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1.
We describe convenient preparations of N,N′-dialkyl-1,3-propanedialdiminium chlorides, N,N′-dialkyl-1,3-propanedialdimines, and lithium N,N′-dialkyl-1,3-propanedialdiminates in which the alkyl groups are methyl, ethyl, isopropyl, or tert-butyl. For the dialdiminium salts, the N2C3 backbone is always in the trans-s-trans configuration. Three isomers are present in solution except for the tert-butyl compound, for which only two isomers are present; increasing the steric bulk of the N-alkyl substituents shifts the equilibrium away from the (Z,Z) isomer in favor of the (E,Z), and (E,E) isomers. For the neutral dialdimines, crystal structures show that the methyl and isopropyl compounds adopt the (E,Z) form, whereas the tert-butyl compound is in the (E,E) form. In aprotic solvents all four dialdimines (as well as the lithium dialdiminate salts) adopt cis-s-cis conformations in which there presumably is either an intramolecular hydrogen bond (or a lithium cation) between the two nitrogen atoms. 相似文献
2.
The step dissociation constants of ethylenediamine-N,N′-diacetic-N,N′-dipropionic and ethylenediamine-N,N,N′,N′-tetrapropionic acids at 298.15 K and ionic strengths of 0.1, 0.5, and 1.0 (KNO3) were determined potentiometrically. The results were extrapolated to zero ionic strength by the equation with one individual parameter. The thermodynamic constants of dissociation were calculated. The results are compared with the corresponding data on related compounds. 相似文献
3.
á. Keszler Béla Kazinczy László Kótai 《Fresenius' Journal of Analytical Chemistry》1999,364(4):328-332
N,N’-dimethyl-N,N’-diphenylcarbamide (centralite) extracted from building materials was quantitated using ion trap GC-MS
detection technique. Both linearity and standard deviation of the calibration curve were dependent on the conditions of the
mass spectral detection. The most precise calibration has been achieved by quantification of a mass ion not participating
in secondary reactions and which is produced via single fragmentation. The best recovery of centralite was obtained after either 30 min of normal extraction with toluene
at 60 °C or 10 min of ultrasonic extraction with chloroform at room temperature. Using the latter method resorption processes
might cause decrease in efficiency of the recovery at longer extraction time.
Received: 3 July 1998 / Revised: 5 November 1998 / Accepted: 26 January 1999 相似文献
4.
《The Journal of chemical thermodynamics》2002,34(2):155-161
The standard ( po = 0.1 MPa) molar enthalpies of combustion in oxygen, at T = 298.15 K, were measured by rotative bomb calorimetry for crystalline N, N -diethyl- N′-furoylthiourea, (2-C4H3O)CONHCSN(C2H5)2, HFET, and N, N -diisobutyl- N′-furoylthiourea, (2-C4H3O)CONHCSN(iso-C4H9)2, HFIB. The standard molar enthalpies of sublimation of both HFET and HFIB were measured by high-temperature Calvet microcalorimetry. These values were used to derive the standard molar enthalpies of formation of the compounds, in their crystalline and gaseous phases. 相似文献
5.
Thermal decomposition of N,N??-diphenylguanidine (DPG) was investigated by simultaneous TG/DSC-FTIR techniques under nonisothermal conditions. Online FTIR measurements illustrate that aniline is a major product of DPG decomposition. The observation that the activation energy depends on the extent of conversion indicates that the DPG decomposition kinetics features multiple processes. The initial elimination of aniline from DPG involves two pathways because of the isomerization of DPG. Mass spectrometry and thin film chromatography suggest that there are two major intermediate products with the major one of C21N3H17. The most probable kinetic model deduced through multivariate nonlinear regression method agrees well with the experimental data with a correlation coefficient of 0.9998. The temperature-independent function of conversion f(??), activation energy E and the pre-exponential factor A of DPG decomposition was also established through model-fitting method in this research. 相似文献
6.
7.
