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1.
E. P. Ivakhnenko Yu. V. Koshchienko P. A. Knyazev K. A. Lysenko A. S. Bogomyakov V. I. Minkin 《Russian Journal of Coordination Chemistry》2016,42(8):509-515
The complex formation between redox active 2,4,6,8-tetrakis(tert-butyl)phenoxazin-1-one (L) and four-coordinate Co(II) complexes, resulting in six-coordinate adducts (I) (C77H82N12O5Co) and (II) (C38H41NO6F12Co) was studied. High-spin structure of the formed cobalt adducts I and II (hs-CoII–BQ) was established by X-ray diffraction analysis and magnetochemistry methods. Adducts I and II are stable over a wide temperature range (5–300 K) and are not involved in the redox process giving low-spin adducts (ls-CoIII–SQ) studied previously. 相似文献
2.
E. P. Ivakhnenko Yu. V. Koshchienko P. A. Knyazev V. B. Nalbandyan K. A. Lyssenko I. V. Ananyev A. S. Bogomyakov V. I. Minkin 《Russian Journal of Coordination Chemistry》2016,42(4):252-259
The six-coordinate cobalt complexes, C57H63.50N4.50O4Co (IIa), C60H69N5O4Co (IIb), C58H67N3O8Co (IIc), C56H61N5O10Co (IId), C56H63N3O6Co (IIe), C58H66N4O6Co (IIf), and C58H63N7O8Co (IIg), adducts of high-spin tetrahedral Co(II) bis(salicylaldiminates) (C29H24.50N3.50O2Co (Ia), C32H30N4O2Co (Ib), C30H28N2O6Co (Ic), C28H22N4O8Co (Id), C28H24N2O4Co (Ie), C30H27N3O4Co (If), and C30H24N6O6Co (Ig)) and redox-active 2,4,6,8-tetrakis(tert-butyl)phenoxazin-1-one (L), were synthesized and studied for structure and magnetic properties. Complexes IIa–IIg have octahedral structure (CIF files CCDC nos. 1403920 (IIf), 1403922 (IIg)) and exist in the ground low-spin state (ls-CoIII-SQ), which arises upon intramolecular single-electron redox process in the ligand–metal system. The presence of substituents of different nature in the azomethine ligands of IIa–IIg does not induce any significant changes in their magnetic properties. 相似文献
3.
V. I. Simakov Yu. Yu. Gorbanev T. E. Ivakhnenko V. G. Zaletov K. A. Lyssenko Z. A. Starikova E. P. Ivakhnenko V. I. Minkin 《Russian Chemical Bulletin》2009,58(7):1361-1370
The reaction of di(tert-butyl) derivatives of pyrocatechol with 2,6-dihydroxyaniline afforded 2,4,6,8-tetra(tert-butyl)-9-hydroxyphenoxazin-1-one. The chemical properties of the reaction product and its ability to form complexes with
metal salts as the tridentate ligand were investigated. The structure of hydroxyphenoxazinone was established by X-ray diffraction. 相似文献
4.
Ju-Lan Zeng Sai-Bo Yu Bo Tong Li-Xian Sun Zhi-Cheng Tan Zhong Cao Dao-Wu Yang Jing-Nan Zhang 《Journal of Thermal Analysis and Calorimetry》2011,103(3):1087-1093
An N-tert-butyloxycarbonylated organic synthesis intermediate, (S)-tert-butyl 1-phenylethylcarbamate, was prepared and investigated by means of differential scanning calorimetry (DSC) and thermogravimetry
(TG). The molar heat capacities of (S)-tert-butyl 1-phenylethylcarbamate were precisely determined by means of adiabatic calorimetry over the temperature range of 80-380 K.
There was a solid–liquid phase transition exhibited during the heating process with the melting point of 359.53 K. The molar
enthalpy and entropy of this transition were determined to be 29.73 kJ mol−1 and 82.68 J K−1 mol−1 based on the experimental C
p–T curve, respectively. The thermodynamic functions, [HT0 - H298.150 H_{T}^{0} - H_{298.15}^{0} ] and [ST0 - S298.150 S_{T}^{0} - S_{298.15}^{0} ], were calculated from the heat capacity data in the temperature range of 80–380 K with an interval of 5 K. TG experiment
showed that the pyrolysis of the compound was started at the temperature of 385 K and terminated at 510 K within one step. 相似文献
5.
