The synthesis, characterization, and decomposition pathway of the 18-crown-6 adduct of bis(allyl)calcium [Ca(η1-C3H 5)(η3-C3H5)(18-crown-6)] (2) are reported. The solid-state structure of adduct 2 features one σ- and one π-bonded allyl ligand at the metal center. 2 is the first structurally characterized example of a mononuclear calcium complex bearing a purely σ-bound allyl ligand. DFT calculations indicate that [Ca(η 1-C3H5)(η3-C3H 5)(18-crown-6)] and [Ca(η1-C3H 5)2(18-crown-6)] conformations are close in energy. In THF solution, η3-allyl ligands are observed exclusively at both ambient temperature and -95 °C. 2 undergoes rapid cleavage of the crown ether to give vinyl-terminated alcoholates of different chain length with a half-life of t1/2 = 2.5 h.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry