Synthesis of soluble halogenated aryloxy substituted indium phthalocyanines

Abstract

Phthalocyanines solubilised by either 8 or 16 aryloxy or haloaryloxy groups are described. A series of phthalocyanine derivatives were prepared containing indium. 1,2-Dinitriles and the corresponding diiminoisoindolines were used as precursors. A naphthalocyanine metallated with indium and solubilised with four tert-butyl groups is reported.

---

Introduction

Optical limiters or reverse saturable absorbers are materials which display diminishing transmittance with increasing incident light intensity. This attenuation of the optical throughput can be used to protect various sensors against damage from pulsed laser sources.^1–5 Phthalocyanines are promising candidates for certain applications.⁶ Peripheral substituents can fine-tune the ground state absorption to help create a good visible window by red shifting the long wavelength Q band absorption. A range of different metals can also be incorporated to help achieve desirable excited state characteristics. Population of triplet excited states from singlet states by intersystem crossing is desirable because more strongly absorbing triplet states can have a longer lifetime and enhance the limiter performance. Heavy metals, halogens and paramagnetic groups are known to promote intersystem crossing and so the synthesis of suitably functionalised phthalocyanines containing these features is of interest.⁶ Phthalocyanines containing the metals Al, Si, V and In have been studied and shown to possess desirable properties.⁶

Results and discussion

This paper reports the synthesis of unmetallated aryloxy substituted phthalocyanines 24–26, metallated phthalocyanines 27–33 and 35–36 containing indium, a phenylthio substituted phthalocyanine 34 containing indium and a naphthalocyanine (a tetrabenzo[b,k,t,c₁]phthalocyanine) 37 containing indium. Aryloxy groups substituted with fluoro, chloro, bromo or iodo groups were incorporated to allow the influence of remote halogens upon optical limiter performance to be investigated. The oxygen group itself causes a bathochromic shift of the long wavelength absorption maximum^7–10 which helps to widen the visible window. 4,5-Diaryloxy substituted dicyanobenzenes 3–9 were prepared by treatment of 4,5-dichloro-1,2-dicyanobenzene 1 with an appropriate phenol and K₂CO₃ in DMSO. Compound 1 was prepared by a literature route from 4,5-dichlorobenzene-1,2-dicarboxylic acid.¹¹ Dinitrile 10 was prepared by treating 1 with thiophenol and base. Tetrakis(4-chlorophenoxy)-1,2-dicyanobenzene 11 was prepared by treating commercially available tetrafluorophthalonitrile 2 with 4-chlorophenol and K₂CO₃ in DMSO. Related tetrakis(aryloxy)-1,2-dicyanobenzenes have been reported previously.¹² 6-tert-Butyl-2,3-dicyanonaphthalene 14 was prepared by the literature route shown in Scheme 1.¹³ This involved free radical bromination of o-xylene 12 to give tetrabromoxylene 13. Treatment with NaI in hot DMF eliminates bromine to give an intermediate diene which is intercepted by cycloaddition with fumaronitrile. Elimination of two more moles of HBr gives naphthalonitrile 14. Treatment of the above dinitriles with ammonia gas in NaOMe–MeOH^14–17 gave the corresponding diiminoisoindolines 15–23. The progress of the reaction can be monitored by IR observing the disappearance of the nitrile peak from 2230–2250 cm⁻¹. A large broad peak in the range 3200–3500 cm⁻¹ corresponding to the NH stretch is observed. The diiminoisoindolines were used for the synthesis of InCl substituted phthalocyanines.

Scheme 1 Reagents and conditions (i) NBS–AIBN, 56%; (ii) NaI–fumaronitrile–DMF, 43%.

Non-metallated phthalocyanines 24–26 substituted with 8 aryloxy groups were prepared by cyclotetramerisation of dinitriles 3, 8 and 9 respectively with the base DBU in hot pentanol.^11,18–20 On cooling the precipitated product was isolated by filtration. Metallated phthalocyanines 28–31 containing indium were prepared by cyclotetramerisation of the corresponding dinitriles by heating with InCl₃ in quinoline.²¹ The other indium containing phthalocyanines were most satisfactorily prepared by heating the appropriate diiminoisoindoline with InCl₃ in quinoline. Treatment of phthalocyanine 29 with PhMgBr displaces the chlorine group with a phenyl group to give compound 36. Similar methods have been used to prepare a range of indium containing phthalocyanines substituted with different axial groups.²¹ Naphthalocyanine 37 was prepared as a mixture of isomers by cyclotetramerisation of dihydrodiimino-1H-benz[f]isoindole 23 by heating with InCl₃ in quinoline.

The UV spectrum of each phthalocyanine is important because a low absorption cross section in the visible region provides the optical window for an RSA device. The octasubstituted aryloxyphthalocyanines 24–26 have a long wavelength absorption at around 700 nm. Substitution with InCl produces little overall change in this absorption maximum. The octakis(arylthio)phthalocyanine 34 containing InCl has a long wavelength maximum at 735 nm which is shifted bathochromically by about 50 nm compared to the value for the corresponding octakis(aryloxy)phthalocyanine 27. Sulfur substituents produce a greater bathochromic shift than oxygen substituents. Phthalocyanine 35 substituted with 16 aryloxy groups shows a maximum at 738 nm which is shifted bathochromically compared to the octakis(aryloxy)phthalocyanine 27. Naphthalocyanines are of particular interest for optical limiters because of the much wider visible window that they exhibit. Naphthalocyanine 37 has a main maximum at 793 nm. This peak is bathochromically shifted compared to the InCl containing phthalocyanines.

