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1.
A. I. Kazakov Yu. I. Rubtsov L. P. Andrienko G. B. Manelis 《Russian Chemical Bulletin》1998,47(3):379-385
The kinetic regularities of the heat release during the thermal decomposition of liquid NH4N(NO2)2 at 102.4–138.9 °C were studied. Kinetic data for decomposition of different forms of dinitramide and the influence of water
on the rate of decomposition of NH4N(NO2)2 show that the contributions of the decomposition of N(NO2)2
− and HN(NO2)2 to the initial decomposition rate of the reaction at temperatures about 100 °C are approximately equal. The decomposition
has an autocatalytic character. The analysis of the effect of additives of HNO3 solutions and the dependence of the autocatalytic reaction rate constant on the gas volume in the system shows that the self-acceleration
is due to an increase in the acidity of the NH4N(NO2)2 melt owing to the accumulation of HNO3 and the corresponding increase in the contribution of the HN(NO2)2 decomposition to the overall rate. The self-acceleration ceases due to the accumulation of NO3
− ions decreasing the equilibrium concentration of HN(NO2)2 in the melt.
For Part 2, see Ref. 1.
Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 395–401 March 1998. 相似文献
2.
A. S. Rozenberg E. I. Aleksandrova G. I. Dzhardimalieva A. N. Titkov A. D. Pomogailo 《Russian Chemical Bulletin》1993,42(10):1666-1672
The thermal decomposition of iron (III) acrylate, [Fe3O(CH2=CHCOO)6 · 3H2O]OH (FeAcr), a monomer with a complex cluster cation, has been studied at 200–370 °C. Thermal transformations of FeAcr occur
in two temperature regions. The rates of gas evolution in the low temperature region (200–300 °C) and the high temperature
region (300–370 °C) are described by first-order equations withk=4.2 · 1021exp[−59000/(RT)] s−1 andk=1.3 · 106exp[−30500/(RT)] s−1, respectively. A study of the qualitative and quantitative composition of the products of FeAcr thermolysis was carried out.
The thermal transformation of FeAcr is a complex process of dehydration, degradation, and polymerization in the solid phase
followed by decarboxylation of the metal-carboxyl groups of the polymer.
for part 33 see Ref. 1.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1743–1750, October, 1993. 相似文献
3.
V. N. Smirnov 《Kinetics and Catalysis》2011,52(2):166-169
The results of our experimental studies and an analysis of the published data on the rate constant for the reaction Fe + O2 = FeO + O in the forward (I) and reverse (−I) direction are reported. The data obtained in this work are described by the
expressions k
1 = 6.2 × 1014exp(−11100 K/T) cm3 mol−1 s−1 and k
−1 = 6.0 × 1013exp(−588 K/T) cm3 mol−1 s−1 (T = 1500–2500 K). The generalized expressions for the temperature dependences of these rate constants derived by combining
our results with the literature data can be presented as k
1 = 9.4 × 1014(T/1000)0.022exp(−11224 K/T) cm3 mol−1 s−1 (T = 1500–2500 K) and k
−1 = 1.8 × 1014(1000/T)0.37exp(−367 K/T) cm3 mol−1 s−1 (T = 200–2500 K). 相似文献
4.
Liang Xue Feng-Qi Zhao Xiao-Ling Xing Zhi-Ming Zhou Kai Wang Hong-Xu Gao Jian-Hua Yi Rong-Zu Hu 《Journal of Thermal Analysis and Calorimetry》2010,102(3):989-992
The thermal decomposition behavior of 3,4,5-triamino-1,2,4-triazole dinitramide was measured using a C-500 type Calvet microcalorimeter
at four different temperatures under atmospheric pressure. The apparent activation energy and pre-exponential factor of the
exothermic decomposition reaction are 165.57 kJ mol−1 and 1018.04 s−1, respectively. The critical temperature of thermal explosion is 431.71 K. The entropy of activation (ΔS
≠), enthalpy of activation (ΔH
≠), and free energy of activation (ΔG
≠) are 97.19 J mol−1 K−1, 161.90 kJ mol−1, and 118.98 kJ mol−1, respectively. The self-accelerating decomposition temperature (T
SADT) is 422.28 K. The specific heat capacity of 3,4,5-triamino-1,2,4-triazole dinitramide was determined with a micro-DSC method
and a theoretical calculation method. Specific heat capacity (J g−1 K−1) equation is C
p = 0.252 + 3.131 × 10−3
T (283.1 K < T < 353.2 K). The molar heat capacity of 3,4,5-triamino-1,2,4-triazole dinitramide is 264.52 J mol−1 K−1 at 298.15 K. The adiabatic time-to-explosion of 3,4,5-triamino-1,2,4-triazole dinitramide is calculated to be a certain value
between 123.36 and 128.56 s. 相似文献
5.
