30964-00-2Relevant articles and documents
Synthesis and Properties of Aromatic-Terminated Diacetylene Organogelators and Their Application to Photopatterning of Polydiacetylenes
Aoki, Ken'Ichi,Horitsugu, Kousuke,Narazaki, Kenta,Seki, Atsushi,Takahashi, Daiki,Tamaoki, Nobuyuki
, p. 13160 - 13169 (2021/11/16)
A series of simply structured diacetylene-diamide-based gelators (DAGs) with aromatic terminals were synthesized, and their gelation and subsequent photopolymerization abilities were analyzed. DAGs with an adequate spacer length (n) and tolyl terminals (DA-Tn) interacted with aromatic solvents, such as benzene and xylenes, at elevated temperatures. During the subsequent cooling process, the DAGs interacted with each other through CH-πinteractions at their terminal positions. They also formed one-dimensional hydrogen bonding arrays through secondary amides, leading to stable organogels. These gels polymerized into π-conjugated polydiacetylenes (PDAs) under ultraviolet irradiation. In the p-xylene gels of DA-Tn, the spacer length exerted characteristic odd-even effects on the photopolymerization rates over a certain range (n = 3-6), which can be explained by periodic changes in the uniformity of the molecular packing modes. When the gelling solvent was changed to cyclohexane, the gelation and photopolymerization abilities were greatly improved because the DA-Tn gel networks became highly crystallized and transparent to ultraviolet light (254 nm). The ultimate conversion to PDA from DA-T8/cyclohexane gels was 45.2 wt %. Applying photolithographic techniques to the DAG with excellent photopolymerizability in the film state, we successfully fabricated microscale photopatterns of PDA. We also established a convenient removal process (development process) of DA monomers in unexposed areas. The resulting PDA patterns were quite stable to ambient light stimuli.
Self-assembly and solid-state polymerization of butadiyne derivatives with amide and trialkoxyphenyl groups
Kikuchi, Kohei,Tatewaki, Yoko,Okada, Shuji
supporting information, p. 298 - 305 (2017/05/10)
Three butadiyne derivatives with amide and tri(dodecyloxy)-phenyl (TDP) groups were synthesized, and four solidification methods were applied to obtain their self-assembling states in various conditions. The solids obtained were characterized by the solid-state polymerization behaviors, stretching vibration wavenumbers of N-H bonds of amide groups, powder X-ray diffraction, the thermal behaviors, and scanning electron microscope (SEM) observations. We found that all compounds had at least two polymorphs. Property differences between two polymorphs depended on the compounds. Two compounds showed clear differences in UV-vis spectra of the photo-polymerized solids, i.e., the polydiacetylene (PDA) structure, and irregularly polymerized form, or two PDA structures. The remaining compound showed the same PDA absorption but the monomer melting points were different. All compounds gave the gels in various organic solvents because of the molecular design with amide and TDP groups. SEM observation clarified the relationship between gel appearance and the nanostructures.
Additional nucleophile-free FeCl3-catalyzed green deprotection of 2,4-dimethoxyphenylmethyl-protected alcohols and carboxylic acids
Sawama, Yoshinari,Masuda, Masahiro,Honda, Akie,Yokoyama, Hiroki,Park, Kwihwan,Yasukawa, Naoki,Monguchi, Yasunari,Sajiki, Hironao
, p. 778 - 784 (2016/07/16)
The deprotection of the methoxyphenylmethyl (MPM) ether and ester derivatives can be generally achieved by the combinatorial use of a catalytic Lewis acid and stoichiometric nucleophile. The deprotections of 2,4-dimethoxyphenylmethyl (DMPM)-protected alcohols and carboxylic acids were found to be effectively catalyzed by iron(III) chloride without any additional nucleophile to form the deprotected mother alcohols and carboxylic acids in excellent yields. Since the present deprotection proceeds via the self-assembling mechanism of the 2,4-DMPM protective group itself to give the hardly-soluble resorcinarene derivative as a precipitate, the rigorous purification process by silica-gel column chromatography was unnecessary and the sufficiently-pure alcohols and carboxylic acids were easily obtained in satisfactory yields after simple filtration.
