Synthese, Kristallstrukturen und thermische Eigenschaften von Bariumsalzen der 4‐Sulfobenzoesäure

Synthesis, Crystal Structures and Thermal Properties of Barium Salts of 4‐Sulfobenzoic Acid The reaction of 4‐sulfobenzoic acid with barium hydroxide in the molar ratio 2 : 1 leads to the formation of Ba(O 3 SC 6 H 4 COOH) 2 ( 1 ). 1· 3H 2 O crystallizes triclinic, space group $\rm P{\bar 1}$ , with a = 719.6(7), b = 1136.9(6), c = 1249.7(10) pm, α = 102.81(5), β = 91.73(7), γ = 106.95(6)° (at 293 K). The barium cations exhibit a ninefold coordination by six oxygen atoms from sulfonate and carboxyl groups and three water molecules. The linkage of the barium cations by bridging 4‐carboxybenzenesulfonate anions leads to a 3D coordination polymer. Ba(O 3 SC 6 H 4 COO) ( 2 ) is obtained from 4‐sulfobenzoic acid and barium hydroxide in equimolar amounts. 2· 2H 2 O crystallizes monoclinic, space group C2/c with a = 2105.5(5), b = 704.1(1), c = 1455.4(3) pm, β = 90.49(3)° (at 220 K). The barium cations are coordinated by seven oxygen atoms from sulfonate and carboxylate groups and two water molecules. The 4‐sulfobenzoate anions act as bridging ligands to form a 3D coordination polymer.