0 Angle General

From these data it follows that increasing ring strain, i.e. smaller C C=C angles, generally leads to a shift to lower wave numbers. A linear correlation between wave numbers and experimental or calculated C C s C bond angles has been proposed 144) however some compounds, like l-cycloocten-4-yne, deviate significantly from the linear correlation. 

A. Lagana, G.O. de Aspuru, E. Garcia, The largest angle generalization of the rotating bond order potential Three different atom reactions, /. Chem. Phys. 108 (10) (1998) 3886-3896. 

In determining the structure of molecules, the lone pair-lone pair interactions are most important, with the lone pair-bonding pair interactions next in importance. In addition, interactions at angles of 90° or less are most important larger angles generally have less influence. In CIF3, structure B can be eliminated quickly because of... 

Photophysical processes are radiative or radiationless transitions by which molecules are promoted from one electronic state to another. No structural change results, although the bond lengths and angles generally differ somewhat in different electronic states. Radiative transitions are associated with the absorption or emission of a photon and are represented as straight arrows ( or j), while radiationless transitions are not associated... 

Conformation of the -(Pro) -fragment varies with the number of adjacent Pro residues and assumes a PLP Il-hke hehcal conformation in all-fnms isomers beginiiing with n = 3. This conformation also includes the Tip residue. Conformational rigidity of the backbone in the PLP Il-hke conformation increases with the growing n. In this conformation the i i(Pro) dihedral angle generally assumes a value in the P-range (+160°). 

There has also been some discussion that the contact angle generally observed is the extrapolation of the profile of the bulk drop to the solid surface ( macroscopic contact angle). The real contact angle ( microscopic ) is quite different. Differential ellipsometry can measnre molecnlar dimensions quite well and show that the microscopic contact angles are indeed qnite different (Heslot et al., 1992). 

Of special interest in biochemistry are P-O-P and P-O-C groups which occur in a wide range of P compounds. They are found to have average dimensions (3.123). The P/O/C angle generally lies within a smaller range than P/O/P, except in ring compounds where it may be as low as 105°... 

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