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1.
Jun Mifune 《Polymer Degradation and Stability》2010,95(8):1305-1312
Cupriavidus necator H16CAc, previously constructed for production of poly((R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate) [P(3HB-co-3HHx)] from soybean oil, was further engineered aiming to increase 3HHx composition in the copolyester. PHA synthase gene derived from Aeromonas caviae on the H16CAc chromosome was replaced by a gene encoding the N149S/D171G mutant and this recombination enhanced PHA productivity as well as slightly increased 3HHx composition. Manipulation of phaACn locus partially reduced the amount of 3HB unit concomitantly with relative increase of 3HHx composition, whereas deletion of phaB1Cn resulted in drastic decline of 3HB unit in P(3HB-co-3HHx). Insertion of phaJAc encoding (R)-specific enoyl-CoA hydratase from A. caviae into pha operon significantly enlarged 3HHx fraction without negative effects on the cell growth and polyester accumulation. Consequently, efficient production of P(3HB-co-3HHx) with 3HHx composition of 5.7-9.9 mol% was successfully achieved from soybean oil by the engineered strains. 相似文献
2.
Alkyl and dialkylammonium tetrafluoroborate promoted cis-trans isomerization of 1,3,5-trimethyl-1,3,5-triphenylcyclotrisiloxane (1) in DMSO-d6 were studied. The isomerization equilibrium constant K are within the range of 3.74-3.30 from 22 to 47 °C. Thermodynamic parameters of ΔH° and ΔS° for the isomerization were −0.95 kcal/mol and −0.59 cal/mol-K respectively. The isomerization rate is first order in [cis-1] and second order in [RnNH4−nBF4]. Both components of RnNH4−n+ and BF4− are essential for the catalytic cis-trans isomerization. The catalytic strength follows the decreasing order of +H3N(CH2)6NH3+>n-C8H17NH3+>n-C16H33NH3+>Me3CNH3+>PhCH2NH3+>Et2NH2+?Ph2CHNH3+, Et3NH+. Inversion region was observed in the plot of ln(kf/T) versus (1/T) with the ceiling located at around 38 °C. The positive activation enthalpy of 9 kcal/mol was estimated at 22-32 °C. The activation enthalpy turns to be slightly negative at T>38 °C. 相似文献
3.
4.
Michael Block Christoph Wagner Dirk Steinborn 《Journal of organometallic chemistry》2011,696(9):1768-1781
Reactions of ω-diphenylphosphinofunctionalized alkyl phenyl sulfides Ph2P(CH2)nSPh (n = 1, 1a; 2, 2a; 3, 3a), sulfoxides Ph2P(CH2)nS(O)Ph (n = 1, 1b; 2, 2b; 3, 3b) and sulfones Ph2P(CH2)nS(O)2Ph (n = 1, 1c; 2, 2c; 3, 3c) with dinuclear chlorido bridged rhodium(I) complexes [(RhL2)2(μ-Cl)2] (L2 = cycloocta-1.5-diene, cod, 4; bis(diphenylphosphino)ethane, dppe, 5) afforded mononuclear Rh(I) complexes of the type [RhCl{Ph2P(CH2)nS(O)xPh-κP}(cod)]1 (n/x = 1/0, 6a; 1/1, 6b; 1/2, 6c; 2/0, 8a; 2/1, 8b; 2/2, 8c; 3/0, 10a; 3/1, 10b; 3/2, 10c) and [RhCl{Ph2P(CH2)nS(O)xPh-κP}(dppe)] (n/x = 1/0, 7a; 1/1, 7b; 1/2, 7c; 2/0, 9a; 2/1, 9b; 2/2, 9c; 3/0, 11a; 3/1, 11b; 3/2, 11c) having the P^S(O)x ligands κP coordinated. Addition of Ag[BF4] to complexes 6-11 in CH2Cl2 led with precipitation of AgCl to cationic rhodium complexes of the type [Rh{Ph2P(CH2)nS(O)xPh-κP,κS/O}L2][BF4] having bound the P^S(O)x ligands bidentately in a κP,κS (13a-18a, 15b-18b) or a κP,κO (13b, 14b, 13c-18c) coordination mode. Unexpectedly, the addition of Ag[BF4] to 6a in THF afforded the trinuclear cationic rhodium(I) complex [Rh3(μ-Cl)(μ-Ph2PCH2SPh-κP:κS)4][BF4]2·4THF (12·4THF) with a four-membered Rh3Cl ring as basic framework. Addition of sodium bis(trimethylsilyl)amide to complexes 6-11 led to a selective deprotonation of the carbon atom neighbored to the S(O)x group (α-C) yielding three different types of organorhodium complexes: a) Organorhodium intramolecular coordination compounds of the type [Rh{CH{S(O)xPh}CH2CH2PPh2-κC,κP}L2] (22a-c, 23a-c), b) zwitterionic complexes [Rh{Ph2PCHS(O)xPh-κP,κS/O}L2] having κP,κS (21a, 21b) and κP,κO (20b/c, 21c) coordinated anionic [Ph2PCHS(O)xPh] ligands, and c) the dinuclear rhodium(I) complex [{Rh{μ-CH(SPh)PPh2-κC:κP}(cod)}2] (19). All complexes were fully characterized spectroscopically and complexes 15b, 15c, 12·4THF and 19·THF additionally by X-ray diffraction analysis. DFT calculations of zwitterionic complexes gave insight into the coordination mode of the [Ph2PCHS(O)Ph] ligand (κP,κS versus κP,κO). 相似文献
5.
