Ortho-chalcogenotetrelate anions as chelating ligands: Syntheses and characterization of [K-6(MeOH)(9)][Sn2Se6][Cr(en)(2)(SnSe4)](2), [Na(H2O)(4)][Cr(en)(3)](2)[GeS3OH](2)[Cr(en)(2)(GeS4)], and [Ba(H2O)(10)][{Cr(en)}(2)(GeSe4)(2)]

Reactions of K-4[SnSe4], Na-4[GeS4] or Ba-2[GeSe4] with different 1,2-diaminoethane (= en) coordinated complexes of CrCl3 ([Cr(en)(2)Cl-2]Cl or [Cr(en)(3)]Cl-3) in MeOH or aqueous solution yielded three novel compounds that contain complexes of Cr3+ with ortho-chalcogenotetrelate anions [E'E-4](4-) (E' = Ge, Sn; E = S; Se): the crystal structures of [K-6(NeOH)(9)][Sn2Se6][Cr(en)(2)-(SnSe4)](2) (1), [Na(H2O)(4)][Cr(en)(3)](2)[GeS3OH](2)[Cr(en)(2)(GeS4)] (2), and [Ba(H2O)(10)][{Cr(en)}(2)(GeSe4)(2)] (4) have been determined by means of single crystal X-ray diffraction (1: triclinic space group PI; lattice dimensions at 203 K: a = 1175.7(2), b = 1315.3(3), c = 1326.7(3) pm, alpha = 61.99(3)degrees, beta = 64.05(3)degrees, gamma = 83.57(3)degrees, V = 1617.4(6)center dot 106 pm(3); R-1 [I > 2a(I)] = 0.0788; wR(2) = 0.1306; 2: monoclinic space group C2/c; lattice dimensions at 203 K: a = 2445.3(5), b = 1442.5(3), c = 1579.3(3) pm, beta = 94.61(3)degrees, V = 5552.9(19)center dot 10(6) pm(3); R-1 [I > 2 sigma(1)] = 0.0801; wR(2) = 0.2046; 4: triclinic space group PI; lattice dimension at 203 K: a = 1198.4(2), b = 1236.8(3), c = 1297.5(3) pm, alpha = 65.69(3)degrees, beta = 63.35(3)degrees, gamma = 81.21(3)degrees, V = 1565.2(5)center dot 10(6) pm(3); R-1 [1 > 2 sigma(I)] = 0.0732; wR(2) = 0.1855). 1 and 2 show the yet unprecedented complexation of transition metal ions by non-bridging, single chalcogenotetrelate ligands to produce dinuclear, heterobimetallic complexes. Compound 2 contains the first structurally characterized complex with an ortho-thiogermanate ligand. The formation of these compounds, and of a by-product of 2, [Cr(en)(3)][GeS3OH](6)center dot H2O (3: monoclinic space group C2/c; lattice dimensions at 203 K: a = 2396.8(5), b = 1463.4(3), c = 1740.1(4) pm, beta = 132.99(3)degrees, V = 4463.8(15)center dot 10(6) pm(3); R-1 [I > 2 sigma(I)] = 0.0462; wR(2) = 0.1058), provides some insight in fundamental differences between the reaction behavior of [SnE4](4-) anions one the one hand and [GeE4](4-) anions on the other hand. The crucial role of the counterion charge becomes evident when comparing the structure motifs of the ternary anions in I and 2 with that observed in the Ba2+ compound 4.