Table 3.

Calculated npa charges on selected atoms in the 2,4-dinitrophenyl halide substrates and their transition states (ts) formed by reaction with dimethylamine and piperidine at carbon-1 (C1).

charge at indicated atom	ArF	ArCl	ArBr
nucleophile = dimethylamine, MP2/6-31+G*//HF/6-31+G* (gas phase)
C1, substrate		−0.073	−0.150
C1, ts	0.459	0.012	−0.047
halogen, substrate		0.088	0.144
halogen, ts	−0.350	0.018	0.063
nucleophile = dimethylamine, MP2/6-31+G*//HF/6-31+G* (methanol)a
C1, substrate	0.420	−0.076	−0.148
C1, ts	0.465	0.017	−0.041
halogen, substrate	−0.325	0.080	0.149
halogen, ts	−0.354	−0.016	−0.060
nucleophile = piperidine, MP2/6-31+G*//HF/6-31+G* (gas phase)
C1, substrate		−0.073	−0.150
C1, ts	0.455	0.005	−0.053
halogen, substrate		0.088	0.144
halogen, ts	−0.347	0.021	0.066
nucleophile = piperidine, MP2/6-31+G*//HF/6-31+G* (methanol)a
C1, substrate	0.420	−0.076	−0.148
C1, ts	0.460	0.010	−0.048
halogen, substrate	−0.325	0.080	0.149
halogen, ts	−0.352	0.017	0.062

^aSolvent calculations used the polarizable continuum model (PCM) applied to the optimized HF/6-31+G* gas phase geometry.