In summary a range of different phthalocyanines have been prepared which will allow a study of the influence of structural factors upon optical limiting performance to be evaluated.

Experimental

Ultraviolet spectra were recorded on a Perkin-Elmer Lambda 15 UV-VIS spectrometer using dichloromethane as the solvent. Infrared spectra were recorded on an ATI Mattson FTIR spectrometer. ¹H and ¹³C NMR spectra were obtained at 250 MHz and 62.9 MHz respectively on a Bruker AC 250 spectrometer and at 400 MHz and 100.5 MHz respectively on a Varian 400 spectrometer. Chemical shifts, δ, are given in ppm relative to SiMe₄. Coupling constants, J, are given in Hz. Mass spectra were carried out at the University of Wales, Swansea using either the low resolution electron impact or fast atom bombardment methods. Butterworth Laboratories, using a PE 2400 CHN analyser, conducted elemental analyses. Melting points were carried out using a Kofler hot-stage microscope and are uncorrected.

4,5-Disubstituted 1,2-dicyanobenzenes

General procedure. 4,5-Dichloro-1,2-dicyanobenzene 1 (1.97 g, 10 mmol) and 60 mmol of a phenol or thiophenol were heated at 90 °C in DMSO (20 ml) with stirring under N₂. K₂CO₃ powder ( 2.76 g, 20 mmol) was added in portions (8 × 20 mmol) every 5 min. The mixture was heated for a further 30 min. After cooling the mixture was added to ice–H₂O (200 ml), filtered and the product was recrystallised from MeOH.

4,5-Diphenoxy-1,2-dicyanobenzene 3. Yield 70%, mp 148–149 °C (lit. 149 °C¹¹) (Found: C, 76.8; H, 3.9; N, 9.1. C₂₀H₁₂N₂O₂ requires C, 76.9; H, 3.85; N, 9.0%); λ_max(EtOH)/nm 296; ν_max (KBr)/cm⁻¹ 688, 747, 818, 876, 906, 1074, 1162, 1210, 1246, 1304, 1397, 1457, 1501, 1561, 1591, 1609 and 2236; δ_H (250 MHz; CDCl₃) 7.08 (4H, d, J 7.6), 7.15 (2H, s), 7.30 (4H, t) and 7.45 (2H, t); δ_C (62.9 MHz; CDCl₃) 110.4, 115.0, 120.0, 122.0, 126.0, 130.6, 152.0 and 154.1; m/z (EI) 312 (M⁺, 100%).

4,5-Bis(p-fluorophenoxy)-1,2-dicyanobenzene 4. Yield 72%, mp 186–188 °C (Found: C, 68.7; H, 3.0; N, 7.8. C₂₀H₁₀N₂O₂F₂ requires C, 69.0; H, 2.9; N, 8.0%); λ_max(EtOH)/nm 291; ν_max (KBr)/cm⁻¹ 784, 854, 863, 1011, 1087, 1190, 1207, 1298, 1384, 1495, 1569, 1617 and 2229; δ_H (400 MHz; CDCl₃) 7.01 (4H, m), 7.10 (4H, m) and 7.12 (2H, s); δ_C (100.5 MHz; CDCl₃) 111.6, 115.9, 118.3, 118.5, 122.5, 122.6, 150.8, 150.9, 152.9, 160.0 and 162.5; m/z (EI) 348 (M⁺, 100%).

4,5-Bis(p-chlorophenoxy)-1,2-dicyanobenzene 5. Yield 70%, mp 188–190 °C (Found: C, 63.2; H, 2.5; N, 7.3. C₂₀H₁₀N₂O₂Cl₂ requires C, 63.0; H, 2.6; N, 7.35%); λ_max(EtOH)/nm 293; ν_max (KBr)/cm⁻¹ 772, 824, 1010, 1090, 1187, 1223, 1303, 1324, 1399, 1483, 1502, 1581, 1599 and 2226; δ_H (250 MHz; CDCl₃) 7.0 (4H, d, J, 9.2), 7.2 (2H, s) and 7.4 (4H, d, J 9.2); δ_C (62.9 MHz; CDCl₃) 111.1, 114.7, 116.7, 121.0, 122.4, 130.7, 151.5 and 152.7; m/z (EI) 380/382/384 (M⁺, 100%).

4,5-Bis(p-bromophenoxy)-1,2-dicyanobenzene 6. Yield 78%, mp 212–214 °C (Found: C, 51.2; H, 1.9; N, 5.9. C₂₀H₁₀N₂O₂Br₂ requires C, 51.1; H, 2.1; N, 6.0%); ν_max(EtOH)/nm 292; ν_max (KBr)/cm⁻¹ 773, 862, 1012, 1067, 1221, 1305, 1323, 1398, 1484, 1503, 1576, 1597 and 2225; δ_H (250 MHz; CDCl₃) 7.0 (4H, d, J 8.9), 7.2 (2H, s) and 7.5 (4H, d, J 8.9); δ_C (62.9 MHz; CDCl₃) 111.2, 114.7, 118.9, 121.4, 122.6, 133.7, 151.4 and 153.3; m/z (EI) 468/470/472 (M⁺, 100%).

