23197-02-6Relevant articles and documents
Structure and properties of small molecule-polymer blend semiconductors for organic thin film transistors
Kang, Jihoon,Shin, Nayool,Do, Young Jang,Prabhu, Vivek M.,Yoon, Do Y.
, p. 12273 - 12275 (2008)
A comprehensive structural and electrical characterization of solution-processed blend films of 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene) semiconductor and poly(α-methylstyrene) (PαMS) insulator was performed to understand and optimize the blend semiconductor films, which are very attractive as the active layer in solution-processed organic thin-film transistors (OTFTs). Our study, based on careful measurements of specular neutron reflectivity and grazing-incidence X-ray diffraction, showed that the blends with a low molecular-mass PαMS exhibited a strong segregation of TIPS-pentacene only at the air interface, but surprisingly the blends with a high molecular-mass PαMS showed a strong segregation of TIPS-pentacene at both air and bottom substrate interfaces with high crystallinity and desired orientation. This finding led to the preparation of a TIPS-pentacene/PαMS blend active layer with superior performance characteristics (field-effect mobility, on/off ratio, and threshold voltage) over those of neat TIPS-pentacene, as well as the solution-processability of technologically attractive bottom-gate/bottom-contact OTFT devices. Copyright
On rearrangements by cyclialkylations of arylpentanols to 2,3-dihydro-1H-indene derivatives. Part 2. An unexpected rearrangement by the acid-catalyzed cyclialkylation of 2,4-dimethyl-2-phenylpentan-3-ol under formation of trans-2,3-dihydro-1,1,2,3-tetramethyl-1H-indene
Giovannini, Edgardo,Hengartner, Urs,Pasquier, Pierre
, p. 1841 - 1849 (2007/10/03)
The acid catalyzed-cyclialkylation of 4-(2-chloro-phenyl)-2,4-dimethylpentan-2-ol (1) gave two products: 4-chloro-2,3-dihydro-1,1,3,3-tetramethyl-1H-indene (2) and also trans-4-chloro-2,3-dihydro-1,1,2,3-tetramethyl-1H-indene (3). A mechanism was proposed in Part 1 (cf. Scheme 1) for this unexpected rearrangement. This mechanism would mainly be supported by the result of the cyclialkylation of 2,4-dimethyl-2-phenylpentan-3-ol (4), which, with respect to the similarity of ion II in Scheme I and ion V in Scheme 2, should give only product 5. This was indeed the experimental result of this cyclialkylation. But the result of the cyclialkylation of 1,1,1,2′,2′,2′-hexadeuterated isomer [2H6]-4 of 4 (cf. Scheme 3) requires a different mechanism as for the cyclialkylation of 1. Such a mechanism is proposed in Schemes 5 and 6. It gives a satisfactory explanation of the experimental results and is supported by the result of the cyclialkylation of 2,4-dimethyl-3-phenylpentan-3-ol (9; Scheme 7). The alternative migration of a Ph or of an i-Pr group (cf. Scheme 6) is under further investigation.