Yuan Zhang Hui Zhang Jing-Yao Liu Xue-Mei Duan Ze-Sheng Li 《Theoretical chemistry accounts》2011,130(1):115-125
Theoretical studies are carried out on the multi-channel reactions of SiH(CH3)3 with Cl (reaction 1, R1) and Br atoms (R2) by direct dynamics method. The minimum energy path is calculated at the MP2/6-31+G(d,p)
level, and energetic information is further refined by the MC-QCISD (single-point) method. The rate constants for individual
reaction channels, R1a, R1b-in, R1b-out, R1c, R1d, R2a, R2b-in, R2b-out, R2c, and R2d, are calculated by the improved canonical
variational transition state theory with small-curvature tunneling correction over the temperature range 200–1,500 K. The
theoretical three-parameter expressions k
1
(T) = 6.30 × 10−15
T
1.36exp(704.94/T) and k
2
(T) = 9.41 × 10−26
T
4.89exp(−1,033.80/T) cm3 molecule−1 s−1 are given. Our calculations indicate that reaction channels R1c and R2c are the major channel. 相似文献
6.
Recent experimental results on the thermal decomposition of N2O5 in N2 are evaluated in terms of unimolecular rate theory. A theoretically consistent set of fall-off curves is constructed which allows to identify experimental errors or misinterpretations. Limiting rate constants k0 = [N2] 2.2 × 10?3 (T/300)?4.4 exp(?11,080/T) cm3/molec·s over the range of 220–300 K, k∞ = 9.7 × 1014 (T/300)+0.1 exp(?11,080/T) s?1 over the range of 220–300 K, and broadening factors of the fall-off curve Fcent = exp(-T/250) + exp(?1050/T) over the range of 220–520 K have been derived. NO2 + NO3 recombination rate constants over the range of 200–300 K are krec,0 = [N2] 3.7 × 10?30 (T/300)?4.1 cm6/molec2·s and krec,∞ = 1.6 × 10?12 (T/300)+0.2 cm3/molec·s. 相似文献
7.
A. I. Kazakov Yu. I. Rubtsov G. B. Manelis L. P. Andrienko 《Russian Chemical Bulletin》1998,47(1):39-45
The kinetic regularities of the thermal decomposition of dinitramide in aqueous solutions of HNO3, in anhydrous acetic acid, and in several other organic solvents were studied. The rate of the decomposition of dinitramide
in aqueous HNO3 is determined by the decomposition of mixed anhydride of dinitramide and nitric acid (N4O6) formed in the solution in the reversible reaction. The decomposition of the anhydride is a reason for an increase in the
decomposition rates of dinitramide in solutions of HNO3 as compared to those in solutions in H2SO4 and the self-acceleration of the process in concentrated aqueous solutions of dinitramide. The increase in the decomposition
rate of nondissociated dinitramide compared to the decomposition rate of the N(NO2)2
− anion is explained by a decrease in the order of the N−NO2 bond. The increase in the rate constant of the decomposition of the protonated form of dinitramide compared to the corresponding
value for neutral molecules is due to the dehydration mechanism of the reaction.
For Part 1, see Ref. 1.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 41–47, January, 1998. 相似文献
8.
9.
Synthesis and thermal decomposition kinetics of La(III) complexwith unsymmetrical Schiff base ligand
Y. H. Fan Z. X. Gao C. F. Bi S. T. Xie X. Zhang 《Journal of Thermal Analysis and Calorimetry》2008,91(3):919-923
A new unsymmetrical solid Schiff base (LLi) was synthesized using L-lysine, o-vanillin and 2-hydroxy-l-naphthaldehyde. Solid lanthanum(III) complex of this ligand [LaL(NO3)]NO3·2H2O have been prepared and characterized by elemental analyses, IR, UV and molar conductance. The thermal decomposition kinetics
of the complex for the second stage was studied under non-isothermal condition by TG and DTG methods. The kinetic equation
may be expressed as: dα/dt=Ae−E/RT(1−α)2. The kinetic parameters (E, A), activation entropy ΔS
# and activation free-energy ΔG
# were also gained. 相似文献
10.