V. B. Vol’eva T. I. Prokof’eva I. S. Belostotskaya N. L. Komissarova D. B. Gorbunov L. N. Kurkovskaya 《Russian Journal of Organic Chemistry》2011,47(9):1310-1312
Alkylation of pyrocatechol with tert-butyl alcohol in benzene in the presence of sulfuric acid gave 3,5-di-tert-butylbenzene-1,2-diol in a higher yield than in analogous reaction with tert-butyl alcohol. This result was rationalized by reduction of inhibitory effect of liberated water, formation of heterogeneous
system, and occurrence of the alkylation process in nonpolar organic phase. Intermediate products were identified and found
to undergo intra- and intermolecular tert-butyl group transfer with formation of more stable 3,5-di-tertbutylbenzene-1,2-diol. The formation of p-di-tert-butylbenzene indicated participation of benzene in crossalkylation processes. 相似文献
6.
S. -Y. Cheng J. -M. Tseng S. -Y. Lin J. P. Gupta C. -M. Shu 《Journal of Thermal Analysis and Calorimetry》2008,93(1):121-126
Tert-butyl peroxybenzoate (TBPB) is one of the sensitive and hazardous chemicals which have been popularly employed in petrifaction
industries in the past. This study attempted to elucidate its unsafe characteristics and thermally sensitive structure so
as to help prevent runaway reactions, fires or explosions in the process environment. We employed differential scanning calorimetry
(DSC) to assess the kinetic parameters (such as exothermic onset temperature (T
0), heat of reaction (ΔH), frequency factor (A)), and the other safety parameters using four different scanning rates (1, 2, 4 and 10°C min−1) combined with curve-fitting method.
The results indicated that TBPB becomes very dangerous during decomposition reactions; the onset temperature and reaction
heat were about 100°C and 1300 J g−1, respectively. Through this study, TBPB accidents could be reduced to an accepted level with safety parameters under control.
According to the findings in the study and the concept of inherent safety, TBPB runaway reactions could be thoroughly prevented
in the relevant plants. 相似文献
7.
L. P. Stepovik M. V. Gulenova I. M. Martynova B. A. Mar’yasin V. K. Cherkasov 《Russian Journal of General Chemistry》2008,78(2):266-276
The reaction of titanium tetra-tert-butoxide with tert-butyl hydroperoxide (1: 2) (C6H6, 20 C) involves the steps of formation of the titanium-containing peroxide (t-BuO)3TiOOBu-t and peroxytrioxide (t-BuO)3TiOOOBu-t. The latter decomposes with the release of oxygen, often in the singlet form, and also homolytically with cleavage of both peroxy bonds. The corresponding alkoxy and peroxy radicals were identified by ESR using spin traps. The title system oxidizes organic substrates under mild conditions. Depending on the substrate structure, the active oxidant species can be titanium-containing peroxide, peroxytrioxide, and oxygen generated by the system. 相似文献
8.
M. Vorona I. Potorochina G. Veinberg S. Belyakov I. Shestakova I. Kanepe E. Lukevics 《Chemistry of Heterocyclic Compounds》2009,45(12):1532-1538
The sulfoxide of 6Z-[2-(methoxyimino)propylidene]penicillanic acid tert-butyl ester and the sulfones of 6Z-[2-(hydroxyimino-, methoxyimino-, benzyloxyimino-, 2-bromo- and 4-bromobenzyloxyimino)-propylidene]penicillanic acid in the
syn and anti forms have been synthesized by the condensation of the sulfoxide and sulfone of 6Z-acetylmethylenepenicillanic acid tert-butyl ester with hydroxylamine, methoxyamine, benzyloxyamine, 2-bromo- and 4-bromobenzyloxyamines. The syn and anti isomers
of 3Z-(2-methoxyiminopropylidene)-4R-(benzothiazolyl-2-dithio)-2-oxoazetidinyl-1R-(2-propenyl)acetic acid tert-butyl ester were obtained by opening of the thiazolidine ring in 6Z-[2-(methoxy-imino)propylidene]-1-oxopenicillanic acid tert-butyl ester with 2-mercaptobenzothiazole. The 3Z-(2-methoxyiminopropylidene)-4R-(methylsulfonyl)-2-oxoazetidinyl-1-(2-propylidene)acetic acid tert-butyl ester was synthesized by the interaction of 1,8-diazobicyclo[5.4.0]undec-7-ene and methyl iodide with 6Z-[2-(methoxyimino)propylidene]-1,1-dioxopenicillanic acid tert-butyl ester. A dependence of the cytotoxic effect in relation to cancer and normal cells in vitro on the structure of the
substituent in position 6 and the syn and anti isomerism of the oxyimino group was established for the synthesized compounds. 相似文献
9.
A. P. Luk’yanenko E. A. Alekseeva S. S. Basok A. V. Mazepa A. I. Gren’ 《Russian Journal of Organic Chemistry》2011,47(4):527-529
A new procedure has been proposed for the synthesis of mono- and bis(2-aminoethoxy)-p-(tertbutyl) calix[4]arenes from the corresponding mono- and bis[2-(1,3-dioxoisoindol-2-yl)ethoxy]-p-(tert-butyl)-calix[4]arenes. 相似文献
10.