The i.r. spectra of diiminosuccinonitrile and N,N′-dichlorodiiminosuccinonitrile were recorded as Nujol mulls, as pellets in KBr and polyethylene matrices and as solutions in CH3CN in the region 4000-30 cm−1. Raman spectra of the pure solids were obtained and polarization data were recorded from saturated solutions in CH3CN.The mutual exclusion of i.r. and Raman lines revealed that both compounds existed in the trans conformation and no additional conformers (gauche or cis) were detected in solution.The fundamental frequencies for both molecules were assigned on basis of i.r. and Raman activities, Raman polarization data and the results of normal coordinate analyses. 相似文献
8.
V. R. Akhmetova N. N. Murzakova G. R. Khabibullina N. F. Galimzyanova 《Russian Journal of Applied Chemistry》2011,84(2):225-229
Possibility of obtaining water-soluble N- and N,N′-coordinated adducts by reacting 3,7-dithia-1,5-diazabicyclo[3.3.0]octane with methyl iodide and Brønsted (HCl, HBr) and Lewis (AlCl3) acids was examined. The fungicidal activity of 3,7-dithia-1,5-diazabicyclo[3.3.0]octane and its water-soluble adducts with hydrobromide and methyl iodide against a number of microscopic fungi affecting cultivated plants and various materials was studied. 相似文献
9.
10.
《Journal of Coordination Chemistry》2012,65(3):309-317
Lanthanide picrate complexes with the ligand N,N'-dimethyl-N,N'-diphenyl-1,2-phenylenedioxydiacetamide (L) [Ln(Pic)3L] (Ln=La,Gd,Er,Y) have been prepared in nonaqueous medium and characterized by elemental analysis, IR and 1H spectra. The Gd(III) complex [Gd(Pic)3L]·3CH3CN is triclinic, space group P&1macr;, with a=14.292(1), b=14.967(2), c=16.571(2)Å, α=97.855(9), γ=113.070(9)°, ν=28706(6)Å3, D c=1.584g/cm3 for Z=2. The structure was refined to R=0.0318 based on 8409 observed reflections. 相似文献
11.
The diamide, N,N-dimethyl-N,N-dihexyl-3-thiopentanediamide (DMDHTPDA) was synthesized and thested for extraction of Eu(III), Am(III), Th(IV) and U(VI). DMDHTPDA shows a very weak complexation with these metal ions, which can be attributed to the soft base nature of the sulfur atom. None of the cations were extracted into the organic phase when DMDHTPDA alone was present. Synergistic extraction was measured for DMDHTPDA plus thenoyltrifluoroacetone. From the extraction dependencies on pH and extractant concentration, formation of mixed TTA+DMDHTPDA complexes were indicated. Except for the Th(IV) system, the separation and synergistic factors were smaller for the TTA+DMDHTPDA extractant than for the system of TTA+DMDHOPDA (the oxo ether analog of DMDHTPDA). 相似文献
12.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1980,36(3):265-272
The i.r. and Raman spectra of N,N,N′,N′-tetramethyl-p-phenylenediamine and the perchlorate salt of its radical cation have been recorded. The frequencies of the fundamental vibrations of the neutral molecule and the radical ion have been computed using force constants transferred from smaller molecules. The observed spectral bands have been assigned and the ionization band shifts have been discussed. Most of the significant band shifts have been observed in the 1700-1300 cm−1 range. The calculations showed that they are primarily due to the variation of the bond strengths of the ring CC and ring-N bonds. 相似文献
13.
O. A. Luk'yanov Yu. B. Salamonov A. G. Bass Yu. A. Strelenko 《Russian Chemical Bulletin》1991,40(1):93-98
Nitroso compounds of the aromatic and aliphatic series react with O-acetylalkanoylamidoximes in the presence of dibromoisocyanurate, forming the previously unknown N-(-acetoximinoalkyl)diazene-N-oxides, which under gaseous NH3 or oxalic acid in methanol lose the acetyl group and as a result are transformed into the previously unknown N-(-hydroximinoalkyl)diazene-N-oxides.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 109–114, January, 1991. 相似文献
14.
