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1.
Salts ofN-(β-hydroxyalkyl)-N′-hydroxydiazeneN-oxides, RCH(OH)CH2N(O)=NO− M+ (R=Me, Pri, or But; and M=Li, Na, K, Ag, NH4, or Me4N), were prepared. Their alkylation with alkyl halides R′X (X=Cl, Br, or I) and dimethyl sulfate was studied. Generally, alkylation
afforded mixtures ofN-(β-hydroxyalkyl)-N′-alkoxydiazeneN-oxides RCH(OH)CH2N(O)=NOR′ andO-alkyl-N-(β-hydroxyalkyl)-N-nitrosohydroxylamines RCH(OH)CH2N(NO)OR′.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1996–2001, October, 1998. 相似文献
2.
Dian-Lei Wang Yan Liang Lin Xie Tong Xie X. T. Wang Sen Yu Guang-Ji Wang Xiao-Dong Liu 《Chromatographia》2008,67(3-4):219-224
To evaluate the pharmacokinetics of a novel analogue of ginkgolide B, 10-O-dimethylaminoethylginkgolide B (XQ-1) in rat plasma in pre-clinical studies, a sensitive and specific liquid chromatographic
method with electrospray ionization mass spectrometry detection (LC–ESI–MS) was developed and validated. After a simple extraction
with ethyl acetate, XQ-1 was analyzed on a Shim-pack C18 column with a mobile phase of a mixture of 1 μmol L−1 ammonium acetate containing 0.02% formic acid and methanol (55:45, v/v) at a flowrate of 0.3 mL min−1. Detection was performed in selected ion monitoring (SIM) mode using target ions at [M + H]+
m/z 496.05 for XQ-1 and m/z 432.10 for the internal standard (lafutidine). Linearity was established for the concentration range from 2 to 1,000 ng mL−1 . The extraction recoveries ranged from 86.0 to 89.9% in plasma at concentrations of 5, 50, and 500 ng mL−1. The lower limit of quantification was 2 ng mL−1 with 100 μL plasma. The validated method was successfully applied to a pharmacokinetic study after intragastic administration
of XQ-1 mesylate in rats at a dose of 20 mg kg−1. 相似文献
3.
Yue Zhang Natsumi Watanabe Yuuko Miyawaki Yutaka Mune Kenta Fujii Yasuhiro Umebayashi Shin-ichi Ishiguro 《Journal of solution chemistry》2005,34(12):1429-1443
Aprotic N,N-dimethylpropionamide (DMPA) and N,N,N′,N′-tetramethylurea (TMU) are both strong donor solvents and coordinate to metal ions through the carbonyl oxygen atom. These
solvents show a different conformational aspect in the bulk phase, i.e., DMPA exists as either a planar cis or a nonplanar staggered conformer, while TMU exists in a single planar cis conformer. It has been established that the manganese(II) ion is solvated by five molecules in both solvents. Interestingly,
although the planar cis conformer of DMPA is more favorable than the nonplanar staggered one in the bulk phase, the reverse is the case in the coordination
sphere of the metal ion, i.e., a conformational change occurs upon solvation. To reveal the thermodynamic aspect of this conformational change, the complexation
of Mn(II) with bromide ions in DMPA and TMU has been studied by titration calorimetry at 298 K. It was found that the Mn(II)
ion forms mono-, di- and tri-bromo complexes in both solvents, and their formation constants, enthalpies and entropies were
obtained. The Δ H∘1 value for MnBr+ strongly depends on the solvent, i.e., it is positive (19.4 kJ-mol−1) in DMPA and negative (−8.7 kJ-mol−1) in TMU, whereas the Δ H^∘2 and Δ H∘3 values for the stepwise formation of MnBr2 and MnBr3− are both small and negative. The enthalpy of transfer ΔtH∘ from DMPA to TMU, which is evaluated on the basis of the extrathermodynamic TATB assumption, is 25.5 kJ-mol−1 for Mn2+ and −3.6 kJ-mol−1 for MnBr+. These values indicate that the difference between the formation enthalpy of MnBr+ in the two solvents, Δ H^∘1 (DMPA) – Δ H∘1 (TMU), is mainly ascribed to the value of ΔtH∘(Mn2+). It is found that the metal ion is also five-coordinated in the monobromo complex, MnBr(DMPA)4+ . The enthalpy for the conformational change of DMPA from its planar cis to the nonplanar staggered form is evaluated to be −11 and −5.5 kJ-mol−1 for Mn(DMPA)52 + and MnBr(DMPA)4+, respectively. Note that these values are significantly smaller than the corresponding value (5.0 kJ-mol−1) in the bulk phase. We thus conclude that, although steric hindrance among solvent molecules is reduced by replacing one
DMPA of Mn(DMPA)52 + with the relatively small bromide ion, DMPA molecules are still sterically hindered in the MnBr(DMPA)4+ complex. 相似文献
4.
