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Author Spotlight: Functionalizing Metal-Organic Frameworks: Advancements, Challenges, and the Power of Post-Synthetic Ligand Exchange
Published on: June 23, 2023
Boron-centered soft ligands based on tetrazole units and their complexes with sodium, potassium and bismuth ions
Muhammad Imran1, Andreas Mix, Beate Neumann
1Universität Bielefeld, Lehrstuhl für Anorganische Chemie und Strukturchemie, Centrum für Molekulare Materialien CM2, Universitätsstraße 25, 33615 Bielefeld, Germany. mitzel@uni-bielefeld.de.
Abstract:
The syntheses of Na(Ttt(Me)) (), K(Ttt(Me)) (), K(Btt(Me)) (), and Na(Btt(Ph)) () are reported, where (Ttt(Me))(-) and (Btt(R))(-) (R = Me, Ph) are tri- and di-substituted boron-centered soft ligands; they were produced by the reaction of NaBH4 and KBH4 with the corresponding tetrazole heterocycles: 1-methyl-5-thiotetrazole (L(1)H) and 1-phenyl-5-thiotetrazole (L(2)H). The syntheses of Na(Ttt(Me)) () and K(Ttt(Me)) () were carried out following Trofimenko's protocol. The anion (Ttt(Me))(-) is a typical Janus scorpionate ligand. Na(Ttt(Me)) () and Na(Btt(Ph)) () were reacted with Bi(CH3COO)3 to observe the coordination pattern of these ligands towards bismuth ions. These reactions afforded the complexes [Bi(Ttt(Me))2(CH3COO)] (), [Bi(L(2))2]2 (, ) and [Bi(L(2))3] (). The products were characterized by NMR spectroscopy, elemental analyses and mass spectrometry. Solid state structures were determined by X-ray diffraction of single crystals of , , , , , , and . M(Ttt(Me)) (M = Na (), K ()) and K(Btt(Me)) () exhibit sheet-like structures. The alkali metal complexes dissociate in solution as observed in (1)H, (13)C NMR and (1)H diffusion NMR experiments. Negative mode ESI-MS data also indicate the presence of monomers. Both the sodium salts of (Ttt(Me))(-) and (Btt(Ph))(-) as well as the Bi complexes and were investigated by absorption and emission spectroscopy.
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