Photoinduced electron transfer of N-[(3- and 4-diarylamino)phenyl]-1,8-naphthalimide dyads: orbital-orthogonal approach in a short-linked D-A system

The photoinduced electron transfer of a series of meta- and para-linked triphenylamine-naphthalimide dyads, N-{3- and 4-[bis(4-R-substituted phenyl)amino]phenyl}-1,8-naphthalimide, 1m,p (R = H), 2m,p (R = Me), 3m,p (R = OMe), and 4m,p (R = NMe2) was investigated in toluene and DMF. The singlet charge-transfer (CT) states were observed in all cases. The decay rates were found to be faster in DMF (tau = 6.5 ps to 100 ps) than those in toluene (tau = 190 ps to 7 ns). The long-lived triplet CT states were observed in toluene for 3 (ca. 10% contribution, tau = 670 ns for 3m, 240 ns for 3p). No long-lived species were detected in DMF. The decay rates were somewhat faster in the para-isomers than in the meta-isomers in most cases. The photolysis of 5 (p-phenylene extended analogue of 3, R = OMe) gave a singlet CT state and a locally excited triplet state on the naphthalimide chromophore.     

Synthesis and langmuir‐blodgett (LB) film properties of functional α,ω‐diamine amphiphilic materials

We have investigated the synthesis and ultrathin film forming properties of α,ω‐diamine derivatives. The amphiphiles were synthesized as precursors to the formation of ionene polymers. Two materials were investigated: oligothiophene and azobenzene functional groups. These type of materials are of great interest for the preparation of ultrathin film layers with applications for photochemical regulation of liquid crystal (LC) orientation, optical storage media, and electroluminescent displays. Azobenzene and its derivatives are well known photochemical systems exhibiting the reversible cis‐trans photoisomerization. Conjugated oligothiophene derivatives, exhibit interesting optical and electronic properties for applications such as light emitting diodes (LED)s, Schottky diodes, and thin film field‐effect transistors (TFT). The two amphiphiles behaved very differently as Langmuir monolayers and LB films. Dye aggregation was observed with the azobenzene derivatives compared with the oligothiophenes.     

Poly[(cis‐3‐(ethanesulfonyloxy)‐2‐pinanyl methacrylate)‐co‐(tert‐butyl methacrylate)] as an acid‐amplifying photoresist

Synthesis and characteristics of novel copolymers bearing both acid amplifier and acid‐sensitive units are described. The acid amplifier units in the polymer side chains were acidolytically transformed to sulfonic acid residues, leading to the deprotection of the acid‐labile tert‐butyl ester side chains introduced as a comonomer unit. The copolymer was 3.2 times more sensitive than poly(tert‐butyl methacrylate) in the presence of a photoacid generator and, therefore, provides practical applicability for photoimaging.