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Reza‐Ali Fallahpour Anthony Linden 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(5):o283-o285
In the nearly planar title compound, C15H10IN3, the three pyridine rings exhibit transoid conformations about the interannular C—C bonds. Very weak C—H...N and C—H...I interactions link the molecules into ribbons. Significant π–π stacking between molecules from different ribbons completes a three‐dimensional framework of intermolecular interactions. Four different packing motifs are observed among the known structures of simple 4′‐substituted terpyridines. 相似文献
3.
Xiaoming Liu Colin A. Kilner Mark Thornton‐Pett Malcolm A. Halcrow 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):1142-1143
The title compound, C17H13N3, is a versatile precursor for polymeric terpyridine derivatives and their metal complexes. The molecule has transoid and near‐coplanar pyridine rings. However, the vinyl group is forced out of the plane of the terpyridyl moiety by a close H?H contact. 相似文献
4.
Ivn Brito Aldo Mundaca Alejandro Crdenas Matías Lpez‐Rodríguez 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(3):o117-o118
In the title compound, C10H6N4O4S2, (I), the molecule has a centre of inversion. The structure is a positional isomer of 5,5′‐dinitro‐2,2′‐dithiodipyridine [Brito, Mundaca, Cárdenas, López‐Rodríguez & Vargas (2007). Acta Cryst. E 63 , o3351–o3352], (II). The 3‐nitropyridine fragment of (I) shows excellent agreement with the bonding geometries of (II). The most obvious differences between them are in the S—S bond length [2.1167 (12) Å in (I) and 2.0719 (11) Å in (II)], and in the C—Cipso—Nring [119.8 (2)° in (I) and 123.9 (3)° in (II)] and S—C—C [122.62 (18)° in (I) and 116.0 (2)° in (II)] angles. The crystal structure of (I) has an intramolecular C—H...O interaction, with an H...O distance of 2.40 (3) Å, whereas this kind of interaction is not evident in (II). The molecules of (I) are linked into centrosymmetric R44(30) motifs by a C—H...O interaction. There are no aromatic π–π stacking and no C—H...π(arene) interactions. Compound (I) can be used as a nucleophilic tecton in self‐assembly reactions with metal centres of varying lability. 相似文献
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Dr. Chang‐Qi Ma Dr. Elena Mena‐Osteritz Dr. Markus Wunderlin Dr. Gisela Schulz Prof. Dr. Peter Bäuerle 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(40):12880-12901
The synthesis of generational dendritic oligothiophenes (DOTs) has been successfully achieved by a divergent/convergent approach that involves halogenation, boronation, and palladium‐catalyzed Suzuki coupling reactions. The key point in the presented synthetic approach is the use of trimethylsilyl (TMS) protecting groups, which allow for the core‐lithiation and subsequent boronation of the dendrons and for the peripheral ipso‐substitution with iodine monochloride or N‐bromosuccimide. In addition, the TMS protecting groups can be completely removed by using tetrabutylammonium fluoride, thus yielding only‐thiophene‐based dendrons and dendrimers. Due to their highly branched structure, all these synthesized DOTs are soluble in organic solvents. Chemical structures were confirmed by NMR spectroscopic, mass spectrometric, and elemental analysis. Concentration‐dependent 1H NMR spectroscopic investigations revealed that the higher generation compounds tend to aggregate in solution. Such an aggregation behavior was further confirmed by measuring with MALDI‐TOF MS. Both MALDI‐TOF MS and gel‐permeation chromatography (GPC) analyses confirmed the monodispersity of the DOTs. Furthermore, GPC results revealed that these DOT molecules adopt a condensed globular molecular shape. Their optical and electronic properties were also investigated. The results indicated that these DOTs comprise various conjugated α‐oligothiophenes with different chain lengths, which results in the higher generation compounds showing broad and featureless UV/Vis absorption spectra and ill‐defined redox waves. 相似文献
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Krzysztof Ejsmont Janusz Kyzio Ewa Nowakowska Jacek Zaleski 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(1):93-94
The title compound, C23H28O2, was obtained from the reaction of acetone with meta‐cresol. The molecular structure consists of two identical subunits which are nearly perpendicular to each other. The oxygen‐containing rings are not planar and the molecule is chiral. The crystal structure consists of chains of molecules of the same chirality arranged along the [010] axis. 相似文献
7.
