Two isostructural 2D → 2D parallel → 3D inclined interpenetrating polycatenane-like metal-organic frameworks were successfully constructed based on length-adjusted tricarboxylate ligands. With the merit of being microporous, IFMC-10 can serve as host for encapsulating lanthanide cations and I(2) to exhibit luminescent sensing and rapid adsorption of iodine.

Four isomers formed by a gold atom attached to a pentacene molecule were investigated by density functional theory due to their potential applications in molecular electronics. The aim of our study is to shed light on the bonding nature and interaction between gold and carbon, to estimate the influence of gold atoms on the electronic spectrum of the pentacene, and to predict second-order nonlinear optical (NLO) properties. The results show that the gold and carbon atom of systems 1 and 2 can form a covalent bond, which has σ single-bond character. However, there are strong donor-acceptor interactions between gold and carbon of systems 3 and 4. The influence of the number of benzene rings on the bonding nature or interactions is also discussed. Adding a gold atom to the pentacene obviously changes the transition nature of pentacene and results in an increase in possible transition, especially for systems 3 and 4. These systems possess moderate molecular second-order polarizabilities compared with the organometallic and organic complexes. The β value of system 4 is greater than that of system 1. Thus, subtle variations in the molecular architecture result in substantial enhancement of the second-order NLO response. In view of high transparency and the moderate β values, our studied systems could become a kind of potential second-order NLO material.

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Crystal structure analysis of the zinc complex establishes it as a distorted octahedral complex, bis(3-methylpicolinato-kappa(2) N,O)(2)(1,10-phenanthroline-kappa(2) N,N)-zinc(II) pentahydrate, [Zn(3-Me-pic)(2)(phen)]x5H(2)O. The trans-configuration of carbonyl oxygen atoms of the carboxylate moieties and orientation of the two planar picolinate ligands above and before the phen ligand plane seems to confer DNA sequence recognition to the complex. It cannot cleave DNA under hydrolytic condition but can slightly be activated by hydrogen peroxide or sodium ascorbate. Circular Dichroism and Fluorescence spectroscopic analysis of its interaction with various duplex polynucleotides reveals its binding mode as mainly intercalation. It shows distinct DNA sequence binding selectivity and the order of decreasing selectivity is ATAT > AATT > CGCG. Docking studies lead to the same conclusion on this sequence selectivity. It binds strongly with G-quadruplex with human tolemeric sequence 5'-AG(3)(T(2)AG(3))(3)-3', can inhibit topoisomerase I efficiently and is cytotoxic against MCF-7 cell line.