Dibenzoberylloles: antiaromatic s-block fluorene analogues.

Among a series of Lewis-base-stabilised antiaromatic dibenzoberylloles (DBBes) the cyclic alkyl(amino)carbene (CAAC) analogue undergoes a complex but highly selective thermal decomposition, involving the breaking and making of four bonds each, which yields a rare beryllium -alkene complex. Two-electron reduction of the CAAC-stabilised DBBe analogue yields an aromatic dianion.

Synthesis, Structural Characterization, and Bonding of Molecular Heavier Beryllium Chalcogenides.

The reactions of a cyclic alkyl(amino)carbene (CAAC)-stabilized beryllium radical with E Ph (E=S, Se, Te) and of a beryllole with HEPh (E=S, Se) yield the corresponding beryllium phenylchalcogenides, including the first structurally authenticated beryllium selenide and telluride complexes. Calculations show that their Be-E bonds are best described by the interaction between the Be and E fragments, with Coulombic forces accounting for ca. 55 % of the attraction and orbital interactions dominated by the σ component.