Three-dimensional alkaline earth metal-organic framework poly[[μ-aqua-aqua-bis-(μ 3 -carba-moyl-cyano-nitro-somethanido)barium] monohydrate] and its thermal decomposition

• Published in: Acta crystallographica. Section E, Crystallographic communications Vol. 80; no. Pt 9; pp. 986 - 992
• Main Authors: Domasevitch, Kostiantyn V, Senchyk, Ganna A, Ponomarova, Vira V, Lysenko, Andrey B, Krautscheid, Harald
• Format: Journal Article
• Language: English
• Published: England International Union of Crystallography 01-09-2024
• Subjects: alkaline earth mof materials; barium; carbamoylcyanonitrosomethanide; crystal structure; nitroso-ligands; Research Communications; crystal structure; barium; nitroso-ligands; carbamoyl­cyano­nitro­somethanide; alkaline earth MOF materials
• ISSN: 2056-9890; 2056-9890
• DOI: 10.1107/S2056989024008375

In the structure of the title salt, {[Ba(μ
-C
H
N
O
)
(μ-H
O)(H
O)]·H
O}
, the barium ion and all three oxygen atoms of the water mol-ecules reside on a mirror plane. The hydrogen atoms of the bridging water and the solvate water mol-ecules are arranged across a mirror plane whereas all atoms of the monodentate aqua ligand are situated on this mirror plane. The distorted ninefold coord-ination of the Ba ions is completed with four nitroso-, two carbonyl- and three aqua-O atoms at the distances of 2.763 (3)-2.961 (4) Å and it is best described as tricapped trigonal prism. The three-dimensional framework structure is formed by face-sharing of the trigonal prisms,
μ-nitroso- and μ-aqua-O atoms, and also by the bridging coordination of the anions
carbonyl-O atoms occupying two out of the three cap positions. The solvate water mol-ecules populate the crystal channels and facilitate a set of four directional hydrogen bonds. The principal Ba-carbamoyl-cyano-nitro-somethanido linkage reveals a rare example of the inherently polar binodal six- and three-coordinated bipartite topology (three-letter notation
). It suggests that small resonance-stabilized cyano-nitroso anions can be utilized as bridging ligands for the supra-molecular synthesis of MOF solids. Such an outcome may be anti-cipated for a broader range of hard Lewis acidic alkaline earth metal ions, which perfectly match the coordination preferences of highly nucleophilic nitroso-O atoms. Thermal analysis reveals two-stage dehydration of the title compound (383 and 473 K) followed by decomposition with release of CO
, HCN and H
O at 558 K.