Email (record): Diaqua­(1,4,7,10,13-penta­oxacyclo­penta­deca­ne)iron(II) bis­(μ-cis-1,2-dicyano-1,2-ethyl­enedithiol­ato)bis­[(cis-1,2-dicyano-1,2-ethyl­enedithiol­ato)ferrate(III)] 1,4,7,10,13-penta­oxacyclo­penta­decane disolvate