A brief review on structural concepts of novel supramolecular proton transfer compounds and their metal complexes

Our research group has been interested in synthesis of proton transfer compounds as new supramolecular synthons for the one-pot preparation of self-assembled transition metal complex-organo-networks since 2000. We have focused on the proton delivery from acids, which are considered as suitable proton donors, to amines as proton acceptors. The results were production of several proton transfer ion pairs possessing some remaining donor site's applied for coordination to metallic centers in preparation of metal-organic structures. Some of the complexes showed contributions of both cationic and anionic fragments of the starting ion pair, while some others contained only one of these species as ligand. Much of the investigations on reviewed compounds focused on the concept of supramolecular systems, co-crystallization, stereochemically active lone pairs, coordination polyhedron and mainly on various interactions involve including van der Waals, ion pairing, hydrogen bondings, face to face pi-pi stackings and edge to face C-H center dot center dot center dot pi, C-O center dot center dot center dot pi, N-H center dot center dot center dot pi, S-O center dot center dot center dot pi, Ti center dot center dot center dot pi and Hg-Cl center dot center dot center dot pi interactions. The mentioned interactions are the most commonly used strategies in the extension of supramolecular structures.