Substantiation to structure-property of pyrazine-based compounds by undeniable impress of its different connectivities

In this review, we explain how pyrazine (hereafter as pz) leds to various structures spanning from multicomponent molecular crystals to coordination polymers. An important factor in the study of pz-based compounds is the crucial roles of the non-covalent interactions; we examined it with pz-based cocrystals and salts and also show that how purposeful selection of ligands with various functional groups can influence the physico-chemical property of the final structures. Furthermore, the CSD analysis revealed that due to the N,N'-exo-bidentate nature of pz, the probability of polymeric compounds are much more than the dimers and monomers counterparts. We also showed that pz-based coordination polymers (CPs) can be categorized into two groups; i) CPs that expanding with only pz ligand into 1D to 3D structures. ii) CPs that are constituted from pz and some auxiliary ligands in which pz linked 2D layers and created porous extended CPs and metal organic frameworks (MOFs). We presented important applications of pz-based compounds in the spin crossover systems. Finally, this review summarized some structural features of pz ligand that are useful for the design and preparation of new materials, serving as a reference in learning more about this particular area which inspired new researchers. (C) 2019 Elsevier B.V. All rights reserved.