Crystal structures, red-shifted luminescence and iodide-anion recognition properties of four novel D-A type Zn(ii) complexes.

Four D-A type Zn(ii) coordination complexes, [Zn(C29H29N3O2)·(CH3OH)]·(CH3OH) (1), Zn2(C74H90N6O4)·(CH3OH) (2), [Zn(C30H28N4O2)·(CH3OH)]·(CH3OH) (3) and [Zn(C38H44N4O2)·(C2H5OH)]·(C2H5OH) (4), were designed, synthesized, and studied. Their fluorescence properties in the solid state and in THF solution were comprehensively analysed based on their single-crystal structures. The results showed that the red-shift of fluorescence emission from complexes 1 to 4 was successfully achieved via the strategy of enhancing intramolecular charge transfer (ICT) effects by increasing the number of electron-pulling and pushing groups gradually. Meanwhile, because of the fluorescence recognition abilities of these four complexes towards iodide anions in THF, they could be regarded as potential fluorescent sensors for I- in this organic solution in the future.

Two novel MOF-74 analogs exhibiting unique luminescent selectivity.

Two MOF-74 analogs with OH groups on 1D channel surfaces have been synthesized through multi-component self-assembly at room temperature. Their guest-free forms demonstrate a potential luminescent probe or sensor for small molecules, and OH-MOF-74 (2a) also showed exceptional fluorescence quenching and enhancement behavior for different types of aromatic molecules.

In situ ligand and complex transformation of an iron(III) Schiff base complex: structural evidence and theoretical calculations.

A C-C coupling reaction has been achieved at room temperature by in situ ligand transformation. The iron(III) complexes before and after the in situ transformation, [FeNaL(1)(2)(H(2)O)(4)](2)·2H(2)O (1) (H(2)L(1) = (Z)-2-(2-hydroxyl)benzylideneamino) and [FeL(2)](2)·7.5H(2)O (2) (H(3)L(2) = (E)-2-(2-hydroxyl-benzylideneamino)-3-hydroxyl-3-(2-hydroxyphenyl), have been studied by elemental analyses, FT-IR, UV-vis, TGA and X-ray single crystal diffraction analysis. The proposed mechanism of this in situ transformation has been determined based on structural evidence and theoretical calculations using the density functional theory (DFT) M06 method.