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1.
Energetic salts containing the nitroformate (trinitromethanide) anion with several nitrogen‐rich cations were investigated, including ammonium nitroformate (ANF), melaminium nitroformate (MNF), guanidinium nitroformate monohydrate (GNFH), aminoguanidinium nitroformate (AGNF), diaminoguanidinium nitroformate (DAGNF) as well as triaminoguanidinium nitroformate (TAGNF). All salts were characterized using vibrational spectroscopy (IR, Raman), mass spectrometry, multinuclear NMR spectroscopy and elemental analysis. The thermal decomposition of the salts was monitored using differential scanning calorimetry. In addition, the impact, friction and electrostatic sensitivity data were determined. Theoretical calculations were carried out in order to predict performance data such as detonation velocities and detonation pressures. The crystal structures of ANF, MNF, GNFH, AGNF, DAGNF and TAGNF were determined using single crystal X‐ray diffraction. In addition, a second polymorph of MNF was determined crystallographically as well as the crystal structures of MNF with methanol and MNF with dimethylsulfoxide. Finally, new polymorphs of potassium nitroformate (KNF) and hydrazinium nitroformate (HNF) were characterized using single crystal X‐ray diffraction. 相似文献
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Thomas G. Müller Magnus R. Buchner Thomas J. Scheubeck Nikolaus Korber Florian Kraus 《无机化学与普通化学杂志》2016,642(14):796-803
The synthesis of ammine metal azides is achieved through a simple route in liquid ammonia solution. Azides of silver, sodium, manganese, and zinc were obtained as ammine complexes from liquid ammonia and the solid compounds were characterized. The NH3 solutions were investigated by means of NMR spectroscopy as well. The triamminesilver(I) azide as well as the unusual tetraamminesilver(I) and pentaamminesodium(I) azides are presented. The structures of the hexaamminemanganese(II) and hexaamminezinc(II) azides, which crystallize with four ammonia molecules of solvation, are elucidated. From these compounds the binary azides Mn(N3)2 and Zn(N3)2 were obtained by (careful) heating. 相似文献
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Kazuaki Ito Yoshihiro Ohba Eita Shinagawa Satoshi Nakayama Shigemi Takahashi Katsuhiko Honda Hidekazu Nagafuji Akane Suzuki Tyo Sone 《Journal of heterocyclic chemistry》2000,37(6):1479-1489
Metacyclophanes were prepared by cyclization reactions between bis(chloromethyl) compounds and piperazine, primary amines, or ethylene glycol. The 1H nmr relaxation time (T1) measurements indicated that the macrocycles feature the up and down motion of the aromatic units around the XCH2Ar (X = N, O) methylene moieties as the axes. Metacyclophanes incorporating piperazine units showed high complexation ability for alkaline metal cations. 相似文献
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Anthony Linden A. S. Muhammad Sofian C. Kuan Lee 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(12):o718-o720
At 160 K, one of the Cl atoms in the furanoid moiety of 3‐O‐acetyl‐1,6‐dichloro‐1,4,6‐trideoxy‐β‐d ‐fructofuranosyl 2,3,6‐tri‐O‐acetyl‐4‐chloro‐4‐deoxy‐α‐d ‐galactopyranoside, C20H27Cl3O11, is disordered over two orientations, which differ by a rotation of about 107° about the parent C—C bond. The conformation of the core of the molecule is very similar to that of 3‐O‐acetyl‐1,4,6‐trichloro‐1,4,6‐trideoxy‐β‐d ‐tagatofuranosyl 2,3,6‐tri‐O‐acetyl‐4‐chloro‐4‐deoxy‐α‐d ‐galactopyranoside, particularly with regard to the conformation about the glycosidic linkage. 相似文献
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Synthesis and Reactivity of 2‐Pyrrolidino‐, 2‐N‐Methylpiperazino‐, 2‐Piperidino‐, and 2‐Morpholino‐1,3,4‐thiadiazines 下载免费PDF全文
Stefanie Knak Wolf‐Diethard Pfeiffer Horst Dollinger Peter Langer 《Journal of heterocyclic chemistry》2015,52(2):450-462
