The crystal structure of form A of potassium caprate

Potassium caprate, KC10H19O2, form A, is monoclinic. The cell contains four molecules and has the dimensions a = 8.119, b = 5.650, c = 28.907 A., β = 108° 2′; density calculated 1.108, observed 1.123 g.cm.−3. The space group is C{₂ₕ^5}–P21/a. Two-dimensional Fourier projections show that the hydrocarbon chains cross each other and that the average distance between two alternate carbon atoms in the chain is 2.598 A. This is significantly greater than the commonly assumed distance 2.522 A., derived from the diamond structure. The angle of tilt of the molecules is 57° 30′.