4,5-Bis(p-iodophenoxy)-1,2-dicyanobenzene 7. Yield 76%, mp 214–217 °C (Found: C, 42.2; H, 1.6; N, 5.0. C₂₀H₁₀N₂O₂I₂ requires C, 42.4; H, 1.8; N, 4.95%); λ_max(EtOH)/nm 292; ν_max (KBr)/cm⁻¹ 768, 830, 1009, 1220, 1305, 1324, 1395, 1481, 1502, 1564, 1598 and 2224; δ_H (250 MHz; CDCl₃) 7.73 (4H, d, J 8.85), 7.21 (2H, s) and 6.80 (4H, d, J 8.85); δ_C (62.9 MHz; CDCl₃) 89.6, 111.2, 114.7, 121.7, 122.7, 139.6, 151.3 and 154.1; m/z (EI) 564 (M⁺, 100%).

4,5-Bis(cumylphenoxy)-1,2-dicyanobenzene 8. Yield 82%, mp 166–168 °C (Found: C, 83.15; H, 5.8; N, 5.3. C₃₈H₃₂N₂O₂ requires C, 83.2; H, 5.8; N, 5.1%); λ_max(EtOH)/nm 292; ν_max (KBr)/cm⁻¹ 701, 798, 1015, 1215, 1319, 1385, 1499, 1561, 1590, 2236 and 2959; δ_H (250 MHz; CDCl₃) 1.71 (12H, s), 6.96 (4H, m), 7.16 (2H, m) and 7.18–7.31 (14H, m); δ_C (62.9 MHz; CDCl₃) 30.7, 42.7, 109.9, 115.2, 119.4, 121.7, 125.9, 126.8, 128.2, 129.0, 148.7, 150.0, 151.8 and 152.1; m/z (EI) 548 (M⁺, 100%).

4,5-Bis(3,5-di-tert-butylphenoxy)-1,2-dicyanobenzene 9. Yield 91%, mp 240–241 °C (Found: C, 80.4; H, 8.0; N, 5.4. C₃₆H₄₄N₂O₂ requires C, 80.6; H, 8.2; N, 5.2%) λ_max(EtOH)/nm 308; ν_max (KBr)/cm⁻¹ 706, 898, 918, 952, 1077, 1220, 1291, 1418, 1435, 1505, 1576, 1605, 2230, 2867, 2903 and 2962; δ_H (250 MHz; CDCl₃) 1.33 (36H, s), 6.90 (4H, s), 7.10 (2H, s) and 7.35 (2H, s); δ_C (62.9 MHz; CDCl₃) 31.4, 35.0, 109.7, 114.7, 115.4, 120.5, 152.5, 153.4, 153.9, 155.0; m/z (EI) 536 (M⁺, 100%).

4,5-Bis(phenylthio)-1,2-dicyanobenzene 10. Yield 46%, mp 157–159 °C (lit. 159 °C⁷) (Found: C, 69.6; H, 3.4; N, 8.0; S, 18.5. C₂₀H₁₂N₂S₂ requires C, 69.8; H, 3.5; N, 8.1; S, 18.6%); λ_max(EtOH)/nm 293; ν_max (KBr)/cm⁻¹ 1210 and 2227; δ_H (250 MHz; CDCl₃) 7.0 (2H, s) and 7.54 (10H, m); δ_C (62.9 MHz; CDCl₃) 111.8, 115.4, 128.6, 130.0, 130.7, 135.2 and 144.2 (one resonance is missing); m/z (EI) 344 (M⁺, 100%).

3,4,5,6-Tetrakis(p-chlorophenoxy)-1,2-dicyanobenzene 11. 4-Chlorophenol (19.3 g, 150 mmol) and 3,4,5,6-tetrafluoro-1,2-dicyanobenzene (3.93 g, 19.63 mmol) in DMSO (50 ml) at 90 °C under N₂ were treated with 12 portions of K₂CO₃ (2.76 g, 20 mmol) at 5 min intervals. After heating for a further 1.5 h the mixture was allowed to cool, added to ice–H₂O (400 ml) and filtered to give the product as a colourless solid which was recrystallised from MeOH. Yield 20%, mp 208–210 °C (Found: C, 60.6; H, 2.4; N, 4.4. C₃₂H₁₆N₂O₄Cl₄ requires C, 60.8; H, 2.5; N, 4.4%); ν_max(EtOH)/nm 290; ν_max (KBr)/cm⁻¹ 650, 824, 982, 1012, 1089, 1166, 1205, 1302, 1375, 1440, 1486, 1561, 1588 and 2231; δ_H (250 MHz; CDCl₃) 6.43 (4H, d, J 8.85), 6.72 (4H, d, J 8.85), 7.11 (4H, d, J 9.2) and 7.22 (4H, d, J 9.2); δ_C (62.9 MHz; CDCl₃) 108.4, 111.1, 116.8, 117.5, 129.5, 129.6, 129.8, 129.9, 146.5, 149.1, 153.9 and 154.8; m/z (EI) 632/634/636/638 (M⁺, 100%).

1,2-Bis(dibromomethyl)-4-tert-butylbenzene 13. ¹³ A mixture of 4-tert-butyl-o-xylene 12 (5.0 g, 31 mmol), N-bromosuccinimide (NBS) (21.9 g, 123 mmol) and a small quantity of AIBN in CCl₄ was heated under reflux for 10 h. The reaction mixture was filtered while hot and the solvent was removed in vacuo and the crude product used without further purification owing to the reactivity of the bis(dibromomethyl) groups. Yield 56%, δ_H (250 MHz; CDCl₃) 1.34 (9H, s), 7.11 (2H, s), 7.18 (1H, s), 7.39 (1H, d, J 8.2) and 7.60 (1H, d, J 8.2); δ_C (62.9 MHz; CDCl₃) 31.1, 36.7, 125.8, 126.0, 127.1, 127.3, 127.8, 129.6, 130.9 and 153.8; m/z (FAB) 474/476/478/480/482 (M⁺, 100%).

