Inexpensive Models of Polyhedral Boranes and Metallocenes A simple and inexpensive method has been devised for the construction of scaled models of polyhedral (closo) boranes and rnetalloeenes, which serve as useful teaching aids in the discussion of symmetry and bonding in these two classes of compounds. For the construction of our models, we used wooden cocktail picks (available in various colors) and swab sticks (Q-tips) sold in supermarkets and drug stores. kssembly of the i d e d r a l skeleton of BlzH122-Serves as an illustration of the general method for eloso-horanes and earboranes. A pentagonal base is first formed by gluing five cocktail picks tip-to-tip with a rubber-base adhesive. When the sdehesive has dried, five mare picks are joined to a common vertex, using the base as a "foundation", to form a pentagonal pyramid. With two pentagonal pyramids positioned face-to-face, the "equatorial" band of ten triangular faces can be completed with ten more picks. The model is quite flexible before the adhesive completely dries uo. . .esoeciallv before the introduction of thelast oick.60 that fineadiustments can be made to eliminateanv noticeable dt.turt~on.The finkhed icoinhedron is already fairly rigid: n drop of epoxy r w n mny he applwd tc, em h vertex for added strength, and bits uf i.