As part of the study of interaction of the Ba2RCu3O6+z (R=lanthanides and Y) superconductor with SrTiO3 buffer, phase equilibria of the subsystem, R2O3-TiO2-CuO (R=Nd, Y, and Yb), have been investigated in air at 960 °C. While the phase relationships of the two phase diagrams with smaller R (Y and Yb) are similar, substantial differences were found in the Nd2O3-TiO2-CuO system, partly due to different phase formation in the binary R2O3-TiO2 and R2O3-CuO systems. R2CuTiO6 and R2Cu9Ti12O36 were the only ternary phases established in all the three diagrams. R2Cu9Ti12O36 belongs to the perovskite-related [AC3](B4)O12 family which is cubic Im3. Depending on the size of R3+, R2CuTiO6 crystallizes in two crystal systems: Pnma (R=La-Gd), and P63cm (R=Dy-Lu). The structure and crystal chemistry of the Pnma series of R2CuTiO6 (R=La, Nd, Sm, Eu, and Gd) are discussed in detail in this paper. Patterns for selected members of R2CuTiO6 have also been prepared and submitted for inclusion in the Powder Diffraction File (PDF). 相似文献
6.
The reaction of lanthanide nitrate with 1,4-di (N,N-diisopropylacetamido)-2,3(1H,4H)-quinoxalinedione (L) yields six novel Ln(III) complexes ([Ln2L2(NO3)6(H2O)2]·H2O) which are characterized by elemental analysis, thermogravimetric analysis (TGA), conductivity measurements, IR, electronic and 1H NMR spectroscopies. A new quinoxalinedione-based ligand is used as antenna ligand to sensitize the emission of lanthanide cations. The lowest triplet state energy level of the ligand in the nitrate complex matches better to the resonance level of Eu(III) and Sm(III) than Tb(III) and Dy(III) ion. The f-f fluorescence is induced in the Eu3+ and Sm3+ complexes by exciting into the π-π* absorptions of the ligand in the UV. Furthermore, the crystal structures of a novel binuclear complex [Nd2L2(NO3)6(H2O)2]·H2O has been determined by single-crystal X-ray diffraction. The binuclear [Nd2L2(NO3)6(H2O)2]·H2O complex units are linked by the intermolecular hydrogen bonds and π-π interactions to form a two-dimensional (2-D) layer supramolecule. 相似文献
7.
Qibo Liu 《Journal of fluorine chemistry》2009,130(10):922-925
(E)-(1,2-Difluoro-1,2-ethenediyl)bis[tributylstannane], 3, readily undergoes a Pd(PPh3)4/CuI-catalyzed cross-coupling reaction with iodotrifluoroethene to yield (E)-octafluoro-1,3,5-hexatriene, 4, in high isomeric purity. (1Z,3E,5Z)-(1,2,3,4,5,6-Hexafluoro-1,3,5-hexenetriyl)bis[tributylstannane], 7, was sequentially prepared from (1Z,3E,5Z)-(1,2,3,4,5,6-hexafluoro-1,3,5-hexenetriyl)bis[triethylsilane], 5, which was prepared via a Pd(PPh3)4/CuI-catalyzed cross-coupling reaction of 3 with (E)-1,2-difluoro-1-iodo-2-triethylsilylethene, 6. Pd(PPh3)4/CuI cross-coupling of 7 with iodotrifluoroethene gave (3E,5E,7E)-dodecafluoro-1,3,5,7,9-decapentaene, 8. 相似文献
8.