6-tert-Butyl-2,3-dicyanonaphthalene 14. A mixture of crude 1,2-bis(dibromomethyl)-4-tert-butylbenzene 13 (14.7 g, 31 mmol), fumaronitrile (2.4 g, 31 mmol) and sodium iodide (30 g, 0.2 mol) in DMF was heated at 75–80 °C for 7 h. The reaction mixture was cooled to room temperature and an aqueous solution of Na₂SO₄ was added. The precipitate was filtered and washed with CH₂Cl₂ to give the title compound (3.1 g, 43%) mp 193–194 °C (lit. 194–195 °C¹³); ν_max (KBr)/cm⁻¹ 471, 840, 901, 926, 1262, 1384, 1624, 2229, 2871, 2904 and 2954; δ_H (250 MHz; CDCl₃) 1.43 (9H, s), 7.90 (3H, m), 8.29 (1H, s) and 8.31 (1H, s); δ_C (62.9 MHz; CDCl₃) 30.9, 35.5, 109.3, 109.9, 116.2, 123.9, 128.4, 130.0, 131.5, 133.4, 135.4, 135.9 and 154.6 (one resonance is missing); m/z (FAB) 234 (M⁺, 100%).

5,6-Disubstituted 1,3-diiminoisoindolines

General procedure. ^14–17 The dicyanobenzene (7 mmol) derivative was gently refluxed in NaOMe–MeOH solution (200 ml, 0.7 g Na in 500 ml MeOH) for 5 h with NH₃ bubbled through the solution. The end point was determined by observing the disappearance of the CN stretch on aliquots examined by IR. The reaction mixture was allowed to cool and concentrated under vacuum to give the crude product. They were used immediately in the preparation of the corresponding InCl phthalocyanines without further purification.

5,6-Diphenoxy-1,3-diiminoisoindoline 15. Yield 97%, λ_max(EtOH)/nm 284; ν_max (KBr)/cm⁻¹ 565, 741, 871, 1030, 1069, 1211, 1270, 1385, 1458, 1490, 1597, 1637, 2853, 2925 and 3430; δ_H (400 MHz; CDCl₃) 6.80 (3H, m, 3 × NH), 7.00 (4H, m), 7.11 (4H, m), 7.20 (2H, s) and 7.34 (2H, m); δ_C (100.5 MHz; CDCl₃) 114.6, 116.5, 120.0, 121.3, 125.8, 131.1, 152.2 and 157.1; m/z 329 (M⁺, 100%).

5,6-Bis(p-fluorophenoxy)-1,3-diiminoisoindoline 16. Yield 97%, λ_max(EtOH)/nm 293; ν_max (KBr)/cm⁻¹ 1201 and 3428; δ_H (400 MHz; CDCl₃) 6.91 (3H, m), 7.11 (4H, m), 7.21 (2H, s) and 7.26 (4H, m); δ_C (100.5 MHz; CDCl₃) 112.7, 118.2, 119.9, 120.1, 126.3, 126.4, 152.3, 152.4, 154.0, 160.2 and 162.9; m/z (EI) 365 (M⁺, 100%).

5,6-Bis(p-chlorophenoxy)-1,3-diiminoisoindoline 17. Yield 97%, λ_max(EtOH)/nm 288; ν_max (KBr)/cm⁻¹ 824, 1010, 1090, 1143, 1213, 1284, 1407, 1485, 1543, 1637, 2854, 2932, 2965 and 3417; δ_H (400MHz; CDCl₃) 6.87 (3H, m), 7.12 (4H, d), 7.24 (2H, s) and 7.49 (4H, d); δ_C (100.5 MHz; CDCl₃) 112.3, 116.2, 118.4, 123.1, 124.6, 131.4, 154.3 and 154.6; m/z (EI) 397/399/401 (M⁺, 100%).

5,6-Bis(p-bromophenoxy)-1,3-diiminoisoindoline 18. Yield 97%, λ_max(EtOH)/nm 289; ν_max (KBr)/cm⁻¹ 822, 1009, 1070, 1164, 1211, 1297, 1411, 1482, 1580 and 3416; δ_H (400 MHz; CDCl₃) 6.80 (3H, m), 7.02 (4H, d), 7.32 (2H, s) and 7.59 (4H, d); δ_C (100.5 MHz; CDCl₃) 112.5, 116.3, 120.8, 122.4, 124.9, 136.3, 152.7 and 155.0; m/z (EI) 485/487/489 (M⁺, 100%).

5,6-Bis(cumylphenoxy)-1,3-diiminoisoindoline 19. Yield 97%, λ_max(EtOH)/nm 286; ν_max (KBr)/cm⁻¹ 701, 867, 961, 1080, 1202, 1298, 1363, 1421, 1479, 1594, 1655, 2867, 2904, 2964 and 3421; δ_H (250 MHz; CDCl₃) 1.66 (12H, s), 6.87 (4H, d, J 8.85), 7.17 (4H, d, J 8.85) and 7.25 (15H, m); δ_C (100.5 MHz; CDCl₃) 30.9, 42.6, 77.3, 112.3, 118.3, 125.8, 126.8, 128.1, 128.4, 146.7, 150.4, 151.2, 154.0 and 165.2; m/z (EI) 565 (M⁺, 100%).

