1328 Bull. Chem. Soc. Jpn., 75, No. 6 (2002)
9-(o-,p-Substituted phenyl)(thio)xanthen-9-yliums
Table 2. 13C NMR Spectral Dataa) for 9-Arylxanthene and -thioxanthene Derivatives.
Com-
pouds
δ
1a
1bb)
1c
1d
1e
1f
1g
1h
1i
162.2, 158.1, 149.6, 128.7, 127.9, 122.4, 116.8, 115.6, 93.1, 71.5 (C–OH), 56.4 (2ꢀ,6ꢀ-MeO), 55.2 (4ꢀ-MeO).
157.3, 149.5, 128.9, 128.4, 128.3, 128.0, 127.8, 123.9, 122.4, 115.5, 106.7, 71.75 (C–OH), 56.5 (2ꢀ,6ꢀ-MeO).
155.9, 150.0, 136.0, 128.8, 128.6, 128.1, 127.0, 125.9, 122.8, 120.4, 115.8, 112.7, 68.8 (C–OH), 55.6 (2ꢀ-MeO).
158.0, 151.2, 142.0, 129.4, 128.9, 128.7, 127.5, 124.1, 123.3, 116.4, 116.1, 113.1, 75.0 (C–OH), 58.8 (4ꢀ-MeO).
158.8, 154.6, 149.5, 133.3, 129.8, 128.4, 127.8, 127.5, 122.6, 115.9, 110.7, 109.7, 72.2, 62.3 (2ꢀ-MeO), 56.5 (6ꢀ-MeO).
149.2, 138.2, 137.2, 136.4, 131.6, 128.9, 128.2, 127.8, 123.4, 116.2, 74.2, 24.2 (4ꢀ-Me), 20.6 (2ꢀ,6ꢀ-Me).
150.0, 143.7, 135.7, 131.9, 129.3, 128.7, 127.8, 125.8, 123.5, 125.7, 125.3, 116.3, 69.8, 20.6 (2ꢀ-Me).
145.1, 136.3, 129.0, 128.9, 128.6, 127.3, 126.1, 123.5, 116.4, 70.3, 21.0 (4ꢀ-Me).
149.6, 147.9, 129.0, 129.0, 127.9, 127.1, 126.7, 126.2, 123.5, 116.4, 70.4.
2a
2b
160.5, 158.4, 139.0, 129.3, 128.5, 126.4, 125.2, 124.5, 116.2, 92.9, 77.0, 56.5 (2ꢀ,6ꢀ-MeO), 55.2 (4ꢀ-MeO).
157.6, 138.6, 129.1, 129.0, 128.6, 126.5, 125.2, 124.3, 123.6, 106.5, 77.0, 56.5 (2ꢀ,6ꢀ-MeO).
2e
157.3, 157.0, 141.2, 138.7, 134.3, 129.4, 128.0, 125.5, 125.1, 122.2, 110.4, 109.7, 78.6, 63.0 (2ꢀ-MeO), 55.5 (6ꢀ-MeO).
157.0, 155.3, 138.0, 133.3, 129.6, 129.5, 128.2, 127.0, 125.4, 125.0, 110.5, 109.9, 77.3, 62.3 (2ꢀ-MeO), 56.6 (6ꢀ-MeO).
2nd
isomer
2f
2g
2h
138.2, 138.2, 137.4, 136.3, 131.5, 128.8, 128.8, 127.5, 126.1, 125.2, 80.0, 24.3 (2ꢀ,6ꢀ-Me), 20.7 (4ꢀ-Me).
147.8, 135.7, 133.4, 132.2, 131.7, 130.9, 127.3, 127.0, 125.4, 124.8, 123.8, 78.0, 23.7 (2ꢀ-Me).
140.2, 140.0, 137.4, 131.4, 128.6, 127.1, 126.8, 126.5, 126.3, 125.9, 76.9, 21.1 (4ꢀ-Me).
143.1, 139.7, 131.4, 127.9, 127.6, 127.1, 126.8, 126.5, 126.3, 126.0, 76.9.
2i
3a
3b
3c
3d
3e
3f
3g
3h
3i
174.3, 167.1, 160.0, 158.9, 144.9, 132.7, 129.7, 125.8, 120.5, 102.2, 92.7, 56.9 (2ꢀ,6ꢀ-MeO), 56.8 (4ꢀ-MeO).
174.9, 159.1, 158.4, 145.5, 135.7, 132.2, 130.1, 125.6, 120.7, 108.9, 105.8, 56.9 (2ꢀ,6ꢀ-MeO).
175.4, 159.3, 157.5, 145.4, 135.0, 132.5, 132.2, 130.1, 125.2, 122.0, 120.2, 118.2, 113.5, 56.7 (2ꢀ-MeO).
175.7, 164.8, 159.1, 144.5, 135.0, 133.1, 124.6, 124.6, 124.2, 120.5, 115.9, 56.7 (4ꢀ-MeO).