Thermal runaway reactions associated with exothermic behaviors of tert-butyl hydroperoxide (TBHP) solutions and TBHP reacting with alkaline contaminants were studied. A differential scanning calorimetry
(DSC) was used to characterize these inherent behaviors of TBHP solutions with KOH, NaOH, LiOH and NH4OH. The exothermic peak in thermal curves of TBHP solutions with different alkali were detected by DSC thermal analysis. By
thermal analysis, we compared various heats of decomposition of TBHP solutions with alkaline impurities, and determined the
incompatible hazards of various TBHP solutions with alkaline contaminants. Comparing with TBHP in various diluents, the adiabatic
runaway reaction via vent sizing package 2 (VSP2) indicated that aqueous TBHP intrinsically possesses the phenomena of thermal
explosion with dramatic self-reactive rate and pressure rise under adiabatic conditions. Many commercial organic peroxides
may have different hazard behaviors. Therefore, using thermal method to classify the hazards is an important subject. 相似文献
11.
L. P. Stepovik Yu. B. Malysheva G. K. Fukin 《Russian Journal of General Chemistry》2015,85(6):1401-1411
9-R-Anthracenes (R = Me, Ph) are effective acceptors of peroxyl and metalalkoxyl radicals in the systems tert-butylhydroperoxide-metal tert-butoxide (M = Al, V, Cr; C6H6, 20°C). Isolation of 9-R-9,10-dihydro-9,10-di-tert-butylperoxyanthracenes, 10-R-10-tert-butylperoxy-9-anthrones as major products reliably confirms the formation of tert-butylperoxy radicals and can be used for quantitative assessment of their content. 相似文献
12.
Mohammad M. Fares Adeeb S. El-faqeeh Hasan Ghanem Mohammad E. Osman Elfatih A. Hassan 《Journal of Thermal Analysis and Calorimetry》2010,99(2):659-666
The synthesis, characterization, and hydrogel properties of starch-g-(tert-butylacrylate) and starch-g-(n-butylacrylate) copolymers were studied. The optimum conditions for the grafting process of tert-butylacrylate into 1.0 g of starch were as follows: [tert-butylacrylate] = 0.04 mol/L, [CAN] = 9.0 × 10−4 mol/L, temperature = 20 °C in 100 mL solution, whereas the results using n-butylacrylate monomer were as follows: [n-butylacrylate] = 0.04 mol/L, [CAN] = 4.0 × 10−3 mol/L, temperature = 30 °C in 100 mL solution. The grafting evidences of monomers into starch were done through TG and its
derivative DTG for thermal changes and mass losses, scanning electron microscope (SEM) for morphological changes, powder X-ray
for crystallinity measurements and FTIR for functional group changes. Acid hydrolysis method was used efficiently to allow
the calculations of the viscosity average molecular weight (M
v) of the grafted chains on starch and consequently the real percent of grafting efficiency (i.e. %GY). The capability of starch-g-(n-BAC) hydrogel to absorb water were found 10 times more than starch-g-(tert-BAC) hydrogel, which were clarified through the X-ray and SEM results. 相似文献
13.
D. A. Köse G. Gökçe S. Gökçe İ. Uzun 《Journal of Thermal Analysis and Calorimetry》2009,95(1):247-251
Three novel mixed ligand complexes of Ni(II), Zn(II) and Cd(II) with p-chlorobenzote and N,N-diethylnicotinamide were synthesised and characterized on the basis of elemental analysis, FTIR spectroscopic
analysis, solid state UV-Vis spectrometric and magnetic susceptibility data. The thermal behavior of the complexes was studied
by simultaneous TG-DTA methods in static air atmosphere and the mass spectra data were recorded.
According to microanalytical results, formulas of complexes are C34H40N4O8ClNi, C34H40N4O8ClZn and C34H44N4O10ClCd. The complexes contain two moles of coordination waters, two moles p-chlorobenzoate and two mole N,N-diethylnicotinamide (dena) ligands per formula unit. In these complexes, the p-chlorobenzoate and N,N-diethylnicotinamide behave as monodentate ligand through acidic oxygen and nitrogen of pyridine ring.
The decomposition pathways and the stability of the complexes are interpreted in the terms of the structural data. The final
decomposition products were found to be as metal oxides. 相似文献
14.
Summary. Treatment of meso-tetra(tert-butyl)porphyrin with sulfuric acid/n-butanol affords a mixture of porphyrin and mono-tert-butylporphyrin in relatively high yield. 相似文献
15.