5,6-Bis(3,5-di-tert-butylphenoxy)-1,3-diiminoisoindoline 20. Yield 97%, λ_max(EtOH)/nm 291; ν_max (KBr)/cm⁻¹ 457, 709, 860, 1015, 1030, 1047, 1118, 1204, 1308, 1364, 1425, 1454, 1556, 1596, 2830, 2868, 2968 and 3436; δ_H (400 MHz; CDCl₃) 1.26 (36H, s), 6.88 (7H, m), 7.19 (2H, s) and 7.21 (2H, s); δ_C (100.5 MHz; CDCl₃) 32.4, 36.1, 112.1, 114.7, 115.4, 119.6, 134.5, 152.7, 154.1 and 156.4; m/z (EI) 553 (M⁺, 100%).

5,6-Bis(phenylthio)-1,3-diiminoisoindoline 21. Yield 97%, λ_max(EtOH)/nm 285; ν_max (KBr)/cm⁻¹ 738, 855, 905, 1023, 1066, 1143, 1174, 1225, 1270, 1318, 1379, 1439, 1533, 1644, 2831, 2854, 2970 and 3427; δ_H (400 MHz; CDCl₃) 6.76 (3H, m), 7.07 (2H, s) and 7.30–7.60 (10H, m); δ_C (100.5 MHz; CDCl₃) 115.2, 117.6, 128.0, 131.0, 131.9, 135.5, 144.8 and 152.5; m/z 361 (M⁺, 100%)

4,5,6,7-Tetrakis(p-chlorophenoxy)-1,3-diiminoisoindoline 22. Yield 97%, ν_max (KBr)/cm⁻¹ 1200 and 3417; λ_max(EtOH)/nm 290 and 322; m/z (EI) 649/651/653 (M⁺, 100%).

6-tert-Butyl-2,3-dihydro-1,3-diimino-1H-benz[f]isoindole 23. Yield 97%, ν_max (KBr)/cm⁻¹ 472, 578, 726, 815, 904, 1030, 1159, 1257, 1384, 1458, 1542, 1626, 2852, 2925, 2952 and 3422; δ_H (400 MHz; CDCl₃) 1.04 (9H, s), 6.91 (3H, s, br), 7.16 (4H, s, br), 7.42 (1H, s, br); δ_C (100.5 MHz; CDCl₃) 31.0, 34.6, 112.0, 120.2, 120.4, 124.1, 125.8, 128.7, 130.8, 131.4, 131.7, 133.8, 149.7 and 171.3; m/z (FAB) 251 (M⁺, 100%)

2,3,9,10,16,17,23,24-Octasubstituted phthalocyanines

General procedure. ^18–20 The appropriate dicyanobenzene (4 mmol) and DBU (0.6g, 4 mmol) in pentanol (50 ml) were refluxed for 48 h. The dark green solution was filtered and the precipitated product Soxhlet extracted with MeOH, then dried under vacuum.

2,3,9,10,16,17,23,24-Octaphenoxyphthalocyanine 24. ¹¹ Yield 58%, mp >275 °C (Found: C, 76.6, H, 3.9; N, 9.0. C₈₀H₅₀N₈O₈ requires C, 76.8; H, 4.0; N, 8.95%); λ_max(EtOH)/nm (log ε/dm³ mol⁻¹ cm⁻¹) 344, 673 and 700 (5.2); ν_max (KBr)/cm⁻¹ 702, 833, 1007, 1203, 1272, 1385, 1399, 1438, 1491, 1618, 1637 and 3416; δ_H (400 MHz; CDCl₃) −0.80 (2H, s), 7.16 (16H, d), 7.24 (16H, t), 7.37 (8H, t) and 8.82 (8H, s); δ_C (100.5 MHz; CDCl₃) 112.7, 115.9, 121.3, 126.5, 128.2, 130.9, 153.1 and 156.7; m/z 1250 (M⁺, 100%).

2,3,9,10,16,17,23,24-Octakis(cumylphenoxy)phthalocyanine 25. Yield 40%, mp 112–114 °C (Found: C, 82.8; H, 5.8; N, 5.1. C₁₅₂H₁₃₀N₈O₈ requires C, 83.1; H, 6.0; N, 5.1%); ν_max(EtOH)/nm (log ε/dm³ mol⁻¹ cm⁻¹) 328, 606, 637, 667 and 701 (5.3); ν_max (KBr)/cm⁻¹ 700, 763, 1014, 1215, 1278, 1351, 1429, 1501, 1599, 2869, 2928, 2966 and 3426; δ_H (400 MHz; CDCl₃) −0.78 (2H, s), 1.68 (48H, s), 7.11–7.27 (72H, m) and 8.75 (8H, s); δ_C (100.5 MHz; CDCl₃) 31.9, 43.7, 118.7, 119.7, 120.1, 126.8, 126.9, 127.8, 129.0, 129.1, 129.2, 129.7, 151.7 and 156.4; m/z (FAB) 2194 (M⁺, 100%).

2,3,9,10,16,17,23,24-Octakis(3,5-di-tert-butylphenoxy)phthalocyanine 26. Yield 46%, mp >275 °C (Found: C, 80.6; H, 8.7; N, 5.5. C₁₄₄H₁₇₈N₈O₈ requires C, 80.5; H, 8.4; N, 5.2%); λ_max(EtOH)/nm (log ε/dm³ mol⁻¹ cm⁻¹) 348, 607, 640, 669 and 703 (5.3); ν_max (KBr)/cm⁻¹ 706, 961, 1011, 1087, 1199, 1298, 1385, 1423, 1439, 1459, 1588, 2867, 2904, 2963 and 3430; δ_H (400 MHz; CDCl₃) −0.89 (2H, s), 1.61 (144H, s), 7.41 (16H, s), 7.53 (8H, s) and 9.33 (8H, s); δ_C (100.5 MHz; CDCl₃) 31.7, 35.3, 113.0, 114.2, 117.7, 133.1, 151.4, 152.8 and 157.1 (one resonance is missing); m/z (FAB) 2146 (M⁺, 100%).