171.9, 159.5, 157.9, 155.5, 145.9, 138.5, 131.9, 130.5, 125.4, 120.8, 116.3, 110.9, 108.8, 62.6 (6ꢀ-MeO), 57.3 (2ꢀ-MeO).
178.8, 159.6, 145.9, 142.3, 136.6, 131.3, 130.8, 129.7, 128.6, 125.3, 121.1, 21.2 (4ꢀ-Me), 20.1 (2ꢀ,6ꢀ-Me).
177.1, 159.6, 145.7, 137.1, 132.4, 132.1, 131.9, 131.7, 130.5, 130.0, 126.9, 125.3, 120.7, 20.0 (2ꢀ-Me).
176.4, 159.3, 145.0, 144.6, 132.8, 132.0, 130.6, 130.1, 129.0, 124.8, 120.5, 21.6 (4ꢀ-Me).
176.2, 159.5, 145.4, 133.2, 132.8, 131.8, 131.4, 130.3, 130.0, 124.9, 120.6.
4a
4b
4e
4f
4g
4h
4i
170.7,c) 165.8, 159.3, 148.5, 138.5, 136.0, 132.1, 132.0, 128.6, 105.0,c) 92.5, 56.8 (2ꢀ,6ꢀ-MeO), 56.7 (4ꢀ-MeO).
170.5, 158.3, 148.7, 138.8, 135.6, 134.5, 132.3, 131.5, 128.7, 112.1, 105.7, 56.8 (2ꢀ,6ꢀ-MeO).
167.1, 157.7, 155.3, 149.0, 138.7, 137.5, 135.2, 132.5, 131.0, 128.8, 119.7, 110.6, 108.8, 62.0 (2ꢀ-MeO), 57.2 (6ꢀ-MeO).
174.0, 149.3, 141.7, 138.9, 136.6, 134.8, 132.8, 132.0, 130.9, 129.7, 129.0, 21.2 (4ꢀ-Me), 19.9 (2ꢀ,6ꢀ-Me).
172.8, 149.5, 138.7, 137.0, 135.8, 135.3, 132.4, 131.7, 131.6, 131.1, 129.8, 128.7, 127.0, 19.8 (2ꢀ-Me).
173.2,c) 149.2, 142.3, 138.4, 136.6, 132.7, 131.9, 131.5, 130.6, 130.2, 128.5, 21.5 (4ꢀ-Me).
172.6, 149.4, 138.5, 136.5, 135.6, 132.0, 131.6, 131.4, 130.3, 129.7, 128.5.
7b
7ib)
8b
8i
158.0, 150.0, 127.8, 127.1, 127.1, 125.4, 117.5, 108.5, 108.0, 106.3, 105.5, 69.4, 57.1 (2ꢀ,6ꢀ-MeO), 56.4, 56.0 (1,8-MeO).
158.0, 149.2, 149.2, 129.1, 126.4, 126.2, 125.4, 115.7, 109.4, 106.7, 70.6, 55.9 (1,8-MeO).
173.0, 162.8, 157.8, 156.2, 146.4, 132.1, 117.8, 111.0, 109.2, 109.2, 104.9, 58.3 (1,8-MeO), 56.7 (2ꢀ,6ꢀ-MeO).
175.7, 162.8, 157.9, 146.8, 140.3, 129.0, 128.3, 125.0, 117.8, 110.7, 109.6, 57.9 (1,8-MeO).
a) In CDCl3 (δ/ppm). b) Data from Ref. 1. c) Uncertain because the signal was very weak.
(+35) > 4b (+50) > 4h (+100) > 4f (+105) > 4i (+120) >
4g (+125) > 4e (+165).
Both series of salts 3 and 4 are deeply colored, and the UV-
visible spectra measured for 1,2-dichloroethane solution
(Table 2) showed one or two bands in the visible region with
log ε = 3.3 – 4.0. The UV-visible spectra of some 9-(p-substi-
tutedphenyl)xanthen-9-ylium and thioxanthen-9-ylium ions
have been reported, as measured in the presence of an ac-
id,14,21–26 as well as the xanthen-9-ylium and thioxanthen-9-yli-
um ions themselves.23 The formation of radicals, such as 5i
and 6i, by intermolecular charge transfer to 3i and 4i has been
inferred.24 In our previous paper, we reported on the UV-visi-
ble spectra of 3b, 3i, 8b, and 8i, as measured in aqueous hydro-
chloric acid.7 These visible band energies at the longest ab-
The E0 or Epc potentials must be parallel to the lowest unoc-
cupied molecular orbital (LUMO) energy of these ions 3, and
4, as shown in Fig. 2. The Epc potentials of 8b,i are also in-
cluded in Fig. 2. We have been interested in the effects of 1,8-
dimethoxy substitutions,7 since the presence of such groups
would increase the stability of 9-arylxanthen-9-ylium by a π-
electron-donation, but would interfere the π-conjugation of the
9-aryl group with the 9-arylxanthen-9-ylium π-system by a
steric interaction between the 1,8-dimethoxy groups and the 9-
aryl group.