Page 88 - Advanced Organic Chemistry Part A - Structure and Mechanisms, 5th ed (2007) - Carey _ Sundberg

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SECTION 1.4
Representation of
Electron Density
Distribution

Fig. 1.29. Representation of the atoms in the second-row hydrides. The hydrides of Li, Be, and
B consist primarily of a core of decreasing radius and a small, but increasing, shared density.
The form of the atoms changes markedly at methane. No core is visible on the C atom, and the
H atoms are reduced in size and lie on the convex interatomic surface. The increasing polarity
of the remaining molecules is reflected in the decreasing size of the H atom and the increasing
convexity of the interatomic surface. Reproduced from R. F. W. Bader, Angew. Chem. Int. Ed.
Engl., 33, 620 (1994), by permission of Wiley-VCH.