[Ta 3 O 3 ]A (A = Li, Na, K) and [Ta 3 O 3 ]B[Ta 3 O 3 ] (B = Ca, Sr, Ba): Sandwich‐Type Complexes Containing Ta 3 O 3 – δ and π Double Aromatic Ligands

A density functional theory investigation on half‐sandwich‐type C 3 v [Ta 3 O 3 ]A (A = Li, Na, K) and full‐sandwich‐type D 3 h [Ta 3 O 3 ]B[Ta 3 O 3 ] (B = Ca, Sr, Ba) complexes containing Ta 3 O 3 – δ and π double aromatic ligands was performed. The Ta 3 O 3 – units serve as robust inorganic ligands in both [Ta 3 O 3 ]A and [Ta 3 O 3 ]B[Ta 3 O 3 ] complex series, which are mainly maintained by A + –[Ta 3 O 3 ] – or [Ta 3 O 3 ] – –B 2+ –[Ta 3 O 3 ] – ionic interactions. These novel complexes turn out to be strongly thermodynamically favored in the gas phases and may be targeted in future experiments to open a new area of coordination chemistry by introducing δ and π double aromatic ligands into complex systems. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)