Tetrel bonding interactions at work: Impact on tin and lead coordination compounds

A tetrel bond can be defined as an interaction between any electron donating moiety and a group 14 element acting as Lewis acid. Experimental and theoretical research on this interaction has rapidly grown in recent years. A reason for that is related to the fact that it can be easily exploited to design supramolecular structures. This review is devoted to highlight the role of heavier tetrel atoms (tin and lead) as promising building blocks for the construction of supramolecular assemblies and supramolecular MOFs based on tetrel bonding interactions. In the case of tin, the number of investigations on this topic is limited, therefore we also provide a survey of crystal structures retrieved from the Cambridge Structural Database where this interaction is crucial for the crystal packing stability. We have subdivided this part taking into consideration the atom or group of atoms acting as lone pair donor atom (O, S, N, halogen) and also the intra- or intermolecular nature of the interaction. This survey evidences that close contacts between Sn and lone-pair-possessing atoms are quite common and oriented along the extension of the covalent bond formed by the Sn and the most electron-withdrawing substituent. Moreover, it provides experimental evidence of the ability to act as electrophilic site (tetrel bond donor). This ability has a prominent role upon the conformations and the packing of Tin organic derivatives in the solid state. For Pb(IV) organic compounds, where the geometry around the metal center is tetrahedral we also provide a survey of crystal structures retrieved from the Cambridge Structural Database. To our knowledge, this type of analysis in Pb(IV) is unprecedented in the literature. For Pb(II), we have selected several works where the tetrel bonding interaction is used as a robust tool in crystal engineering and supramolecular chemistry. (C) 2019 Elsevier B.V. All rights reserved.