Metallated phthalocyanines

General procedure. ^21,13,15 The appropriate dicyanobenzene (6.5 mmol, for compounds 28–31) or diiminoisoindoline (6.5 mmol, for compounds 27 and 32–37) and InCl₃ (2.2 mmol) in dry quinoline (15 ml) were refluxed for 2 h. After cooling MeOH was added to precipitate the product. The product was washed thoroughly with MeOH (500 ml) and dried under vacuum.

2,3,9,10,16,17,23,24-Octaphenoxyphthalocyaninatoindium chloride 27. Yield 43%, mp >275 °C (Found: C, 68.4; H, 3.2; N, 7.9. C₈₀H₄₈N₈O₈InCl requires C, 68.6; H, 3.5; N, 8.0%); λ_max(EtOH)/nm (log ε/dm³ mol⁻¹ cm⁻¹) 346, 612 and 683 (5.4); ν_max (KBr)/cm⁻¹ 688, 743, 891, 1030, 1088, 1162, 1204, 1272, 1332, 1399, 1450, 1489 and 1589; δ_H (400 MHz; CDCl₃) 7.00–7.41 (40H, m) and 8.80 (8H, s); δ_C (100.5 MHz; CDCl₃) 126.8, 129.1, 130.7, 133.0, 133.2, 135.1, 136.7 and 153.4; m/z (FAB) 1398/1400 (M⁺, 100%), 1364 (M⁺ − Cl).

2,3,9,10,16,17,23,24-Octakis(p-fluorophenoxy)phthalocyaninatoindium chloride 28. Yield 52%, mp >275 °C (Found: C, 62.0; H, 2.8; N, 7.2. C₈₀H₄₀N₈O₈F₈ClIn requires C, 62.25; H, 2.6; N, 7.3%); λ_max(EtOH)/nm (log ε/dm³ mol⁻¹ cm⁻¹) 366, 627 and 697 (5.15); ν_max (KBr)/cm⁻¹ 831, 894, 1029, 1091, 1136, 1195, 1274, 1339, 1401, 1452, 1502 and 1608; δ_H (400 MHz; CDCl₃) 7.20 (16H, m), 7.21 (16H, m) and 8.74 (8H, s); δ_C (100.5 MHz; CDCl₃) 114.4, 117.4, 117.7, 117.9, 134.2, 152.4, 153.4, 159.3 and 161.7; m/z (FAB) 1542/1544 (M⁺, 100%), 1508 (M − Cl).

2,3,9,10,16,17,23,24-Octakis(p-chlorophenoxy)phthalocyaninatoindium chloride 29. Yield 0.6 g, 48%, mp >275 °C (Found: C, 57.5; H, 2.6; N, 6.5. C₈₀H₄₀N₈O₈Cl₉In requires C, 57.3; H, 2.3; N, 6.7%); λ_max(EtOH)/nm (log ε/dm³ mol⁻¹ cm⁻¹) 364, 630, 669 and 690 (5.42); ν_max (KBr)/cm⁻¹ 1088, 1208, 1268, 1398, 1451, 1485 and 1585; δ_H (400 MHz; CDCl₃) 7.13 (16H, d, J 8.9), 7.39 (16H, d, J 8.9) and 8.97 (8H, s); δ_C (100.5 MHz; CDCl₃) 120.7, 121.1, 130.4, 130.9, 131.1, 134.6, 151.6 and 156.4; m/z (FAB) 1670/1672/1674/1676 (M⁺, 100%).

2,3,9,10,16,17,23,24-Octakis(p-bromophenoxy)phthalocyaninatoindium chloride 30. Yield 34%, mp 243–245 °C (Found: C, 47.1; H, 1.8; N, 5.4. C₈₀H₄₀N₈O₈Br₈ClIn requires C, 47.3; H, 2.0; N, 5.5%); λ_max(EtOH)/nm (log ε/dm³ mol⁻¹ cm⁻¹) 364, 629, 667 and 698 (5.05); ν_max (KBr)/cm⁻¹ 1090, 1209, 1281, 1399, 1451, 1482, 1560, 1579 and 1618; δ_H (400 MHz; CDCl₃) 7.06 (16H, d, J 8.9), 7.53 (16H, d, J 8.9) and 8.00 (8H, s); δ_C (100.5 MHz; CDCl₃) 116.1, 117.8, 120.4, 121.1, 121.5, 134.1, 151.5 and 157.1; m/z (FAB) 2024/2026/2028/2030 (M⁺, 100%).

2,3,9,10,16,17,23,24-Octakis(p-iodophenoxy)phthalocyaninatoindium chloride 31. Yield 23%, mp 220–222 °C (Found: C, 39.9; H, 1.5; N, 4.8. C₈₀H₄₀N₈O₈I₈ClIn requires C, 39.9; H, 1.7; N, 4.7%); λ_max(EtOH)/nm (log ε/dm³ mol⁻¹ cm⁻¹) 363, 629, 671 and 699 (5.1); ν_max (KBr)/cm⁻¹ 894, 1007, 1098, 1208, 1281, 1400, 1449, 1479, 1560 and 1618; δ_H (400 MHz; CDCl₃) 6.96 (16H, d, J 8.9), 7.83 (16H, d, J 8.9), 8.98 (8H, d); δ_C (100.5 MHz; CDCl₃) 96.1, 116.2, 121.4, 122.3, 140.0, 140.3, 153.8 and 156.5; m/z (FAB) 2406/2408 (M⁺, 100%).

