George Olah passed away on March 8th. He was part of the generation of scientists in the post-war 1950s who had access to chemical instrumentation that truly revolutionised chemistry.
AbstractThe structure of the 1,2,4,7‐anti‐tetramethylbicyclo[2.2.1]heptan‐2‐yl cation (1) was redetermined by X‐ray crystal structure analysis of its Sb2F11 salt at 110 K (P21/c, R1 = 5.76%). The most important structural features of 1 are: C(1)C(2) = 1.409(9), C(1)C(6) = 1.710(8), and C(2)…C(6) = 2.113(9) Å and C(2)C(1)C(6) = 84.7(4)°. These results agree with those obtained earlier by other methods for the rapidly equilibrating, partially s̀‐delocalized 1,2‐dimethylbicyclo[2.2.1]heptan‐2‐yl cation (2). The detailed experimental procedure for the preparation of crystalline 1 · Sb2F11 and the crystal selection and mounting are described.
A Nonclassical Conclusion The concept of valence, which underlies the Periodic Table, originated in studies of reactivity rather than structure. Nonetheless, when studies in the mid-20th century suggested that the transient norbornyl cation (C 7 H 11 + ) reacted as though a carbon center had adopted a formally pentacoordinate motif, this nonclassical structural hypothesis engendered tremendous controversy. Scholz et al. (p. 62 ) have now succeeded in characterizing the norbornyl cation by x-ray crystallography and confirm the symmetrical fivefold motif.