Crystal structures of three complexes structurally similar to KTbW(CN)8 · 7H2O

Abstract

Three complexes that crystallize into structures like KTbW(CN)8 · 7H2O (triclinic crystal system, space group P\( \bar 1 \)) were structurally characterized by X-ray diffraction: KYMo(CN)8 · 7H2O, a = 7.6371(5), b = 9.2569(6), c = 14.4976(2) A, α = 80.782(6)°, β = 87.644(5)°, γ = 77.645(5)°, V = 988.23(11) A3, Z = 2, ρcalcd = 1.876 g/cm3; KHoW(CN)8 · 7H2O, a = 7.5887(4), b = 9.2232(5), c = 14.4479(9) A, α = 80.709(5)°, β = 87.525(5)°, γ = 77.457(5)°, V = 974.12(10) A3, Z = 2, ρcalcd = 2.462 g/cm3; KErW(CN)8 · 7H2O, a = 7.6180(5), b = 9.2356(6), c = 14.4903(11) A, α = 80.655(6)°, β = 87.492(6)°, γ = 77.557(6)°, V = 982.29(13) A3, Z = 2, ρcalcd = 2.449 g/cm3. The coordination polyhedra of the d element atoms [M(CN)8] (M4+ = Mo and W) are dodecahedra; the coordination polyhedra of the rare-earth metal atoms [RN4(OH2)4] (R3+ = Y, Ho, and Er) are tetragonal antiprisms. Four bridging cyano groups are coordinated to the W/Mo and rare-earth metal atoms through the C and N atoms, respectively, to form a polymeric 3D structure involving potassium atoms. The coordination polymers can be formulated as {[K(H2O)][R(H2O)4][M(CN)8] · 2H2O}n (R3+ = Y, M4+ = Mo; R3+ = Ho and Er, M4+ = W).