Two new neodymium complexes, [Nd2(abglyH)6(2,2′-bipy)2(H2O)2] · 4H2O 1 and {[Nd(abglyH)3(H2O)2] · (4,4′-bipy) · 7H2O}n
2 (abglyH2 = N-P-acetamidobenzenesulfonyl-glycine acid, 2,2′-bipy = 2,2′-bipyridine, 4,4′-bipy = 4,4′-bipyridine), have been synthesized and
their structures have been measured by X-ray crystallography. In 1, nine-coordinated Nd(III) ions are bridged by two syn–syn bidentate and two tridentate bridging carboxylate groups from four different abglyH− anions to form dinuclear motifs, which are further connected into a 3-D supramolecular framework via hydrogen bonds between
the binuclear motifs and the uncoordinated water molecules. In 2, eight-coordinated Nd(III) ions are linked by six carboxylate groups adopting a syn–syn bidentate bridging fashion to form a 1-D inorganic–organic alternating linear chain. These polymeric chains generate microchannels
extending along the a direction, and these cavities are occupied by discrete tetradecameric water clusters, which interact with their surroundings
and finally furnish the 3-D supramolecular network via hydrogen bonds. At the same time, π–π stacking interactions between
benzene rings from abglyH− anions also play an important role in stabilizing the network. 相似文献
5.
Summary. Conformational analysis and frequency calculation were achieved for 1-phenyl-1,2-propandione 1-oxime and its four tautomers:
1-nitroso-1-phenyl-1-propen-2-ol, 1-nitroso-1-phenyl-2-propanone, 2-hydroxy-1-phenyl-propenone oxime, and 3-nitroso-3-phenyl-propen-2-ol.
Calculations were carried out at the Hartree–Fock (HF), Density Functional Theory (B3LYP), and the second-order M?ller–Plesset perturbation (MP2) levels of theory using 6-31G* and 6-311G** basis sets. Five conformers with no imaginary vibrational frequency were obtained by free rotations around three single bonds
of 1-phenyl-1,2-propandione-1-oxime: Ph–C(NOH)C(O)CH3, PhC(NOH)–C(O)CH3, and PhC(N–OH)C(O)CH3. Similarly, eight structures with no imaginary vibrational frequency were encountered upon rotations around three single
bonds of 1-nitroso-1-phenyl-1-propen-2-ol: Ph–C(NO)C(OH)CH3, PhC(N–O)C(OH)CH3, and PhC(NO)C(–OH)CH3. In the same manner, six minima were found through rotations around three single bonds of 1-nitroso-1-phenyl-2-propanone:
Ph–CH(NO)C(O)CH3, PhCH(–NO)C(O)CH3, and PhCH(NO)–C(O)CH3. Also, two minima were found through rotations around four single bonds of 2-hydroxy-1-phenyl-propenone oxime: Ph–C(NOH)C(OH)CH2, PhC(N–OH)C(OH)CH2, PhC(NOH)–C(OH)CH2, and Ph-C(NOH)C(–OH)CH2. Finally, two minima were found through rotations around four single bonds of 3-nitroso-3-phenyl-propen-2-ol: Ph–CH(NO)C(OH)CH2, PhCH(–NO)C(OH)CH2, PhCH(NO)–C(OH)CH2, and PhCH(NO)C(–OH)CH2. Interconversions within the above sets of conformers were probed through scanning (one and/or two dimensional), and/or QST3
techniques. The order of the stability of global minima encountered was: 1,2-propandione-1-oxime > 1-nitroso-1-phenyl-2-propanone
> 1-nitroso-1-phenyl-1-propen-2-ol > 2-hydroxy-1-phenyl-propenone oxime > 3-nitroso-3-phenyl-propen-2-ol. Hydrogen bonding
appears significant in tautomers of 1-nitroso-1-phenyl-1-propen-2-ol and 2-hydroxy-1-phenyl-propenone oxime. The CIS simulated
λmax for the first excited singlet state (S1) of 1-phenyl-1,2-propandione 1-oxime is 300.4 nm, which was comparable to its experimental λmax of 312.0 nm. The calculated IR spectra of 1-phenyl-1,2-propandione 1-oxime and its tautomers were compared to the experimental
spectra. 相似文献
6.
