHOR]

A luminescent three-dimensional coordination polymer (CP) of [CdII(pmd){AgI(CN)2}2] (1; pmd = pyrimidine) comprising two different coordination modes of Ag+ ions was synthesised herein. 1 exhibited thermochromic luminescence, accompanied by positive thermal elongation of the Ag⋯Ag distance. Moreover, 1 showed a bright phosphorescence with the highest photoluminescence quantum yield (Φem), approximately 60% at room temperature, among previously reported phosphorescent Ag-based CPs or metal–organic frameworks. [ABSTRACT FROM AUTHOR]

This study reports the facile syntheses of tetra‐boron difluoride (tetra‐BF2) complexes, flag‐hinge‐like molecules that exhibit intense green‐to‐orange luminescence in solution and yellow‐to‐red emission in the solid states. Single‐crystal structure analysis and density functional theory calculations suggested a bent structure of this series of compounds. The complexes also exhibited excellent optical properties, with quantum yields reaching 100 % and a large Stokes shift. These properties were attributed to the altered bending angle of the molecule in the S1 excited state. As the rotational motion was suppressed around the 2,2′‐bipyrrole axis, atropisomers with axial chirality were formed, which are optically resolvable into (R) and (S)‐enantiomers through a chiral column. The atropisomers thus function as circularly polarized luminescent (CPL) materials, in which the color (green, green‐yellow, and yellow) can be varied by controlling the aggregation state. This rational design of multi‐BF2 complexes can potentially realize novel photofunctional materials. [ABSTRACT FROM AUTHOR]

A ReV complex demonstrates methanol selective luminescent color changes from red to green together with enhancements of the corresponding luminescence quantum yields twenty-three times. These characteristic responses are caused by the switching of the characters of the emissive states from metal-to-ligand charge transfer to d–d transition along with a single-crystal-to-single-crystal ligand exchange reaction. [ABSTRACT FROM AUTHOR]