Adel A. Mohamed 《International journal of quantum chemistry》2000,79(6):367-377
Conformational properties of 2,2′‐bithiazole and 4,4′‐dimethyl‐2,2′‐ bithiazole have been studied by using AM1 and PM3 semiemperical methods and ab initio HF/6‐311+G* and B3LYP/6‐311+G* calculations. All methods agree that the planar s‐trans conformation is the global minimum and the perpendicular conformation is the transition state. Additional local minima were found using the Hartree–Fock (HF) and B3LYP levels for 2,2′‐bithiazole while for 4,4′‐dimethyl derivative the minima was located only at the MP2//B3LYP level. The barrier heights for rotation are 1.72, 7.69, and 7.88 kcal/mol at the PM3, HF, and B3LYP levels, respectively, and methyl substitution did not affect appreciably this value. Fourier expansion terms and bond orders were used to explain the origins of the rotational barrier in terms of π conjugation, electrostatic interaction, and steric effects, which represent the main factors in the shape of the rotational barrier. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 79: 367–377, 2000 相似文献
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David G. Billing Cedric W. Holzapfel Kevin Blann D. Bradley G. Williams 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(11):e522-e523
The crystal structure of the title compound, C20H18O4, contains a crystallographic inversion center. The C—C bond linking the two halves of the molecule is slightly elongated at 1.577 (3) Å. 相似文献
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Yasushi Kai Jun Sakamoto Takashi Nakagawa Nobuko Kanehisa Masahiro Katsura 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):e596-e597
In the title compound, C14H10N4, all the atoms are close to being coplanar (r.m.s. deviation 0.0098 Å) except for the imino H atoms. The molecule forms a one‐dimensional chain through intermolecular N—H?N hydrogen bonds. 相似文献
10.
Alexander J. Blake Pamela V. Mason Claire Wilson Neil R. Champness 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(6):m280-m282
The single‐crystal X‐ray structures of dimethyl 2,2′‐bipyridine‐6,6′‐dicarboxylate, C14H12N2O4, and the copper(I) coordination complex bis(dimethyl 2,2′‐bipyridine‐6,6′‐dicarboxylato‐κ2N,N′)copper(I) tetrafluoroborate, [Cu(C14H12N2O4)2]BF4, are reported. The uncoordinated ligand crystallizes across an inversion centre and adopts the anticipated anti pyridyl arrangement with coplanar pyridyl rings. In contrast, upon coordination of copper(I), the ligand adopts an arrangement of pyridyl donors facilitating chelating metal coordination and an increased inter‐pyridyl twisting within each ligand. The distortion of each ligand contrasts with comparable copper(I) complexes of unfunctionalized 2,2′‐bipyridine. 相似文献
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Pawe Wagner David L. Officer Maciej Kubicki 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(7):o400-o404
In the crystal structures of four thiophene derivatives, (E)‐3′‐[2‐(anthracen‐9‐yl)ethenyl]‐2,2′:5′,2′′‐terthiophene, C28H18S3, (E)‐3′‐[2‐(1‐pyrenyl)ethenyl]‐2,2′:5′,2′′‐terthiophene, C30H18S3, (E)‐3′‐[2‐(3,4‐dimethoxyphenyl)ethenyl]‐2,2′:5′,2′′‐terthiophene, C22H18O2S3, and (E,E)‐1,4‐bis[2‐(2,2′:5′,2′′‐terthiophen‐3′‐yl)ethenyl]‐2,5‐dimethoxybenzene, C36H26O2S6, at least one of the terminal thiophene rings is disordered and the disorder is of the flip type. The terthiophene fragments are far from being coplanar, contrary to terthiophene itself. The central C—C=C—C fragments are almost planar but the bond lengths suggest slight delocalization within this fragment. The crystal packing is determined by van der Waals interactions and some weak, relatively short, C—H...S and C—H...π directional contacts. 相似文献
12.
Alexander N. Chernyshev Vadim Yu. Kukushkin Matti Haukka 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(12):1133-1137
Two noble metal complexes involving ancillary chloride ligands and chelating 2,2′‐bipyridylamine (Hdpa) or its deprotonated derivative (dpa), namely [bis(pyridin‐2‐yl‐κN)amine]tetrachloridoplatinum(IV), [PtCl4(C10H9N3)], and [bis(pyridin‐2‐yl‐κN)aminido]dichloridogold(III), [AuCl2(C10H8N3)], are presented and structurally characterized. The metal atom in the former has a slightly distorted octahedral coordination environment, formed by four chloride ligands and two pyridyl N atoms of Hdpa, while the metal atom in the latter has a slightly distorted square‐planar coordination environment, formed by two chloride ligands and two pyridyl N atoms of dpa. The difference in conjugation between the pyridine rings in normal and deprotonated 2,2′‐dipyridylamine is discussed on the basis of the structural features of these complexes. The influence of weak interactions on the supramolecular structures of the complexes, providing one‐dimensional chains of [PtCl4(C10H9N3)] and dimers of [AuCl2(C10H8N3)], are discussed. 相似文献
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Introduction Optically active 1,1'-bi-2-naphthol (BINOL) and its derivatives have been widely used as chiral ligands of catalysts for asymmetric reactions and effective host compounds for the isolation or optical resolution of a wide range of organic guest molecules through the for-mation of crystalline inclusion complexes.1,2 The wide-ranging and important applications of these com-pounds in organic synthesis have stimulated great inter-est in developing efficient methods for their prepara-… 相似文献
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Maciej Kubicki 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(8):o512-o514
The two almost perfectly planar imidazole rings in the title compound, C8H8N6O4·H2O, make a dihedral angle of 63.01 (10)°. The water molecule acts as a double donor and double acceptor of strong and linear hydrogen bonds, including an exceptionally short C—H⋯O bond. These bonds create a tight three‐dimensional structure and are probably responsible for the relatively high melting point of the compound. 相似文献
15.