A variety of 2‐pyrrolidino‐, 2‐N‐methylpiperazino‐, 2‐piperidino‐, and 2‐morpholino‐1,3,4‐thiadiazines were prepared by cyclocondensation of phenacyl halides with thiosemicarbazides. Heating of the products resulted in desulfurization and formation of pyrazoles. The rate of this process strongly depends on the substitution pattern of the 1,3,4‐thiadiazines. 相似文献
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Anion‐, Solvent‐, Temperature‐, and Mechano‐Responsive Photoluminescence in Gold(I) Diphosphine‐Based Dimers 下载免费PDF全文
Dr. Andrea Deák Csaba Jobbágy Gábor Marsi Miklós Molnár Zoltán Szakács Dr. Péter Baranyai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(32):11495-11508
A series of [Au2(nixantphos)2](X)2 (nixantphos=4,6‐bis(diphenylphosphino)‐phenoxazine; X=NO3, 1 ; CF3COO, 2 ; CF3SO3, 3 ; [Au(CN)2], 4 ; and BF4, 5 ) complexes that exhibit intriguing anion‐switchable and stimuli‐responsive luminescent photophysical properties have been synthesized and characterized. Depending on their anions, these complexes display yellow ( 3 ), orange ( 4 and 5 ), and red ( 1 and 2 ) emission colors. They exhibit reversible thermo‐, mechano‐, and vapochromic luminescence changes readily perceivable by the naked eye. Single‐crystal X‐ray studies show that the [Au2(nixantphos)2]2+ cations with short intramolecular Au ??? Au interactions are involved as donors in an infinite N?H ??? X (X=O and N) hydrogen‐bonded chain formation with CF3COO? ( 2 C ) and aurophilically linked [Au(CN)2]? counterions ( 4 C ). Both crystals show thermochromic luminescence; their room temperature red ( 2 C ) and orange ( 4 C ) emission turns into yellow upon cooling to 77 K. They also exhibit reversible mechanochromic luminescence by changing their emission color from red to dark ( 2 C ), and orange to red ( 4 C ). Compounds 1 – 5 also display reversible mechanochromic luminescence, altering their emission colors between orange ( 1 ) or red ( 2 ) to dark, as well as between yellow ( 3 ) or orange ( 4 and 5 ) to red. Detailed photophysical investigations and correlation with solid‐state structural data established the significant role of N?H ??? X interactions in the stimuli‐responsive luminescent behavior. 相似文献
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《Macromolecular bioscience》2018,18(7)
In contrast to chemical routes, enzymatic polymerization possesses favorable characteristics of mild reaction conditions, few by‐products, and high activity toward cyclic lactones which make it a promising technique for constructing polymeric materials. Meanwhile, it can avoid the trace residue of metallic catalysts and potential toxicity, and thus exhibits great potential in the biomedical fields. More importantly, lipase‐catalyzed polymer synthesis usually shows favorable enantio‐, regio‐, and chemoselectivity. Here, the history and recent developments in lipase‐catalyzed selective polymerization for constructing polymers with unique structures and properties are highlighted. In particular, the synthesis of polymeric materials which are difficult to prepare in a chemical route and the construction of polymers through the combination of selective enzymatic and chemical methods are focused. In addition, the future direction is proposed especially based on the rapid developments in computational chemistry and protein engineering techniques. 相似文献
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Stephen W. Wright 《Journal of heterocyclic chemistry》2012,49(2):442-445
Procedures are reported to prepare the tert‐butyl esters of 2‐aminonicotinic acid, 4‐aminonicotinic acid, 5‐aminonicotinic acid, and 6‐aminonicotinic acid from 2‐chloronicotinic acid, 4‐chloronicotinic acid, 5‐bromonicotinic acid, and 6‐chloronicotinic acid, respectively, without need for purification of intermediates. J. Heterocyclic Chem., (2012). 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
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Dipl.‐Chem. Florian Hinderer Prof. Dr. Uwe H. F. Bunz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(26):8490-8496
