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Acta Crystallographica. Section C, Structural Chemistry

Marc Hebrant
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October 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
Chi Nguyen Thi Thanh, Thong Pham Van, Hai Le Thi Hong, Luc Van Meervelt
Crystallization experiments with the dinuclear chelate ring complex di-μ-chlorido-bis[(η(2)-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC(1))platinum(II)], [Pt2(C15H19O4)2Cl2], containing a derivative of the natural compound eugenol as ligand, have been performed. Using five different sets of crystallization conditions resulted in four different complexes which can be further used as starting compounds for the synthesis of Pt complexes with promising anticancer activities. In the case of vapour diffusion with the binary chloroform-diethyl ether or methylene chloride-diethyl ether systems, no change of the molecular structure was observed...
October 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
Rüdiger W Seidel, Richard Goddard, Nils Nöthling, Christian W Lehmann
Acetic anhydride (ethanoic anhydride), (CH3CO)2O, is a widely used acetylation reagent in organic synthesis. The crystal and molecular structure, as determined by single-crystal X-ray analysis at 100 K, is reported for the first time. A crystal of the title compound (m.p. 200 K) suitable for X-ray diffraction was grown from the melt at low temperature. The title compound crystallizes in the orthorhombic space group Pbcn, with Z = 4. In the crystal, the molecule adopts an exact C2-symmetric conformation about a crystallographic twofold axis...
October 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
Eric Bosch
Weak interactions between organic molecules are important in solid-state structures where the sum of the weaker interactions support the overall three-dimensional crystal structure. The sp-C-H...N hydrogen-bonding interaction is strong enough to promote the deliberate cocrystallization of a series of diynes with a series of dipyridines. It is also possible that a similar series of cocrystals could be formed between molecules containing a terminal alkyne and molecules which contain carbonyl O atoms as the potential hydrogen-bond acceptor...
October 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
Md Ashraf Ali, Shuji Noguchi, Miteki Watanabe, Yasunori Iwao, Shigeru Itai
7-Ethyl-10-hydroxycamptothecin [systematic name: (4S)-4,11-diethyl-4,9-dihydroxy-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H,12H)-dione, SN-38] is an antitumour drug which exerts activity through the inhibition of topoisomerase I. The crystal structure of SN-38 as the monohydrate, C22H20N2O5·H2O, reveals that it is a monoclinic crystal, with one SN-38 molecule and one water molecule in the asymmetric unit. When the crystal is heated to 473 K, approximately 30% of SN-38 is hydrolyzed at its lactone ring, resulting in the formation of the inactive carboxylate form...
October 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
Daniel E Lynch, Graham Smith, Tony D Keene, Peter N Horton
The study of ternary systems is interesting because it introduces the concept of molecular preference/competition into the system where one molecule may be displaced because the association between the other two is significantly stronger. Current definitions of a tertiary system indicate that solvent molecules are excluded from the molecule count of the system and some of the latest definitions state that any molecule that is not a solid in the parent form at room temperature should also be excluded from the molecule count...
October 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
Zachary N Vealey, Brandon Q Mercado, Patrick H Vaccaro
Tropolone long has served as a model system for unraveling the ubiquitous phenomena of proton transfer and hydrogen bonding. This molecule, which juxtaposes ketonic, hydroxylic, and aromatic functionalities in a framework of minimal complexity, also has provided a versatile platform for investigating the synergism among competing intermolecular forces, including those generated by hydrogen bonding and aryl coupling. Small members of the troponoid family typically produce crystals that are stabilized strongly by pervasive π-π, C-H...
October 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
Qi Meige Hasi, Yan Fan, Chen Hou, Xiao Qiang Yao, Jia Cheng Liu
In coordination chemistry and crystal engineering, many factors influence the construction of coordination polymers and the final frameworks depend greatly on the organic ligands used. N-Donor ligands with diverse coordination modes and conformations have been employed to assemble metal-organic frameworks. Carboxylic acid ligands can deprotonate completely or partially when bonding to metal ions and can also act as donors or acceptors of hydrogen bonds and are thus good candidates for the construction of supramolecular architectures...
