MÖbius Aromatics arising from a C=C=C ring component.

Sonsoles Martin-Santamaria, Balasundaram Lavan and Henry S. Rzepa*

Department of Chemistry, Imperial College of Science, Technology and Medicine, London, SW7 2AY, UK.

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Supplemental Data.

Table.Energies (kcal mol^-1 for AM1, Hartree for RHF/6-31G(d)) and NICS values (ppm) for the ground states.

	AM1	RHF/6-31G(d)	NICS	Dihedral angle (^o)^a
1	155.3 (orbitals)	b	-	8
2	147.1	-191.4900	2.1	-
3	c	c	-	-
4	57.3	-230.0200	-9.8	-
5	95.7	-268.4477^d	-6.5	51
6	117.0	-268.4241	-7.0	-
8	279.1	-306.6502	-5.6	65
9	575.9^e	-344.6697	-3.3	86
10	96.8	-383.7313	-5.1	87
11	173.6	-347.4759^f	-14.2	41
12	200.7	-420.9538	-4.7	37
13	178.5	-420.9954	-14.9	-
14	273.8	-963.7914	-10.9	27
15	72.9	-1415.9675	-0.4^g	75
16	140.0	-344.1344	-3.3	67
17	229.2	-304.9946	-11.1	53
18	138.7	-306.2419	-2.1	50
19	175.5	-344.0594	+0.3	50
20a^h	182.2	-422.0950	-5.7	66
20b^h	181.0	-499.0069	+0.3	66
20c^h	183.5	-575.9171	-2.2	69

^a Dihedral angle between the two termini of the allene. ^b Converges to 2 on optimisation. ^c Converges to 4 on optimisation. ^d The energy for 5 was &endash;270.2424 Hartree and the NICS value was &endash;5.7 at the B3LYP/6-31G(d) level. ^e Triplet energy of neutral form 133.0 kcal mol^-1. ^f B3LYP/6-31G(d) energy; RHF/6-31G(d) optimisation converges to a planar geometry. ^g The energy for 1,3,5,2,4-trithiadiazepine was &endash;1378.1686 Hartree and the NICS value was &endash;9.3 at the RHF/6-31G(d) level. ^h 20a is the analogue of 10-trannulene; 20b is the analogue of 12-trannulene; 20 is the analogue of 14-trannulene.

Figure 2. Calculated geometry (, AM1 (RHF-6-31G*) [B3LYP/6-31G*] and form of the HOMO and HOMO-1 orbitals for 5.

Figure 3. Calculated AM1 form of (a) the HOMO and HOMO-1 orbital for 17 and (b) the HOMO and HOMO-1 orbital for 16.