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Brian J. Grimmond Joyce Y. Corey Nigam P. Rath 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(1):53-55
The first title metallocene, 1,3‐bis(dichlorotitanocene)‐1,1,3,3‐tetramethyldisiloxane dichloromethane solvate, [(η5‐C5H5)TiCl2(η5‐C5H4SiMe2)]2O·CH2Cl2, (I), crystallizes in space group P21/c. Compound (I) represents the first crystal structure of a bimetallic siloxy‐bridged titanocene. The geometric parameters of (I) are similar to those of the parent titanocene; however, the disiloxane substituents adopt an unexpected eclipsed conformation. The second title metallocene, 1,3‐bis[(pentamethylcyclopentadienyl)(cyclopentadienyl)titanium dichloride]‐1,1,3,3‐tetramethyldisiloxane, [(η5‐C5‐Me5)TiCl2(η5‐C5H4SiMe2)]2O, (II), represents the second crystal structure of a bimetallic siloxy‐bridged titanocene and crystallizes in the space group P21/n. Compound (I) possesses non‐crystallographic twofold molecular symmetry and both metal centers adopt pseudo‐tetrahedral geometries. The geometric parameters of (II) are similar to those of the mixed titanocene Cp*CpTiCl2 (Cp* = C5Me5) and the disiloxane substituents adopt a staggered conformation. 相似文献
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Two new Complexes(Cp)2Ti(Cin)2and (CP2)Ti(Tzea)2(CP=Cyclopentadienyl η^5-C5H5)have been synthesized in THF by the reaction of HCin(Cincofen,2-phenylquinoline-4-carboxylic acid)or HTzea(5-phenyltetrazolyl-2-ethanoic acid)with(Cp)2TiCl2,and characterized by elemental analyses,IR,1H NMR and 13C NMR,UV spectra,molar conductivity,TGDTA.In the complexes the carboxyl groups are coordinated to Ti(IV)in a monodentate manner,The inhibitory actions of the complexes on mice ear tumefaction caused by croton oil and the rat foot granulation growth produced by cotton wool are higher than those of the corresponding ligands HCin,HTzea and [(Cp)2TiCl2],while their toxicities are lower than those of the free ligands.ηη 相似文献
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Brette M. Chapin Lauren D. Hughs James A. Golen Arnold L. Rheingold Adam R. Johnson 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(7):m191-m193
The title complex, [Ti(C5H5)(C2H6N)2Cl], exhibits two nearly planar dimethylamide groups oriented approximately perpendicular to each other. The Ti→cyclopentadienyl centroid vector lies nearly in the plane of one of the dimethylamide groups. Long‐range contacts between Ti—Cl and cyclopentadienyl H—C groups give rise to geometric ordering in the extended solid. 相似文献
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Zhi‐Min Jin Bin Tu Lin He Mao‐Lin Hu Jian‐Wei Zou 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(4):m197-m199
The title compound, (C6H9N2)[ZnCl3(C6H8N2)], consists of one 2‐amino‐5‐methylpyridinium cation and one (2‐amino‐5‐methylpyridine)trichlorozincate(II) anion, which are held together by N—H·Cl hydrogen bonds and π–π interactions. The cation and the pyridine ligand show similar geometric features, except for the N—C bond lengths. Molecules of the title compound are connected by N—H·Cl hydrogen bonds to form chiral chains; these chains are associated further by C—H·Cl hydrogen bonds to form layers, which are in turn linked by π–π interactions. 相似文献
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SimonaC. Jurczyk JanosT. Kodra Jeong-Ho Park StevenA. Benner ThomasR. Battersby 《Helvetica chimica acta》1999,82(7):1005-1015
The syntheses of the 5′-triphosphates of 2′-deoxyisoguanosine (=p3isoGd) and 2′-deoxy-5-methylisocytidine (=p3me5isoCd), two new bases for the genetic alphabet, are described. The triphosphates were synthesized from the corresponding nucleosides using a transient-protection procedure. The introduction of a methyl group at the 5-position of 2′-deoxyisocytidine remarkably improved the stability of the triphosphate. Characterization of the triphosphates included enzymatic incorporation opposite the complementary base in a template oligonucleotide. 相似文献
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Dieter Naumann Thomas Roy Bernd Caeners Dirk Hütten Karl‐Friedrich Tebbe Theo Gilles 《无机化学与普通化学杂志》2000,626(4):999-1003
