Deprotonation of calixarenes by alkali metal in methanol using simple benchtop procedures is effective in the formation of novel monomeric and dimeric titanium(iv) complexes. For the larger alkali metal cations, K+ and Cs+, favourable complexation within the π-basic calixarene cavity facilitates the formation of monomeric titanium(iv) complexes when oligomer formation is inhibited by an acetylacetonate ligand. In contrast, the smaller Li+ and Na+ ions preferentially form dimeric complexes with exo-bridging alkali and titanium(iv) metal centres. A dimeric complex is also obtained for potassium in the absence of acetylacetonate. The solid state structures of the K–Ti and Na–Ti calixarene dimer complexes show different structural characteristics depending on the nature of the alkali metal.
|Number of pages||8|
|Journal||Journal of the Chemical Society. Dalton Transactions|
|Publication status||Published - 2 Dec 2003|
- Alkali metals
- Calixarenes, crown ethers, cryptands, cyclophanes
- Coordination chemistry
- Molecular structure