Nitrogen Configurations

Therefore, the nitrogen configuration in BENA and the energy barriers for both stereodynamic processes are influenced by two opposite factors and it is a priori difficult to predict the final result. 

Fig. 11.3 Nitrogen configuration example Indoline/cytochrome C peroxidase complex (PDB laek). Alternative hydrogen positions indicated by dotted lines.

The last example (Figure 11.3) underlines the importance of the correct nitrogen configuration. In the indoline/cytochrome C peroxidase complex, only one of the three sketched hydrogen positions allows for an interaction with an active site aspartate. 

All three approaches to isomerism - formal charges, tautomers, and nitrogen configurations - and the duplicate removal are put together in a nested loop as shown in the following piece of pseudocode ... 

For all nitrogen configurations Calculate hash code If not duplicate hash code Write isomer Save hash code... 

A determination of the structure of l,4-dibromocycl[3,2,2]azine (lp) was complicated by the considerable anisotropy of thermal motion of the bromine atoms. It was concluded that the nitrogen configuration is probably planar, but, if not, the nitrogen atom is less than 0.07 A out of the mean plane of the molecule.55... 

O2 has 16 electrons, 2 more than in Nj. These 2 extra electrons go into the (Iwg) orbitals. If we write this (Ng )(l7Tg, in which (Ng) stands for the closed nitrogen configuration, we see that different arrangements of the electrons in the (iTTg) orbitals are possible. Specifically, the electrons can be in different orbitals with the same or with opposite spin. 

Fig. 1. Basic Sets of Asymmetric Nitrogen Configurations in M(cyclam) and M(CTH) ...

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