The reaction of 1,2-C6H4(NHCH2PPh 2)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)(PPh 3)2] and [RhCl(PPh3)3] to afford the structurally characterized silyl pincer complexes [RuCl(CO)(PPh 3){κ3-P,Si,P′-SiPh(NCH2PPh 2)2C6H4}] (3) and [RhHCl(PPh 3){κ3-P,Si,P′-SiPh(NCH2PPh 2)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. © 2014 American Chemical Society.