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Isabella Karle Richard D. Gilardi Ch. Chandrashekhar Rao K.M. Muraleedharan Subramania Ranganathan 《Journal of chemical crystallography》2003,33(10):727-749
Benzenehexacarboxylic acid, mellitic acid (MA), has been used as a core motif to study possible radial self-assembly using complementary aromatic bases. By mixing water solutions of the components, crystals of the salts of MA with 4-aminopyridine (AP), 4-dimethylamino-pyridine (DM), 2,2-bipyridine (DP), o-phenanthroline (PL), and melamine (ML) have been obtained. The MA–n
ions have assembled in either extended sheets for MA–2 or extended ribbons for MA–4 by direct hydrogen bonding between MA and MA and additionally through mediation of hydrogen bonds to water molecules that distribute the negative charges throughout the MA sheet or ribbon. Most of the O atoms in carboxyl groups in the MA ions in the five complexes have been rotated significantly out of the plane of the central benzene ring. There are multiple base molecules, two or four, for each mellitic acid ion in the five complexes. Most of the NH+ moieties in all five bases make direct NH+ O–C hydrogen bonds with MA–n
. The planar base ions are generally arranged in stacks in which the components range from being parallel, with interplanar separations of 3.5 Å, to having a considerable tilt with respect to each other with nearest interplanar separation of atoms greater than 3.9 Å. These geometric characteristics are reflected in the color of the crystals. The three-dimensional networking makes some of the crystals very hard. Cell dimensions: 1, C32H30N8O12 2H2O, C2/c, a =13.764(2) Å, b =18.053(3) Å, c =14.876(4) Å, =105.99(2)° 2, C26H26N4O12 3H2O, P21/n, a =15.891(1) Å, b =10.444(1) Å, c =18.242(1) Å, =97.00(1); 3, C64H44N8O24
7H2O, P21/c, a =23.016(4) Å, b =15.241(2) Å, c =19.124(2) Å, =100.60(1)° 4, C36H22N4O12, P21/n, a =14.581(1) Å, b =10.472(1) Å, c =20.607(2) Å, =106.43(1); 5, C18H18N12O12 2H2O,
, a =8.257(2) Å, b =8.986(2) Å, c =9.383(1) Å, =98.60(1)°, =96.38(2)°, =117.07(1)°. 相似文献
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De-Hui Tuo Chao Chen Huapeng Ruan Prof. Dr. Qi-Qiang Wang Dr. Yu-Fei Ao Prof. Dr. Xinping Wang Prof. Dr. De-Xian Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(33):14144-14147
Radical pimers are the simplest and most important models for studying charge-transfer processes and provide deep insight into π-stacked organic materials. Notably, radical pimer systems with magnetic bi- or multistability may have important applications in switchable materials, thermal sensors, and information-storage media. However, no such systems have been reported. Herein, we describe a new pimer consisting of neutral N-(n-propyl) benzene triimide ([BTI-3C]) and its anionic radical ([BTI-3C]−.) that exhibits rare magnetic multistability. The crystalline pimer was readily synthesized by reduction of BTI-3C with cobaltocene (CoCp2). The transition occurred with a thermal hysteresis loop that was 27 K wide in the range of 170–220 K, accompanied by a smaller loop with a width of 25 K at 220–242 K. The magnetic multistability was attributed to slippage of the π-stacked BTI structures and entropy-driven conformational isomerization of the side propyl chains in the crystalline state during temperature variation. 相似文献
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将适量的苯六羧酸和La(NO3)3·nH2O在水中混合,在50℃下析出[La2(C6(COO)6)(H2O)8]·2H2O晶体.单晶X-射线衍射分析表明,晶体属于单斜晶系,P21/n(No.14)空间群,晶胞参数a=0.866 5(2)nm,b=1.326 1(3)nm,c=0.969 1(2)nm,β=96.16(3),V=1.107 1(4)nm3,Dc=2.382g/cm3,Z=2,F(000)=7 642 544个独立衍射点中,2 344个可观测点满足F20≥2σ(F20),R1=0.0220,wR2=0.054 4.标题配合物中中心原子La和9个氧原子配位,形成畸变的三帽三方棱柱的配位多面体,每个苯六羧酸根桥联6个La原子,通过这种桥联作用形成具有三维网络结构的配位聚合物. 相似文献
