Arylsulfonylnitrene and arenesulfonyl azide complexes of palladium

Reaction of [Pd2Cl2(dppm)(2)] 1 with arenesulfonyl azides RSO2N3 in CH2Cl2 at ambient temperature resulted in the formation of dimeric palladium compl exes with bridging arylsulfonylnitrene ligands [Pd2Cl2(dppm)(2)(mu-NSO2R)] 2 (R = phenyl a, 4-methylphenyl b, 4-nitrophenyl c, 2-nitrophenyl d, 2-naph thyl e or ferrocenyl I). According to their NMR spectra, complexes 2a-2f ar e typical A-frame adducts, which has been verified by single crystal X-ray diffraction studies on 2d-2f. The short N(I)-S(I) distances [1.541(3)-1.565 (3) Angstrom] reflect the double bond character of these bonds and indicate a d(pi)-p(pi) interaction of the sulfur atom and the imido nitrogen atom. With 2-nitrobenzene-sulfonyl azide a by-product was observed in a yield of 10-15%. Based on spectroscopic properties (H-1 and P-31 NMR, IR) and elemen tal analysis, this compound contains a bridging arenesulfonyl azide ligand, [Pd2Cl2(dppm)(2)(mu-2-O2NC6H4SO2N3)] 3d. Irradiation with light of lambda > 455 nm caused selective dissociation of 3d into 1 and 2-O2NC6H4SO2N3. The azide complex 3d is not an intermediate in the formation of the correspond ing nitrene complex 2d.