Abstract
Thermally robust expanded ring carbene adducts of AlH3 have been synthesized with a view to probing their ligating abilities via Al–H σ-bond coordination. While κ2 binding to the 14-electron [Mo(CO)4] fragment is readily demonstrated, interaction with [Mo(CO)3] results in μ:κ1,κ1 and μ:κ2,κ2 bridging linkages rather than terminal κ3 binding.