Table 2. Ionization Potentials (IP), Electron Affinities (EA), Exciton Binding Energies (E_exc), and Average Nucleus-Independent Chemical Shifts (<NICS(1)>) for the Cyclic and Linear Paraphenylenes. The NICS(1) Values Were Calculated at the PBE0/6-31G(d,p) Level of Theory, and All Other Properties Were Computed from PBE0/6-31+G(d,p) Electronic Energies on the N − 1, N, and N + 1 Electron Systems at the Neutral PBE0/6-31G(d,p)-Optimized Geometries.

	cyclic paraphenylenes				linear paraphenylenes
number of benzene rings	IP (eV)	EA (eV)	Eexc (eV)	<NICS(1)> (ppm)	IP (eV)	EA(eV)	Eexc (eV)	<NICS(1)>(ppm)
5	6.34	1.17	3.09	−8.14	7.05	0.51	2.62	−10.39
6	6.34	1.22	2.82	−8.92	6.90	0.66	2.46	−10.32
7	6.35	1.25	2.60	−9.46	6.80	0.76	2.32	−10.30
8	6.50	1.10	2.44	−10.17	6.71	0.84	2.21	−10.27
9	6.45	1.16	2.29	−10.12	6.64	0.92	2.10	−10.24
10	6.39	1.25	2.16	−9.99	6.58	0.98	2.02	−10.21
11	6.43	1.20	2.07	−10.13	6.52	1.04	1.93	−10.18
12	6.43	1.20	1.99	−10.17	6.48	1.08	1.87	−10.19
13	6.37	1.27	1.90	−10.06	6.45	1.12	1.81	−10.16
14	6.39	1.25	1.85	−10.15	6.41	1.16	1.75	−10.16
15	6.36	1.28	1.79	−10.12	6.38	1.19	1.70	−10.15
16	6.34	1.31	1.73	−10.10	6.35	1.22	1.65	−10.14
17	6.31	1.33	1.68	−10.07	6.33	1.24	1.61	−10.14
18	6.32	1.33	1.65	−10.11	6.31	1.26	1.57	−10.14