Angewandte Fluororganische Chemie: Synthese ... - Fluorine
Angewandte Fluororganische Chemie: Synthese ... - Fluorine
Angewandte Fluororganische Chemie: Synthese ... - Fluorine
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4.3. Polare Endgruppen: Die Pentafluorsulfuranylgruppe<br />
Dielectric anisotropy<br />
Conventional Terminal Groups<br />
Δε<br />
20<br />
8<br />
6<br />
4<br />
Terminal group<br />
X<br />
-CN<br />
-CF 3<br />
-F<br />
???<br />
-OCF 3<br />
Ways to increase<br />
• Polar terminal group<br />
• Lateral fluorination<br />
• Polar ring increments<br />
(e.g. 1,3-dioxane or 1,3-dithiane)<br />
R X<br />
The Pentafluorosulfuranyl Group<br />
• W. A. Sheppard, J. Am. Chem. Soc. 1960, 82, 4751-4752.<br />
• W. A. Sheppard, J. Am. Chem. Soc. 1962, 84, 3064-3071.<br />
• W. A. Sheppard, J. Am. Chem. Soc. 1962, 84, 3072-3076.<br />
• V. Reiffenrath, R. Eidenschink, G. Weber (Merck KGaA), DE 3721268, 1987.<br />
• P. Kirsch, M. Bremer, M. Heckmeier, K. Tarumi, Angew. Chem. Int. Ed. Engl. 1999, 38, 1989-1992.<br />
H 7 C 3<br />
• Highly polar but non-coordinating group<br />
• High stability against basic or acidic hydrolysis<br />
• High thermal stability<br />
• Sensitive only against strong reductive agents<br />
O<br />
O<br />
CF 3<br />
μ = 2.6 D<br />
SF 5<br />
μ = 3.44 D<br />
SF 5 Based Liquid Crystals<br />
X-Ray Structure<br />
F F<br />
S<br />
F F<br />
F<br />
181 pm<br />
C1-S1-F1: 92.3°<br />
158 pm<br />
158 pm<br />
2-Ring Liquid Crystals for Different Applications<br />
P. KIRSCH: <strong>Angewandte</strong> fluororganische <strong>Chemie</strong>: <strong>Synthese</strong>, Pharmazeutika, Flüssigkristalle 44<br />
Virtual Clearing Point / o C<br />
30<br />
10<br />
-10<br />
-30<br />
-50<br />
-70<br />
-90<br />
-110<br />
-130<br />
-150<br />
O 2 N<br />
SF 5<br />
NO 2<br />
H 7 C 3 X CN<br />
F<br />
OCF 3<br />
CF 3<br />
0 5 10 15 20 25 30 35 40<br />
H7 C 3<br />
H 7 C 3<br />
lateral fluorination Dielectric Anisotropy ( )<br />
cyclohexane 1,3-dioxane<br />
10% F 2 /N 2 ,<br />
CH 3 CN; -5 o C<br />
S<br />
S NO 2<br />
SF 5<br />
NH 2<br />
SF 5<br />
SF 5<br />
SF 5<br />
Br<br />
H 7 C 3<br />
cyano materials<br />
TN, STN displays<br />
“super fluorinated materials” (SFM)<br />
TFT displays<br />
SF 5<br />
OH<br />
SF 5<br />
CHO<br />
H 11 C 5<br />
H 7 C 3<br />
SF 5<br />
H 7 C 3<br />
H 7 C 3<br />
• P. Kirsch, M. Bremer, M. Heckmeier, K. Tarumi, Angew. Chem. Int. Ed. Engl. 1999, 38, 1989-1992.<br />
New 2-Ring Liquid Crystals for Various Applications<br />
Virtual Clearing Point / o C<br />
30<br />
10<br />
-10<br />
-30<br />
-50<br />
-70<br />
-90<br />
-110<br />
-130<br />
-150<br />
H 7 C 3<br />
F<br />
OCF 3<br />
CF 3<br />
0 5 10 15 20 25 30 35 40<br />
lateral fluorination<br />
cyclohexane 1,3-dioxane<br />
1,3-dioxane 1,3-dithiane<br />
X<br />
SF 5<br />
CN<br />
SF 5 derivatives<br />
SFM materials<br />
Dielectric Anisotropy ( )<br />
O<br />
O<br />
S<br />
S<br />
O<br />
O<br />
SF 5<br />
cyano materials<br />
SF 5<br />
SF 5<br />
SF 5
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