Crystal structure and Hirshfeld surface analysis of a conformationally unsymmetrical bischalcone: (1E,4E)-1,5-bis(4-bromophenyl)penta-1,4-dien-3- one

Abstract

Many publications have highlighted the rich diversity and potential of metal complexes for the design of novel therapeutic agents. The intrinsic nature of metal centres, characteristic coordination modes, accessible redox states and tuneable thermodynamic and kinetic properties allow metal complexes to offer potential advantages over organic agents alone. In addition, many researchers stated that “the ligands not only control the reactivity of the metal but also play critical roles in determining the nature of interactions involved in the recognition of biological target sites such as deoxyribonucleic acid (DNA) enzymes and protein receptors”. The great expansion of research in the coordination chemistry of nitrogen- and sulphur-containing ligands such as Schiff bases derived from thiosemicarbazones and dithiocarbazates has taken place during recent years. Schiff base metal complexes have played a prominent role in the development of coordination chemistry. This area of research has a wide spectrum, ranging from synthesis to application in many diverse fields. Schiff bases are condensation products of primary amines and aldehydes or ketones (e.g. RCH=NR’, where R and R’ may represents alkyl and/or aryl substituents) that have often been used as chelating ligands for preparation of complex compounds which are useful as catalysts, in various biological systems, polymers and dyes besides some uses as antifertility and enzymatic agents. Since this class of ligands possess both hard nitrogen and soft sulphur donor atoms, they are capable to act as good chelating agents for various metal ions. The flexibility and bioactivity of nitrogen and sulphur containing Schiff bases have also been associated with the presence of both imino (-N=CH-) and thioamino (-(C=S)-NH-) moieties in their structures. Coordination of such compounds with metal ions often enhances their activities. The low cost as well as the relatively easy preparation of Schiff base derivatives also provide a major attraction in creating novel leads that can be synthesized in a practical and step-economical fashion. In this work, di-p-methoxybenzalacetone have been synthesised using base catalysed Aldol condensation to synthesise Schiff base from the reaction with Sbenzyldithiocarbazate. Five novel metal complexes have been synthesised, fully characterised and their cytotoxicity have been tested against two types of bladder cancer cell lines the minimum-invasive human bladder cancer carcinoma cell line,RT112, and the invasive human bladder carcinoma cell line, EJ28, and two types of breast cancer cell lines.