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The growing interest of industry in the field of bi(hetero)arenes compounds, motivated us to synthesize these compounds via homogeneous catalytic route by using Pd PEPPSI-type complexes through direct arylation. In this work, the five new Pd PEPPSI-type complexes bearing NHC spectator ligands were synthesized and characterized by a bunch of spectroscopic techniques. Further confirmations of structural details were provided by a single crystal X-ray diffraction study of one pro-ligand and one complex. All these newly synthesized Pd-carbene complexes were found significantly active as catalysts toward direct arylation of five members heterocyclic compounds such as n-propylthaizole, 2-acetylfurane and 2-acetylthiophene with aryl bromides derivatives. These catalysts give significantly good results within two hours with just 1 mol % catalyst loading.

The goal of our research is to synthesis homogeneous catalysts, for which we take start from two novel precursors of 1-(3-methyloxetane-3-yl)benzimidazole and 5,6-dimethyl-1-((3-methyloxetane3-yl)benzimidazole. A series of ligands containing 1,3-disubstituted benzimidazolium salts were synthesized from the corresponding precursors to form N-heterocyclic carbene (NHC) ligands. Furthermore, four new Pd(NHC)-PEPPSI type complexes were synthesized from these ligands. The structure elucidation of all the synthesized ligands, and complexes was confirmed by various spectroscopic techniques such as NMR, FT-IR. The compounds 1b, 2b, 3a, 3d were confirmed by the X-ray technique. All these complexes were found significantly active as catalysts toward the C-C cross-coupling reaction. (c) 2021 Elsevier B.V. All rights reserved.

A series of different substituted terpyridine-based ligands have been synthesized by Kröhnke method. Their binding behaviour was evaluated by complexing them with Co(II), Fe(II), and Zn(II) ions which resulted in interesting coordination compounds with formulas, [Zn(mttpy)2]PF6, [Co(mttpy)2](PF6)2, [Fe(mttpy)2](PF6)2 and interesting spectroscopic properties. Their absorption and emission behaviours in dilute solutions were investigated in order to explain structure–property associations and demonstrate the impact of different aryl substituents on the terpyridine scaffold as well as the role of the metal on the complexes. Photo-luminescence analysis of the complexes in acetonitrile solution revealed a transition from hypsochromic to bathochromic shift. All the compounds displayed remarkable photo-luminescent properties and various maximum emission peaks owing to the different nature of the functional groups. Furthermore, the anti-microbial potential of ligands and complexes was evaluated with docking analyses carried out to investigate the binding affinity of terpyridine-based ligands along with corresponding proteins (shikimate dehydrogenase and penicillin-binding protein) binding sites. To obtain further insight into molecular orbital distributions and spectroscopic properties, DFT calculations were performed for representative complexes. The photophysical activity and interactions between chromophore structure and properties were both investigated experimentally as well as theoretically.