The photophysical properties of a series of para‐substituted donor–acceptor cruciform fluorophores ( p 1 – 4 ) were investigated and compared with their meta and ortho isomers ( m 1 – 4 and o 1 – 4 ). The structural variations were found to have a significant effect on the solvatochromism, fluorescence quantum yields (Φfl), fluorescence lifetimes (τfl), and response upon addition of trifluoroacetic acid. The observed spectral shifts in absorption and emission caused by protonation of the cruciforms make them promising candidates as chemosensors. Additional computational studies provided more insight into the electronic structure of the systems. 相似文献
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Zikri Altun Erdi A. Bleda Carl Trindle Jason Wang 《International journal of quantum chemistry》2014,114(10):675-687
N‐heterocyclic carbenes (NHCs) based on imidazole‐2‐ylidene ( 1 ) or the saturated imidazolidine‐2‐ylidene ( 2 ) scaffolds are long‐lived singlet carbenes. Both benefit from inductive stabilization of the sigma lone pair on carbon by neighboring N atoms and delocalization of the N pi lone pairs into the nominally vacant p‐pi atomic orbital at the carbene carbon. With thermochemical schemes G4 and CBS‐QB3, we estimate the relative thermodynamic stabilization of smaller ring carbenes and acyclic species which may share the keys to NHC stability. These include four‐membered ring systems incorporating the carbene center, two trivalent N centers, and either a boron or a phosphorus atom to complete the ring. Amino‐substituted cyclopropenylidenes have been reported but three‐membered rings containing the carbene center and two N atoms are not known. Our calculations suggest that amino‐substituted cyclopropenylidenes are comparable in stability to the four‐membered NHCs but that diazacyclopropanylidenes would be substantially less effectively stabilized. Concluding the series are acyclic carbenes with and without neighboring N atoms and a series of “two‐membered ring” azapropadienenylidene cations of form :C?N?W with W = an electron‐withdrawing agent. We have studied W = NO2, CH2(+), CF2(+), and (CN)2C(+). Although these systems display a degree of stabilization and carbene‐like electronic structure, the stability of the NHCs is unsurpassed. © 2014 Wiley Periodicals, Inc. 相似文献
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Ring‐Opening Regio‐, Diastereo‐, and Enantioselective 1,3‐Chlorochalcogenation of Cyclopropyl Carbaldehydes 下载免费PDF全文
Jan Wallbaum Lennart K. B. Garve Prof. Dr. Peter G. Jones Prof. Dr. Daniel B. Werz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(52):18756-18759
meso‐Cyclopropyl carbaldehydes are treated in the presence of an organocatalyst with sulfenyl and selenyl chlorides to afford 1,3‐chlorochalcogenated products. The transformation is achieved by a merged iminium–enamine activation. The enantioselective desymmetrization reaction, leading to three adjacent stereocenters, furnished the target products in complete regioselectivity and moderate to high diastereo‐ and enantioselectivities (d.r. up to 15:1 and e.r. up to 93:7). 相似文献
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Novel Synthesis of Some Imidazolyl‐, Benzoxazinyl‐, and Quinazolinyl‐2,4‐dioxothiazolidine Derivatives 下载免费PDF全文
Ali M. Youssef Ahmed K. EL‐Ziaty Wael S. I. Abou‐Elmagd Sayed K. Ramadan 《Journal of heterocyclic chemistry》2015,52(1):278-283
2‐(2,4‐Dioxothiazolidin‐5‐yl)acetic acid 1 and its chloride derivative 2 were allowed to react with different aromatic amines such as o‐phenylenediamine, o‐aminothiophenol, p‐aminoacetophenone, and anthranilic acid to give the biologically active nuclei such as imidazoles, thiazoles, benzoxazines, and quinazolines incorporated with the thiazolidindione nucleus. The antimicrobial activity of five of the synthesized compounds was examined against one gram positive bacteria (Staphylococcus aureus), one gram negative bacteria (Escherichia coli), and two fungi (Aspergillus flavus and Candida albicans). Four compounds showed moderate antibacterial and antifungal activities. 相似文献
