Perhydroazulenes - A
New Class of Liquid Crystalline Materials

Henning Hopf; Zakir Hussain; Rajeev S. Menon; Vitaly Raev; Peter G. Jones; Ludwig M. Pohl

doi:10.1055/s-0030-1260551

LETTER

Perhydroazulenes - A New Class of Liquid Crystalline Materials

Henning Hopf*^a, Zakir Hussain^a, Rajeev S. Menon^a, Vitaly Raev^a, Peter G. Jones*^b, Ludwig M. Pohl^a
^a Institut für Organische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
Fax: +49(531)3915388; e-Mail: H.Hopf@tu-bs.de;
^b Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Postfach 3329, 38023 Braunschweig, Germany
Fax: +49(531)3915387; e-Mail: P.Jones@tu-bs.de;

Abstract

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Abstract

A new class of mesogenic compounds, the perhydroazulenes, carrying substituents in their para positions (HAZ derivatives), has been synthesized. The new liquid crystalline materials display a broad enantiotropic nemantic mesophase slightly above room temperature without any additional smectic phase. Their physical properties reveal that the perhydroazulene moiety can replace the currently often used cyclohexyl and biscyclohexyl units in liquid crystalline materials.

Key words

liquid crystals - perhydrogenated azulenes - nematic materials - electrooptical displays

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References

References and Notes

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Perhydroazulene-2,6-dione Ethylene Ketal 9
^¹H NMR (400.14 MHz, CDCl₃): δ = 3.86 (s, 4 H), 2.30-2.48 (m, 4 H), 1.92-2.04 (m, 2 H), 1.77-1.88 (m, 2 H), 1.51-1.69 (m, 6 H) ppm. ^¹³C NMR (100.62 MHz, CDCl₃): δ = 219.2, 111.5, 64.3 (+), 64.2 (+), 45.5 (+), 39.0 (-), 36.6 (+), 25.8 (+) ppm. MS (IE): m/z (%) = 210 (9) [M⁺], 126 (5), 99 (100), 86 (10), 55 (8); IR (diamond ATR): ν = 2990, 2931, 2880, 1731 cm^-¹. UV (MeCN): λ_max = 284 nm.

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Liquid Crystalline Derivative 16
^¹H NMR (300.13 MHz, CDCl₃): δ = 6.86 (ddd, 1 H, J ₁ = 0.3 Hz, J ₂ = 2.4 Hz, J ₃ = 8.9 Hz), 6.47 (dd, 1 H, J ₁ = 2.0 Hz, J ₂ = 7.6 Hz), 4.08 (q, 2 H, J = 7.0 Hz), 2.96-3.12 (m, 1 H), 2.19-2.38 (m, 2 H), 1.59-1.96 (m, 12 H), 1.43 (t, 3 H, J = 7.0 Hz), 1.23-1.38 (m, 4 H), 0.81-0.99 (m, 4 H) ppm. ^¹³C NMR (75.47 MHz, CDCl₃): δ = 149.1 (dd, J ₁ = 10.3 Hz, J ₂ = 245.0 Hz), 145.9 (dd, J ₁ = 3.0 Hz, J ₂ = 8.2 Hz), 141.5 (dd, J ₁ = 15.3 Hz, J ₂ = 246.5 Hz), 129.1 (dd, J ₁ = 1.5 Hz, J ₂ = 12.3 Hz), 120.9 (+, dd, J ₁ = 4.6 Hz, J ₂ = 6.0 Hz), 109.3 (+, d, J = 2.5 Hz), 65.4 (+), 40.8 (+), 39.8 (-), 39.5 (-), 37.9 (+), 37.5 (-), 31.8 (+), 29.2 (+), 21.9 (+), 14.8 (-), 14.4 (-) ppm. MS (IE): m/z (%) = 337 (22) [M + H⁺], 336 (100) [M⁺], 198 (13), 197 (20), 184 (52), 171 (14), 169 (12), 156 (36), 143 (24), 83 (15). IR (diamond ATR): ν = 2931, 2889, 2857, 1511, 1473, 1296, 1116, 1081, 805 cm^-¹. UV (CH₂Cl₂): λ_max = 229, 268 nm. For mp see Table [¹] .

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