Another aspect in which the four Lewis adducts were compared are their solid state packing and short contacts, whereby latter are defined as distances between individual atoms of different molecules smaller than the sum of their van der Waals radii. Thus, they may indicate weak intermolecular interactions. Graphical illustrations for the packing of 3 -6 are provided in the SI (section 4). Only H-H interactions between hydrogen atoms of proximate Si(CH3)3 were found for 3 while the terminal imine moieties of the DAD ligand were not involved in any kind For the discussion of structural details however, a subdivision of pyrrolyl coordinated complexes 8 and 9 on the one hand and amido-amino coordinated complexes 10 and 11 on the other, was consequential. The Co1-N1 bond distance between the pyrrolyl nitrogen in amino pyrrolyl complex 7, Co(AMPR)2, was found to be 1.9568(45) Å and thus slightly shorter than the respective bond in imino pyrrolyl compound 9, Co(IMPR)2, (1.9813( ) Å, see Table ).