NHC-Stabilised Parent Tripentelyltrielanes.

A missing family of the extremely air sensitive tripentelyltrielanes was discovered. Their stabilisation was achieved by using the bulky NHC IDipp (NHC=N-heterocyclic carbene, IDipp=1,3-bis(2,6-diisopropylphenyl)-imidazolin-2-ylidene). The tripentelylgallanes and tripentelylalanes IDipp ⋅ Ga(PH ) (1 a), IDipp ⋅ Ga(AsH ) (1 b), IDipp ⋅ Al(PH ) (2 a) and IDipp ⋅ Al(AsH ) (2 b) were synthesised by salt metathesis of IDipp ⋅ ECl (E=Al, Ga, In) with alkali metal pnictogenides such as NaPH /LiPH  ⋅ DME and KAsH , respectively. Moreover, the detection of the first NHC-stabilised tripentelylindiumane IDipp ⋅ In(PH ) (3) was possible by multinuclear NMR spectroscopy. Initial investigations of the coordination ability of these compounds resulted in the successful isolation of the coordination compound [IDipp ⋅ Ga(PH ) (μ -PH {HgC F } )] (4) by reaction of 1 a with (HgC F ) . The compounds were characterised by multinuclear NMR spectroscopy as well as single crystal X-ray diffraction studies. Supporting computational studies highlight the electronic features of the products.