Fig. 3: Water molecule distribution in POCs.
Structures of D2O in CC3 (a) and CC19 (b), determined from neutron powder diffraction measurements. Carbon, gray; nitrogen, blue; hydroxyl oxygen, pink. The oxygen atoms from deuterium oxide are presented in balls with various colors (i.e., red, orange, yellow, and light yellow) to indicate crystallographically independent D2O species. Deuterium and hydrogen atoms are omitted for clarity. c Arrangement of oxygen atoms (red) of D2O in four closely packed CC19 molecules. Peripheral oxygen atoms are omitted for clarity. Crystallographic arrangement of D2O in the internal cavity (d) and inter-POC space (e) of CC3 with possible hydrogen bonding between the D2O molecules and the POC. Nitrogen atoms from CC3 are represented as blue spheres. Note that the orientational disorder of D2O was expected at room temperature, and the D2O molecules were modeled with multiple deuterium sites.
