An unusual mixed-valence Cu(I)-Cu(II) 3-D framework

The reaction of Cu(CH3CN)(4)ClO4 with 2-pyridylacrylic acid (2-HPYA) affords an unusual mixed-valence Cu(l)-Cu(ll) 3-D framework {[Cu(II)(2-PYA)(2)](3).[Cu(l)(2-PYA)](2).(H2O)(2)}(n) (1) with a novel topology which features Cu(II) dimeric units (or paddle-wheel unit). The almost perpendicular coordinating direction between the N atom of pyridyl and the O atom of carboxylate groups may be responsible for the formation of such a novel network.