Reaction of 1a with 2-6-dimethylphenylisocyanide for 3 h at 25 °C in benzene led to selective formation of the bis(imine) complex 2a derived from a 2:1 reaction stoichiometry (Scheme 1). Insertion of the isocyanide occurs exclusively at only one of the two possible types of hydride sites in 1a. 2a was characterised by diagnostic resonances in the 1 H NMR spectrum (C6D6) at  = 8.83 (s) and 3.38 (s) ppm each integrating to 2H and assigned to the CH=NAr imine proton and unreacted hydride ligands respectively. The former resonance shows a cross-peak in the HSQC data to a C resonance at  = 157.7 ppm assigned to the CH=NAr imine carbon atom. In the solid-state, 2a retains a tetrametallic structure with the dinucleating ligands templating a close arrangement of four magnesium atom in an approximate tetrahedral arrangement (Figure ). The newly formed imine ligands adopt a  2 -C,N coordination mode, bridging two of the magnesium sites of the tetrahedra, the remaining two metals are bridged by the unreacted hydrides. The Mg-C bond lengths of the metalated imine are 2.1778 (17) and 2.1830(17) Å, while the Mg-N bond lengths are 2.1185(15) and 2.1428(14) Å.