Syntheses and Properties of Pentafluoroethylcopper(I) and ‐copper(III) Compounds: CuC2F5 · D, [Cu(C2F5)2]–, and (C2F5)2CuSC(S)N(C2H5)2 The reactions of Cd(C2F5)2 · D and Zn(C2F5)2 · D (D = 2 CH3CN, 2 DMF), respectively, with copper(I) halides in the presence of halides quantitatively yield the CuC2F5 compounds CuC2F5 · D and [Cu(C2F5)2]–. The CuC2F5 complexes are identified by NMR spectroscopy, while [Cu(C2F5)2]– is isolated as PNP salt (PNP = (C6H5)3PNP(C6H5)3+). Both compounds are excellent C2F5 group transfer reagents, even at low temperature. Oxidation of [Cu(C2F5)2]– with [(C2H5)2NC(S)S]2 yields the crystalline Cu(III) compound (C2F5)2CuSC(S)N(C2H5)2 (monoclinic, C2/c). 相似文献
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Mamiko Odoko Kyouta Yamamoto Nobuo Okabe 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(9):m469-m470
In the title compound, [Ca(C6H5O4)2(C6H6O4)2]·4H2O, which is a kojic acid–Ca2+ complex, the Ca atom is on a twofold axis and is octacoordinated by O atoms from four pyrone ligand molecules. The hydroxyl and ketone O atoms of each ligand form a five‐membered chelate ring with the Ca atom. The crystal structure is stabilized by partial stacking and O—H?O hydrogen bonds. 相似文献
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We describe the synthesis of (5′S)‐5′‐C‐butylthymidine ( 5a ), of the (5′S)‐5′‐C‐butyl‐ and the (5′S)‐5′‐C‐isopentyl derivatives 16a and 16b of 2′‐deoxy‐5‐methylcytidine, as well as of the corresponding cyanoethyl phosphoramidites 9a , b and 14a , b , respectively. Starting from thymidin‐5′‐al 1 , the alkyl chain at C(5′) is introduced via Wittig chemistry to selectively yield the (Z)‐olefin derivatives 3a and 3b (Scheme 2). The secondary OH function at C(5′) is then introduced by epoxidation followed by regioselective reduction of the epoxy derivatives 4a and 4b with diisobutylaluminium hydride. In the latter step, a kinetic resolution of the diastereoisomer mixture 4a and 4b occurs, yielding the alkylated nucleoside 2a and 2b , respectively, with (5′S)‐configuration in high diastereoisomer purity (de=94%). The corresponding 2′‐deoxy‐5‐methylcytidine derivatives are obtained from the protected 5′‐alkylated thymidine derivatives 7a and 7b via known base interconversion processes in excellent yields (Scheme 3). Application of the same strategy to the purine nucleoside 2′‐deoxyadenine to obtain 5′‐C‐butyl‐2′‐deoxyadenosine 25 proved to be difficult due to the sensitivity of the purine base to hydride‐based reducing agents (Scheme 4). 相似文献
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Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes. XVII [1] [Co(g5‐Me5C5)(g3‐tBu2PPCH–CH3)] from [Co(g5‐Me5C5)(g2‐C2H4)2] and tBu2P–P=P(Me)tBu2 [Co(η5‐Me5C5)(η3‐tBu2PPCH–CH3)] 1 is formed in the reaction of [Co(η5‐Me5C5)(η2‐C2H4)2] 2 with tBu2P–P 4 (generated from tBu2P–P=P(Me)tBu2 3 ) by elimination of one C2H4 ligand and coupling of the phosphinophosphinidene with the second one. The structure of 1 is proven by 31P, 13C, 1H NMR spectra and the X‐ray structure analysis. Within the ligand tBu2P1P2C1H–CH3 in 1 , the angle P1–P2–C1 amounts to 90°. The Co, P1, P2, C1 atoms in 1 look like a „butterfly”︁. The reaction of 2 with a mixture of tBu2P–P=P(Me)tBu2 3 and tBu–C?P 5 yields [Co(η5‐Me5C5){η4‐(tBuCP)2}] 6 and 1 . While 6 is spontaneously formed, 1 appears only after complete consumption of 5 . 相似文献
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Syntheses and characteristics of the heterobimetalorganics of the silicon with the 2‐(dimethylaminomethyl)ferrocenyl ligand FcN (η5‐C5H5)Fe[η5‐C5H3(CH2NMe2)]— The heterobimetallic lithiumorganyl [2‐(dimethylaminomethyl)ferrocenyl] lithium, LiFcN, reacts with silicon(IV)‐chlorid, SiCl4, under the formation of heterobimetallic silicon(IV) organyl [(FcN)3SiCl] ( 1 ). The heterobimetallic organosilanol [(FcN)3SiOH] ( 2 ) is formed at hydrolysis of 1 . A detailed characterization of the defined compounds 1 and 2 was carried out by NMR‐ rsp. mass‐spectrometry and by crystal X‐ray analysis of 2 . 相似文献
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Xiao‐Qin Wang Jian Zhang Zhao‐Ji Li Yi‐Hang Wen Jian‐Kai Cheng Yuan‐Gen Yao 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(12):m657-m658
The title compound, [Nd(C7H3O6S)(H2O)]n or [Nd(SSA)(H2O)]n (H3SSA is 5‐sulfosalicylic acid), was synthesized by the hydrothermal reaction of Nd2O3 with H3SSA in water. The compound forms a three‐dimensional network in which the asymmetric unit contains one NdIII atom, one SSA ligand and one coordinated water molecule. The central NdIII ion is eight‐coordinate, bonded to seven O atoms from five different SSA ligands [Nd—O = 2.405 (4)–2.612 (4) Å] and one aqua O atom [Nd—OW = 2.441 (4) Å]. 相似文献
