Stereoscopic representation molecules

Figure 5-14 (A) Stereoscopic drawing showing two layers of water molecules that form a "spine" or "ribbon" of hydration in the minor groove of B-DNA. The inner layer is shown as larger filled circles water molecules of the outer layer are depicted with smaller dots and are numbered. Hydrogen bonds are shown as dashed lines. (B) Electron density map. (A) and (B) from Tereshko et at.95 (C) Stereoscopic representation of the superimposed electron densities of 101 water molecules observed to hydrate 14 guanine rings found in 14 B-DNA molecules for which high-resolution X-ray structures were available. Positions of 101 water molecules within 0.34 nm from any atom of the 42 guanines are plotted. From Schneider and Berman.94...

Figure 2. Stereoscopic representations of the crystal structure for aspartame (Form I). (a) unit cell, showing phenyl rings interacting in the center of each cell and hydrogen-bonded water molecules at the edges (b) columnar representation, showing hydrogen-bonded stacks of water molecules and zwitterionic aspartyl amino and carboxylate groups in center with stacked phenyl rings at edges. Reproduced from [9].

Figure 2.1.19 Stereoscopic representation of the crystal packing of 25 (Cc) [53] on (010) but turned around Y by 10° for a better view showing layers of steep molecules (62°) that interlock in the cleavage plane, which is not suitable for migration.

Figure 2.1.49 Stereoscopic representation of the crystal packing of 64a on (110) showing layers that very strongly interlock and a pair of the closely arranged molecules that cannot photodimerize due to lack of migrational capability of the crystal.

Fig. 30. Stereoscopic space filling illustrations of inclusion ohannels present in 1 alcohol clathrates 2). In each illustration, one of the guest molecules included in the channel is specified by shading (atoms of the guest molecules are shown with 20 % of their van der Waals radii throughout these representations) (a) 1 MeOH (1 2) (b) 1 2-PrOH (1 2) and 1 EtOH (1 2). Due to isomorphism only the 2-PrOH structure is shown (guest H atoms are omitted for the sake of clarity) (c) 1 2-BuOH (1 1).

Fig. 32. Packing relations and steric fit of the 26 acetic acid (1 1) clathrate (isomorphous with the corresponding propionic acid clathrate of 26)1U- (a) Stereoscopic packing illustration acetic acid (shown in stick style) forms dimers in the tunnel running along the c crystal axis of the 26 host matrix (space filling representation, O atoms shaded), (b) Electron density contours in the plane of the acetic acid dimer sa First contour (solid line) is at 0.4 eA" while subsequent ones are with arbitrary spacings of either 0.5 and 1 eA 3. Density of the enclosing walls comes from C and H atoms of host molecules.

Figure 23-24 (A) Stereoscopic view of a hexameric (a(3)3 phycobiliprotein. (B) The (3 subunit of the complex with two molecules of bound phyco-ery throbilin and one of phy-courobilin. From Chang et al.279 (C) Schematic representation of a phycobilosome of a strain of the cyanobacterium Anabaena. Each disk in the structure contains an (a(3)3 phycobiliprotein. The circles marked AP are cross-sections of rods, each one composed of about four disks of allophycocyanin (AP).

FIGURE 18. Packing in the crystal clathrate of 73 with MeCN (1/1). Stereoscopic view. The guest molecules are shown in van der Waals representation. Reproduced with permission from E. Weber et ai, J. Am. Chem. Soc., Ill, 7866-7872. Copyright (1989) American Chemical Society... 

---