V. P. Kazakov A. I. Voloshin S. S. Ostakhov I. A. Khusainova E. V. Zharinova 《Russian Chemical Bulletin》1997,46(4):693-698
Photocatalytic decomposition of dispiro(diadamantane-1,2-dioxetane) (1) to adamantanone (2) initiated by Ce(ClO4)3 in the excited state in the MeCN−CHCl3 (2∶1) mixture was studied. The bimolecular rate constants of quenchingk
q were determined from the kinetics of quenching of Ce3+* by dioxetane at different temperatures. The Arrhenius parameters of the quenching were calculated from the temperature dependence
ofk
q:E
a=3.2±0.3 kcal mol−1 and logA=11.6±6. The quantum yields of photolysis of 1 depending on its concentration and the rate constant of the chemical reaction
of Ce3+* with 1 were determined. The latter coincides withk
q:k
ch=(2.6±0.3)·109 L mol−1 s−1 (T=298 K). The fact that the maximum quantum yield of decomposition of dioxetane is equal to 1 indicates the absence of physical
quenching of Ce3+* with 1. Nonradiative deactivation of Ce3+* in solutions of MeCN and in MeCN−CHCl3 mixtures was studied. It is caused by the replacement of H2O molecules in the nearest coordination surroundings of Ce3+ by solvent molecules and reversible transfer of an electron to the ligand. The activation parameters of the nonradiative
deactivation of Ce+* were determined.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 724–729, April, 1997. 相似文献
11.
Rate constants of the reactions of O(3P) atoms with Br2 and NO2 over the temperature range 220-950 K
The kinetics of the reactions of Br2 and NO2 with ground state oxygen atoms have been studied over a wide temperature range, T = 220-950 K, using a low-pressure flow tube reactor coupled with a quadrupole mass spectrometer: O + NO2 → NO + O2 (1) and O + Br2 → Br + BrO (2). The rate constant of reaction (1) was determined under pseudo–first-order conditions, either monitoring the kinetics of O-atom or NO2 consumption in excess of NO2 or of the oxygen atoms, respectively: k1 = (6.1 ± 0.4) × 10−12 exp((155 ± 18)/T) cm3 molecule−1 s−1 (where the uncertainties represent precision at the 2σ level, the estimated total uncertainty on k1 being 15% at all temperatures). The temperature dependence of k1, found to be in excellent agreement with multiple previous low-temperature data, was extended to 950 K. The rate constant of reaction (2) determined under pseudo–first-order conditions, monitoring the kinetics of Br2 consumption in excess of O-atoms, showed upward curvature at low and high temperatures of the study and was fitted with the following three-parameter expression: k2 = 9.85 × 10−16 T1.41 exp(543/T) cm3 molecule−1 s−1 at T = (220-950) K, which is recommended from the present study with an independent of temperature conservative uncertainty of 15% on k2. 相似文献
12.
Hui Zhang Gui-ling Zhang Jing-yao Liu Miao Sun Bo Liu Ze-sheng Li 《Theoretical chemistry accounts》2011,128(3):317-325
Theoretical investigations are carried out on the multichannel reactions CH3COCH3 + F (R1) and CH3COCH3 + Br (R2) by means of direct dynamics methods. The minimum energy path (MEP) is obtained at the MP2/6-31 + G(d,p) level,
and energetic information is further refined at the MC-QCISD (single-point) level. The rate constants are calculated by the
improved canonical variational transition-state theory (ICVT) with the small-curvature tunneling (SCT) contributions in a
wide temperature range 200–1,500 K for the title reactions, H-abstraction channel is favored for the two reactions. The theoretical
overall rate constants are in good agreement with the available experimental data and are found to be k
1a
= 3.22 × 10−15 T
1.51exp(1,190.91/T) cm3 molecule−1 s−1, k
2
= 5.95 × 10−18 T
1.98exp(−4,622.45/T) cm3 molecule−1 s−1. Furthermore, the rate constants of reaction Cl + CH3COCH3 (R3) calculated in the other paper are added to discuss the reactivity trend of different halogen reaction with acetone on
the rate constants of this class of hydrogen abstraction reactions. 相似文献
13.
