A　65·8　CdSO4-type　3-D　framework　built　by　hexa-CuII　sandwiched　polyoxotungstates　[Cu(en)2]　2[Cu(deta)(H2O)]2[Cu6(en)　2(H2O)2(B-α-GeW9O　34)2]·6H2O　(1)　(en　=　ethylenediamine　and　deta　=　diethylenetriamine)　has　been　hydrothermally　synthesized　and　structurally　characterized　by　elemental　analysis,　IR　spectrometry,　thermogravimetric　analysis　and　single-crystal　X-ray　diffraction.　To　the　best　of　our　knowledge,　1　represents　the　first　3-D　TMSP　with　65·8　CdSO4　topology　in　polyoxometalate　chemistry.　Magnetic　measurements　performed　on　1　indicate　the　occurrence　of　ferromagnetic　interactions　within　the　copper　ions　and　the　coupling　constants　can　be　determined.　©　2009　The　Royal　Society　of　Chemistry.