A visible light-induced magnetization change of the 3d-4f heterometallic, [Nd(DMF)4(H2O)3(μ-NC)Co(CN)5]·H2O (DMF=N,N-dimethylformamide), is observed and described. The plots of χMT versus T of the complex showed that the χMT values, after visible light illumination, were enhanced by about 25% as compared to before irradiation in the temperature range of 5-40 K. 相似文献
9.
Masaoki Oku Toetsu Shishido Takeshi Shinohara Qiang Sun Yoshiyuki Kawazoe Kazuo Nakajima Kazuaki Wagatsuma 《Journal of solid state chemistry》2004,177(2):457-460
The solid solutions of ScBRh3-ScRh3 and CeBRh3-CeRh3 are synthesized by the arc melting method, where RBRh3 and RRh3 (R=rare earth element) have perovskite and AuCu3 type structures, respectively. The binding energy of Sc 2p3/2 for ScBxRh3 increases with the boron concentration. The Knight shift of 45Sc observed by nuclear magnetic resonance spectroscopy decreases with increase of boron concentration. The decrement of the Knight shift corresponds the Sc 4s electron density at the Fermi level. The intensity ratio of f2: f1: f0 of Ce 3d XPS spectrum changes with boron concentration of CeBxRh3. It is concluded that in both cases of ScBxRh3 and CeBxRh3 the charge on the atoms on A-site changes with the concentration of the atoms on B-site, where the atoms are not directly bound. 相似文献
10.
George Eng Xueqing Song Angel C. de Dios Robert D. Pike 《Journal of organometallic chemistry》2007,692(6):1398-1404
A series of triorganotin 2-(p-chlorophenyl)-3-methylbutyrates, (R3SnO2CCH(CH(CH3)2)C6H4Cl-4), where R = methyl, ethyl, n-propyl, n-butyl, phenyl and cyclo-hexyl, have been synthesized. Elemental analyses, Mössbauer, Infrared and NMR spectroscopies have been used to characterize their structures. Based on the spectroscopic results, all the complexes with the exception of the tricyclohexyl compound were found to be five-coordinated in the solid state while the tricyclohexyltin derivative was determined to be four-coordinated. Structural assignments based on spectroscopic data are supported by the crystallographic results of four of the triorganotin butyrates (trimethyl-, tri-n-propyl-, tri-n-butyl- and tricyclohexyltin 2-(p-chlorophenyl)-3-methylbutyrate). Multinuclear NMR spectroscopy studies indicated that all the complexes were tetrahedral in solution. Larvicidal activities of the complexes were evaluated against the 2nd instar stage of the Anopheles stephensi, Aedes aegypti and Culex pipiens quinquefasciatus mosquitoes. The toxicity data indicate that there does not appear to be any significant differences of the compounds towards the different mosquito species based on their averaged toxicity values. In addition, the toxicity of the triorganotin compounds towards the mosquito larvae was concluded to be dependent on both the compound and the species of mosquito larvae. 相似文献
11.
Treatment of 4-nitrophenyl chloroformate with alkylammonium hydrochloride salts and solid anhydrous Na2CO3 in either CH2Cl2 or CH3CN gave 4-nitrophenyl N-methylcarbamate and other N-alkylcarbamate analogues in excellent yields. Of particular interest is the observation that 4-nitrophenyl N-methylcarbamate, a safer alternative to the highly toxic methyl isocyanate, is obtained in quantitative yield (?95% pure as determined by 1H NMR) after simple filtration and solvent evaporation. 相似文献
12.
Konstantinos A. Chatziapostolou Alexios Grigoropoulos Aris Terzis Panayotis Kyritsis Georgios Pneumatikakis 《Journal of organometallic chemistry》2007,692(19):4129-4138
The complexes [Rh(CO)(PPh3){Ph2PNP(O)Ph2-P,O}] (3), [Rh(CO)2{Ph2P(Se)NP(Se)Ph2-Se,Se′}] (5), and [Rh(CO)(PPh3){Ph2P(Se)NP(Se)Ph2-Se,Se′}] (6), were synthesised by stepwise reactions of CO and PPh3 with [Rh(cod){Ph2PNP(O)Ph2-P,O}] (2) and [Rh(cod){Ph2P(Se)NP(Se)Ph2-Se,Se′}] (4), respectively. The complexes 3, 5 and 6 have been studied by IR, as well as 1H and 31P NMR spectroscopy. The ν(CO) bands of complexes 3 and 6 appear at approximately 1960 cm−1, indicating high electron density at the RhI centre. The structure of complexes 3 and 6 has been determined by X-ray crystallography, and the 31P NMR chemical shifts have been resolved via low temperature NMR experiments. Both complexes exhibit square planar geometry around the metal centre, with the five-membered ring of complex 3 being almost planar, and the six-membered ring of complex 6 adopting a slightly distorted boat conformation. The C-O bond of the carbonyl ligand is relatively weak in both complexes, due to strong π-back donation from the electron rich RhI centre. The catalytic activity of the complexes 2, 3 and 6 in the hydroformylation of styrene has been investigated. Complexes 2 and 3 showed satisfactory catalytic properties, whereas complex 6 had effectively no catalytic activity. 相似文献
13.