October 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
Xiao Qing Cai, Bei Tian, Jian Nan Zhang, Zhi Min Jin
A fixed hydrogen-bonding motif with a high probability of occurring when appropriate functional groups are involved is described as a `supramolecular hydrogen-bonding synthon'. The identification of these synthons may enable the prediction of accurate crystal structures. The rare chiral hydrogen-bonding motif R5(3)(10) was observed previously in a cocrystal of 2,4,6-trichlorophenol, 2,4-dichlorophenol and dicyclohexylamine. In the title solvated salt, 2C4H12N(+)·C6H3Cl2O(-)·(C6H3Cl2O(-)·C6H4Cl2O)·2C4H8O, five components, namely two tert-butylammonium cations, one 2,4-dichlorophenol molecule, one 2,4-dichlorophenolate anion and one 2,6-dichlorophenolate anion, are bound by N-H...
October 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
Akihiko Nakatsuka, Kazumasa Sugiyama, Makio Ohkawa, Osamu Ohtaka, Keiko Fujiwara, Akira Yoshiasa
The Sr-Ge-O system has an earth-scientific importance as a potentially good low-pressure analog of the Ca-Si-O system, one of the major components in the constituent minerals of the Earth's crust and mantle. However, it is one of the germanate systems that has not yet been fully examined in the phase relations and structural properties. The recent findings that the SrGeO3 high-pressure perovskite phase is the first Ge-based transparent electronic conductor make the Sr-Ge-O system interesting in the field of materials science...
October 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
Wilhelm Maximilian Hützler, Ernst Egert, Michael Bolte
A path to new synthons for application in crystal engineering is the replacement of a strong hydrogen-bond acceptor, like a C=O group, with a weaker acceptor, like a C=S group, in doubly or triply hydrogen-bonded synthons. For instance, if the C=O group at the 2-position of barbituric acid is changed into a C=S group, 2-thiobarbituric acid is obtained. Each of the compounds comprises two ADA hydrogen-bonding sites (D = donor and A = acceptor). We report the results of cocrystallization experiments of barbituric acid and 2-thiobarbituric acid, respectively, with 2,4-diaminopyrimidine, which contains a complementary DAD hydrogen-bonding site and is therefore capable of forming an ADA/DAD synthon with barbituric acid and 2-thiobarbituric acid...
September 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
Dohyun Moon, Yong Pyo Hong, Jong Ha Choi
Constrained cyclam derivatives have been found to exhibit anti-HIV effects. The strength of binding to the CXCR4 receptor correlates with anti-HIV activity. The conformation of the macrocyclic compound is very important for co-receptor recognition. Therefore, knowledge of the conformation and crystal packing of macrocycles has become important in developing new highly effective anti-HIV drugs. Structural modifications of N-functionalized polyaza macrocyclic compounds have been achieved using various methods...
September 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
Yingying Wang, Meixia Wen, Zhongjun Gao, Ning Sheng
Polynuclear complexes are an important class of inorganic functional materials and are of interest particularly for their applications in molecular magnets. Multidentate chelating ligands play an important role in the design and syntheses of polynuclear metal clusters. A novel linear tetranuclear Co(II) cluster, namely bis{μ3-(E)-2-[(2-oxidobenzylidene)amino]phenolato}bis{μ2-(E)-2-[(2-oxidobenzylidene)amino]phenolato}bis(1,10-phenanthroline)tetracobalt(II), [Co4(C14H11NO2)4(C12H8N2)2], was prepared under solvothermal conditions through a mixed-ligand synthetic strategy...
September 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
Christina A Capacci-Daniel, Jeffery A Bertke, Shoaleh Dehghan, Rupa Hiremath-Darji, Jennifer A Swift
Hydrogen bonding between urea functionalities is a common structural motif employed in crystal-engineering studies. Crystallization of 1,3-bis(3-fluorophenyl)urea, C13H10F2N2O, from many solvents yielded concomitant mixtures of at least two polymorphs. In the monoclinic form, one-dimensional chains of hydrogen-bonded urea molecules align in an antiparallel orientation, as is typical of many diphenylureas. In the orthorhombic form, one-dimensional chains of hydrogen-bonded urea molecules have a parallel orientation rarely observed in symmetrically substituted diphenylureas...
