Luminescent organoboron complexes featuring substituted 8-quinolinolates as chelating ligands have been synthesized and characterized. Substitution of the quinolinolate has been achieved in the 5 and the 7 positions introducing phenyl, biphenyl, and 9,9‘-dihexylfluorenyl substituents by reacting 8-benzyloxy-5,7-dibromoquinoline with the corresponding boronic acid derivatives in a Suzuki-type cross-coupling reaction. Upon deprotection, the 8-quinolinol derivatives have been transformed into the target compounds upon reaction with BPh3. (κ2-(N,O)-5,7-dibromo-8-quinolinolate)diphenylborane (9), (κ2-(N,O)-5,7-diphenyl-8-quinolinolate)diphenylborane (10), (κ2-(N,O)-5,7-bis(biphenyl-4-yl)-8-quinolinolate)diphenylborane (11), and (κ2-(N,O)-5,7-bis(9,9-dihexylfluoren-2-yl)-8-quinolinolate)diphenylborane (12) have been investigated by nuclear magnetic resonance and infrared spectroscopy, matrix-assisted laser desorption ionization time-of-flight mass spectrometry, thermal analysis, cyclic voltammetry, UV−vis absor...