Crystal Engineering Across Tetrel Bonds in Donor-Acceptor Complexes with Triphenyltin Chloride and Various Phosphorus Compounds

Abstract

Supramolecular chemistry is a field of study that focuses on the design, synthesis, and characterization of large molecular assemblies held together by non-covalent interactions. One of the latest developments in this field is the concept of tetrel bonding, which is a type of non-covalent interaction between an electron-deficient atom from the group of 14 elements (carbon, silicon, germanium, tin, and lead) and a Lewis base. The nature of tetrel bonding is electrostatic, and it can lead to the formation of supramolecular assemblies with unique properties and functions. The use of tetrel bonding as an alternative to traditional hydrogen bonding in supramolecular chemistry has recently gained significant attention, given its potential applications in materials science, catalysis, and drug delivery. Thus, the primary objective of this project is to prepare novel tetrel-bonded cocrystals using heavier pnictogens such as phosphorus as electron donors. Multiple attempts were made to achieve the intended objective. One of the initial experiments involved the slow evaporation process of triphenyltin chloride and triphenylphosphine, resulting in the formation of our first novel cocrystal. Subsequently, a second experiment utilized triphenyltin chloride and cyclohexyldiphenylphosphane, leading to the creation of our second novel cocrystal. To further investigate, cocrystal 1 underwent analysis through powder X-ray diffraction (PXRD) and Nuclear Magnetic Resonance (NMR) techniques. These analyses confirmed the presence of the first-ever purposely engineered cocrystal featuring a tetrel bond between tin and phosphorus, marking a noteworthy development in our exploration of molecular interactions.