3534-25-6Relevant academic research and scientific papers
Crystallographic and spectroscopic investigations on oxidative coordination in the heteroleptic mononuclear complex of cerium and benzoxazine dimer
Chansaenpak, Kantapat,Chuanopparat, Nutthawat,Hanlumyuang, Yuranan,Kanjanaboos, Pongsakorn,Kongsamai, Peetikamol,Suetrong, Natapol,Wannapaiboon, Suttipong,Wattanathana, Worawat
, (2021/09/13)
Among lanthanide-based compounds, cerium compounds exhibit a significant role in a variety of research fields due to their distinct tetravalency, high economic feasibility, and high stability of Ce(IV) complexes. Herein, a systematic investigation of crystallographic information, chemical properties, and mechanistic formation of the novel Ce(IV) complex synthesized from cerium(III) nitrate hexahydrate and 2,2′-(methylazanediyl)bis(methylene)bis(4-methylphenol) (MMD) ligand has been explored. According to the analysis of the crystallographic information, the obtained complex crystal consists of the Ce(IV) center coordinated with two nitrate ligands and two bidentate coordinated (N-protonated and O,O-deprotonated) MMD ligands. The fingerprint plots and the Hirshfeld surface analyses suggest that the C–H· · · O and C–H· · · π interactions significantly contribute to the crystal packing. The C–H· · · O and C–H· · · π contacts link the molecules into infinite molecular chains propagating along the [100] and [010] directions. Synchrotron powder X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) techniques have been employed to gain an understanding of the oxidative complexation of Ce(IV)-MMD complex in detail. This finding would provide the possibility to systematically control the synthetic parameters and wisely design the precursor components in order to achieve the desired properties of novel materials for specific applications.
Self termination of ring opening reaction of p-substituted phenol-based benzoxazines: An obstructive effect via intramolecular hydrogen bond
Chirachanchai, Suwabun,Laobuthee, Apirat,Phongtamrug, Suttinun
experimental part, p. 714 - 721 (2009/12/01)
(Chemical Equation Presented) The ring opening polymerizations of p-substituted phenol-based benzoxazines are self-terminated as soon as dimers form. The polymerization of benzoxazine monomers does not proceed according to the theoretical mechanism even though the conditions, temperature, molar ratio, solvent polarity, and reactant ratio are varied. The speculated mechanism, involving the unique structure of a dimer with interand intramolecular hydrogen bonds, is applied to explain an obstructive effect on ring opening polymerization. In this article, we clarify an important case which the stereo structure of the compound controls the reaction and prevents the polymerization expected from the theoretical mechanism.
Benzoxazine oligomers: Evidence for a helical structure from solid-state NMR spectroscopy and DFT-based dynamics and chemical shift calculations
Goward, Gillian R.,Sebastiani, Daniel,Schnell, Ingo,Spiess, Hans Wolfgang,Kim, Ho-Dong,Ishida, Hatsuo
, p. 5792 - 5800 (2007/10/03)
A combination of molecular modeling, DFT calculations, and advanced solid-state NMR experiments is used to elucidate the supramolecular structure of a series of benzoxazine oligomers. Intramolecular hydrogen bonds are characterized and identified as the d