A. B. Burdukov N. V. Pervukhina M. A. Vershinin Ya. Z. Voloshin 《Journal of Structural Chemistry》2007,48(2):358-361
The structure of 1,8-bis(fluoroboro)-2,7,9,14,15,20-hexaoxa-3,6,10,13,16,19-hexaaza-4,5,11,12-tetraphenyl-17,18-bisc(tert-butylamino)-bicyclo[6.6.6]eicosa-3,5,10,12,16,18-hexaene(2−)iron(2+) tris-dioximate clathrochelate was determined by X-ray diffraction (XRD) analysis. The compound has a molecular structure and crystallizes
as triclinic crystals: a = 10.7673(2) Å, b = 11.9520(4) Å, c = 22.5473(7) Å, α = 75.729(1)°, β = 89.161(1)°, γ = 65.334(1)°, V = 2542.64(13) Å3, Z = 2, space group 1. P1ˉ.
Original Russian Text Copyright ? 2007 by A. B. Burdukov, N. V. Pervukhina, M. A. Vershinin, and Ya. Z. Voloshin
__________
Translated from Zhurnal Strukturnoi Khimii, Vol. 48, No. 2, pp. 366–369, March–April, 2007. 相似文献
16.
17.
O. G. Strukov V. B. Kondrat’ev Z. V. Vlasova V. A. Petrunin 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2017,91(1):100-105
Conformers of the biologically active compounds CH3P(O)(OR)(SCH2CH2NR 2 ′ ), where (I) R = i-C4H9, R′ = C2H5 and (II) R = C2H5, R′ = i-C3H7, are calculated within the AM1 level of theory. The elongated and twisted forms with maximum and minimum distances between a nitrogen atom and those of a phosphorus tetrahedron, respectively, and bearing a syn and anti oriented alkoxy group relative to a phosphoryl oxygen, are studied. It is found that the differences between the energy, electronic, and geometric parameters of these forms are apparent in differences between their properties, e.g., the ability to participate in complexation and protonation, reactions that to some extent simulate the interaction between a substance and a biological object. 相似文献
18.
V. O. Gel'mbol'dt L. V. Koroeva Ya. E. Filinchuk 《Russian Journal of Coordination Chemistry》2005,31(11):775-779
Fluosilicic acid reacts with solutions of N,N-di-tert-butylurea (DTBU) in methanol or acetone to form crystalline compounds 2DTBU ? H2SiF6 and 2DTBU ? H2SiF6 ? Me2CO, which were characterized by the IR and 19F NMR spectra and mass spectroscopy supplemented by theoretical calculations. According to the data of IR and 19F NMR spectra, the complexes are hexafluorosilicates of O-protonated DTBU. They undergo hydrolysis in organic media with water traces; their solubility in water is very low (0.10 and 0.14 wt %, respectively). In the DTBU structure, two independent ligand molecules are joined by hydrogen bonds NH?O(N?O) 2.888(5)–2.944(5) Å). 相似文献
19.
T. F. Ibragimov M. G. Levkovich V. A. Saprykina Kh. M. Shakhidoyatov 《Chemistry of Natural Compounds》2010,46(5):767-770
N-Chloroacetylcytisine was synthesized by acylation of (–)-cytisine. Stable Z- and E-conformers with respect to rotational isomerism around the N-12–CO bond were found in PMR spectra at room temperature. The
point at which PMR resonances of the Z- and E-conformers coalesced upon heating was measured. The transition barrier between the conformers was estimated. 相似文献
20.
In this work, tert-butyl peroxypivalate initiator was newly used in the solution polymerization of acrylic copolymers with 2-ethylhexyl acrylate, butyl acrylate, methyl methacrylate and acrylic acid monomers for application of pressure-sensitive adhesives (PSAs). Its proper dosage was determined to vary from 0.6 to 1.2 wt % when a high monomer conversion (>99%) was ensured. In this amount range, polymer properties and adhesive performance of the PSAs were investigated. The results indicated that with the amount of tert-butyl peroxypivalate increased, the molecular weights of the polymer decreased and the molecular weight distribution became wider. It was also observed that the synthesized PSAs had high interfacial adhesion and low cohesion strength, and thus exhibited cohesive failure during the peel test. So cross-linking agent was employed to improve the shear strength of the PSAs and to eliminate the adhesive residue while at the sacrifice of loop tack and peel strength. As a whole, the optimal performance was obtained by using 1.2 wt % amount of initiator and 0.5 wt % concentration of cross-linker. In this case, the peel and shear strength have achieved the best balance. In addition, for the cross-linked PSA tapes, the peel strength slightly decreased with the dwell time. 相似文献