R. Bruce King 《Journal of mathematical chemistry》2008,44(1):5-19
The special projective linear groups PSL(2ℓ + 1) or L
2(2ℓ + 1) of order 2ℓ(2ℓ + 1)(ℓ + 1) can be used to study atomic shells of electrons with angular momentum quantum number ℓ
corresponding to the atomic p, d, f, and g shells for ℓ = 1, 2, 3, 4, respectively. For the atomic g shell the group L
2(9) is isomorphic with the alternating group A
6 on six objects of order 360 or the symmetry group of the 5-dimensional simplex, a 5-dimensional analogue of the tetrahedron
with 6 vertices and 15 edges. This leads to the subgroup chain SO(9) ⊃ SO(5) ⊃ L
2(9) for the atomic g shell analogous to the subgroup chain SO(7) ⊃ G
2 ⊃ L
2(7) ≈7
O for the atomic f shell. In the L
2(9) group only the representations of spherical harmonics or sums thereof, Γ(Yℓ), with dimensions dim Γ(Yℓ) or dim Γ(Yℓ) ± 1 divisible by 9 are found to be individually reducible to irreducible representations (irreps) or sums of irreps of L
2(9). This leads to term groupings such as S, PD, G, PF, DH, L, PK, DI, FH, M, FI, PO, DN, HK, R, etc., of increasing total
dimension for the irreps of SO(9) for various g
n
configurations in the atomic g shell. 相似文献
7.
N. Sh. Lebedeva R. S. Kumeev G. A. Al’per E. V. Parfenyuk A. S. Vashurin T. V. Tararykina 《Journal of solution chemistry》2007,36(6):793-801
For the first time the interactions between zinc(II)tetra-4-alkoxybenzoyloxiphthalocyanine (Zn(4—O—CO—C6H4—OC11H23)Pc) and 1,4-diazabicyclo[2.2.2]octane (DABCO) in o-xylene and chloroform have been studied by calorimetric titration and NMR and electron absorption spectroscopic methods.
It has been found that in o-xylene at concentrations of Zn(4—O—CO—C6H4—OC11H23)Pc higher than 6×10−4 mol⋅L−1
π–π dimers species are formed (λ
max= 685 nm). Additions of DABCO to the solution up to mole ratio 1 : 8 (Zn(4—O—CO—C6H4—OC11H23)Pc : DABCO) lead to a shift of the aggregation equilibrium towards monomer species due to formation of monoligand axial complexes.
Further increasing the DABCO concentration results in formation of Zn(4—O—CO—C6H4—OC11H23)Pc—DABCO—Zn(4—O—CO—C6H4—OC11H23)Pc sandwich dimers (λ
max= 675 nm). 相似文献
8.
Yuan Yang Jinnan Zhang Surong Luo Xiaohong Song Qi Li 《Frontiers of Chemistry in China》2007,2(3):296-302
Two new inclusion compounds (n-C4H9)4N+C18-H13O4
−·B(OH)3 (1) and (n-C4H9)4N+C18H13O4
− (2) were prepared and characterized by X-ray crystallography. Crystal data: compound 1, monoclinic P2(1)/c, a = 1.569 9(1) nm, b = 0.995 5(6) nm, c = 2.293 3(1) nm, β = 109.962(3)°, Z = 4, and R
1 = 0.0434, wR = 0.075 9; compound 2, monoclinic C2/c, a = 1.400 5(3) nm, b = 1,282 1(2) nm, c = 1.765 7(3) nm, β = 100.388(1)°, Z = 4, and R
1 = 0.0584, wR = 0.096 6. In the crystal structure of 1, the tetramers formed by two trans-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylic acid (EADA) anions and two boric acid molecules were connected through
O—H⋯O hydrogen bonds to generate a channel type host lattice. The tetra-n-butylammonium cations were stacked to give two columns within each channel with cross-sectional size of about 2.30 nm × 0.93
nm. In the crystal structure of 2, similar honeycomb host lattices with big size were also formed along the [101] direction
by three-dimensional accumulation of EADA anions. The tetra-n-butylammonium cations were accommodated in a zigzag fashion within each channel.