Hui Zhang Gui-ling Zhang Jing-yao Liu Miao Sun Bo Liu Ze-sheng Li 《Theoretical chemistry accounts》2008,119(5-6):445-451
Theoretical investigations are carried out on the reaction multi-channel CH3COCH3 + Cl (R1) and CH3 COCH3 + CH3 (R2) by means of direct dynamics methods. The minimum energy path (MEP) is obtained at the MP2/6-31 + G(d,p) level, and energetic
information is further refined at the BMC–CCSD (single-point) level. The rate constants are calculated by the improved canonical
variational transition state theory (ICVT) with the small-curvature tunneling (SCT) correction in a wide temperature range
200–3,000 K. The theoretical overall rate constants are in good agreement with the available experimental data and are found
to be k
1 = 3.08 × 10−17
T
2.03exp(−32.96/T) and k
2 = 1.61 × 10−23
T
3.53 exp(−3969.51/T) cm3molecule−1s−1.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
14.
We have used the single‐pulse shock tube technique with postshock GC/MS product analysis to investigate the mechanism and kinetics of the unimolecular decomposition of isopropanol, a potential biofuel, and of its reaction with H atoms at 918‐1212 K and 183‐484 kPa. Experiments employed dilute mixtures in argon of isopropanol, a radical scavenger, and, for H‐atom studies, two different thermal precursors of H. Without an added H source, isopropanol decomposes in our studies predominantly by molecular dehydration. Added H atoms significantly augment decomposition, mainly by abstraction of the tertiary and primary hydrogens, reactions that, respectively, lead to acetone and propene as stable organic products. Traces of acetaldehyde were observed in some experiments above ≈ 1100 K and establish branching limits for minor decomposition pathways. To quantitatively account for secondary chemistry and optimize rate constants of interest, we employed the method of uncertainty minimization using polynomial chaos expansions (MUM‐PCE) to carry out a unified analysis of all datasets using a chemical model–based originally on JetSurF 2.0. We find: k(isopropanol → propene + H2O) = 10(13.87 ± 0.69) exp(?(33 099 ± 979) K/ T) s?1 at 979‐1212 K and 286‐484 kPa, with a factor of two uncertainty (2σ), including systematic errors. For H atom reactions, optimization yields: k(H + isopropanol → H2 + p‐C3H6OH) = 10(6.25 ± 0.42) T2.54 exp(?(3993 ± 1028) K /T) cm3 mol?1 s?1 and k(H + isopropanol → H2 + t‐C3H6OH) = 10(5.83 ± 0.37) T2.40 exp(?(1507 ± 957) K /T) cm3 mol?1 s?1 at 918‐1142 K and 183‐323 kPa. We compare our measured rate constants with estimates used in current combustion models and discuss how hydrocarbon functionalization with an OH group affects H abstraction rates. 相似文献
15.
Hirudonine sulphate (C9H23N7. 1·5 H2SO4. 2·5 H2O) is triclinic inPI space group with cell constantsa=7·168(9),b=14·534(6),c=11·918(5) ?, α=110·50(3), β=108·75(6) and γ=79·16(6)°,V=1097(2)?3,Mr=421·4,Z=2,d
x=1·358(2) gcm−3,d
c=1·276 gcm−3. MoKα (λ=0·7903 ?), μ=1·94 cm−1,F(000)=436,T=295 K,R(F)=0·144. The structure was solved by direct methods and refined to a final R factor of 0·144 for 1036 unique reflections. One
of the sulphur atoms is in special position and is disordered. The amine molecule is hydrogen-bonded to the sulphate oxygen
through water molecules. Water channels are formed at unique places involving water oxygens, amine and sulphate oxygens along
thea axis.
DCB contribution Number 712. 相似文献
16.
17.
At near neutral pH (approx. 5.5), the OH-adduct of chlorogenic acid (CGA), formed on pulse radiolysis of N2O-saturated aqueous CGA solutions (λ
max = 400 and 450 nm) with k = 9 × 109 dm3 mol−1 s−1, rapidly eliminates water (k = 1 × 103 s−1) to give a resonance-stabilized phenoxyl type of radical. Oxygen rapidly adds to the OH-adduct of CGA (pH 5.5) to form a
peroxyl type of radical (k = 6 × 107 dm3 mol−1 s−1). At pH 10.5, where both the hydroxyl groups of CGA are deprotonated, the rate of reaction of · OH radicals with CGA was
essentially the same as at pH 5.5, although there was a marked shift in the absorption maximum to approx. 500 nm. The CGA
phenoxyl radical formed with more specific one-electron oxidants, viz., Br
2
·−
and N
3
·
radicals show an absorption maximum at 385 and 500 nm, k ranging from 1–5.5 × 109 dm3 mol−1 s−1. Reactions of other one-electron oxidants, viz., NO
2
·
, NO· and CCl3OO· radicals, are also discussed. Repair rates of thymidine, cytidine and guanosine radicals generated pulse radiolytically at
pH 9.5 by CGA are in the range of (0.7–3) × 109 dm3 mol−1 s−1. 相似文献
18.
