Electron Distribution in (NH4)2C2O4–H2O and the Structure of the Oxalate Group

Abstract

The electron distribution of (NH₄)₂C₂O₄–H₂O projected on (001) was obtained by a Fourier analysis making use of quantitative intensity measurements of x‐ray scattering from (hk0). This analysis combined with a determination of the atomic parameters perpendicular to (001) gave the complete structure. Separations of covalently linked atoms in the C₂O₄^{— —} group are C–C, 1.581±0.01A; C–O, 1.25±0.02A; and C–O, 1.23±0.02A with the angle O–C–O=129°±2°. In this compound the O–C–O parts of an oxalate group are in planes at an angle of 28° while in H₂C₂O₄–2H₂O, α and β H₂C₂O₄ the parts are coplanar.