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Synthesis and Crystal Structure of the Heterobimetallic Diorganotindichloride (FcN, N)2SnCl2 (FcN, N—: (η5‐C5H5)Fe{η5‐C5H3[CH(CH3)N(CH3)CH2CH2NMe2]‐2}—) The heterobimetallic title compound [(FcN, N)2SnCl2] ( 1 ) was obtained by the reaction of [LiFcN, N] with SnCl4 in the molar ratio 1:1 in diethylether as a solvent. The two FcN, N— ligands in 1 are bound to Sn through a C‐Sn σ‐bond; the amino N atoms of the side‐chain in FcN, N— remain uncoordinated. The crystals contain monomeric molecules with a pseudo‐tetrahedral coordination at the Sn atom: Space group P21/c; Z = 4, lattice dimensions at —90 °C: a = 9.6425(2), b = 21.7974(6), c = 18.4365(4) Å, β = 100.809(2)°, R1obs· = 0.051, wR2obs· = 0.136. 相似文献
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Ramamurthy Charubala Wolfgang Pfleiderer Robert W. Sobol Shi Wu Li Robert J. Suhadolnik 《Helvetica chimica acta》1989,72(6):1354-1361
The chemical synthesis of adenylyl-(2′–5′)-adenylyl-(2′–5′)-8-azidoadenosine ( 15 ) was performed by the phosphotriester approach. Enzymatic phosphorylation of 15 by [γ-32P]ATP led to the corresponding labelled 5′-monophosphate 16 . Photoinsertion of 16 took place on UV irradiation by covalent cross linking to a protein of Mr 80 K known to be RNase L. Radiobinding and core-cellulose assays as well as photoaffinity labelling experiments with 16 are described. 相似文献
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Alexander S. Lyakhov Pavel N. Gaponik Yuri V. Grigoriev Ludmila S. Ivashkevich 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(7):o381-o383
In the title compound, alternatively named 5,5′‐diphenyl‐2,2′‐methyleneditetrazole, C15H12N8, the dihedral angles between the tetrazole and benzene rings in the two 5‐phenyltetrazole fragments are 2.45 (6) and 10.01 (9)°. There is weak intermolecular C—H?N hydrogen bonding involving the H atoms of the methylene groups, which is responsible for the formation of two‐membered aggregates. C—H?π interactions in the crystal structure are discussed. 相似文献
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Prof. Dr. Thomas M. Klapötke Andreas Preimesser Jörg Stierstorfer 《无机化学与普通化学杂志》2012,638(9):1278-1286
4, 4′,5, 5′‐Tetranitro‐2, 2′‐bisimidazole (TNBI) was synthesized by nitration of bisimidazole (BI) and recrystallized from acetone to form a crystalline acetone adduct. Its ammonium salt ( 1 ) was obtained by the reaction with gaseous ammonia. In order to explore new explosives or propellants several energetic nitrogen‐rich 2:1 salts such as the hydroxylammonium ( 3 ), guanidinium ( 4 ), aminoguanidinium ( 5 ), diaminoguanidinium ( 6 ) and triaminoguanidinium 7 4, 4′,5, 5′‐tetranitro‐2, 2′‐bisimidazolate were prepared by facile metathesis reactions. In addition, methylated 1, 1′‐dimethyl‐4, 4′,5, 5′‐tetranitro‐2, 2′‐bisimidazole (Me2TNBI, 8 ) was synthesized by the reaction of 2 and dimethyl sulfate. Metal salts of TNBI can also be easily synthesized by using the corresponding metal bases. This was proven by the synthesis of pyrotechnically relevant dipotassium 4, 4′,5, 5′‐tetranitro‐2, 2′‐bisimidazolate ( 2 ), which is a brilliant burning component e.g. in near‐infrared flares. All compounds were characterized by single crystal X‐ray diffraction, NMR and vibrational spectroscopy, elemental analysis and DSC. The sensitivities were determined by BAM methods (drophammer and friction tester). The heats of formation were calculated using CBS‐4M electronic enthalpies and the atomization method. With these values and mostly the X‐ray densities different detonation parameters were computed by the EXPLO5 computer code. Due to the great thermal stability and calculated energetic properties, especially guanidinium salt 4 could be served as a HNS replacement. 相似文献
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Vishnumurthy R. Hegde Katherine L. Seley Stewart W. Schneller 《Journal of heterocyclic chemistry》2000,37(5):1361-1362
A preparation of (1′R,2′S,3′R,4′S)‐1‐(2′,3′,4′‐trihydroxycyclopent‐1′‐yl)‐lH‐cytosine (5′‐norcarbodine, 3 ) has formally been achieved in 2 steps from (+)‐(1R,4S)‐4‐hydroxy‐2‐cyclopenten‐1‐yl acetate ( 4 ) and cytosine. The L‐like enantiomer of 3 (that is, 6 ) is also reported using the enantiomer of 4 (that is, 7 ). In evalu ating 3 and 6 for antiviral potential against a number of viruses, compound 3 was found to have activity towards Epstein‐Barr virus (EBV). 相似文献