Bis(mu(3)-barbiturato-O,O,O ')-(mu(2)-aqua)- aqua-barium(II): crystal structure, spectroscopic and thermal properties

Solovyov, Leonid A.; Golovnev, Nicolay N.; Molokeev, Maxim S.; Lesnikov, Maxim K. JOURNAL OF COORDINATION CHEMISTRY, 70 (12):1984-1993; Doi: 10.1080/00958972.2017.1319943 2017

A polymeric coordination compound, [Ba(H2O) 2(Hba)2] (1) (H2ba – barbituric acid, C4H4N2O3), was obtained. The structure of 1 was solved using powder X-ray diffraction methods. The Ba2+ ion in 1 formed a three-capped trigonal prism. The BaO9 polyhedra, connected with each other by the edges and faces, formed a chain. Several 4- and 12-membered cycles due to the bridging μ2-H2O and bridging μ3-Hba also formed implementing a 3-D polymer structure. The structures of 1 and other thiobarbiturate complexes were compared. The replacement of a S atom by an O atom in the heterocyclic ligand Htba (thiobarbiturate ion) of the compound Ba(H2O)2(Htba)2 resulted in changes of the coordination number Ba(II) and supramolecular structure. The intermolecular hydrogen bonds O–H⋯O and N–H⋯O formed a 3-D net where pronounced 2-D layers of Hba ions could be found. A new topological net in 1 was observed. The IR and thermal stability were investigated.

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