N‑Heterocyclic Silyl Pincer Ligands

The reaction of 1,2-C6H4(NHCH2PPh2)2 with chlorosilanes Cl2SiHR (R = Ph, Cl) affords the benzosiladiazoles RHSi­(NCH2PPh2)2C6H4 (R = Ph, 1; Cl, 2). The phenyl derivative 1 undergoes chelate-assisted Si–H activation with [RuPhCl­(CO)­(PPh3)2] and [RhCl­(PPh3)3] to afford the structurally characterized silyl pincer complexes [RuCl­(CO)­(PPh3)­{κ3-P,Si,P′-SiPh­(NCH2PPh2)2C6H4}] (3) and [RhHCl­(PPh3)­{κ3-P,Si,P′-SiPh­(NCH2PPh2)2C6H4}] (4). The reaction of 4 with [Et2NH2]­[S2CNEt2] affords the complex [RhH­(S2CNEt2)­{κ3-P,Si,P′-SiPh­(NCH2PPh2)2C6H4}] (5), structural data for which demonstrate a pronounced trans influence for the σ-silyl donor.