Table 1. Changes in the Nuclear Independent Chemical Shift ΔNICSzz(1) (values in ppm) with Respect to Pure Couplers and Intramolecular Magnetic Exchange Coupling Constants (J, cm–1)a.
| coupler/diradical | ΔNICSzz(1), ppm | ΔNICSzz(1), ppm average | J, cm–1 UB3LYP/6-311++G(d,p) | J, cm–1 UMN12SX/6-311++G(d,p) | |
|---|---|---|---|---|---|
| I | I-A | (+3.85, −3.41, −3.41, +3.85) | +0.22 | 9.72 | 0.00 |
| I-B | (+3.89, −2.87, −2.87, +1.80) | –0.01 | –10.76 | –4.56 | |
| II | II-A | (+1.54, −3.09, +1.54) | 0.00 | 21.79 | 18.00 |
| II-B | (+1.53, −2.98, +1.53) | +0.03 | –26.72 | –20.80 | |
| III | III-A | (−5.25, −4.45, −5.25) | –4.98 | –95.8 | –41.69 |
| III-B | (−9.93, −15.98, −15.82) | –13.91 | 1200.77 | 153.38 | |
| IV | IV-A | (−0.07, −0.16, −0.16, −0.07) | –0.12 | –923.02 | –218.08 |
| IV-B | (−8.05, −14.65, −16.37, −9.56) | –12.16 | 350.29 | 272.24 | |
| V | V-A | (−3.92, −1.52, −1.52, −3.92) | –2.72 | 15.09 | 54.08 |
| V-B | (−0.28, −17.72, −18.63, −9.62) | –11.56 | 218.75 | 193.02 | |
| VI | VI-A | (−21.49, −17.94, −21.72) | –20.38 | –1181.17 | –568.12 |
| VI-B | (−30.38, −26.28, −29.95) | –28.87 | 571.42 | 289.18 | |
a
Optimized geometries and J values are calculated at the UB3LYP/6-311++G(d,p) Level of Theory.