Attempts to transfer these methods to the more sterically demanding silylaryl/amide ligand {N(Dipp)(SiMe3)} -(Dipp = 2,6-diisopropylphenyl) yielded exclusively solvated AE(II) bisamide complexes in all cases. All compounds 1-3-AE were fully characterized via multinuclear NMR spectroscopy, IR spectroscopy, elemental analyses and single crystal X-ray diffraction. Structural authentication of the AE(II) tris-amide complexes reveals the desired 3-coordinate arrangement about the AE centre (Figure and Figure -40, Tables and), with the only exception a 4-coordinate complex 3-Ba•THF (Figure ). The [AE{N(SiMe3)2}3] -anions in 1-AE and 2-AE display near-perfect trigonal planar geometries, with the metal centres in close proximity to the N^N^N planes and N-AE-N bond angles close to the ideal value of 120° (Table ). The [AE{N(Mes)(SiMe3)}3K] monomers of 3-AE are also close to ideal trigonal planar geometries, with the potassium cation encapsulated by mesityl substituents to give polymeric arrays (Table ). The orientation of the mesityl substituents varies in each structure, largely influenced by the presence of the potassium cations intercalated within each coordination polymer. For 3-Mg, two of the mesityl substituents point in the same direction with respect to the N^N^N plane and encapsulate a potassium cation, whilst the third ring points below the plane and interacts with a potassium cation from a neighbouring unit. In the case of 3-Ca all three mesityl groups are positioned on the same face of the molecule. Finally, in 3-Sr the orientation of the aryl substituents is analogous to that observed for 3-Mg, though each potassium cation is encapsulated by three mesityl rings each belonging to different units. The Ca-N bond distances in [Ca{N(SiMe3)2}3] -anions [1-Ca: 2.3103(10)-2.3121(10) Å; 2-Ca: 2.309(3)-2.318(2) Å] are comparable to those observed in 3-Ca, with the exception of one elongated metal-ligand interaction [2.390 (11) Å]. This could be due to the potassium cation encapsulated between aryl ligands in 3-Ca, since steric properties of {N(Mes)(SiMe3)} -(3-Ca %VBur = 28.9-29.9%, Table , Figure ) and {N(SiMe3)2} -(1-Ca and 2-Ca %VBur = 29.0-29.7%, Table , Figures and) are comparable. Analogous conclusions can be drawn also when comparing 1-Sr with 3-Sr (Table and).