trans-Bis(ethylenediamine)dinitrocobalt(III) perchlorate

The reaction of cobalt(II) perchlorate with ethylenediamine and sodium nitr ite in aqueous solution gave the title Co-III compound, [Co(NO2)(2)(C2H8N2) (2)]ClO4, as yellow crystals. The complex crystallizes in three different c onformations in the asymmetric unit, two on centers with (1) over bar symme try and one in a general position. Numerous hydrogen bonds occur between mo lecules, but most are quite weak. The ethylenediamine N atoms occupy the eq uatorial sites with the NO2 ions bonded in axial positions. The NO2 moietie s nearly eclipse a pair of trans amine-N atoms in one independent molecule [O-N-Co-N angles range from -1.4(6) to 4.3(5)degrees], while they bisect th e N-Co-N angle in the other two [O-N-Co-N angles range from -44.8 (6) to 52 .1(5)degrees].