Solvothermal Synthesis and Structure of the [Ge2Se7]4- Anion in (enH2)[{Mn(en)2(enH)}2(μ-en)](Ge2Se7)2 and [Mn(dien)2]2Ge2Se7

(enH(2))[{Mn(en)(2)(enH)}(2)(mu-en)](Ge2Se7)(2) (1) and [Mn(dien)(2)](2)Ge2Se7 (2) can be prepared by solvothermal reaction of elemental Ge and Se with Mn(OOCCH3)(2).4H(2)O in respectively superheated ethylenediamine/methanol (3:2 mixture, 150degrees) and di-ethylenetriamine (dien, 130 degreesC). The cyclic Ge2Se74- anion contains two tetrahedral GeSe4 building units linked at one corner Se atom and through an Se-Se bond. 1 also contains a novel complex cation in which Mn(II) atoms are coordinated by one terminal, one bridging and two chelating en ligands.