Triethanolamine Complexes of H⁺, Li⁺, Na⁺, Sr²⁺, and Ba²⁺ Perchlorates

The syntheses of the perchlorate salts of H(TEA)⁺ (1), Li(TEA)⁺ (2), Na(TEA)⁺ (3), Sr(TEA)₂²⁺ (4), and Ba-(TEA)₂²⁺ (5), wherein TEA = triethanolamine, are reported. Characterizational NMR spectral results (¹H, ¹³C, ⁷Li, ²³Na) as well as crystal structures for 1,3, and 5 are discussed. The structures of 1,3, and 5 reveal respectively the cation H(TEA)⁺ in which the proton is in a tetrahedral environment, a seven-coordinate sodium weakly coordinated by a monodentate ClO₄^- and two OH oxygens from neighboring units, and a [Ba(TEA)ClO₄]₂²⁺ cation in which two weakly coordinating perchlorates bridge two Ba²⁺ ions in a bidentate fashion. Extensive hydrogen bridging via ClO₄^- ions occurs in all three compounds giving rise to parallel sheet structures. Crystal data: 1 (at 22 °C), a = 9.086(1) A and c = 23.919(6) A, with Z = 6 in space group R3c; 3 (at 20 °C), a = 9.617(1) Å, b = 7.787(1) Å, c = 15.914(2) Å, and β = 105.80°, with Z = 4 in space group P2₁/c; 5 (at -50 °C), a = 7.498(2) Å, b = 10.492(2) Å, c = 15.749(3) Å, α= 76.06(2)°, β = 80.56(2)°, and γ= 76.70(2)°, with Z = 2 in space group P[formula ommited].