2,3,9,10,16,17,23,24-Octakis(cumylphenoxy)phthalocyaninatoindium chloride 32. Yield 2.8 g, 66%, mp 139–141 °C (Found: C, 77.6; H, 5.3; N, 4.5. C₁₅₂H₁₂₈N₈O₈InCl requires C, 77.85; H, 5.5; N, 4.8%); λ_max(EtOH)/nm (log ε/dm³ mol⁻¹ cm⁻¹) 366, 629 and 699 (5.17); ν_max (KBr)/cm⁻¹ 764, 893, 1029, 1084, 1172, 1211, 1270, 1385, 1399, 1476, 1637, 2868, 2924 and 2965; δ_H (400 MHz; CDCl₃) 1.71 (48H, s), 7.08–7.28 (72H, m) and 9.02 (8H, s); δ_C (100.5 MHz; CDCl₃) 32.1, 43.7, 118.9, 119.8, 126.8, 127.9, 129.2, 129.4, 134.9, 147.2, 151.7, 152.4, 153.7 and 156.4; m/z 2342/2344 (M⁺, 100%).

2,3,9,10,16,17,23,24-Octakis(3,5-di-tert-butylphenoxy)phthalocyaninatoindium chloride 33. Yield 1.83 g, 46%, mp >200–202 °C (Found: C, 74.9; H, 7.75; N, 4.7. C₁₄₄H₁₇₆N₈O₈InCl requires C, 75.3; H, 7.7; N, 4.9%); λ_max(EtOH)/nm (log ε/dm³ mol⁻¹ cm⁻¹) 356, 633 and 703 (5.3); ν_max (KBr)/cm⁻¹ 712, 961, 1036, 1090, 1200, 1270, 1296, 1399, 1458, 1586, 1609, 2866, 2904 and 2964; δ_H (400 MHz; CDCl₃) 1.33 (144H, s), 7.13 (16H, s), 7.25 (8H, s), 9.08 (8H, s); δ_C (100.5 MHz; CDCl₃) 32.5, 36.2, 113.8, 115.4, 118.7, 134.5, 152.7, 153.8, 153.9 and 157.8; m/z (FAB) 2294/2296 (M⁺, 100%).

2,3,9,10,16,17,23,24-Octakis(phenylthio)phthalocyaninatoindium chloride 34. Yield 50%, mp 169–171 °C (Found: C, 62.7; H, 3.1; N, 7.5; S, 17.0. C₈₀H₄₈N₈S₈InCl requires C, 62.9; H, 3.2; N, 7.3; S, 16.8%); λ_max(EtOH)/nm (log ε/dm³ mol⁻¹ cm⁻¹) 357, 659 and 735 (5.16); ν_max (KBr)/cm⁻¹ 688, 741, 838, 943, 1023, 1063, 1111, 1175, 1278, 1324, 1368, 1402, 1475, 1580, 1677 and 1719; δ_H (400 MHz; CDCl₃) 7.12–7.35 (40H, m) and 8.72 (8H, s); δ_C (100.5 MHz; CDCl₃) 126.8, 129.1, 130.8, 133.0, 135.1, 136.8, 142.2 and 153.8; m/z (FAB) 1526/1528 (M⁺, 15%), 1491 (M⁺ − Cl, 100%).

1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-Hexadecakis(p-chlorophenoxy)phthalocyaninatoindium chloride 35. Yield 38%, mp 188–190 °C (Found: C, 57.35; H, 2.2; N, 4.3. C₁₂₈H₆₄N₈O₁₆Cl₁₇In requires C, 57.2; H, 2.4; N, 4.2%); λ_max(EtOH)/nm (log ε/dm³ mol⁻¹ cm⁻¹) 344, 659, 682 and 738 (5.29); ν_max (KBr)/cm⁻¹ 1206; δ_H (400 MHz; CDCl₃) 6.41 (16H, d, J 8.9), 6.70 (16H, d, J 8.9), 6.90 (16H, d, J 8.9) and 7.04 (16H, d, J 8.9); δ_C (100.5 MHz; CDCl₃) 117.6, 120.2, 128.0, 129.1, 129.8, 130.2, 130.3, 145.3, 145.4, 152.8, 156.0 and 157.4; m/z (FAB) 2680/2682/2684/2686 (M⁺, 100%).

