A first comparison of solid state and solution structure of a complex between lanthanum nitrate and 1,9-diaza-18-crown-6

[GRAPHICS] The structure of the complex between lanthanum(III)nitrate and 1,9 diaza-18-crown-6 is analyzed with three independent methods. The conformation observed by analysis of vicinal NMR coupling constants in solution agrees with both the one found by a single crystal Xray study and with simulations by molecular orbital and force field calculations, In the acetonitrile solution, the NMR data show a bent crown conformation with nearly C-2v symmetry, which is stable on the NMR time scale.