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Benign‐by‐Design Solventless Mechanochemical Synthesis of Three‐, Two‐, and One‐Dimensional Hybrid Perovskites 下载免费PDF全文
Alexander D. Jodlowski Dr. Alfonso Yépez Prof. Rafael Luque Prof. Luis Camacho Prof. Gustavo de Miguel 《Angewandte Chemie (International ed. in English)》2016,55(48):14972-14977
Organic–inorganic hybrid perovskites have attracted significant attention owing to their extraordinary optoelectronic properties with applications in the fields of solar energy, lighting, photodetectors, and lasers. The rational design of these hybrid materials is a key factor in the optimization of their performance in perovskite‐based devices. Herein, a mechanochemical approach is proposed as a highly efficient, simple, and reproducible method for the preparation of four types of hybrid perovskites, which were obtained in large amounts as polycrystalline powders with high purity and excellent optoelectronics properties. Two archetypal three‐dimensional (3D) perovskites (MAPbI3 and FAPbI3) were synthesized, together with a bidimensional (2D) perovskite (Gua2PbI4) and a “double‐chain” one‐dimensional (1D) perovskite (GuaPbI3), whose structure was elucidated by X‐ray diffraction. 相似文献
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Mechanistic Studies of Hoveyda–Grubbs Metathesis Catalysts Bearing S‐, Br‐, I‐, and N‐coordinating Naphthalene Ligands 下载免费PDF全文
Krzysztof Grudzień Karolina Żukowska Maura Malińska Prof. Krzysztof Woźniak Dr. Michał Barbasiewicz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(10):2819-2828
Derivatives of the Hoveyda–Grubbs complex bearing S‐, Br‐, I‐, and N‐coordinating naphthalene ligands were synthesized and characterized with NMR and X‐ray studies. Depending on the arrangement of the coordinating sites on the naphthalene core, the isomeric catalysts differ in activity in model metathesis reactions. In particular, complexes with the Ru?CH bond adjacent to the second aromatic ring of the ligand suffer from difficulties experienced on their preparation and initiation. The behavior most probably derives from steric hindrance around the double bond and repulsive intraligand interactions, which result in abnormal chemical shifts of benzylidene protons observed with 1H NMR. Furthermore EXSY studies revealed that the halogen‐chelated ruthenium complexes display an equilibrium, in which major cis‐Cl2 structures are accompanied with small amounts of isomeric forms. In general, contents of the minor forms, measured at 80 °C, correlate with the observed activity trends of the catalysts, although some exceptions complicate the mechanistic picture. We assume that for the family of halogen‐chelated metathesis catalysts the initiation mechanism starts with the cis‐Cl2?trans‐Cl2 isomerization, although further steps may become rate‐limiting for selected systems. 相似文献
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Jasmin Chmiel Beate Neumann Dr. Hans‐Georg Stammler Prof. Dr. Norbert W. Mitzel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(39):11906-11914
Potential host systems based on a rigid 1,8‐diethynylanthracendiyl backbone were synthesised by treatment of 1,8‐diethynylanthracene with the Group 13 trialkyls AlMe3, GaMe3, InMe3, AlEt3 and GaEt3. The resulting products were characterised by IR and multinuclear NMR spectroscopy, elemental analyses and determination of their crystal structures by X‐ray diffraction. The compounds are dimeric in the solid state and comprise two M2C2 heterocycles. Depending on the steric demand of the alkyl substituents at the metal atom, different types of binding modes were observed, which can be classified to lie between the ideals of side‐on coordination with almost linear primary M? C?C units and the 3c–2e coordination with symmetrically bridging alkynyl units in M‐C‐M bonds. As a solution in THF the dimers are broken into monomers and some are found to undergo ligand scrambling reactions. 相似文献