Translated from Acta Chimica Sinica, 2006, 64(18): 1904–1910 [译自: 化学学报] 相似文献
9.
E. J. Padma Malar 《Theoretical chemistry accounts》2005,114(1-3):213-221
Structure and bonding in triple-decker cationic complexes [(η5-Cp)Fe(μ,η:η5-E5) Fe(η5-Cp)]+ (1: E = CH, 2: E = P, 3: E = As) and [(η5-Cp)Fe(μ,η:η5-Cp)Fe(η5-E5)]+ (E = P, As) are examined by density functional theory (DFT) calculations at the B3LYP/6-31+G* level. These species exhibit
the lowest energy when all the three ligands are eclipsed. In the complexes with bifacially coordinated cyclo-E5, the perfectly eclipsed D5h sandwich structure a is found to be a potential minimum. The energy difference between the fully eclipsed and the staggered conformations b and c are within 1.0, 2.1, and 6.3 kcal/mol, respectively, for E = CH, P, and As. The isomeric species with monofacially coordinated
cyclo-E5 (E =P, As), [(η5 -Cp)Fe(μ,η :η5-Cp)Fe(η5-E5)]+ are predicted to be about 30 and 60 kcal/mol higher in energy , respectively, for E = P and As. The calculations predict
that the bifacially coordinated cyclo-E5 (E =P, As) undergoes significant ring expansion leading to ``loosening of bonds' as observed experimentally. The consequent
loss of aromaticity in the central cyclo-E5 indicates that significant π-electron density from the ring can be directed towards bonding with the iron centers on both sides. The diffuse nature of
the π-orbitals of cyclo-P5 and cyclo-As5 can lead to better overlap with the iron d-orbitals and result in stronger bonding. This is reflected in the bond order values
of 0.377 and 0.372 for the Fe-P and Fe-As bonds in 2a and 3a, respectively. The natural population analysis reveals that the Fe atom that is coordinated to a cyclo-E5 (E = P, As) possesses a negative charge of −0.23 to −0.38 units due to transfer of electron density from the inorganic ring
to the metal center. 相似文献
10.
Comparison between Different Hydrolysis Processes of Vine-Trimming Waste to Obtain Hemicellulosic Sugars for Further Lactic Acid Conversion 总被引:1,自引:0,他引:1
Moldes AB Bustos G Torrado A Domínguez JM 《Applied biochemistry and biotechnology》2007,143(3):244-256
Trimming vine shoot samples were treated with water under selected operational conditions (autohydrolysis reaction) to obtain
a liquid phase containing hemicellulose-decomposition products. In a further acid-catalyzed step (posthydrolysis reaction),
xylooligosaccharides were converted into single sugars for the biotechnological production of lactic acid using Lactobacillus
pentosus. A wide range of temperatures, reaction times, and acid concentrations were tested during the autohydrolysis–posthydrolysis
process to investigate their influence on hemicellulose solubilization and reaction products. The maximum concentration of
hemicellulosic sugars was achieved using autohydrolysis at 210 °C followed by posthydrolysis with 1% H2SO4 during 2 h. Data from autohydrolysis–posthydrolysis were compared with the results obtained at the optima conditions assayed
for prehydrolysis (3% H2SO4 at 130 °C during 15 min) based on previous works. Prehydrolysis extracted more hemicellulosic sugars from trimming vine shoots;
however, the protein content in the hydrolysates from autohydrolysis–posthydrolysis was higher. The harsher conditions assayed
during the autohydrolysis process and the higher content of protein after this treatment could induce Maillard reactions decreasing
consequently the concentration of hemicellulosic sugars in the hydrolysates. Therefore, despite the several advantages of
autohydrolysis (less equipment caused by the absence of mineral acid, less generation of neutralized sludges, and low cost
of reagents) the poor results obtained in this work with no detoxified hydrolysates (Q
P = 0.36 g/L h, Q
S = 0.79 g/L h, Y
P/S = 0.45 g/g, Y
P/Sth = 61.5 %) or charcoal-treated hydrolysates (Q
P = 0.76 g/L h, Q
S = 1.47 g/L h, Y
P/S = 0.52 g/g, Y
P/Sth = 71.5 %) suggest that prehydrolysis of trimming vine shoots with diluted H2SO4 is more attractive than autohydrolysis-posthydrolysis for obtaining lactic acid through fermentation of hemicellulosic sugars
with L. pentosus. Besides the higher hemicellulosic sugars concentration achieved when using the prehydrolysis technology, no detoxification
steps are required to produce efficiently lactic acid (Q
P = 1.14 g/L h; Q
S = 1.64 g/L h; Y
P/S = 0.70 g/g; Y
P/Sth = 92.6 %), even when vinification lees are used as nutrients (Q
P = 0.89 g/L h; Q
S = 1.54 g/L h; Y
P/S = 0.58 g/g; Y
P/Sth = 76.1 %). 相似文献
11.