Teresa Mancilla Dolores Castillo Lourdes Carrillo Norberto Farfn 《Heteroatom Chemistry》1999,10(2):133-139
The reaction of N‐methyl‐2,2′‐diphenolamine 1 and 2,2′‐diphenolamine 2 with some diorganotin(IV) oxides [R1/2SnO: R1 = Me, n‐Bu, t‐Bu and Ph] led to the syntheses of diorgano[N‐methyl‐2,2′‐diphenolato‐O,O′,N]tin (IV) 3–6 and diorgano[2,2′‐diphenolato‐O,O′,N]tin (IV) 7–9 . All compounds (except 7 ) studied in this work were characterized by 1H, 13C, 119Sn NMR, infrared, and mass spectroscopy. Their 119Sn NMR data show that the tin atom is tetracoordinated in CDCl3 but penta and hexacoordinated in DMSO‐d6. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 133–139, 1999 相似文献
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Anwar Usman Ibrahim Abdul Razak Hoong‐Kun Fun Suchada Chantrapromma Bao‐Guo Zhao Jian‐Hua Xu 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):o24-o25
In the title compound, C20H16N2O5, both of the 1‐acetylisatin (1‐acetyl‐1H‐indole‐2,3‐dione) moieties are planar and form a dihedral angle of 74.1 (1)°. Weak intermolecular hydrogen bonds and C—H?π interactions stabilize the packing in the crystal. 相似文献
17.
The synthetic route to the dimesitylpalladium(II) complex [(bpy)PdMes2] ( 1 ) (Mes = mesityl = 2,4,6‐trimethyl phenyl) does not only give the desired compound but also the 6‐mesityl‐2,2′bipyridyldimesitylpalladium [(6‐Mes‐bpy)PdMes2] ( 2 ) complex and the free ligand 6,6′‐dimesityl‐2,2′‐bipyridine in reasonable yields. Single crystals of 2 were examined by X‐Ray diffraction. The compound reveals a sterically crowded molecular structure. An intramolecular π‐stacking interaction was found between the mesityl substituent on the bipyridine ligand and the adjacent mesityl ligand. The electrochemical behaviour of 1 and 2 together with a related compound was examined at various temperatures showing two reversible reduction reactions and reversible one‐electron oxidation steps at low temperatures. The latter are assigned to PdII/PdIII couples. 相似文献
18.
By two different routes, 4,4′′′′‐azobis[2,2′: 6′,2″‐terpyridine] was synthesized. Its ruthenium complexes show interesting metal‐to‐ligand charge transfer (MLCT) absorption maxima in the electronic spectra. They represent the first ruthenium complexes of terpyridine units to give blue solutions. 相似文献
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Aleksandar Vinjevac Biserka Koji‐Prodi Marijana Vinkovi Kata Mlinari‐Majerski 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(6):o314-o316
The conformational features of the title compound, C28H44S6, are compared with previously reported analogous macrocycles. The type of substituent affects considerably the conformation of the macrocycle. A 1H NMR titration of the title compound with AgBF4 indicated the formation of the 1:1 complex, which was not crystallized. 相似文献
20.
W. Mark Barnett Russell G. Baughman Paula M. Secondo Charles J. Hermansen 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(9):o565-o567
The crystal structures of the title compounds, alternatively called 2,2′‐(2,2′‐biimidazole‐1,1′‐diyl)diacetohydrazide monohydrate, C10H14N8O2·H2O, (I), and 3,3′‐(2,2′‐biimidazole‐1,1′‐diyl)dipropionohydrazide, C12H18N8O2, (II), respectively, have been determined. The molecules consist of half‐molecule asymmetric units related by a twofold rotation in (I) and by a center of inversion in (II). The imidazole rings of both molecules crystallize in a nearly coplanar fashion [dihedral angles of 5.91 (3) and 0.0 (1)° for (I) and (II), respectively]. Both planar hydrazinocarbonylalkyl substituents are essentially planar and assume the E orientation. 相似文献