The synthesis and reactivity of the first Group 13 complexes bearing a dearomatized phosphino-amido ligand L are reported, i.e. alane AlEt 2 (L) 1, gallane GaCl 2 (L) 2 and borane B(Cl)(Ph)(L) 3. The three complexes react very differently with Group 13 trihalogenides, providing access to zwitterionic anti-3·GaCl 3 and the unique bis(metalloid) 5·BCl 2 , with the boron center part of a highly unusual anionic four-mem-bered ring (charge on C) and Ga bound to P. The coordination chemistry and the various transformations are supported by DFT calculations, X-ray crystallography and multinuclear NMR spectroscopic data.