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1.
1-Phenylamino-2-imidazolines3 and 1,2,5,6-tetrahydro-1,2,4-triazines4, 5 and6 are synthesized from N-(2-chloralkyl)-imidchlorides1 and phenylhydrazines. As intermediates are obtained the hydrochlorides of amidrazones2 which cyclise. The structure of the different heterocyclic systems are determined by1H- and13C-NMR-spectroscopy.
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2.
A detailed study of early colour change in Scots pine (Pinus sylvestris) due to accelerated simulated sunlight exposure was undertaken focusing on the first 24 h of change. Colour changes were monitored with a Datacolor check spectrophotometer and compared with a set of controls. Measurements on both samples and controls were performed hourly for the first 24 h and there after daily until 168 h’ exposure with extra measurements at 200, 350 and 500 h. A subset of samples was extracted prior to exposure to check the effects of any colour change due to the presence of extractives. Data was analysed using the reflectance spectra (400–700 nm) as well as the CIE-L*a*b* system and ΔE. The majority of colour changes were found to occur within the first 24 h. This was unaffected by the removal of extractives from the wood and was independent of temperature. Mechanical properties and weight changes were also monitored to allow a comparison of sensitivity between the differing methods.  相似文献   

3.
The structure of galactomannans isolated from seeds of G. delavayi and G. aquatica was studied by 1H and 13C NMR spectroscopy. It was found that the galactomannans consisted mainly of β-1-4-bound mannopyranoses, a part of which was substituted on the C-6 hydroxyl by terminal units of α-galactopyranose.__________Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 12–13, January–February, 2005.  相似文献   

4.
Lithium salts of hydrazines react with fluorosilanes under formation of fluorosilylhydrazines and LiF. Five membered rings are obtained in the reaction of bis(fluorosilyl)-hydrazines with lithiated amines. The mass,1H-and19F-nmr spectra of the compounds are reported.
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5.
A precise, reliable, sensitive, and selective method for the determination of titanium(IV) is described. Titanium(IV) reacts withN 1-hydroxy-N 1,N 2-diphenylbenzamidine (HDPBA) and thiocyanate to form an orange-coloured mixed-ligand complex of stoichiometry 112 (Ti SCN HDPBA). The complex is quantitatively extractable into toluene from 0.05–0.15M hydrochloric acid. The spectrum of the complex exhibits an absorption maximum at 400 nm with a molar absorptivity of 20000M –1 cm–1 and the coloured system obeys Beer's law in the concentration range 0.20–3.0 gml–1 titanium. The effects of foreign ions and of various experimental parameters have been studied to establish the optimum conditions for the extraction and determination of titanium. The precision of the method has been evaluated and the relative standard deviation has been found to be 0.53%. The method has been successfully applied to the determination of titanium in synthetic matrices corresponding to titanium-containing ores, minerals, and alloys.  相似文献   

6.
Raman and infrared spectra of polycrystalline6Li2C2O4 and7Li2C2O4 have been investigated in the wavenumber region from 1,800 to 40 cm–1. The internal C2O4 –2 vibrations have been studied on the basis of a D2h molecular structure and the correlation field splittings have been found to be about 40 cm–1 for the stretching modes and about 15 cm–1 for the bending modes. The external vibrations of the Li+ and C2O4 –2 sites have been discussed by considering the results of the factor group analysis and the6Li/7Li isotope effect on the normal vibrations.
Raman- und Infrarot-Spektren von6Li2C2O4 und7Li2C2O4
Zusammenfassung Es wurdenRaman- und IR-Spektren von polykristallinem6Li2C2O4 und7Li2C2O4 im Bereich der Wellenzahlen von 1800 bis 40 cm–1 untersucht. Die internen Schwingungen wurden auf der Basis einer D2h Molekülstruktur analysiert. Für die Streckschwingungen wurde eine Korrelationsaufspaltung von etwa 40 cm–1 gefunden, für die Deformationsschwingungen etwa 15 cm–1. Die Diskussion der externen Schwingungen von Li+ und C2O4 –2 erfolgte unter Berücksichtigung der Resultate der Faktorgruppenanalyse und des6Li/7Li Isotopeneffekts auf die Normalschwingungen.
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7.
Trimethylsilylacetamide and trimethylsilyltrifluoroacetamide react with halogenodiorganylboranes to monomeric or dimeric amidoboranes depending on the organyl substituents. The compounds were characterized analytically and spectroscopically (NMR:1H,19F,11B; MS; IR).
21. Mitt.:A. Meller, W. Maringgele, K. Hennemuth undU. Sicker, J. Z. anorg. allg. Chem., im Druck.  相似文献   

