A solvothermal reaction of a cupric salt and tetrazole in acetonitrile generates a tetrazolate (tta)- and cyano-bridged homometallic mixed-valence copper(I,II) molecular ferrimagnet, [Cu-5(tta)(6)(CN)(2)] (see figure), that exhibits a field-induced transition from a 3D antiferromagnetic state to a ferrimagnetic state at 7.9 K.