Bond lengths and hybridization

Tablel3.1 Carbon-Carbon Single Bond Lengths and Hybridization State Compound Hybridization State Bond Length (A)...

Table 5.2-1 Correlation between force constant, bond length and hybridization for some hydrocarbons...

Table 8.3 Carbon-Hydrogen Single Bond Lengths and Hybridization Compound Length, A Hybridization...

Analogues of Alternative Transition States. The chair- and boat-like transition state structures are shown diagrammatically in Figure 2. They illustrate two problems of transition state analogue design. First, the partial bonds in transition state structures give rise to bond lengths and hybridization states which cannot be reproduced in stable molecules. Second, the number and variety of chemical features in transition state structures may be incompatible with synthetic feasibility. 

TABLE 13.1 CARBON-CARBON SiNGLE-BOND LENGTHS AND HYBRiDiZATiON STATE ... 

Ph2SnX2 have monomeric, tetrahedral structures (103, 121). The calculated values for the chlorides (1.66 and 1.92 mm sec ) are serious underestimates (observed 2.48, 2.82 mm sec ) which are low by a factor of cibout 1.5. This shows that the contribution of a ligand to the EFG is not independent of the coordination number (103, 115), which is consistent with the dependence of bond lengths and hybridization schemes and hence covalency on coordination number and stereochemistry. Separate scales may be necessary for each... 

Klasinc and Schulte-Frohlinde (1968), who also used HMO for the investigation of substituted benzene diazonium ions, were the first to realize that the remarkable distortion of bond lengths and angles of the benzene ring by the diazonio group (Sec. 4.2) has a significant influence on its reactivity. They found that the sp2-hybridization at the carbon atoms of the benzene ring varied from 1.75 for C(l) to 2.16 for C(2). 

As is well known, the intermediate bond orders of such a resonance hybrid correspond to bond lengths (and other bond properties) that are intermediate between the idealized single and double bonds of unconjugated species. 

Figure 2.47. (Bottom, left) Calculated XAS spectra of adsorbed -octane for different —C bond lengths and — —C angles corresponding to the indicated hybridization schemes. (Right) Calculated XES spectra for change in (top) carbon hybridization, (middle) distance to surface and (bottom) CH distance and orientation. From Ref. [96].

A number of structural questions will be addressed. What is the range of typical P=C bond lengths and how does this vary with substituent Is the C planar or pyramidal, and does this depend on substituents What is the geometry about P The answers to these questions will determine the hybridization of the P and C atoms. We shall also examine the density distribution to determine the charges on the atoms and the degree of d orbital participation. 

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