Investigation of supramolecular assemblies, Hirshfeld surfaces and DFT analyses, and fluorescence properties of three newly synthesized multinuclear Co(II), Ni(II) and Zn(II) complexes.

Three new complexes 1 – 3 coordinated to a more flexible salamo-based ligand have been successfully prepared and characterized structurally. The structure of the complex 3 is novel, and self-assemblied by a more flexible salamo-based ligand. • Three complexes have been successfully prepared. • These complexes have been characterized structurally. • Due to the flexibility of ligands, the structure of complex 3 is more unique. Three new multinuclear complexes, [{CoL(MeOH)(μ -OAc)} 2 Co]·6CH 3 OH (1) [{NiL(H 2 O)(μ -OAc)} 2 Ni]·6CH 3 OH·0.442H 2 O (2) and [{Zn 2 L 2 (μ -OH)} 2 ]·2NH(CH 2 CH 3) 3 ·4CH 3 OH·H 2 O (3) , based on a more flexible salamo-based ligand H 2 L containing coumarin functional groups have been synthesized and characterized structurally. The complex 1 is trinuclear, and all Co(II) atoms have octahedral geometries. A similar trinuclear complex 2 involving three Ni(II) atoms with hexa -coordinated octahedral geometries was obtained. For the complex 3 , it is a novel symmetric tetranuclear structure, and four Zn(II) atoms have penta -coordinated trigonal bipyramidal geometries. It is worth noting that the intramolecular self-assembly is achieved by changing the flexibility of salamo-based ligand in the complex 3. In addition, fluorescence titration experiments of the three complexes were carried out. The supramolecular structures of the three complexes were constructed via intermolecular hydrogen bond or π-π stacking interactions, and Hirshfeld surfaces analyses and DFT calculations were performed on the three complexes. [ABSTRACT FROM AUTHOR]