8.
Raman spectral data of polycrystals of four isotopically substituted lithium hydroxide monohydrates,6LiOH·H2O,7LiOH·H2O,6LiOD·D2O and7LiOD·D2O, have been investigated in the 4,000–50 cm–1 region. The observed spectra have been analyzed and discussed taking into account the results of the factor group analysis and the H/D and6Li/7Li isotope effects on the fundamental wavenumbers.
Raman-spektroskopische Untersuchung von vier isotopisch substituierten Lithiumhydroxid-Monohydraten
Zusammenfassung Raman-spektroskopische Daten von6LiOH·H2O,7LiOH·H2O,6LiOD·D2O und7LiOD·D2O werden im Bereich von 4000 bis 50 cm–1 angegeben. Die beobachteten Spektren werden analysiert und im Hinblick auf Faktorgruppenanalyse und auf die Isotopeneffekte H/D und6Li/7Li diskutiert.
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9.
The reaction of trimethylsilylcarbonamides with halogeno-diorganyl-boranes resp. trihalogenoboranes or organodihalogenoboranes gives monomeric resp. dimeric amidoboranes (borylcarbonamides) and derivatives of 4,8-diaza-1,5-dibora-2,6,9-trioxabicyclo[3.3.1]nonadienes. By reaction of the free acylamides with halogenoboranes in most cases the imide halides could be isolated as the only products. By reaction of the hydrochloride of bis(dimethylamino)-hydroxyborane withn-butyl-lithium followed by addition of the imide halides, the corresponding imidoylamines were formed.1H,11B, and19F-nmr spectra, mass spectra and characteristic ir group frequencies are reported.
15. Mitt.:W. Maringgele undA. Meller, Z. anorg. allg. Chem., im Druck.  相似文献   

10.
The application of combined1H- and13C-NMR-technics is used exemplarily for the elucidation of the type of substitution at the phenyl nucleus of indoles in 6,6-bis-indolylarylmethanes (1,2). These methods can be applied in general to analogous structure problems.
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11.
采用微波固相法制备了CaWO4xEu3+,ySm3+,zLi+红色荧光粉。测量样品的XRD图、激发谱、发射谱及发光衰减曲线,研究并分析了Eu3+、Sm3+、Li+的掺杂浓度,对样品微结构、光致发光特性、能量传递及能级寿命的影响。结果表明,Eu3+、Sm3+、Li+掺杂并未引起合成粉体改变晶相,仍为CaWO4单一四方晶系结构。Eu3+、Sm3+共掺样品中,Sm3+掺杂为3%时,Sm3+对Eu3+的能量传递最有效。Li+掺杂起到了助熔剂和敏化剂的作用,使样品发光更强。在394 nm激发下,与CaWO4:3%Eu3+样品比较,3%Eu3+、3%Sm3+共掺CaWO4及3%Eu3+、3%Sm3+、1%Li+共掺CaWO4样品的发光分别增强2倍及2.4倍。同一激发波长下,单掺Eu3+样品寿命最短,Sm3+、Eu3+共掺样品随Sm3+浓度增加,寿命先减小后增加,且掺杂了Li+的样品比不掺Li+的样品5D0能级寿命有所增加。  相似文献   

12.
Summary 1H,13C, and CP/MAS13C NMR spectra of sixp-substituted 1-aryl-3-arylamino-2-propen-1-ones in solution and in the solid state are reported and discussed. In the proteon-accepting solvent dimethylsulfoxide, electronegative substituents shift the isomeric equilibrium to the (E)-isomer. Bulky substituents promote crystallization of the (Z)-form.
NMR-Spektroskopische Untersuchung der (Z)/(E)-Isomerie von 1-Aryl-3-arylamino-2-propen-1-onen in Lösung und im Kristallzustand (Kurze Mitt.)
Zusammenfassung 1H-,13C- und CP/MAS-13C-NMR Spektren von sechsp-substituierten 1-Aryl-3-arylamino-2-propen-1-onen in gelöstem und festem Zustand werden berichtet und diskutiert. In protonenakzeptierendem Dimethylsulfoxid verschieben elektronegative Substituenten das Gleichgewicht zum (E)-Isomer. Große Substituenten begünstigen die Kristallisation in der (Z)-Form.
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13.
Determination of copper using inductively coupled plasma mass spectrometry (ICP-MS) suffers from polyatomic overlays originating from Na+ and Mg2+ matrix elements due to the formation of 40Ar23Na+ and 40Ar25Mg+ in the mass-to-charge ratios of 63 and 65, respectively. The collision/reaction cell technology belongs to the most modern methods used to overcome polyatomic interferences. Gas-filled collision/reaction cell can cause an additional mass bias effect influencing analytical precision of the method. In this study, the additional mass bias effect of the hexapole collision/reaction cell ICP-MS was studied on an example of n(65Cu)/n(63Cu) isotope ratio. As a result, a method for suppressing polyatomic interference on the mass-to-charge ratio of 63 and 65 was introduced and additional mass bias of the collision/reaction cell was lowered to an acceptable level.  相似文献   

14.
The formation of spin triplet, quintet, and singlet ground states within the 3d 6 electron configuration is investigated inD 4h , andD 3d symmetries employing irreducible tensor operator methods. Significant differences in the possible ground states are encountered between a complete CI and spin-orbit interaction treatment and an approximate calculation within the cubic5 T 2,1A1,3 T 1, and3 T 2 parents.  相似文献   

