Search results for "4-benzoquinone"
showing 10 items of 18 documents
Influence of Proton Conducting Cations on the Structure and Properties of 2D Anilate-Based Magnets
2017
The syntheses, structures, magnetic, and proton conductivity properties of a family of bimetallic anilate-based compounds with inserted alkylammonium cations are presented. The structures of (Me2NH2)[MnIICrIII(Br2An)3]·2H2O (1), (Et2NH2)[MnIICrIII(Br2An)3] (2), (Et3NH)[MnIICrIII(Cl2An)3] (3), and [(Et)(i-Pr)2NH]-[MnIICrIII(Br2An)3]·(CHCl3)0.5·(H2O) (4) contain a 2D anionic network formed by Mn(II) and Cr(III) ions linked through anilate ligands. In 1, 2, and 3, the hexagonal holes of this network are occupied by Me2NH2+, Et2NH2+, or Et3NH+ cations. Interestingly, the small increase of size of the templating cation in 4 ([(Et)(i-Pr)2NH]+ in the place of Me2NH2+, Et2NH2+ or Et3NH+), gives ris…
Revisiting the charge density analysis of 2,5-dichloro-1,4-benzoquinone at 20 K
2017
A high-resolution X-ray diffraction measurement of 2,5-dichloro-1,4-benzoquinone (DCBQ) at 20 K was carried out. The experimental charge density was modeled using the Hansen–Coppens multipolar expansion and the topology of the electron density was analyzed in terms of the quantum theory of atoms in molecules (QTAIM). Two different multipole models, predominantly differentiated by the treatment of the chlorine atom, were obtained. The experimental results have been compared to theoretical results in the form of a multipolar refinement against theoretical structure factors and through direct topological analysis of the electron density obtained from the optimized periodic wavefunction. The si…
Understanding the influence of lewis acids in the regioselectivity of the diels-alder reactions of 2-methoxy-5-methyl-1,4-benzoquinone: a dft study
2009
The mechanisms of the Diels–Alder (DA) reactions of 2-methoxy-5-methyl-1,4-benzoquinone 1 with 2-methyl-1,3-butadiene 2, in the absence and in the presence of LA catalysts, have been studied using the DFT method at the B3LYP/6-31G(d) level of theory. The uncatalyzed DA reactions between 1 and 2 take place via synchronous concerted TSs. The large activation barrier as well as the low stereo and regioselectivity associated with the uncatalyzed process are in clear agreement with the non-polar character of the cycloaddition. Coordination of the LA catalysts, BF3 or SnCl4, to the oxygen atoms of the benzoquinone 1 produces a large acceleration of the reaction, which can be associated with the l…
ESR, ENDOR and TRIPLE resonance studies on radical reactions of 1,4-benzoquinone and 1,4-hydroquinone in alkaline methanol and liquid ammonia
1990
The relative signs and absolute values of the hyperfine coupling constants of different methoxy-1,4-benzoquinones were measured by ESR, ENDOR and TRIPLE resonance spectroscopy. Reactions of 1,4-benzoquinone and 1,4-hydroquinone with methanol took place in alkaline methanol, giving rise to methoxy-substituted 1,4-benzoquinones. The same substitution reaction occurred in a mixture of ammonia and methanol. The reactions depended on temperature and the alkali concentration. Coupling constants were assigned by the modified additivity relationship method. An extremely small line width of 0.014 G was measured in the ESR spectrum of deuterated 2,5-dimethoxy-1,4-benzoquinone.
CCDC 1550937: Experimental Crystal Structure Determination
2017
Related Article: Z. Chua, B. Zarychta, C.G. Gianopoulos, V.V. Zhurov, A.A. Pinkerton|2017|Acta Crystallogr.,Sect.B:Struct.Sci.,Cryst.Eng. and Mat.|73|654|doi:10.1107/S2052520617007363
CCDC 1550938: Experimental Crystal Structure Determination
2017
Related Article: Z. Chua, B. Zarychta, C.G. Gianopoulos, V.V. Zhurov, A.A. Pinkerton|2017|Acta Crystallogr.,Sect.B:Struct.Sci.,Cryst.Eng. and Mat.|73|654|doi:10.1107/S2052520617007363
CCDC 1032218: Experimental Crystal Structure Determination
2015
Related Article: Samia Benmansour, Cristina Vallés-García, Patricia Gómez-Claramunt, Guillermo Mínguez Espallargas, Carlos J. Gómez-García|2015|Inorg.Chem.|54|5410|doi:10.1021/acs.inorgchem.5b00451
CCDC 1054373: Experimental Crystal Structure Determination
2015
Related Article: Alexandre Abhervé, Samuel Mañas-Valero, Miguel Clemente-León, Eugenio Coronado|2015|Chemical Science|6|4665|doi:10.1039/C5SC00957J
CCDC 1054372: Experimental Crystal Structure Determination
2015
Related Article: Alexandre Abhervé, Samuel Mañas-Valero, Miguel Clemente-León, Eugenio Coronado|2015|Chemical Science|6|4665|doi:10.1039/C5SC00957J
CCDC 953849: Experimental Crystal Structure Determination
2013
Related Article: Matteo Atzori, Samia Benmansour, Guillermo Mínguez Espallargas, Miguel Clemente-León, Alexandre Abhervé, Patricia Gómez-Claramunt, Eugenio Coronado, Flavia Artizzu, Elisa Sessini, Paola Deplano, Angela Serpe, Maria Laura Mercuri, and Carlos J. Gómez García|2013|Inorg.Chem.|52|10031|doi:10.1021/ic4013284