Aryldimethylelement cations of the heavier group 14 elements. An essentially three-coordinate plumbylium ion.

The kinetically stabilized group 14 cations [R ind EMe 2 ][B(C 6 F 5 ) 4 ] (E = Si, Sn, Pb) were prepared and fully characterized (R ind = dispiro[fluorene-9,3'-(1',1',7',7'-tetramethyl- s -hydrindacen-4'-yl)-5',9''-fluorene). The deshielded heteronuclear NMR chemical shifts ( δ ( 29 Si) = 160.4, δ ( 119 Sn) = 619.9, δ ( 207 Pb) = 1549.5) are indicative of the low coordination numbers.