15.
Dehydrohalogenation and metallation of boranato-bis-trimethylphosphonium salts (1), using two equivalents of a lithiumalkyl in tetrahydrofuran, leads to a solvated organolithium reagent H2B[(CH3)2PCH2]2Li (3) which can be converted into a 1:1n1-complex with tetramethylethylenediamin (4).3 reacts with anhydrous metal(II) halides to form spirocyclic coordination compounds of the type H2B[(CH3)2PCH2]2 M[CH2P(CH3)2]2BH2 (5–9,M=Be, Mg, Zn, Cd, Hg). The reaction of [(CH3)3PBH2P(CH3)3]Br (1) with lithium tetramethylmetalates Li[M(CH3)4],M=Al, Ga, on heating in the absence of a solvent affords the metallocycles H2B[(CH3)2PCH2]2 M(CH3)2 (10, 11) with evolution of methane. The products can be sublimed from the reaction mixture. The proposed structures of the new compounds, with tetrahedrally coordinated central atoms and strong covalent metal-carbon interactions, are supported by mass, IR and1H,7Li,11B,13C, and31P NMR spectra. Compound9 represents a rare case of a tetracoordinate organomercurial, compound5 is the first nonionic tetraalkylberyllate.
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16.
讨论了辛基(苯基)-N,N-二异丁基胺甲酰基甲基氧化膦(CMPO)/1-烷基-3-甲基咪唑双(三氟甲烷磺酰)亚胺盐([Cnmim][NTf2],n=2,8,12)萃取体系分别对硝酸溶液中的铕离子(Eu3+)和铀酰根离子(UO22+)的萃取行为。主要研究了硝酸浓度、接触时间、温度、CMPO浓度对CMPO/[Cnmim][NTf2]体系萃取性能的影响,并选取CMPO/[C2mim][NTf2]体系对模拟高放废液中的镧锕元素进行了萃取分离。结果表明:随着离子液体侧链长度增长,萃取平衡时间逐渐延长;CMPO/[C2mim][NTf2]体系对Eu3+的萃取是放热反应,萃取率随酸度增加而逐渐降低,对UO22+则是吸热反应,萃取率随酸度增加而逐渐升高;通过机理研究,推测出对Eu3+的萃取反应是离子交换,而对UO22+的萃取反应则是中性配位;CMPO/[C2mim][NTf2]体系能有效的萃取模拟高放废液中的镧系、锕系元素,且在高酸下有一定的镧锕分离效果。  相似文献   

17.
29Si-NMR spectras of some new cyclosilane derivatives were measured. First aspects of the dependence of chemical shift on ring size and kind of substituents are given.
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18.
Nitropyrazoles     
The structures of substitutedN-aminonitropyrazoles and 1- and 2-amino-4-nitro-1,2,3-triazoles as well as the site of protonation of 1-aminopyrazole were determined based on the1H,13C, and15N (14N) NMR spectra. The13C NMR spectra were recorded under conditions of13C-{1H,14N} triple resonance. Effects of substituents in the pyrazole ring on the13C and14N chemical shifts were studied. The13C,1H and15N,1H spin-spin coupling constants, obtained using techniques of [1H]13C and [1H]15N polarization transfer (SPT, INEPT), were measured, fully assigned, and discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2181–2186, November, 1995.For Part 8, see Ref. 1.  相似文献   

19.
The crystal and molecular structure of the polyunsaturated macrocyclic carbosilane 1,4,4,7,7,10,13, 13,16,16-decamethyl-1,4,7,10,13,16-hexasilabicyclo-[8.8.2]-eucosa-5,14-diene-2,8,11,17-tetrain containing SiC(sp), SiC(sp 2), and SiC(sp 3) endocyclic bonds was studied by XRD. The two strained 12-membered rings of this molecule have different (trans-zigzag and staggered) conformations. The lengths of the endocyclic bonds SiC(sp) are 1.821–1.852 Å, SiC(sp 2) 1.855–1.874 Å, and SiC(sp 3) 1.847–1.853 Å. The structure of the rings was solved by direct methods and refined by the full-matrix least-squares method. Calculations were carried out with SHELXTL PLUS 5.1 software.  相似文献   

20.
In tandem mass spectra of phosphopeptides, intact sequence ions are often missing or appear weakly. Instead, dephosphorylated sequence ions appear prominently. In this work, we used photodissociation (PD) multi-stage (MSn) time-of-flight mass spectrometry that can monitor reaction intermediates with lifetime as short as 100 ns to study the formation of dephosphorylated sequence ions such as yn-H3PO4. yn-H3PO4 was found to be formed mainly by H3PO4 loss from yn. For doubly phosphorylated peptides, yn seemed to lose H3PO4 stepwise and form yn-H3PO4 and yn-2H3PO4. Even when yn was absent in PD-MS2 spectrum, its m/z could be predicted from those of yn-H3PO4 and/or yn-2H3PO4. Complete sequence coverage was possible when the data from PD-MS2 and PD-MS3 were combined, demonstrating the utility of transient ion detection by PD-MS3 for structure analysis.  相似文献   

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