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Structure and NMR properties of the dinuclear complex di-?-azido-?⁴ N ¹:N ¹-bis-[(azido-?N)(pyridine-2-carboxamide-?² N ¹,O)zinc(II)].

ABSTRACT: The new diamagnetic complex, [Zn₂(N₃)₄(C₆H₆N₂O)₂] or [Zn₂(pca)₂(?_1,1-N₃)₂(N₃)₂] was synthesized using pyridine-2-carboxamide (pca) and azido ligands, and characterized using various techniques: IR spectroscopy and single-crystal X-ray diffraction in the solid state, and nuclear magnetic resonance (NMR) in solution. The mol-ecule is placed on an inversion centre in space group P . The pca ligand chelates the metal centre via the pyridine N atom and the carbonyl O atom. One azido ligand bridges the two symmetry-related Zn²⁺ cations in the end-on coordination mode, while the other independent azido anion occupies the fifth coordination site, as a terminal ligand. The resulting five-coordinate Zn centres have a coordination geometry inter-mediate between trigonal bipyramidal and square pyramidal. The behaviour of the title complex in DMSO solution suggests that it is a suitable NMR probe for similar or isostructural complexes including other transition-metal ions. The diamagnetic nature of the complex is reflected in similar ¹H and ¹³C NMR chemical shifts for the free ligand pca as for the Zn complex.

PROVIDER: S-EPMC7869550 | BioStudies |

REPOSITORIES: biostudies

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