Hypercoordinate compounds of the Group 14 elements containing κ n - C,N- , C,O -, C,S - and C,P - ligands

•3 Center–4 electron bonding leads to hypercoordinated group 14 compounds.•Detailed synthetic routes to hypercoordinate group 14 compounds are described.•Structural and NMR evidence for κn-C,N- and C,O-ligands bound to group 14 metal centers presented.•The NMR resonances of 4- and 5-coordinate group 14 compounds are compared.