Structural characterisation of difluoro-boron chelates of quino[7,8-h]quinoline

We report a milder synthetic route for the compounds 4,9-dichloroquino[7,8-h]quinoline L-1 and quino[7,8-h]quinoline L-2 and we utilise these ligands in the synthesis of boron difluoride chelates. X-ray crystallographic analysis of L-1, [HL1]BF4 and the coordinated structures of [BF2L1]BF4 and [BF2L2]BF4 reveal the flexible nature of the ligand. (C) 2011 Elsevier B.V. All rights reserved.