Theoretical studies on the reactions of hydroxyl radicals with trimethylsilane and tetramethylsilane
Hui Zhang Gui-Ling Zhang Ying Wang Xiao-Yang Yu Bo Liu Jing-Yao Liu Ze-Sheng Li 《Theoretical chemistry accounts》2008,119(4):319-327
The multiple-channel reactions OH + SiH(CH3)3 → products (R1) and the single-channel reaction OH + Si(CH3)4 → Si(CH3)3CH2 + H2O (R2) have been studied by means of the direct dynamics method at the BMC-CCSD//MP2/6-311+G(2d,2p) level. The optimized geometries,
frequencies and minimum energy path are all obtained at the MP2/6-311+G(2d,2p) levels, and energy information is further refined
by the BMC-CCSD (single-point) level. The rate constants for every reaction channels are calculated by canonical variational
transition states theory (CVT) with small-curvature tunneling (SCT) contributions over the temperature range 200–2,000 K.
The theoretical total rate constants are in good agreement with the available experimental data, and the three-parameter expression
k
1 = 2.53×10−21
T
3.14 exp(1, 352.86/T), k
2 = 6.00 × 10−19
T
2.54 exp(−106.11/T) (in unit of cm3 molecule−1 s−1) over the temperature range 200–2,000 K are given. Our calculations indicate that at the low temperature range, for reaction
R1, H-abstraction is favored for the SiH group, while the abstraction from the CH3 group is a minor channel.
Electronic Supplementary Material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
19.
Xing Chen Wen-Tao Yin Qian Huang Hong-Rong Zuo Jia-Rong Zhou Lin-Liang Yu Chun-Lin Ni Xue-Lei Hu 《Transition Metal Chemistry》2010,35(2):143-149
Two new salts, [BzTPP]2[Cu(mnt)2] (1) and [4NO2BzTPP]2[Cu(mnt)2] (2) (BzTPP+ = benzyltriphenylphosphonium and mnt2− = maleonitriledithiolate) have been prepared and characterized by elemental analyses, UV, IR, molar conductivity and single-crystal
X-ray diffraction. The single-crystal structure analysis shows that 1 crystallizes in the monoclinic space group P21/n, while 2 crystallizes in the triclinic space group P−1. The effects of weak intramolecular interactions such as C–H···O, C–H···S, C–H···N, C–H···Cu hydrogen bonds and p···π, π···π stacking interactions in the solids generate a 3D network structure. It is noted that the change in the molecular
topology of the counteraction when the 4-substituted group in the benzyl ring is changed from H to NO2 results in differences in the crystal system, space group, weak interactions and the stacking mode of the cations and anions
of 1 and 2. The magnetic susceptibilities of these salts measured in the temperature range 2.0 to 300 K show weak ferromagnetic coupling
features with θ = 2.05 × 10−2 K for 1 and 5.13 × 10−3 K for 2. 相似文献
20.
K. Wnorowski A. Jowko K. Wojciechowski 《Journal of Radioanalytical and Nuclear Chemistry》2008,278(1):31-37
The kinetics of the peroxy radicals RHFO2 reactions with NO has been studied by using pulse radiolysis and UV absorption spectroscopy. The rate constants of interaction
of oxygen atoms with NO − k
2 = 2.2±0.2·10−12 cm3·s−1 and NO2 − k
3 = 2.1±0.2·10−11 cm3·s−1 were found in agreement with the literature values. The bath gases (SF6 or CO2) have got minor effect on the rate constants of RHFO2+NO→NO2+prod. reactions; RHFO2 = CH3CH2O2, CH3CHFO2, CH3CF2O2, CF3CH2O2, CF3CHFO2. The obtained rate coefficients are in the scope of the literature values, although they are lower than those recommended
in NIST database. The reasons are discussed. 相似文献