Summary
N,N,N,N-Tetramethylisophthalthioamide (Hmpt) was cyclopalladated with PdCl2 in hot dimethylsulphoxide to give [PdCl(mpt)]. The structure was determined by X-ray analysis. The thioamide is metallated at C(2) to act as an S528-01C528-02S tridentate anionic ligand. There is appreciable steric repulsion between the benzene ring H(4, 6) and the dimethylamino groups. The hydrogens and the methyl groups mutually deviate from the coordination plane in opposite directions. The stability of the fused 5,5-membered chelate ring formed by the S528-03C528-04S ligand seems to overcome the steric hindrance. Derivatives were prepared by replacement of the chloride ion with iodide, diethyldithiocarbamate, 4-tert-butylpyridine, or tri-n-butylphosphine, and characterized spectroscopically. The S528-05C528-06S-fused chelate ring was maintained in these derivatives. 相似文献
15.
16.
《Journal of Inorganic and Nuclear Chemistry》1981,43(6):1155-1158
New complexes of VOCl3 with N,N′-Diarylformamido-N″-substituted thiocarbamides and N-Benzoyl formamido-N′-substituted thiocarbamides having the general formula [VOCl3(L)] where L is the bidentate ligand, have been synthesized. The ligand appears to coordinate through sulfur and nitrogen. 相似文献
17.
Tolstikova L. L. Danilevich Yu. S. Shainyan B. A. 《Russian Journal of Organic Chemistry》2018,54(7):1103-1105
The alkylating activity of N-allyl- and N-propargyltriflimides toward N,N′-dicyclohexyl- and N,N′-diphenylcarbodiimides has been studied. Activation of the nitrogen atom by two electron-withdrawing trifluoromethanesulfonyl groups favors cleavage of the C–N bond in the absence of a catalyst with the formation of N-substituted unsaturated ureas.
相似文献18.
A method for the preparation ofN-monoacyl imidazolidines and hexahydropyrimidines (as hydrochlorides) by interaction of monoacylated derivatives of ethylenediamine and trimethylenediamine with chloromethyl methyl ether was developed. Also a method for the preparation ofN,N-diacylimidazolidines and hexahydropyrimidines either by acylation of their monoacyl derivatives or by reaction of the correspondingN,N-diacyl alkylenediamine derivatives with dimethoxymethane, diacetoxymethane, 1,3,5-trioxane or chloromethyl methyl ether was designed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1452–1456, August, 1994. 相似文献
19.
S. G. Il’yasov A. A. Lobanova I. Yu. Bagryanskaya T. V. Rybalova Yu. V. Gatilov 《Journal of Structural Chemistry》2009,50(6):1066-1070
The properties and behavior of dinitrourea and its potassium and dipotassium salts in different solvents have been studied
by IR and UV spectroscopy. In different media, dinitrourea can exist in several tautomeric forms. An XRD study of the potassium
and dipotassium salts of dinitrourea revealed a tendency toward equalization of the bond lengths of the C-N−-NO2 fragments compared with those of C-NH-NO2, which agrees with the results of quantum-chemical calculations. 相似文献
20.
《Journal of Coordination Chemistry》2012,65(13):2378-2387
New iron(III) and cobalt(III) complexes, [Fe(2,2′-dpdtc)3], [Fe(3,3′-dpdtc)3], [Co(2,2′-dpdtc)3], and [Co(3,3′-dpdtc)3] (dpdtc?=?dipicolyldithiocarbamate) have been synthesized and their molecular structures and spectroscopic properties determined. The 2,2′- and 3,3′-dpdtc ligands have four donors, S, S′, N, and N′. These complexes are insoluble in water, but soluble in acidic solution. Crystal structures of these metal complexes reveal that the central metal ions have MS6 (M?=?Fe and Co) octahedral structures and all dipicolyl groups do not coordinate. 相似文献