Vadim A. Pestunovich Nataliya F. Lazareva Alexander I. Albanov 《Monatshefte für Chemie / Chemical Monthly》2006,137(8):1005-1013
Summary. The first representative of the N-silylmethylamides of phosphoric acid O=P[NMe(CH2SiMe
n
(OEt)3-n
]3 have been synthesized by interaction of MeNHCH2SiMe
n
(OEt)3-n
(n = 2, 3) with POCl3. The interaction of the N,N′,N″-trimethyl-N,N′,N″-tris[(ethoxydimethyl- silyl)methyl]triamide phosphoric acid with BF3·Et2O or BCl3 results in the formation of the N,N′,N″-trimethyl-N,N′,N″-tris[(fluorodimethyl-silyl)methyl]triamide phosphoric acid or N,N′,N″-trimethyl-N,N′,N″-tris[(chlorodimethylsilyl)methyl]triamide phosphoric acid. NMR data show on the tetracoordinate state of silicon in these
products.
Professor Vadim Aleksandrovich Pestunovich, our chief, teacher and friend died on July 4th, 2004 相似文献
12.
The results of kinetic and equilibrium experiments with the set of reaction of proton abstraction from 4-nitrophenyl[bis(ethylsulphonyl)]methane
in acetonitrile are reported. Two strong organic bases are used: 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene
(MTBD).
The rates of proton transfer reaction have been measured by T-jump method in the presence of perchlorate of the appropriate
base as a common cation BH+ and supporting electrolyte-tetrabutylammonium perchlorate (TBAP) in the temperature range between 20–40°C are: k
H
=1.32×107−2.00×107 and 2.82×107−4.84×107 dm 3mol−1s−1 for MTBD and TBD respectively. The enthalpies of activation ΔH
MTBD
≠
=13.5 and ΔH
TBD
≠
=18.1 kJmol−1. The entropies of activation are negative: ΔS
MTBD
≠
=−62.3 and ΔS
TBD
≠
=−40.3 Jmol−1K−1.
The change of the absorbance of the anion of 4-nitrophenyl[bis9ethylsulphonyl)]methane at the temperature 25°C in the presence
of common cation BH+ gives the equilibrium constants K=705 and 906 M−1 for MTBD and TBD respectively.
Kinetic and equilibrium results are discussed. The possible mechanism of proton transfer reaction between 4-nitrophenyl[bis(ethylsulphonyl)]methane
and cyclic organic bases: MTBD and TBD in acetonitrile is proposed. 相似文献
13.
G. A. Abakumov V. K. Cherkasov V. I. Nevodchikov N. O. Druzhkov V. A. Kuropatov 《Russian Chemical Bulletin》1998,47(5):875-878
The influence of the nature of the metal (metallofragment) on the spin density distribution in radical anions ando-semiquinone metal complexes (derivatives of sterically hindered 5,5′-di-tert-butyl-2,2′-dimethylbiphenyl-3,4,3′,4′-diquinone) was studied by ESR spectroscopy. Despite the difference in the characters
of the spin density distribution between the radical anion derivatives (M=Li, Na, K, and CoCp2) ando-semiquinone complexes (MLn=Tl, SnPh3, TlMe2, Cu(PPh3)2, Cu(CNR)2, and Mn(CO)4) in all cases significant delocalization of the spin density of an unpaired electron into theo-quinone ring is observed.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 904–907, May, 1998. 相似文献
14.
