In Situ Assembled Polynuclear Zinc Oxo Clusters Using Modified Schiff Bases as Ligands

[Image: see text] A series of different cores and nuclearity zinc metal clusters 1–5 have been synthesized using Zn(ClO(4))(2)·6H(2)O, Schiff-base primary ligands, and dibenzoyl methane (DBM) or monoethanolamine (MEA) as co-ligand in a room-temperature reaction. The structure of the complexes is characterized using single-crystal X-ray diffraction. Among them, (1) [Zn(L1)(DBM)] is mononuclear; (2) [Zn(4)(L2)(2)(DBM)(4)], (3) [Zn(4)(L2)(4)(H(2)O)(2)(ClO(4))(2)]·2CH(2)Cl(2), and (4) [Zn(4)(L3)(2)(DBM)(4)] have a cubane core; and (5) [Zn(4)(L4)(4)(MEA)(2)(ClO(4))(2)] has a ladderlike core structure. Compounds 1–5 have also been characterized using UV–vis absorption and emission spectroscopies. For an in-depth understanding of the absorption spectra of 1 and 3, density functional theory (DFT) calculations have been performed, which suggest that the transitions correspond to the π → π* intraligand charge transfer (ILCT) transitions.