Ortho‐ Chalcogenotetrelate Anions as Chelating Ligands: Syntheses and Characterization of [K 6 (MeOH) 9 ][Sn 2 Se 6 ][Cr( en ) 2 (SnSe 4 )] 2 , [Na(H 2 O) 4 ][Cr( en ) 3 ] 2 [GeS 3 OH] 2 [Cr( en ) 2 (GeS 4 )], and [Ba(H 2 O) 10 ][{Cr( en )} 2 (GeSe 4 ) 2 ]

Reactions of K 4 [SnSe 4 ], Na 4 [GeS 4 ] or Ba 2 [GeSe 4 ] with different 1,2‐diaminoethane (= en ) coordinated complexes of CrCl 3 ([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 Cr 3+ with ortho ‐chalcogenotetrelate anions [E′E 4 ] 4− (E′ = Ge, Sn; E = S; Se): the crystal structures of [K 6 (MeOH) 9 ][Sn 2 Se 6 ][Cr( en ) 2 (SnSe 4 )] 2 ( 1 ), [Na(H 2 O) 4 ][Cr( en ) 3 ] 2 [GeS 3 OH] 2 [Cr( en ) 2 (GeS 4 )] ( 2 ), and [Ba(H 2 O) 10 ][{Cr( en )} 2 (GeSe 4 ) 2 ] ( 4 ) have been determined by means of single crystal X‐ray diffraction ( 1 : triclinic space group $P{\bar 1}$ ; lattice dimensions at 203 K: a = 1175.7(2), b = 1315.3(3), c = 1326.7(3) pm, α = 61.99(3)°, β = 64.05(3)°, γ = 83.57(3)°, V = 1617.4(6)·10 6 pm 3 ; R 1 [ I > 2 σ ( I )] = 0.0788; wR 2 = 0.1306; 2 : monoclinic space group C 2/ c ; lattice dimensions at 203 K: a = 2445.3(5), b = 1442.5(3), c = 1579.3(3) pm, β = 94.61(3)°, V = 5552.9(19)·10 6 pm 3 ; R 1 [ I > 2 σ ( I )] = 0.0801; wR 2 = 0.2046; 4 : triclinic space group $P{\bar 1}$ ; lattice dimension at 203 K: a = 1198.4(2), b = 1236.8(3), c = 1297.5(3) pm, α = 65.69(3)°, β = 63.35(3)°, γ = 81.21(3)°, V = 1565.2(5)·10 6 pm 3 ; R 1 [ I > 2 σ ( 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 ][GeS 3 OH]·6H 2 O ( 3 : monoclinic space group C 2/ c ; lattice dimensions at 203 K: a = 2396.8(5), b = 1463.4(3), c = 1740.1(4) pm, β = 132.99(3)°, V = 4463.8(15)·10 6 pm 3 ; R 1 [ I > 2 σ ( I )] = 0.0462; wR 2 = 0.1058), provides some insight in fundamental differences between the reaction behavior of [SnE 4 ] 4− anions one the one hand and [GeE 4 ] 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 1 and 2 with that observed in the Ba 2+ compound 4 .