Use of Se4N4 and Se(NSO)(2) in the preparation of palladium adducts of diselenium dinitride, Se2N2; Crystal structure of [PPh(4)](2)[Pd2Br6(Se2N2)]

Reaction of Se4N4 with [NBu(4)(n)](2)[Pd2Br6] at 100 degrees C in CH2Cl2 resulted in [NBu(4)(n)](2)[Pd2Br6(Se2N2)] 1a in high yield (67%). In contrast to the reaction of [PPh(4)](2)[Pd2Br6] with S4N4, which generates a number of products, the tetrabutylammonium salt generated only [NBu(4)(n)](2)[Pd2Br6(S2N2)] 1b; comparison of the IR spectra of la and Ib allows unambiguous identification of the two bands due to E(2)N(2) vibrations: While reaction of S(NSO)(2) with [Pt(PPh(3))(3)] leads to a mixture of [Pt(S2N2)(PPh(3))(2)] and [Pt(NSO)(2)(PPh(3))(2)], only the latter species forms in the analogous reaction of Se(NSO)(2). Two different results were also found in-reactions with [PPh(4)](2)[Pd2Br6]; while S(NSO)(2) appeals surprisingly inert to this reagent, Se(NSO)(2) reacts, when-present in excess, to give the unexpected product [PPh(4)](2)[Pd2Br6(Se2N2)] 1c. The crystal structure of the latter confirms the presence of the adducted diselenium dinitride unit.