Static and Dynamic Configurations

Stereochemistry of Pentacoordinate Phosphorus Derivatives 2.1. Static and Dynamic Configurations 

The molecules are trigonal bipyramids or distorted trigonal bipyramids rather than the alternative square pyramid. 

The more electronegative substituents (fluorine) preferentially occupy the axial sites in the trigonal bipyramid. 

Axial bonds are longer than the corresponding equatorial bonds. 

All the corresponding bond lengths and the ratio of the length of the axial bonds to that of the equatorial bonds, r /r, increase, the former linearly, as the number of methyl substituents increases. 

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Atd = A t s atoms move at velocity just slow enough to be trapped by and/or fast enough to escape from the potential, d>(% ). The static and dynamic configuration therefore... 

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