A new tripodal ligand that features three selenium donors, namely the tris(2-seleno-1-mesitylimidazolyl)hydroborato ligand, [TseMes], has been constructed via the reaction of KBH4 with 1-mesitylimidazole-2- selone; comparison of the IR spectroscopic data of [TseMes]Re(CO) 3 with those of a variety of related LRe(CO)3 complexes demonstrates that the [TseMes] ligand is more strongly electron donating than Cp, Cp*, [Tp], [TpMe2] and [Tm Mes] ligands. © The Royal Society of Chemistry 2006.