Reaction between Os(SiCl3)Cl(CO)(PPh3)2 and five equivalents of MeLi produces a colourless intermediate, tentatively formulated as the lithium salt of the six-coordinate, dimethyl, trimethylsilyl-containing complex anion, Li[Os(SiMe3)(Me)2(CO)(PPh3)2]. Reaction of this material with ethanol releases methane and gives the red, coordinatively unsaturated methyl, trimethylsilyl-containing complex, Os(SiMe3)(Me)(CO)(PPh3)2 (1). An alternative synthesis of 1 is to add one equivalent of MeLi to Os(SiMe3)Cl(CO)(PPh3)2, which in turn is obtained by adding three equivalents of MeLi to Os(SiCl3)Cl(CO)(PPh3)2. Treatment of 1 with p-tolyl lithium, again gives a colourless intermediate which may be Li[Os(SiMe3)(Me)(p-tolyl)(CO)(PPh3)2], and reaction with ethanol gives the red complex, Os(SiMe3)(p-tolyl)(CO)(PPh3)2 (3). Complexes 1 and 3 are readily carbonylated to Os(SiMe3)(Me)(CO)2(PPh3)2 (2) and Os(SiMe3)(p-tolyl)(CO)2(PPh3)2 (4), respectively. Heating Os(SiMe3)Cl(CO)(PPh3)2 in molten triphenylphosphine results only in loss of the trimethylsilyl ligand and formation of the previously known complex containing an ortho-metallated triphenylphosphine ligand, Os(κ2(C,P)-C6H4PPh2)Cl(CO)(PPh3)2. In contrast, heating the five-coordinate osmium-methyl complex, Os(SiMe3)(Me)(CO)(PPh3)2 (1), in the presence of triphenylphosphine results mainly, not in tetramethylsilane elimination, but in ortho-silylation as well as ortho-metallation of different triphenylphosphine ligands giving, Os(κ2(Si,P)-SiMe2C6H4PPh2)(κ2(C,P)-C6H4PPh2)(CO)(PPh3) (5). A byproduct of this reaction is the non-silicon containing di-ortho-metallated complex, Os(κ2(C,P)-C6H4PPh2)2(CO)(PPh3) (6). A similar reaction occurs when Os(SiMe3)(Me)(CO)(PPh3)2 (1) is heated in the presence of tri(N-pyrrolyl)phosphine producing Os(κ2(Si,P)-SiMe2C6H4PPh2)(κ2(C,P)-C6H4PPh2)(CO)[P(NC4H4)3] (7) but a better synthesis of 7 is to treat 5 directly with tri(N-pyrrolyl)phosphine. Heating the six-coordinate complex, Os(SiMe3)(Me)(CO)2(PPh3)2 (2), gives two complexes both containing ortho-metallated triphenylphosphine, one with loss of the trimethylsilyl ligand, giving the known complex, Os(κ2(C,P)-C6H4PPh2)H(CO)2(PPh3), and the other with retention of the trimethylsilyl ligand, giving Os(SiMe3)(κ2(C,P)-C6H4PPh2)(CO)2(PPh3) (8). Crystal structure determinations for 5, 6, 7 and 8 have been obtained. 相似文献
14.
Layered compounds have been synthesized and structurally characterized for the n=5 and 6 members of the perovskite-related family La4Srn−4TinO3n+2 by combining X-ray diffraction and transmission electron microscopy. Their structure can be regarded as comprising [(La,Sr)5Ti5O17] and [(La,Sr)6Ti6O20] perovskite blocks joined by crystallographic shears along the a-axis, with consecutive blocks shifted by 1/2 [100]p. The n=5 member is similar to the previously reported n=5 member of other AnBnO3n+2-related series. The n=6 member, which has only been briefly reported in other systems previously, is also a well-behaved member of this AnBnO3n+2 series. 相似文献
15.