September 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
Nutalapati Venkatramaiah, Ricardo F Mendes, Artur M S Silva, João P C Tomé, Filipe A Almeida Paz
The preparation of coordination polymers (CPs) based on either transition metal centres or rare-earth cations has grown considerably in recent decades. The different coordination chemistry of these metals allied to the use of a large variety of organic linkers has led to an amazing structural diversity. Most of these compounds are based on carboxylic acids or nitrogen-containing ligands. More recently, a wide range of molecules containing phosphonic acid groups have been reported. For the particular case of Ca(2+)-based CPs, some interesting functional materials have been reported...
September 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
Felix Katzsch, Tobias Gruber, Edwin Weber
The syntheses of three bis(benzo[b]thiophen-2-yl)methane derivatives, namely bis(benzo[b]thiophen-2-yl)methanone, C17H10OS2, (I), 1,1-bis(benzo[b]thiophen-2-yl)-3-(trimethylsilyl)prop-2-yn-1-ol, C22H20OS2Si, (II), and 1,1-bis(benzo[b]thiophen-2-yl)prop-2-yn-1-ol, C19H12OS2, (III), are described and their crystal structures discussed comparatively. The conformation of ketone (I) and the respective analogues are rather similar for most of the compounds compared. This is true for the interplanar angles, the Caryl-Cbridge-Caryl angles and the dihedral angles...
September 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
Tholappanavara H Suresha Kumara, Gopalpur Nagendrappa, Nanjappa Chandrika, Haliwana B V Sowmya, Manpreet Kaur, Jerry P Jasinski, Christopher Glidewell
Hydrazone derivatives exhibit a wide range of biological activities, while pyrazolo[3,4-b]quinoline derivatives, on the other hand, exhibit both antimicrobial and antiviral activity, so that all new derivatives in these chemical classes are potentially of value. Dry grinding of a mixture of 2-chloroquinoline-3-carbaldehyde and 4-methylphenylhydrazinium chloride gives (E)-1-[(2-chloroquinolin-3-yl)methylidene]-2-(4-methylphenyl)hydrazine, C17H14ClN3, (I), while the same regents in methanol in the presence of sodium cyanoborohydride give 1-(4-methylphenyl)-4,9-dihydro-1H-pyrazolo[3,4-b]quinoline, C17H15N3, (II)...
September 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
Badiadka Narayana, Hemmige S Yathirajan, Ravindranath S Rathore, Christopher Glidewell
4-Antipyrine [4-amino-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one] and its derivatives exhibit a range of biological activities, including analgesic, antibacterial and anti-inflammatory, and new examples are always of potential interest and value. 2-(4-Chlorophenyl)-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)acetamide, C19H18ClN3O2, (I), crystallizes with Z' = 2 in the space group P\overline{1}, whereas its positional isomer 2-(2-chlorophenyl)-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)acetamide, (II), crystallizes with Z' = 1 in the space group C2/c; the molecules of (II) are disordered over two sets of atomic sites having occupancies of 0...
September 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
Yang Liu, Yong Lan Feng, Wei Wei Fu
The design and synthesis of functional coordination polymers is motivated not only by their structural beauty but also by their potential applications. Zn(II) and Cd(II) coordination polymers are promising candidates for producing photoactive materials because these d(10) metal ions not only possess a variety of coordination numbers and geometries, but also exhibit luminescence properties when bound to functional ligands. It is difficult to predict the final structure of such polymers because the assembly process is influenced by many subtle factors...
September 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
Li Yang Zhang, Li Ping Lu, Si Si Feng
Coordination polymers are a thriving class of functional solid-state materials and there have been noticeable efforts and progress toward designing periodic functional structures with desired geometrical attributes and chemical properties for targeted applications. Self-assembly of metal ions and organic ligands is one of the most efficient and widely utilized methods for the construction of CPs under hydro(solvo)thermal conditions. 2-(Pyridin-3-yl)-1H-imidazole-4,5-dicarboxylate (HPIDC(2-)) has been proven to be an excellent multidentate ligand due to its multiple deprotonation and coordination modes...
August 1, 2016: Acta Crystallographica. Section C, Structural Chemistry
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