A series of novel Cp*-based (Cp*=η5-C 5Me5) agostic, bis(σ-borate) and boratrane complexes have been synthesized from diruthenium and dirhodium analogues of pentaborane(9). The synthesis and structural characterization of the first neutral ruthenadiborane(6) analogue are also reported. This new route offers a very efficient method for the isolation of bis(σ-borate) and agostic complexes from diruthenapentaborane(9). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.