26 June 1952

Mr. Roger Hayward

920 Linda Vista

Pasadena 2, California

Dear Roger:

Could you make four drawings for me, for the new edition of GENERAL CHEMISTRY. These are only four out of perhaps 30 or 40 that we shall need.

I enclose a reprint on the structure of chlorine hydrate. The drawings are involved in a discussion of this structure, which, however, is devoted to xenon hydrate rather than chlorine hydrate. The drawings are the following.

Fig. /15-12. Drawing showing the icosahedron and the pentagonal dodecahedron, as polyhedra - essentially in the style of Fig. 11-4, page 239 of COLLEGE CHEMISTRY.

Fig. 15-13. A pentagonal dodecahedron of 20 water molecules. I suggest that you use the style of the bottom part of Fig. 15-11, page 335, COLLEGE CHEMISTRY. The hydrogen atoms are to be placed arbitrarily close to or away from an oxygen atom, except that each oxygen atom must have two hydrogen atoms near it. Of the 20 oxygen atoms that are at the comers of the pentagonal dodecahedron, 10 should have a hydrogen atom sticking out radially, away from the center of the polyhedron, and 10 should not have this hydrogen atom, but should be using both of their hydrogen atoms in the formation of hydrogen bonds along the edges of the dodecahedron.

Fig. 15-14. A representation of the structure indicated in Figures 1 and 2 of the paper. I do not know what the best way of showing the structure is. I believe that we should indicate the unit cube, because I refer to the unit cube in the text. Also, there should be some indication of the larger and smaller polyhedra. I do not like the indication in Figure 2 of the extra water molecules - these are really water molecules that form tetrahedral bonds, each one binding 4 dodecahedra together. Perhaps a sphere could be represented inside of one or two of the polyhedra in this figure, corresponding to the noble gas atom. The diameter of a xenon atom is 1.9 A. The oxygen-oxygen distance along the edges of the dodecahedron is 2.76 A.

Fig. 15-15. A drawing similar to Fig. 15-13, showing the tetra-kaidecahedron, which has two hexagonal faces (not regular hexagons) and 12 pentagonal faces.

Mr. Hayward 26/6/52

I an planning to have some of the original figures for GENERAL CHEMISTRY and some of the new ones for COLLEGE CHEMISTRY used, and I suggest that your style be roughly intermediate between these.

Let me know if you have any questions - you can telephone me at home. I am pretty busy at the moment, or I would come over to talk with you about these figures.

Cordially yours,

Linus Pauling:W