Formation and Properties of the Trichloroberyllate Ion

The activation of C–Cl bonds in dichloromethane and chloroform was observed by BeCl 2 in the presence of PMe 3 and PCy 3 . This leads to the formation of [Me 3 PCH 2 Cl]Cl and [Cy 3 PCHCl 2 ][BeCl 3 ]. The latter compound is the first example of a tricoordinated beryllium species with nonbulky ligands and proof of the existence and stability of the long-predicted [BeCl 3 ] − ion. In analogy to the isoelectronic BCl 3, the trichloroberyllate anion exhibits Lewis acidic behavior toward electron-pair donors and was probed for the electronic and steric influence of the Lewis base. [BeCl 3 ] − can also act as a chloride ion donor or acceptor, leading to the formation of neutral phosphane adducts to BeCl 2 and [BeCl 4 ] 2– . The existing equilibria between these species were investigated and showed high chloride mobility.