Double bonds have been realized for a wide variety of elements in the p-, d-, and f-blocks. However, no s-block metal complexes with a double bond have been identified. Here we report the synthesis and characterization of a di-ortho-beryllated carbodiphosphorane, which exhibits a double dative BeC bond. This species shows an unprecedented bonding situation at the metal center, which was extensively analyzed by experimental and computational means.

Reactions of [K(crypt-222)] (TlBi )⋅0.5 en (1 b) with [Ru(cod)(H CC(Me)CH ) ] (A) in 1,2-diaminoethane (en) led to the formation of two compounds with new bismuth-rich cluster anions, [K(crypt-222)] [Bi {Ru(cod)} ]⋅1.5 en (2) and [K(crypt-222)] [Tl Bi {Ru(cod)}]⋅2 tol (3), alongside the salt of a binary nido cluster, [K(crypt-222)] (Tl Bi )⋅2 en (4). The anions in 2 and 3 are two further examples of rare heterometallic clusters containing Ru atoms. As one cod ligand is retained on each Ru atom in both clusters, the anions may be viewed as intermediates on the way towards larger, ligand-free intermetalloid clusters. Quantum-chemical studies provided insight into the bonding situation in these clusters. According to these studies, the anion of 2 features both electron-precise and electron-deficient parts. Electrospray ionization mass spectrometry analysis indicated that the clusters undergo stepwise fragmentation.

The influence of the beryllium atom's partial charge on its coordination sphere was investigated experimentally and computationally on NEt3 adducts to BeCl2, BeBr2 and BrI2.

The activation of C-Cl bonds in dichloromethane and chloroform was observed by BeCl in the presence of PMe and PCy. This leads to the formation of [MePCHCl]Cl and [CyPCHCl][BeCl]. 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] ion. In analogy to the isoelectronic BCl, 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] can also act as a chloride ion donor or acceptor, leading to the formation of neutral phosphane adducts to BeCl and [BeCl]. The existing equilibria between these species were investigated and showed high chloride mobility.