Phenyl[2,3,9,10,16,17,23,24-octakis(p-chlorophenoxy)phthalocyaninato]indium 36. A freshly prepared solution of PhMgBr (3 M, 2 ml) was added dropwise to a stirred solution of phthalocyanine 29 (200 mg, 0.074 mmol) in dry THF (20 ml). After monitoring the reaction by TLC (silica gel/toluene), the reaction was stopped when all of the phthalocyanine complex had been consumed. The resulting deep green solution was then poured onto ice, extracted several times with Et₂O, washed with water and dried over MgSO₄. The solvent was evaporated in vacuo and the residue was subjected to column chromatography. Elution with dichloromethane gave the title compound as a green solid (24 mg, 12%) mp >275 °C (Found: C, 57.5; H, 2.6; N, 6.5. C₈₆H₄₅N₈O₈Cl₉In requires C, 57.3; H, 2.4; N, 6.7%); λ_max(EtOH)/nm (log ε/dm³ mol⁻¹ cm⁻¹) 384, 627 and 697 (5.24); ν_max (KBr)/cm⁻¹ 692, 735, 1020, 1088, 1161, 1209, 1268, 1283, 1398, 1453, 1488 and 1585; δ_H (400 MHz; CDCl₃) 4.00 (2H, s, br), 5.93 (2H, s), 6.11 (1H, s), 7.15 (16H, d, J 8.9), 7.41 (16H, d, J 8.9) and 9.01 (8H, s); δ_C (100.5 MHz; CDCl₃) 121.5, 121.9, 123.0, 123.1, 126.6, 130.9, 131.3, 131.7, 131.9, 134.9, 152.3 and 156.7 (4 resonances are missing); m/z (FAB) 2722/2724/2726 (M⁺, 100%).

Tetra-tert-butyltetrabenzo[b,k,t,c₁]phthalocyaninatoindium chloride (tetra-tert-butylnaphthalocyaninatoindium chloride) 37. Yield 26%, mp >275 °C (Found: C, 70.3; H, 5.2; N, 9.9. C₆₄H₅₆N₈InCl requires C, 70.6; H, 5.3; N, 10.3%); ν_max(EtOH)/nm (log ε/dm³ mol⁻¹ cm⁻¹) 324, 706, 749 and 793 (5.39); ν_max (KBr)/cm⁻¹ 472, 544, 569, 1022, 1084, 1102, 1259, 1355, 1459, 1560, 1626, 1637, 1655, 2905, 2930 and 2955; δ_H (400 MHz; CDCl₃) 1.80 (36H, s) and 8.05–8.98 (20H, m); m/z (FAB) 1086/1088 (M⁺, 100%), 1051 (M⁺ − 35(Cl)).

Acknowledgements

We are grateful to the EPSRC national mass spectrometry service center for mass spectra.

References

1. “Materials for optical limiting”, ed. R. Crane, K. Lewis, E. van Stryland and M. Khoshnevisan, Proc. Mater. Res. Soc., 1996, 374.
2. K. Mansour, D. Alvarez, K. J. Perry, I. Choong, S. R. Marder and J. W. Perry, Proc. SPIE – Int. Soc. Opt. Eng., 1993, 1853, 132.
3. K. Mansour, P. Fuqua, S. R. Marder, B. Dunn and J. W. Perry, Proc. SPIE – Int. Soc. Opt. Eng., 1994, 2143, 239.
4. (a) J. W. Perry, K. Mansour, S. R. Marder, C.-T. Chen, P. Miles, M. E. Kenney and G. Kwag, Proc. MRS, 1996, 374, 257; (b) P. Le Barny, V. Dentan, P. Robin, F. Soyer and M. Vergnolle, Proc. SPIE – Int. Soc. Opt. Eng., 1996, 2852, 201.
5. P. V. Bedworth, J. W. Perry and S. R. Marder, Chem. Commun., 1997, 1353.
6. J. W. Perry, K. Mansour, I.-Y. S. Lee, X.-L. Wu, P. V. Bedworth, C.-T. Chen, D. Ng, S. R. Marder, P. Miles, T. Wada, M. Tian and H. Sasabe, Science, 1996, 273, 1533.
7. M. J. Cook, A. J. Dunn, S. D. Howe, A. J. Thomson and K. J. Harrison, J. Chem. Soc., Perkin Trans. 1, 1988, 2453.
8. N. B. McKeown, I. Chambrier and M. J. Cook, J. Chem. Soc., Perkin Trans. 1, 1990, 1169.
9. A. N. Cammidge, M. J. Cook, K. J. Harrison and N. B. McKeown, J. Chem. Soc., Perkin Trans. 1, 1991, 3053.
10. G. J. Clarkson, N. B. McKeown and K. E. Treacher, J. Chem. Soc., Perkin Trans. 1, 1995, 1817.
11. D. Wohrle, M. Eskes, K. Shigehara and A. Yamada, Synthesis, 1993, 194.
12. W. Eberhardt and M. Hanack, Synthesis, 1997, 95.
13. E. I. Kovshev, V. A. Puchnova and E. A. Luk'yanets, J. Org. Chem. USSR, 1971, 364.
14. M. K. Lowery, A. J. Starshak, J. N. Esposito, P. C. Krueger and M. E. Kenney, Inorg. Chem., 1965, 4, 128.
15. B. L. Wheeler, G. Nagasubramanian, A. J. Bard, L. A. Schechtman, D. R. Dininny and M. E. Kenney, J. Am. Chem. Soc., 1984, 106, 7404.
16. W. E. Ford, M. A. J. Rodgers, L. A. Schechtman, J. R. Sounik, B. D. Rihter and M. E. Kenney, Inorg. Chem., 1992, 31, 3371.
17. M. Hanack, P. Haisch, H. Lehmann and L. R. Subramanian, Synthesis, 1993, 387.
18. H. Tomoda, S. Saito, S. Ogawa and S. Shiraishi, Chem. Lett., 1980, 1277.
19. H. Tomoda, S. Saito and S. Shiraishi, Chem. Lett., 1983, 313.
20. D. Wohrle, G. Schnurpfeil and G. Knothe, Dyes Pigm., 1992, 18, 91.
21. M. Hanack and H. Heckmann, Eur. J. Inorg. Chem., 1998, 367.

---