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Isabella L. Karle Y. B. R. D. Rajesh Subramania Ranganathan 《Journal of chemical crystallography》2005,35(10):835-845
Benzenehexacarboxylic acid (mellitic acid) is an ideal substrate for the study of radially arranged ionic interactions with
organic bases. Earlier work has shown that the net charge in MA (−4, −3, or −2) influences its assembly, respectively, either
as ribbons or sheets. In the former case the cations intersperse the ribbons forming a tight network. In the MA sheets from
the latter, the cations are arranged in orthogonal stacks. In the MA-phenanthroline complex such stacks are arranged exactly
parallel resulting in significant π–π interactions. The present work relates to the modification of the phenanthroline motif
to flexible structures. The reported ability of 2,3-bis-(2′-pyridyl) pyrazine (P2), prepared from 2,2′-pyridyl by reaction
with ethylenediamine (EDA) followed by dehydrogenation of the resulting 2,3-bis-(2′-pyridyl)-5,6-dihydropyrazine, to form
helical structures made it an obvious choice for complexation studies with MA. These resulted not only in the formation of
the desired 7 MAP2 complex but also, surprisingly, with the dihydroprecursor complex with EDA 3 (MAEDA), a compound that eluded direct preparation with MA and EDA. The crystal structure of MAEDA reports the first complex
of MA where MA−5 ions are encountered. The 15 hydrogen bonds, three for each N, result in hard packing. The complex with P2 7 (MAP2) showed the common features of MA−2 sheets. Unlike phenanthroline, the nonplanar disposition of the pyridine rings made it possible for both pyridine protons
to be available for salt formation, resulting in the arrangement of the cations in layers interposed between the sheets of
MA−2 ions. The pyrazine ring does not participate in hydrogen bonding or stacking in the crystal. 相似文献
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Jin Nie Xiaoyong Li Dafan Liu Rong Luo Liqiong Wang 《Journal of fluorine chemistry》2004,125(1):27-31
The facile preparation and characterization on a novel trisodium salt based on bis[(perfluoroalkyl)sulfonyl]triimide trianion were reported for the first time. High oxidation potential was observed for the new salt in organic solvent. Ionic conductivities of this new salt and other monomeric sodium salts were determined in different organic solvents over a temperature range between 10 and 100 °C. 相似文献
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De‐Hui Tuo Chao Chen Huapeng Ruan Qi‐Qiang Wang Yu‐Fei Ao Xinping Wang De‐Xian Wang 《Angewandte Chemie (International ed. in English)》2020,59(33):14040-14043
Radical pimers are the simplest and most important models for studying charge‐transfer processes and provide deep insight into π‐stacked organic materials. Notably, radical pimer systems with magnetic bi‐ or multistability may have important applications in switchable materials, thermal sensors, and information‐storage media. However, no such systems have been reported. Herein, we describe a new pimer consisting of neutral N‐(n‐propyl) benzene triimide ([BTI‐3C]) and its anionic radical ([BTI‐3C]?.) that exhibits rare magnetic multistability. The crystalline pimer was readily synthesized by reduction of BTI‐3C with cobaltocene (CoCp2). The transition occurred with a thermal hysteresis loop that was 27 K wide in the range of 170–220 K, accompanied by a smaller loop with a width of 25 K at 220–242 K. The magnetic multistability was attributed to slippage of the π‐stacked BTI structures and entropy‐driven conformational isomerization of the side propyl chains in the crystalline state during temperature variation. 相似文献
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