From Stimuli-Responsive Polymorphic Organic Dye Crystals to Photoluminescent Cationic Open-Framework Metal Phosphate

Abstract

Four photoluminescent dye crystals, TPB-n (n = 1-3) and TPCH, have been synthesized in isolation from carbon-carbon coupling of 4,4'-trimethylene-dipyridine (tmdp) in the absence of organic solvent and catalyst via in situ one-pot metal/ligand oxidative-dehydrogenation reactions. Large crystals have been obtained and readily separated from reaction products without the need for purification. Their structures were characterized: TPB and TPCH represent two dissimilar oxidized forms of tmdp dimers; TPCH was less oxidized but accompanied with partial hydrolysis with molecular formula further confirmed by FAB-MASS analysis. They exhibit distinct photoluminescence (PL) with quantum efficiency measured up to 42%. TPB-2 and TPB-3 are two polymorphic dihydrates, stimuli-responsive toward photoluminescence color changes; both can transform to TPB-1 upon gentle heating. Importantly, the three TPB-n crystals establish the first tetrapyridyl-type ligands adapted by metal phosphates to create a cationic luminescent framework, NTHU-12. This study serves as an inspiring route beyond conventional C-C bond formation reactions and has generated four tmdp dimers in isolation. The facile syntheses have resulted in ample production of a rare type of tetrapyridyl ligands, leading to the discovery of the first positively charged hybrid topology in nanoporous solids. The features of the four luminescent tmdp dimers and NTHU-12 embodied in synthesis, structure, and optical property are reported.

Mechanochromic Luminescence of Copper Iodide Clusters

“…In this context,t he study of crystalline polymorphs [18] show different emission properties can give as traightforward correlation between the molecular structure andt he optical properties . [19][20][21][22][23][24][25][26] Therefore, obtaining crystalline polymorphs of am echanochromic luminescentc ompound appearst ob ea n efficient approacht oe lucidate the factors responsible for the mechanochromism. This strategy has been rarely reported in the literature for organics [27] and even lessf or metal-based compounds.…”

New 3 D Tubular Porous Structure of an Organic–Zincophosphite Framework with Interesting Gas Adsorption and Luminescence Properties

“…In one case, a two‐dimensional zinc phosphate had a dual role of a tetraimidazol‐type ligand (one role as a tetradentate bridging linker and a second role as a bidentate bridging ligand) in its structure . In the other case, another tetrapyridyl‐type ligand adaptable to metal phosphites was used to generate a 3D network with rectangular channels occupied by carboxylate molecules . However, in our case, the title compound is the first example of inorganic zincophosphite chains being interlinked through 1,2,4,5‐tetrakis(imidazol‐1‐ylmethyl)benzene tetraimidazol‐type linkers to form a tubular porous framework with unusual hybrid channels.…”

Metal Phosphides and Phosphates‐based Electrodes for Electrochemical Supercapacitors

“…The term “phosphate” refers to oxyanions of pentavalent phosphorus, which ranges from the simple PO 4 3− through ring and chain anions to infinite networks . Owing to the variations in their structural assembles, the large number of cations to which they can coordinate, and the presence of additional anions or molecules, metal phosphates occur in large diversity . Transition metals phosphates demonstrate variations in valence states and/or coordination numbers .…”

“…[55] Owing to the variations in their structural assembles, the large number of cations to which they can coordinate, and the presence of additional anions or molecules, metal phosphates occur in large diversity. [56,57] Transition metals phosphates demonstrate variations in valence states and/or coordination numbers. [58][59][60] Several of the transition metal phosphates, as an open-framework solid with large channels and cavities, are shown to possess excellent ion/charge conductivity, and have thus been studied as pseudocapacitive electrodes.…”