Bonding comparison

These structures show that RpII essentially consists of the small core of four-stranded )9-sheet and three relatively large loops. Residues 6-16, 23-30, and 35-40 form loops 1, 2, and 3, respectively, and the chain reversals are accomplished by tight turns involving residues D8-D11, E28-E31, and V36-P39. Segments involved in )5-sheet strands and loops alternate in the primary sequence of Rp toxins. As mentioned above, these structures indicate that the )5-sheet is highly twisted in order to form the correct disulfide bonds. Comparison of different refined structures of RpII indicate that the structure of loop 1 in RpII is less well defined than... 

Both sand and silt surfaces are dominated by oxygen and its lone pairs of electrons in p orbitals. In some instances, broken surfaces may also have silicon-hybridized sp3 orbitals4 available for bonding. Comparison of sand, silt, and clay reveals the surface area of sand and silt to be low and the interaction between surface bonding orbitals and components in the surrounding medium relatively weak. 

Finally, if one has completed ring probe and fragment probe searches for a specific query structure and is still confronted with a sizeable file of compounds that satisfy the criteria that were nominated, a sub-structure search through this file may be carried out. This involves an atom-by-atom, bond-by-bond comparison of every struc-... 

The obtained group of k possible candidates is much shorter than the entire file. On the k candidates atom-by-atom and bond-by-bond comparison must be made (Fig. 4.5). 

To ascertain the relative configurations of the dimers, each was synthesized specifically, using protecting groups that allow directed formation of disulfide bonds. Comparison of retention behavior of the specifically synthesized dimers with those synthesized non-specifically showed that F2 corresponds to the antiparallel dimer (Fig. 1) and the slower eluting component to the parallel isomer. 

Significance of force constants for chemical bonding. Comparison with other properties of bonds... 

Over the last decade, developments in high-resolution NMR techniques for solids have been extended to mercury nuclei. Solid-state NMR studies provide more definitive characterization of mercury complexes since their interpretation is not compromised by exchange processes or solvent coordination. While medium effects on spectra are not absent in the solid-state, they are generally more defined and therefore studied more readily. Furthermore, the chemical shift anisotropy, coupling constant anisotropy, and dipolar coupling constants obtained by solid-state NMR provide an additional probes into structure and bonding. Comparison of solid-state NMR spectra of structurally characterized complexes with solution-state NMR spectra promises to reveal significant differences between the solution and solid-state structures. 

HO-6 group by a hydrogen bond. Comparison of intermolecular contacts of the substituent group indicates that the (S)-2-hydroxypropyl group is better fitted to the cavity than the (i )-2-hydroxy-propyl group. 

Key properties of noble gases are summarized in Table 1 other properties are in refs. 6 and 11. The formation and detection of M-Ng bonds provide many of the same challenges as for transition metal-alkane bonds. Comparison of spectra and energetics of species such as Cr(CO)5Xe and Cr(CO)s(alkane) points to further similarities in bond enthalpies. Recent reviews tackle complexes of alkanes in detail . Since investigations of alkane complexes are more frequent than those of xenon complexes, we may use these results to anticipate the formation of further M-Ng bonds [e.g., to HMn(CO)4]. 

Gilli, P., Bertolasi, V., Ferretti, V., and Gilli, G., Chemical classification and H-bond energy evaluation for the heteronuclear intermolecular N-H- - -O bond. Comparison with the homo-nuclear O-H- - -O case (http //www.xray.cz/ecm-cd/ ecm/abstract/all/311.htm). 

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