Pyramid, Great

A great deal of information on the electronic structure and geometry of radicals in solution can be extracted from their ESR spectra, as it is well established that the values of hyperfine coupling constants (hfcc), arising from the spin density of the s-orbitals, markedly increase with increasing of the SOMO s-character. The pyramidalization of the radicals is manifested in higher values of their hfccs (o-radicals), whereas smaller values of the hfccs are indicative of the more planar radicals (tt-radicals). 

Doreal, M. Kabbalistic alchemical, and occult symbolism of the great pyramid. Denver (CO) Brotherhood of the White Temple, 1938. 47p. 

Compound 4a was isolated as a yellow solid and recrystallized from n-pentane at +4°C to give the first X-ray-structure of a phosphasilene [5] (Figure 1). The P=Si bond (2.094 A) is a little shorter than the P-Si bonds in 3a-c (2.11-2.13 A) but longer than the theoretically calculated values (2.04-2.06 A) [6]. This may be caused by a significant pyramidalization of the Si-atom (E, = 356.7°) and great steric hindrance. The Pl-Sil-P2-P3 atoms almost form a planar trapezoid with a rather short Pl-P3-distance (3.68 A). 

We can see so many lanthanide clusters behave as efficient SMMs in those p -O-fixed complexes. Especially, the energy barrier record (530 K) for polynuclear lanthanide SMMs, held by the p5-0-fixed Dy5 with a square-based pyramid, has not been broken by the end of 2013. Such a structural characteristic should support the isolation of a robust SMM to a great extent, which provides a change to explore new methods for achieving SMMs with high barriers. 

The uniqueness of the innervation of their targets by the granule cells underscores their function as gatekeeper. That is, excitatory principal neurons (e.g. CA3 pyramidal cell innervation of its targets in CA1) of mammalian forebrain typically innervate other excitatory neurons directly in great quantitative preference to inhibitory interneurons... 

Two of the worst outliers were N,N-dimethylformamide and N,N-dimethyl-acetamide. For both of these, solubility in water was greatly underestimated. This may illustrate a situation in which conformation does assume importance. In the gas phase structures used to compute the surface properties, the nitrogens are planar. There is reason to believe, however, that interaction with water molecules will cause the nitrogens to become pyramidal,48 since that produces more localized lone pairs that better attract water hydrogens. Thus, analysis involving planar nitrogens would not indicate the true strength of the interaction. 

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