Molecular Packing Dependent Solid State Fluorescence Response of Supramolecular Metal–Organic Frameworks: Phenoxo-Bridged Trinuclear Zn(II) Centered Schiff Base Complexes with Halides and Pseudohalides

Abstract

Molecular packing plays a key role in determining the photophysical properties in the aggregated state, but fine controlling of molecular packing is a great challenge. Here we report a series of new phenoxo-bridged homometallic trinuclear Zn (II) metal complexes (BN3, BNCS, BN(CN)2, BCl, BBr, and BI [complexes 1–6] having different anions with an aim to vary the photophysical properties of the complexes, where B stands for the ligand, N,N′-bis(3-ethoxysalicylidenimino)-1,4-diaminobutane. All the complexes are structurally characterized by single crystal X-ray diffraction technique. The crystallographic investigation indicates that the complexes contain two types of Zn (II) centers: distorted square pyramidal and octahedral. The crystal structures are stabilized by intermolecular hydrogen bonding and C–H---π interactions leading to distinct supramolecular frameworks. The ground state and excited state electronic properties of these metal complexes have been investigated. In solution state, all the metal co...