Bismuth Tri‐ and Tetraarylcarboxylates: Crystal Structures, In Situ X‐ray Diffraction, Intermediates and Luminescence

Abstract

A systematic investigation of the systems Bi(3+)/carboxylic acid/HNO3 for the tri- and tetracarboxylic acids pyromellitic acid (H4Pyr), trimellitic acid (H3Tri) and trimesic acid (H3BTC) acid led to the discovery of five new bismuth carboxylates. Structural characterisation allowed the influence of the linker geometry and the Bi(3+):linker molar ratio in the starting solution on the crystal structure to be determined. The crystallisation of three selected compounds was investigated by in situ energy-dispersive X-ray diffraction. Three new crystalline intermediates were observed within minutes, and two of them could be isolated by quenching of the reaction mixture. Their crystal structures were determined from laboratory and synchrotron X-ray powder diffraction data and allowed a possible reaction pathway to be established. In depth characterisation of the luminescence properties of the three bismuth pyromellate compounds was carried out. Fluorescence and phosphorescence could be assigned to (mainly) ligand- and metal-based transitions. The polymorphs of Bi(HPyr) exhibit different luminescence properties, although their structures are very similar. Surprisingly, doping of the three host structures with Eu(3+) and Tb(3+) ions was only successful for one of the polymorphs.

Synthesis, Transformation, Catalysis, and Gas Sorption Investigations on the Bismuth Metal–Organic Framework CAU‐17

“…To investigate the chemical stability of CAU‐17, 20 mg of the MOF were each stirred in different solvents for 24 h at room temperature, filtered and washed with methanol. The exposure to water and aqueous HCl/NaOH at different pH led to a (partial) structural transformation of CAU‐17 ([Bi(BTC)(H 2 O)]) into the dense pseudo‐polymorph [Bi(BTC)(H 2 O)] · H 2 O ( 4 ) or resulted in the full degradation of the CAU‐17 structure. However, in organic solvents, the structure was maintained in most stability tests.…”

“…In‐situ powder X‐ray diffraction (PXRD) has been an invaluable tool for understanding such crystallization processes . In an investigation of the synthesis mechanisms of bismuth trimesates hydrothermally synthesized in water in‐situ PXRD revealed rapid formation of the first crystalline product, followed by sequential transformations into a second and third crystalline phase after extended heating time . The evolution of the materials with heating time was elucidated by quenching the reaction to isolate the three individual phases for crystal structure determination .…”

“…In an investigation of the synthesis mechanisms of bismuth trimesates hydrothermally synthesized in water in‐situ PXRD revealed rapid formation of the first crystalline product, followed by sequential transformations into a second and third crystalline phase after extended heating time . The evolution of the materials with heating time was elucidated by quenching the reaction to isolate the three individual phases for crystal structure determination . In total, six crystalline bismuth trimesate structures have been reported thus far, and the large number of crystal structures that can be synthesized from the same combination of Bi 3+ and linker is attributed to the flexible coordination environment of Bi 3+ ions.…”

“…In total, six crystalline bismuth trimesate structures have been reported thus far, and the large number of crystal structures that can be synthesized from the same combination of Bi 3+ and linker is attributed to the flexible coordination environment of Bi 3+ ions. However, apart from CAU‐17, which is synthesized in methanol, the remaining five crystalline phases are dense nonporous materials …”

High-Performance Blue-Excitable Yellow Phosphor Obtained from an Activated Solvochromic Bismuth-Fluorophore Metal–Organic Framework

“…26 reported bismuth based MOFs (we were able to establish < 20). [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44] Notably, zur Loye and coworkers have reported a number of Bi coordination polymers and their fluorescence properties using pyridine dicarboxylate as ligand. [44][45][46][47][48] Stock, Cheetham and co-workers have also reported a small variety of interesting Bi-MOFs.…”