Distibanes and Distibenes from Reduction of Sb(NON )Cl by using Mg Reagents.

The bis(amidodimethyl)disiloxane antimony chlorides Sb(NON )Cl (NON =[O(SiMe NR) ] ; R=tBu, Ph, 2,6-Me C H =Dmp, 2,6-iPr C H =Dipp, 2,6-(CHPh ) -4-tBuC H =tBu-Bhp) are reduced to Sb and Sb species by using Mg reagents, [Mg(BDI )] (BDI=[HC{C(Me)NR'} ] ; R'=2,4,6-Me C H =Mes, Dipp). Stoichiometric reactions with Sb(NON )Cl (R=tBu, Ph) form dimeric Sb stibanes [Sb(NON )] , shown crystallographically to contain Sb-Sb single bonds. The analogous distibane with R=Dmp substituents has an exceptionally long Sb-Sb interaction and exhibits spectroscopic and reactivity properties consistent with radical character in solution. When R=Dipp, reductions with Mg reagents directly give distibenes [Sb(μ-NON )Mg(BDI )(THF) ] (R'=Mes, n=1; R'=Dipp, n=0). Crystallographic analysis shows a trans-substitution of the Sb=Sb double bond, with bridging NON -ligands between the Sb and Mg centres. An attempt to access the NON -analogue using the same protocol afforded the polystibide cluster Sb [μ ,η -Mg(BDI )] , which co-crystallized with the ligand transfer product, [Mg(BDI )] (μ-NON ).