Lengths compilation

Details of bond lengths and bond angles for all the X-ray structures of heterocyclic compounds through 1970 are listed in Physical Methods in Heterocyclic Chemistry , volume 5. This compilation contains many examples for five-membered rings containing two heteroatoms, particularly pyrazoles, imidazoles, Isoxazoles, oxazoles, isothlazoles, thlazoles, 1,2-dlthloles and 1,3-dlthloles. Further examples of more recent measurements on these heterocyclic compounds can be found in the monograph chapters. 

M. P. Seah and W. A Dench. Surf. Interface Anal. 1,1, 1979. Of the many compilations of measured mean free path length versus KE, this is the most thorough, readable, and useful. 

Sulfone molecular structures, including sulfuryl halides, have been repeatedly reviewed through the late seventies28 and early eighties5. Scheme 1 contains a list of the compounds discussed in these references. While the structures of these compounds will be discussed, recent structural information that was not included in the above compilations will be described initially. The relevant substances are listed in Table 3 along with the S=0 bond lengths and OSO bond angles. 

Table 8-4. Compilation of mean absolute deviations for bond lengths [A] / bond angles [degrees] for small main group molecules from different sources.

The compilation of bond length and angle information, all of which must agree with known chemical principles, enables one to deduce the molecular conformation of the molecule in question. Such illustrations are usually provided in the form of ORTEP drawings, where atomic sizes are depicted in the form of ellipsoids at the 50% probability level. The molecular conformation of theophylline in the anhydrate and monohydrate phase is shown in Fig. 7.4. As would be expected from a rigid and planar molecule, these conformations do not differ significantly. 

As compiled in Table 2, the sequence C60 —1 [C60] — [C60]2- displays variations in the typical C/C bond lengths which agree with the theoretical assumption that the tlu orbitals are antibonding with respect to the 6 6 carbon/carbon double bonds and bonding with respect to the 5 6 carbon/carbon single bonds. 

The corresponding neutral congener possesses a substantially similar geometry. Table 10 compiles the most significant bond lengths of the redox couple. 

All the square planar members of the series [Ni(dmit)2]2-/ [Ni(dmit)2] /[Ni(dmit)2]° have been structurally characterized and their significant bond lengths are compiled in Table ll.80... 

In Tables -A, we report oscillator strengths for some fine structure transitions in neutral fluorine, chlorine, bromine and iodine, respectively. Two sets of RQDO/-values are shown, those computed with the standard dipole length operator g(r) = r, and those where core-valence correlation has been explicitly introduced, Eq. (10). As comparative data, we have included in the tables /-values taken from critical compilations [15,18], results of length and velocity /-values by Ojha and Hibbert [17], who used large configuration expansions in the atomic structure code CIVS, and absolute transition probabilities measured through a gas-driven shock tube by Bengtson et al. converted... 

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