Anion-assisted supramolecular assemblies of zinc(II) complexes with isonicotinamide. Issue 7 (July 2022)

• Record Type: Journal Article
• Authors: Soldin, Željka; Kukovec, Boris-Marko; Debač, Tamara; Đaković, Marijana; Popović, Zora
• Is Part Of: Heliyon. Volume 8:Issue 7(2022)
• Publication Date: 2022-07
• Subjects: Anion-assisted assembly -- Coordination polyhedron -- Isonicotinamide -- Zinc(II) -- Amide-amide homosynthon; Research -- Periodicals; Medical sciences -- Periodicals; Natural history -- Periodicals; Social sciences -- Periodicals; Earth sciences -- Periodicals; Physical sciences -- Periodicals; 507.2
• DOI: 10.1016/j.heliyon.2022.e09943
• Languages: English
• ISSNs: 2405-8440

Abstract

Abstract: Five zinc(II) coordination compounds, [ZnCl2 (isn)2 ] (1 ), [ZnBr2 (isn)2 ] (2 ), [Zn(NO3 )2 (H2 O)(isn)2 ] (3 ), [Zn(CH3 COO)2 (isn)]2 (4 ) and [Zn(isn)4 (H2 O)2 ](ClO4 )2 (5 ) (isn = isonicotinamide), were prepared by the reactions of the isonicotinamide (pyridine-4-carboxamide, isn) and corresponding zinc(II) salts. Their crystal structures were determined by the single-crystal X-ray diffraction method. The coordination environment of zinc(II) is tetrahedral in the compounds containing small halide anions (chloride, bromide), 1 and 2 . An expansion of the zinc(II) coordination environment to the octahedral is observed in the presence of the monodentate and bridging nitrate ions in 3. The coordination environments of both zinc(II) ions in dimeric acetate complex 4 is also enlarged in the comparison with 1 and 2, one zinc(II) ion being octahedrally coordinated and the other being pentacoordinated. The zinc(II) ion in 5 also reaches higher coordination environment (octahedral), which is enabled by binding of additional water molecules, since the perchlorate ion is uncoordinated. The supramolecular amide-amide homosynthon R 2 2 ( 8 ) is preserved in the presence of halide, nitrate and acetate ions (1 –4), but it is completely disrupted in the crystal packing of 5 due to the presence of the bulky perchlorate anion. Spectroscopic analysis of compounds 1–5 was performed by IR spectroscopy in the solid state and by 13 C NMR spectroscopy in the DMSO solutions. The NMR data support a complete decomposition of 3 in the DMSO solution, but 1, 2, 4 and 5 remain unchanged in the solution. Thermal properties of the coordination compounds were also investigated by TGA and DSC methods. Graphical abstract: Image 1 Abstract : Anion-assisted assembly; Coordination polyhedron; Isonicotinamide; Zinc(II); Amide-amide homosynthon