Quinolino[7,8-]quinoline: a 'just right' ligand for beryllium(II) coordination.

We report the synthesis and crystal structure of the first quinolino[7,8-]quinoline beryllium(II) complex of the general formula [BeL2(MeCN)Br]Br·MeCN, containing the ligand 4,9-dihydroxyquinolino[7,8-]quinoline (L2). The Be(II) cation is a great size match for the dinitrogen binding pocket of the quinolino[7,8-]quinoline ligand as indicated by minimal out-of-plane displacement and ligand distortion parameters.

Synthesis and Basicity Studies of Quinolino[7,8-]quinoline Derivatives.

Quinolino[7,8-]quinoline is a superbasic compound, with a p in acetonitrile greater than that of 1,8-bis(dimethylaminonaphthalene) (DMAN), although its synthesis and the synthesis of its derivatives can be problematic. The use of halogen derivatives 4,9-dichloroquinolino[7,8-]quinoline () and 4,9-dibromoquinolino[7,8-]quinoline () as precursors has granted the formation of a range of substituted quinolinoquinolines. The basicity and other properties of quinolinoquinolines can be modified by the inclusion of suitable functionalities.