S. A. Chesnokov V. K. Cherkasov Yu. V. Chechet N. I. Nevodchikov G. A. Abakumov O. N. Mamysheva 《Russian Chemical Bulletin》2000,49(9):1506-1511
Photoreduction ofo-benzoquinones irradiated at the wavelengths λmax ≈ 400 and 600 nm corresponding to the S(π → π*) and S(n → π*) electron transitions in the >C=0 groups, respectively, in the presence ofN,N-dimethylaniline and its derivatives was studied. The apparent rate constants of the photoreduction (k
H) ofo-quinones are determined by the free energy of electron transfer from the amine molecule to a photoexcitedo-quinone molecule (ΔG
e.t). The ΔG
e.t. values are calculated as the sums of the energies of the 0→0 transitions of the lowest triplet excited state ofo-quinones, the reduction energies ofo-quinones, and the oxidation energies of amines (the last two terms are numerically equal to the corresponding redox potentials).
The maximum rate of photoreduction was found for ΔG
e.t≈0. The reaction mechanism is proposed, in which the reversible formation of a triplet exiplex is the rate-determining stage
and hydrogen transfer proceeds in parallel with electron transfer within the exiplex.
Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1515–1521, September, 2000. 相似文献
15.
T. M. Polyanskaya M. K. Drozdova V. V. Volkov K. G. Myakishev 《Journal of Structural Chemistry》2009,50(2):368-372
A new compound [MNII(Phen)3]2+(B6H7)2− is synthesized; its crystal structure is studied by XRD at 100 K. Crystallographic data: C36H38B12N6Mn, M = 739.39, triclinic symmetry, space group P
, unit cell parameters: a = 10.3131(3) ?, b = 13.4839(4) ?, c = 15.1132(4) ?; α = 97.696(1)°, β = 108.324(1)°, γ = 102.211(1)°; V = 1903.9(1) ?3, Z = 2, d
calc = 1.290 g/cm3. The structure is solved by direct and Fourier methods and refined by full-matrix LSM in the anisotropic (isotropic for hydrogen
atoms) approximation to the final factor R
1 = 0.036 for 10169 I
hkl
≥ 2σ
I
(Bruker-Nonius X8 APEX CCD diffractometer, λMoK
α). The structure contains two crystallographically different anions.
Original Russian Text Copyright ? 2009 by T. M. Polyanskaya, M. K. Drozdova, V. V. Volkov, and K. G. Myakishev
__________
Translated from Zhurnal Strukturnoi Khimii, Vol. 50, No. 2, pp. 381–385, March–April, 2009. 相似文献
16.
Peña-Calva A Olmos-Dichara A Viniegra-González G Cuervo-López FM Gómez J 《Applied biochemistry and biotechnology》2004,119(3):195-208
Denitrification of the electron donors toluene-C(15–100 mg/L), m-xylene-C (15–70 mg/L), benzene-C (5–25 mg/L), and acetate-C as experimental reference (50–140 mg/L) was carried out in batch
culture. An initial concentration of 1.1±0.15 g of volatile suspended solids/L of denitrifying sludge without previous exposure
to aromatic compounds was used as inoculum. The results showed toluene and nitrate consumption efficiency (E
T
and E
N′
respectively) of 100%. Toluene was completely mineralized (oxidized) to CO2. In all cases, the N2 (γN2) and HCO
3
−
yields (γHCO3) were 0.97±0.01 and 0.8±0.05, respectively. The consumption efficiency (E
x
) of m-xylene (53±5.7%) was partial. The γN2 and γHCO3 were 0.96±0.01 and 0.86±0.02, respectively. Benzene was not consumed under denitrifying conditions. The specific consumption
rates of toluene (q
T
) and m-xylene (q
X
) were lower than that of acetate (q
A
). The differences in specific consumption rates were probably owing to the negative effect of benzene, toluene, and isomers
of xylene on the cell membrane. 相似文献
17.
四氯合铂酸钾分别与邻、间、对磺基苯甲酸在乙腈和水中利用水热合成获得了3个铂的N-(1-亚氨基乙基)乙脒配合物:[Pt(NIA)_2]·(2-sb)·2H_2O(1),[Pt(NIA)_2]·(3-sb)·3H_2O(2)和[Pt(NIA)_2]·(1,4-dsb)·2H_2O(3)(NIA=N-(1-亚氨基乙基)乙脒,2-sb~2-=2-磺基苯甲酸二价阴离子、3-sb~2-=3-磺基苯甲酸二价阴离子、1,4-dsb~2-=1,4-二磺基苯二价阴离子)。合成过程中发生了乙氰三聚以及4-sb~2-转变为1,4-dsb~2-的反应。对配合物进行了元素分析、红外、紫外、荧光、热重和粉末X射线衍射表征,并利用单晶X射线衍射测定了配合物的晶体结构。3个配合物为阳离子-阴离子物种,阳离子为[Pt(NIA)_2]~(2+),中心金属离子四配位平面构型;阴离子与阳离子、水形成氢键,组成一个三维网络结构,但3个配合物的氢键模式不同。配合物在热稳定性、荧光性质上有一定差异。 相似文献
18.