Mecheril V. Nandakumar 《Tetrahedron》2005,61(41):9775-9782
A Pd2dba3/P(i-BuNCH2CH2)3N catalyzed one-pot synthesis of unsymmetrically substituted trans-4-N,N-diarylaminostilbenes and both symmetrically and unsymmetrically substituted N,N-diarylaminostyrene derivatives is reported. The procedure involves two or more palladium catalyzed sequential coupling reactions (an amination and an inter-molecular Heck reaction) in one-pot using the same catalyst system with two different aryl halides, including aryl chlorides and hetero aryl halides as the coupling partners. 相似文献
16.
Aihua Zhou 《Tetrahedron》2006,62(17):4093-4102
2-Alkyloxazolines and 2-alkylthiazolines react with 2-halobenzoyl chlorides to form N-(2-halobenzoyl)-cyclic ketene-N,O-acetals and N-(2-halobenzoyl)-cyclic ketene-N,S-acetals in excellent yields, respectively. These ketene acetals readily undergo stereocontrolled aryl radical cyclizations to afford the central six-membered rings of substituted-2,3,10,10α-tetrahydrooxazolo[3,2-b]isoquinolin-5-ones and their 2,3,10,10α-tetrahydrothiazolo[3,2-b]isoquinolin-5-one analogs. The tertiary N,O- and N,S-radicals formed upon aryl radical reaction at the ketene-N,X(X=O, S)-acetal double bond appear to have reasonable stability. The stereoselectivity in hydrogen abstractions by these intermediate radicals from both Bu3SnH and (Me3Si)3SiH was investigated. The N,S-heterocyclic fused ring products may have potential medical value. 相似文献
17.
Vincent Gaumet Emmanuel Moreau Abbass Taleb Johan Neyts Claire Lartigue Olivier Chavignon Alain Gueiffier Jacques Métin 《Tetrahedron letters》2010,51(47):6082-6085
Access to N-protected or N-free imidazo[1,2-a]pyrrolo[3,2-c]pyridine derivatives as potential antiviral compounds was achieved in good yields from N-protected 7-amino-8-halo-2-methylimidazo[1,2-a]pyridines by catalytic coupling of terminal acetylenes under mild conditions using [PdCl2(PPh3)2] or [Cu(Phen)(PPh3)2]NO3. 相似文献
18.
Bojan Kozlevčar Lea Glažar Gordana Pirc Zvonko Jagličić Amalija Golobič Primož Šegedin 《Polyhedron》2007
Two novel polynuclear complexes with methanoate anions and 3-hydroxypyridine ligands [Cu(μ-HCO2)2(3-pyOH)]n (1) and [Cu2(μ-HCO2)2(μ-3-pyOH)2(3-pyOH)2(HCO2)2]n (2), respectively, were synthesized and characterized. The central copper atom in 1 is surrounded by four methanoates and a 3-pyOH molecule, forming a square-pyramidal CuO3NO chromophore. All the methanoates are bidentate and serve as bridges between the adjacent copper ions via syn-anti and anti–anti coordination. The basal square coordination axes are formed by O(syn), N(3-pyOH) (1.974(2), 2.016(2) Å) and O(anti), O(anti) (1.945(2), 1.960(2) Å), while the third O(anti) (2.247(2) Å) is on the top of the pyramid. A ferromagnetic transition with an exchange constant 2J/kB = 9.2 cm−1 is found for 1 below 20 K. This interaction probably takes place through two syn-anti methanoates extended in a chain through the 2D structure. On the other hand, two monoatomic Cu–O–Cu intra-dinuclear asymmetric (1.986(2), 2.415(2) Å) bridges of two methanoates in [Cu2(HCO2)4(3-pyOH)4] (2) are present. An elongated distorted octahedral coordination sphere around each copper(II) atom is completed by an additional monodentate terminal methanoate (1.975(2) Å), two N-coordinated 3-pyOH (2.005(2), 2.002(2) Å) and the third weakly O-coordinated 3-pyOH (2.732(2) Å). Although a shorter Cu?Cu distance is noticed in 2 than in 1 (4.690(1) Å 1, 3.442(1) Å 2), much weaker ferromagnetism is found in 2. 相似文献
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The interactions of cyclic trinuclear copper {[3,5-(CF3)2Pz]Cu}3 and silver {[3,5-(CF3)2Pz]Ag}3 complexes with polyhedral borate anions [B10H10]2− and [B12H12]2− in solvents of low-polarity were studied using IR spectroscopy (190-290 K). Two types of complexes were found in solution: {[((3,5-CF3)2PzM)3][BnHn]}2− and {[((3,5-CF3)2PzM)3]2[BnHn]}2− (M = Ag, Cu; n = 10, 12). The stability constants of these complexes were determined from IR-spectra. 相似文献