Reactivity of Osmium(VI) Nitrides with the Azide Ion. A New Synthetic Route to Osmium(II) Polypyridyl Complexes

There is an extensive reactivity chemistry between trans-[Os(VI)(tpy)(Cl)(2)(N)](+) (1) (tpy = 2,2':6',2"-terpyridine) and N(3)(-). Reaction of 1 with N(3)(-) in CH(2)Cl(2) or acetone occurs by electron transfer to give trans,trans-(tpy)(Cl)(2)Os(II)(N(2))Os(II)(Cl)(2)(tpy). In CH(3)CN, trans-Os(II)(tpy)(Cl)(2)(N(2)) forms but undergoes solvolysis to give trans-Os(II)(tpy)(Cl)(2)(CH(3)CN). 1 reacts with excess N(3)(-) in CH(3)CN to give Os(III)(tpy)(Cl)(2)(5-CH(3)-tetrazolate), which has been characterized by X-ray crystallography. This is the first known Os-tetrazolato complex. 1 reacts with N(3)(-) in the presence of CS(2) to give trans-[Os(II)(tpy)(Cl)(2)(NS)](+), SCN(-), and N(2).