Novel polyoxometalate hybrids consisting of copper-lanthanide heterometallic/lanthanide germanotungstate fragments.

Three organic-inorganic hybrid copper-lanthanide heterometallic germanotungstates, {[Cu(en)(2)(H(2)O)] [Cu(3)Eu(en)(3)(OH)(3)(H(2)O)(2)](α-GeW(11)O(39))}(2)·11H(2)O (1), {[Cu(en)(2)(H(2)O)][Cu(3)Tb(en)(3)(OH)(3)(H(2)O)(2)](α-GeW(11)O(39))}(2)·11H(2)O (2) and {[Cu(en)(2)(H(2)O)][Cu(3)Dy(en)(3)(OH)(3)(H(2)O)(2)](α-GeW(11)O(39))}(2)·10H(2)O (3) and three polyoxometalate hybrids built by lanthanide-containing germanotungstates and copper-ethylendiamine complexes, Na(2)H(6)[Cu(en)(2)(H(2)O)](8){Cu(en)(2)[La(α-GeW(11)O(39))(2)](2)}·18H(2)O (4), K(4)H(2)[Cu(en)(2)(H(2)O)(2)](5)[Cu(en)(2)(H(2)O)](2)[Cu(en)(2)](2){Cu(en)(2)[Pr(α-GeW(11)O(39))(2)](2)}·16H(2)O (5) and KNa(2)H(7)[enH(2)](3)[Cu(en)(2)(H(2)O)](2)[Cu(en)(2)](2){Cu(en)(2)[Er(α-GeW(11)O(39))(2)](2)}·15H(2)O (6) (en = ethylenediamine) have been hydrothermally synthesized and structurally characterized by elemental analyses, inductively coupled plasma atomic emission spectrometry (ICP-AES) analyses, IR spectra, powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS) and single-crystal X-ray diffraction. 1-3 are essentially isomorphous and their main skeletons display the interesting dimeric motif {[Cu(3)Ln(en)(3)(OH)(3)(H(2)O)(2)](α-GeW(11)O(39))}(2)(4-), which is constructed from two {Cu(3)LnO(4)} cubane anchored monovacant [α-GeW(11)O(39)](8-) fragments through two W-O-Ln-O-W linkers. The primary backbones of 4-6 exhibit the tetrameric architecture {Cu(en)(2)[Ln(α-GeW(11)O(39))(2)](2)}(24-) built by two 1:2-type [Ln(α-GeW(11)O(39))(2)](13-) moieties and one [Cu(en)(2)](2+) bridge, albeit they are not isostructural. To our knowledge, 1-6 are rare polyoxometalate derivatives consisting of copper-lanthanide heterometallic/lanthanide germanotungstate fragments. 1 exhibits antiferromagnetic coupling interactions within the {Cu(3)EuO(4)} cubane units, while 2 and 3 display dominant ferromagnetic interactions between the Tb(III)/Dy(III) and Cu(II) cations. The room-temperature solid-state photoluminescence properties of 1-3 have been investigated.