Solid state molecules

Chapter 6. The outer contour in this map is for a density of 0.001 au, which has been found to represent fairly well the outer surface of a free molecule in the gas phase, giving a value of 190 pm for the radius in the direction opposite the bond and 215 pm in the perpendicular direction. In the solid state molecules are squashed together by intermolecular forces giving smaller van der Waals radii. Figure 5.2b shows a diagram of the packing of the Cl2 molecules in one layer of the solid state structure of chlorine. From the intermolecular distances in the direction opposite the bond direction and perpendicular to this direction we can derive values of 157 pm and 171 pm for the two radii of a chlorine atom in the CI2 molecule in the solid state. These values are much smaller than the values for the free molecule in the gas phase. Clearly the Cl2 molecule is substantially compressed in the solid state. This example show clearly that the van der Waals of an atom radius is not a well defined concept because, as we have stated, atoms in molecules are not spherical and are also compressible. 

A Solid State, Molecule-based Sensor for CO The Solid-state Electrochemistry of Ferrocenyl Ferraazetine in MEEP/LiCF3S03. 

Solid-state CD can provide information on solute-solvent interactions when compared with the solution spectra in various solvents. The effects of solvents on the rotatory power are often the results of the formation of some kind of coordination compound between the solvent and the optically active molecules concerned in solution [10,18]. This may affect the optical activity of the molecule by way of conformation alteration in the case of flexible compounds, or through vicinal effects. In contrast, in the solid state, molecules are densely packed and are under a much stronger influence of neighboring molecules. In one sense, this situation can be regarded as an extreme case of the solvent effect [11]. Thus an unusual conformation of a chiral molecule that is unstable in solution may be... 

In the solid state, molecules line up in a pattern forming a crystal lattice similar to that of an ionic solid, but with less attraction between particles. The structure of the crystal lattice depends on the shape of the molecule and the type of intermolecular force. Most information about molecules, including properties, molecular shape, bond length, and bond angle, has been determined by studying molecular solids. 

Phosphonic acid (commonly called phosphorous acid) may be crystallized from the solution obtained by adding ice-cold water to P4O6 (equation 14.118) or PCI3 (equation 14.72). Pure H3PO3 forms colourless, deliquescent crystals (mp 343 K) and in the solid state, molecules of the acid (Table... 

Fig. 17.11 In the solid state, molecules of HIO3 fonn hydrogen-bonded chains. The structure was determined by neutron diffraction [K. Staahl (1992) Acta Chetn. Scand., vol. 46, p. 1146]. Colour code I, gold O, red H, white.

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