TY  - JOUR
A1  - Fudickar, Werner
A1  - Linker, Torsten
T1  - Novel anthracene materials for applications in lithography and reversible photoswitching by light and air
N2  - Herein we demonstrate how the photoreaction between anthracenes and singlet oxygen (O-1(2)) is employed for applications either as photoswitch or as photoresist. Thin Films of the diaryl-alkyl anthracene 1 and the analogous oligomeric species 2 were it-radiated under photomasks to generate pattern structures composed of 1/1-O-2 and 2/2-O-2. Kelvin probe force microscopy (KPFM) provided a powerful and nondestructive method to image the pattern information. The following studies based on AFM, KPFM and contact angle measurements unfold that the two species 1 and 2 underwent different progressions after the imaging step. Degrading is observed for the monomeric compound 1 and the pattern eventually becomes recognizable in topography. In the oxidized state (1-O-2) the monomeric species remains physically stable. In consequence, the unreacted portion is removable and the remaining oxygenated form 1-O-2 is sufficiently stable to protect in underlying substrate (e.g., silver) from etching. Thus, the system 1/1-O-2 operates as photoresist. Oil the other hand, both states of the oligomier 2 remain stable. The Film is stable up to temperatures > 120 degrees C required to erase the pattern within acceptable time by cycloreversion. Anthracene 2 therefore acts as erasable and rewritable photochromic switch. The different behavior between 1 and 2 is explained by phase transitions which cause crystallization and finally ablation. Such transitions affect only the monomeric system 1/1-O-2 and not the oligomeric system 2/2-O-2. In conclusion, we designed two very similar materials based on diarylanthracenes, which can act either as a photoresist or as a rewritable photochrornic switch.
Y1  - 2010
UR  - http://pubs.acs.org/journal/langd5
U6  - https://doi.org/10.1021/La904299n
SN  - 0743-7463
ER  - 
TY  - JOUR
A1  - Bramborg, Andrea
A1  - Linker, Torsten
T1  - Selective synthesis of 1,4-dialkylbenzenes from terephthalic acid
N2  - Terephthalic acid reacts with alkyl halides under Birch conditions to substituted 1,4-cyclohexadienes in high yields and good stereoselectivities. Electrophiles containing ester or nitrile groups undergo a surprising fragmentation under the reaction conditions. Subsequent treatment with chlorosulfonic acid proceeds by an interesting tandem decarbonylation/decarboxylation, affording 1,4-dialkylbenzenes in excellent regioselectivity. Thus our new method is superior to classical Friedel-Crafts alkylations.
Y1  - 2010
UR  - http://www3.interscience.wiley.com/cgi-bin/jhome/77002176
U6  - https://doi.org/10.1002/adsc.201000322
SN  - 1615-4150
ER  -