Directed Structure Formation in Tetranuclear Xylaratogermanates(IV) with Complex Phenanthrolinecopper(II) Cations

New xylatogermanates with the same homogermanate complex anion and various phenanthrolinecopper(II) cations, namely, [Cu(Phen)(3)](2)[(OH)(2)Ge-2(mu-HXylar)(4)Ge-2(mu-OH)(2)] center dot 8H(2)O (I), [Cu(H2O)(Phen)(2)](2)[(OH)(2)Ge-2(mu-HXylar)(4)Ge-2(mu-OH)(2)] center dot 8H(2)O (II), and [CuCl(Phen)(2)](4)[(OH)(2)Ge-2(mu-HXylar)(4)Ge-2(mu-OH)(2)] center dot 8H(2)O (III), have been synthesized by the developed method and studied by IR spectroscopy and thermogravimetry. According to X-ray diffraction data, they represent ionic type complexes with the [(OH)(2)Ge-2(mu-HXylar)(4)Ge-2(mu-OH)(2)](4-) tetranuclear germanium-containing complex anion and three complex cations: [Cu(Phen)(3)](2+) (I), [Cu(H2O)(Phen)(2)](2+) (II), and [CuCl(Phen)](+) (III). The Ge atoms in the complex anion have two types of coordination: they are five- or six-coordinated. Each Ge atom is linked to the deprotonated carboxylic and hydroxyl groups of two xylaric acid molecules. The five-coordinated Ge atom is additionally linked to one terminal hydroxyl ligand, and the six-coordinated Ge atom is linked to two bridging hydroxyl groups. In crystal structures I and II, cations and anions form alternating layers, which are interchangeably composed of cations and anions. In crystal structure III, cations form "porous" layers, whose cavities accommodate chains of anions. The layers of cations are linked by weak stacking-interactions between the pi-systems of Phen.