V. N. Lebedev E. V. Balagurova F. M. Dolgushin A. I. Yanovskii L. I. Zakharkin 《Russian Chemical Bulletin》1997,46(3):550-558
Hydridorhodacarboranes 3,3-(Ph2RP)2-3-H-3,1,2-RhC2B9H11−n
F
n
(R=Ph, Me;n=1, 2, 4) containing F atoms at the B atoms of the π-carborane ligand were synthesized from (Ph3P)3RhCl or (Ph2MeP)3RhCl andnido-7,8-C2B9H12−n
F
n
− (n=1, 2, 4) salts. Hydridorhodacarboranes 3,3-(Ph2MeP)2-3-H-3,1,2-RhC2B9H11−n
F
n
readily exchange the H atom at the Rh atom for the Cl atom under the action of CH2Cl2 to give 3,3-(Ph2MeP)2-3-Cl-3,1,2-RhC2B9H11−n
F
n
. The structures of the 3,3-(Ph3P)2-3-H-3,1,2-RhC2B9H7F4 and 3,3-(Ph2MeP)2-3-Cl-3,1,2-RhC2B9H9F2 complexes were determined by X-ray diffraction analysis. Catalytic properties of the rhodacarbonanes obtained in hydrosilylation
of styrene and phenylacetylene by PhMe2SiH were studied.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 570–578, March, 1997. 相似文献
19.
Akram M. El-Didamony 《Central European Journal of Chemistry》2005,3(3):520-536
Three simple, accurate, and sensitive spectrophotometric methods (A, B and C) have been described for the indirect assay of
diltiazem hydrochloride (DIL.HCl), either in pure form or in pharmaceutical formulations. The first method (A) is based on
the oxidation of DIL.HCl by N-bromosuccinimide (NBS) and determination of unconsumed NBS by measuring the decrease in absorbance
of amaranth dye (AM) at a suitable λ
max
=521 nm. Other methods (B) and (C) involve the addition of excess cerric ammonium sulfate (CAS) and subsequent determination
of the unconsumed oxidant by a decrease in the red color of chromotrope 2R (C2R) at a suitable λ
max
=528 nm or a decrease in the orange-pink color of rhodamine 6G (Rh6G) at λ
max
=525 nm, respectively. Regression analysis of Beer-Lambert plots showed good correlation in the concentration ranges 3.0–9.0,
3.5–7.0 and 3.5–6.3 μg ml−1 for methods A, B and C, respectively. The apparent molar absorptivity, Sandell's sensitivity, detection and quantification
limits were calculated. The proposed methods have been applied successfully for the analysis of the drug in its pure form
and its dosage form. No interference was observed from a common pharmaceutical adjuvant. Statistical comparison of the results
with the reference method shows excellent agreement and indicates no significant difference in accuracy and precision. 相似文献
20.
Penna Thereza Christina Vessoni Chiarini Eb Machoshvili Irene Alexeevna Ishii Marina Pessoa Adalberto 《Applied biochemistry and biotechnology》2002,98(1-9):791-802
The recombinant green fluorescent protein (gfp
uv
) was expressed by Escherichia coli DH5-α cells transformed with the plasmid pGFPuv. The gfp
uv
was selectively permeabilized from the cells in buffer solution (25 mM Tris-HCl, pH 8.0), after freezing (−70°C for 15 h), by four freeze (−20°C)/thaw cycles interlaid by sonication. The average
content of released gfp
uv
(experiment 2) was 7.76, 34.58, 39.38, 12.90, and 5.38%, for the initial freezing (−70°C) and the first, second, third and
fourth freeze/thaw cycles, respectively. Superfusion on freezing was observed between −11°C and −14°C, after which it reached
−20°C at 0.83°C/min. 相似文献