Osmium(vi) Complexes of Sulphonyl Amid0 Ligand. Crystal Structures Of

Interactions of [PPh4]2[0s02C14] and [Bu”,Nl[OsNCl~] with LiZL [H2L = 1,2bis(p-toluenesulphonylamido)benzene] gave binuclear osmium(V1) compounds (PPh,),[Osz 04LZ(p-OH)d (1) and OS~N~L&-OH)~ (2), respectively. The structures of both compounds have been determined by X-ray crystallography. The crystal structure of the [OsZ04LZ@0H),12anion contains two trans-0s02(L) units bridged by two OH groups; the OS-0(0x0) bond length is ca 1.74 %i. The crystal structure of 2 contains two OsN(L) units bridged by two OH groups ; the Os-N(nitrido) bond length is ca 1.56 8. Multianionic chelating ligands are of current interest because they can stabilize metal ions in high oxidation states. High-valent metal complexes with deprotonated amido ligands, e.g. those of manganese(V),’ iron( cobalt(IV),3 nickel(III)4 and copper(III),’ are well documented. However, there are relatively few studies on complexes of sulphonyl amido groups. As the sulphonyl group is more electron-withdrawing than the carbonyl group one might expect that sulphonyl amido ligands can be deprotonated more readily and hence could display interesting coordination chemistry. To this end we set out to investigate the chemistry of complexes containing chelating sulphonyl amido ligands, e.g. bis-(toluenesulphonylamido)benzene (H,L), as shown in Fig. 1. The unique features of the ligand H2L are : (a) it is bidentate and dianionic ; (b) it can stabilize highly oxidizing metal centres due to the * Author to whom correspondence should be addressed. t Author to whom inquiries concerning X-ray crystallography should be addressed. strong a-donating deprotonated sulphonyl amido groups ; and (c) it is sterically bulky. Recently, the crystal structures of some copper complexes of H2L have been described.6 We herein report the synthesis and crystal structures of two osmium(V1) compounds of the ligand.