Inductive Effects on Lewis Acidity and Basicity

TABLE 6.11 Blue Shifts in the 4n- Complexes in Heptane at 15° C - 9o- Transition in Ij 

Data from Lewis Basicity and Affinity Scales Data and Measurement, John Wiley and Sons, p. 33, 91-101, 295-302. 

Additional substitution increases the effect, with the following resulting order of Lewis base strength in the gas phase  

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