Zur Struktur von Cellulose-II-Einkristallen aus verduennter Kupfer(II)-bis(ethylendiamin)-Loesung

Special cellulose-II-crystals may be produced from copper (II)-bis-(ethylene diamine) solution by means of isothermal gas diffusion of hydrogen chloride. In this case cellulose crystallizes in the form of ultrathin platelets and the fibre axis c of the unit cell is shown to lie in the plane of the platelets. The chain structure of the cellulose II in the crystallographic bc-plane was verified using transmission electron microscopy at high magnification and electron crystallographic methods, in particular optical, and in this case digital, diffractometry. Given these conditions, cellulose forms two-dimensional crystal platelets. The magnitude of the diffracting, crystalline area (1,500×900 nm) may be determined by dark field microscopy with intermittent reflexes. It was also shown that the diffraction condition is not fulfilled unless several cellulose-II platelets are superimposed to form a three-dimensional crystal. Individual lamellae at the periphery of the crystal do not contribute towards diffraction. The spot diffraction patterns give an impressive demonstration of the superior order of the cellulose II crystal.