Sm(II) reduction chemistry of heteroalkynes: stable adducts, reductive coupling, reductive C-C/C-N bond cleavage and trapping of the tert-butyl fragment with bulky nitriles, phosphaalkynes and isonitriles.

Reactions of a dimetallated N,N'-dimethyl substituted porphyrinogen Sm(II) complex with a series of t-butyl substituted heteroalkynes affords a diverse range of reactivity. The phosphaalkyne t-BuC[triple bond]P gives a dinuclear Sm(III) P-P reductively coupled complex of (t-BuC=PP=C-t-Bu)(2-) featuring a new mu-eta(2)(1,2-C,P) binding mode. In contrast, the nitrile aza analogue t-BuC[triple bond]N forms Sm(II) adducts that undergo reductive C-C bond cleavage at elevated temperatures to afford a trimeric Sm(III) cyanide (mu-C[triple bond]N(-)) complex.