Two-step postsynthetic modifications of a dinuclear Zn(II) coordination compound: Investigating the stability of the coordination chromophore

Attempted two-step postsynthetic modifications (Click reaction and recrystallization) of a dinuclear Zn(II) coordination compound Zn2(OOC–C6H4–N3)4(quinoline)2 lead to the formation of a mononuclear Zn(II) compound – Zn(OOC–C6H4–C2HN3–COOCH3)2(quinoline)·DMSO. In this feasibility study, the relatively low stability of the coordination chromophore around Zn(II) in the starting material is evidenced by Hirshfeld surface analysis and results in the transformation of coordination chromophore during the postsynthetic reaction. Diffusion Ordered Spectroscopy NMR experiments confirmed that the intermediate complex Zn(OOC–C6H4–C2HN3–COOCH3)2 formed by Click reaction exists in the coordinated form in the solution phase despite the loss of the neutral ligand-quinoline. The final product Zn(OOC–C6H4–C2HN3–COOCH3)2·(quinoline)·DMSO with a mononuclear crystal structure was formed by recrystallizing the intermediate with presence of quinoline.