503-29-7Relevant articles and documents
An ESR Study of the Aziridine and Azetidine Radical Cations: Evidence for the C...C Ring-Opened Aziridine Radical Cation
Qin, Xue-Zhi,Williams, Ffrancon
, p. 2292 - 2296 (1986)
The radical cations from aziridine and azetidine have been characterized by ESR spectriscopy following their generation in the solid state by γ irradiation of dilute solutions of the parent compounds in the CFCl3 maarix at 77 K.The ESR parameters of the azetidine radical cation are typical of those for nitrogen-centered amine radical cations such as Me2NH.+.On the other hand, the radical cation formed from aziridine has very different ESR parameters that compare closely to those for the isoelectronic C...C ring-opened form of the oxirane radical cation and the allyl radical.The radical cation formed from azetidine is therefore assigned a ring-closed structure with the unpaired electron in a 2pz orbital on nitrogen perpendicular to the ring plane, whereas the cation from aziridine is an allylic C...C ring-opened planar isomer with the unpaired electron in a nonbonding ? orbital centered mainly on the two end carbon atoms.The neutral 1-aziridinyl and 1-azetidinyl radicals have been detected as radical products following the γ-irradiation of the parent compounds in the CFCl2CF2Cl and CF3CCl3 matrices.In particular, the 1-azetidinyl radical is produced cleanly from the azetidine radical cation in the CFCl2CF2Cl matrix at ca. 100 K.
Living anionic polymerization of N-methacryloylazetidine: Anionic polymerizability of N,N-dialkylmethacrylamides
Suzuki, Takashi,Kusakabe, Jun-Ichi,Kitazawa, Keita,Nakagawa, Takeshi,Kawauchi, Susumu,Ishizone, Takashi
, p. 107 - 116 (2010)
Anionic polymerization of a series of N,N-dialkylmethacrylamides such as TV-methacryloylazetidine (M4), N-methacryloylpyrrolidine (M5), and N-methacryloylpiperidine (M6) was carried out with diphenylmethyllithium (Ph2CHLi) or diphenylmethylpotassium (Ph2CHK) in the presence of LiCl or Et2Zn in THF to clarify the relationship between polymerizability and monomer structure. Poly(M4)s possessing predicted molecular weights and very narrow molecular weight distributions MwM n 2CHLi/LiCl or Ph2CHK/Et2Zn at -40 to 0 °C within 24 h. From the polymerizations of M4 at the various temperatures ranging from -40 to -20 °C, the apparent rate constant and the activation energy of the anionic polymerization were determined as follows: In kpap = -6.17 x 103/r+22.4 Lmol-1s-1 and 51 ± 5 kJ mol-1, respectively. Compared to the previous report on the anionic polymerization of N-methacryloyl-2-methylaziridine (M3), the polymerization rate of M4 was significantly slower and the activation energy was slightly larger, indicating the lower polymerizability of M4. The acryloyl counterpart, N-acryloylazetidine (A4), also underwent the anionic polymerization to afford the well-defined polymer quantitatively. The polymerizations of M5 gave the polymers in 30-77% yields but did not complete even after 1 week at 0 °C. By contrast, no polymer was obtained from the anionic polymerization system of M6 similar to the case of N.N-dimethylmethacrylamide (DMMA). From the experimental results, it was demonstrated that the polymerizability of a series of N,N-dialkylmethacrylamides with cyclic substituents decreased drastically with increasing the ring size from three to six (M3 > M4 > M5M6 = DMMA). The observed relative polymerizability was well correlated with the chemical shifts of vinyl β-carbons for monomers in the 13C NMR spectra. The NMR data suggested that the polymerizable M3 and M4 attained effective conjugation between C=C and C=O double bonds, while M5, M6, and DMMA had negligible conjugation effects.
Synthesis of common-sized heterocyclic compounds by intramolecular cyclization over halide cluster catalysts
Nagashima, Sayoko,Sasaki, Tomoaki,Kamiguchi, Satoshi,Chihara, Teiji
supporting information, p. 764 - 766 (2015/06/22)
Five- to seven-membered common-sized heterocyclic compounds containing an oxygen, sulfur, or nitrogen were synthesized by the intramolecular condensation of α,ω-hydroxy, mercapto, or amino alkanes, respectively, over halide cluster complexes as a thermally stable molecular solid weak acid catalyst in the gas phase at temperatures ≥150 °C. From ω- mercapto and ω-amino alcohols, cyclic sulfides and amines were obtained, respectively. These unimolecular reactions are thermodynamically and kinetically favored.
Vapor-phase transport as a novel route to hyperbranched polyamine-oxide hybrid materials
Chaikittisilp, Watcharop,Didas, Stephanie A.,Kim, Hyung-Ju,Jones, Christopher W.
, p. 613 - 622 (2013/05/08)
A new method to prepare hyperbranched polyamine-oxide hybrid materials by means of a vapor-phase transport is developed. In this method, hybrid materials having hyperbranched amine polymers covalently bound to an oxide support are formed by exposing the oxide support to the vapor of small nitrogen-containing heterocyclic monomers, in contrast to the conventional liquid-phase method, in which the support is dispersed in an organic solution containing monomer species. The aziridine and azetidine monomers are polymerized on the surface of the oxide supports (i.e., silica and alumina), resulting in poly(ethylenimine) or poly(propylenimine) chains attached to the porous solid support. The results suggest that the hybrid materials can be prepared over a wide range of preparation conditions with organic contents comparable to or even higher than those obtained from the standard liquid-phase method. It is demonstrated that supports with more acidity result in the hybrid materials with higher organic content. Interestingly, the resulting supported polyamines have lower molecular weights than the previously reported materials prepared by the liquid-phase method. It is anticipated that the vapor-phase synthesis can be applied for the efficient introduction of polyamines into structural forms of supports such as fibers, membranes, and monoliths, for which the liquid-phase method may be inappropriate or inefficient.
