1. Molecular niobium(V) complexes with mononuclear {Nb1} and dinuclear oxo species {Nb2O} connected through aryl di- or tetra-carboxylate linker.
- Author
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Andriotou, Despoina, Duval, Sylvain, Trivelli, Xavier, Volkringer, Christophe, and Loiseau, Thierry
- Subjects
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NIOBIUM , *X-ray powder diffraction , *LIGANDS (Chemistry) , *MOLECULES , *COORDINATION polymers , *NUCLEAR magnetic resonance spectroscopy - Abstract
Several aryl polycarboxylic ligands (pyromellitic acid, 4,4′-azobenzenedicarboxylic acid and 3,3′,5,5′-azobenzenetetracarboxylic acid) have been used to react with the pentavalent ethoxide niobium(V) precursor Nb(OEt)5. Three new crystalline molecular compounds (1 with pyromellitate, 2 with 4,4′-azobenzenedicarboxylate and 3 with 3,3′,5,5′-azobenzenetetracarboxylate) were isolated from slow crystallization at room temperature from the mother liquid containing the precursor Nb(OEt)5. They are composed of one polycarboxylate ligand fully coordinated to mononuclear or dinuclear octahedrally-coordinated niobium(V) units. For the dimers, the two adjacent niobium centers are bridged by one μ-O and one μ-OEt groups and complexed by only one of the syn–syn bidentate carboxylate function arms from the polytopic ligand. Compounds 1–3 were characterized in solid state by single-crystal and powder X-ray diffraction analysis. Insight into the formation of the three compounds was supported by the help of infrared and liquid 1H NMR spectroscopy. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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