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1.
Daniel A. Ruddy Donald H. Berry Chip Nataro 《Journal of organometallic chemistry》2008,693(1):169-172
New synthetic routes to 1-methyl-1-silaindane (1b) and 1-methyl-1-germaindane (1b) were developed and the desired products were obtained in good isolated yield. Compounds 1a and 1b were fully characterized by mass spectroscopy, 1H and 13C{1H} NMR, and infrared spectroscopy. 相似文献
2.
G. Chambaud W. Gabriel T. Schmelz P. Rosmus A. Spielfiedel N. Feautrier 《Theoretical chemistry accounts》1993,87(1-2):5-17
Summary The three-dimensional potential energy functions have been calculated from highly correlated multireference configuration interaction electronic wavefunctions for theX
3
B
1,a
1
A
1, andb
1
B
1 states of the NH
2
+
ion. For the quasi-linear electronic ground state this information and the electric dipole moment functions have been used to calculate spectroscopic constants, line intensities and rotationally resolved absorption spectra. For thea
1
A
1-b
1
B
1 bent/quasi-linear Renner-Teller system ro-vibronic energy levels have been obtained from a variational approach accounting for anharmonicity, rotation-vibration and electronic angular momenta coupling effects. The vibronic levels are given for energies up to 13 500 cm–1 for the bending levels and up to 8000 cm–1 for the stretching and combination levels.Dedicated in the honor of Prof. Werner Kutzelnigg 相似文献
3.
Yukio Yamaguchi Timothy J. Van Huis C. David Sherrill Henry F. Schaefer III 《Theoretical chemistry accounts》1997,97(1-4):341-349
Four electronically low-lying states of silylene (SiH2) have been studied systematically using high level ab initio electronic structure theory. Self-consistent field (SCF), two-configuration
(TC) SCF, complete active space (CAS) SCF, configuration interaction with single and double excitations (CISD), and CASSCF
second-order (SO) CI levels of theory were employed with eight distinct basis sets. The zeroth-order wave functions of the
ground (X˜
1A1 or 1 1A1) and B˜
1A1 (or 2 1A1) excited states are appropriately described by the first and second eigenvectors of the TCSCF secular equations. The TCSCF-CISD,
CASSCF, and CASSCF-SOCI wave functions for the B˜
1A1 (or 2 1A1) state were obtained by following the second root of the CISD, CASSCF, and SOCI Hamiltonian matrices. At the highest level
of theory, the CASSCF-SOCI method with the triple zeta plus triple polarization augmented with two sets of higher angular
momentum functions and two sets of diffuse functions basis set [TZ3P(2f,2d)+2diff], the energy separation (T0) between the ground (X˜
1A1) and first excited (a˜
3B1) states is determined to be 20.5 kcal/mol (0.890eV,7180cm−1), which is in excellent agreement with the experimental T0 value of 21.0 kcal/mol (0.910eV,7340cm−1). With the same method the T0 value for the a˜
1B1−X˜
1A1 separation is predicted to be 45.1 kcal/mol (1.957 eV,15780 cm−1), which is also in fine agreement with the experimental value of 44.4 kcal/mol (1.925 eV,15530 cm−1). The T0 value for the B˜
1A1−X˜
1A1 separation is determined to be 79.6 kcal/mol (3.452 eV,27 840 cm−1). After comparison of theoretical and experimental T0 values for the a˜
3B1 and a˜
1B1 states and previous studies, error bars for the B˜
1A1 state are estimated to be ±1.5 kcal/mol (±525 cm−1). The predicted geometry of the B˜
1A1 state is re(SiH)=1.458 and θe=162.3∘. The physical properties including harmonic vibrational frequencies of the B˜
1A1 state are newly determined.
Received: 10 March 1997 / Accepted: 2 April 1997 相似文献
4.
Zhang Shuyan Wang Xizhong Wang Zishu Cheng Wenyuan Jin Jianan Zhang Jiazao Xu Daoquan Shao Yuesheng Luo Changrong Wang Juan Wu Kejia Zhou Maolun 《Journal of Radioanalytical and Nuclear Chemistry》1989,131(1):73-80
Na2 1 1At and2 1 1At–Te colloid injections were prepared. By comparison with tissue distribution of Na2 1 1At and2 1 1At–Te colloid injections it has been demonstrated that the2 1 1At–Te colloid is stable in vivo. It has been shown that the radiohalogen,2 1 1At, has huge and extensive radiobiological effects in studying on the changes in histopathology, enzyme histochemistry, chromosome aberration, micronucleus frequency of bone-marrow polychromatic erythrocytes and the injury effect of2 1 1At on experimental Ehrlich ascites cells. 相似文献
5.
Kurt Moedritzer Raymond E. Miller 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):279-284
Abstract 2,3-Dibromo-1-hydroxyphospholane 1-oxide and 3,4-dibromo-1-hydroxyphospholane 1-oxide were prepared in high yield by bromine addition to 1-hydroxyphosphol-2-ene 1-oxide or 1-hydroxyphosphol-3-ene 1-oxide, respectively. Both compounds were characterized by 1H, 31P and 13C nmr, IR, Laser Raman and mass spectrometry. 相似文献
6.
Gilbert Hamus Ivan K. Nielsen Peter Laur 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-2)
Abstract In the absence of previous systematic investigations, we have embarked on the study of the NMR spectra of thioglycosides, as we needed structural information in connection with our work on the spectroscopic properties of these compounds. In this sommunication, data will be presented on alkyl α - and β-thiogluco- and -thiogalactopyranosides and some related compounds, including certain natural products like lincomycin, sinigrin, and glucocapparin. The 1H spectra of the strongly coupled carbohydrate portion can readily be analyzed at 270 MHz in the case of the thiogalactosides, whereas the spectrum of the thioglucose moiety in, e.g., thioglucose sodium salt, remains a system of higher order even at 360 MHz, giving rise to multiple lines and virtual coupling. The assignment of the 13 spectra proceeded basically via selective or via frequency dependant off-resonance heteronuclear double resonance experiments at 68 MHz; the C-H coupling pattern (triplet) directly reveals the position of C-(6). Application of the increment method of the 13C chemical shift in connection with the thioalkyl grouping presented no complications. Tetraacetylation of the thioglycosides shifts the ring 13C resonances in a systematic manner and is, therefore, an additional aid. All the compounds investigated adopt the 4C1 conformation; in the α-series, 3J(H-1/H-2) = ca. 5.5 Hz, i.e., relatively large. Long range 13C- 1H coupling constants were measured in a few cases only. Values of 1J (13C- 1H) were also obtained from satellite lines in the appropriate high-field 1H spectra. From the spectra of the fully or partly analyzed compounds rules can be deduced that are especially helpful in the examination of 13C spectra of other thioglycosides, employing, e.g., chemical shift data, coupling constants, and T1 data. 相似文献
7.
D. Charalambidis B. H. Feng C. Fotakis 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1989,14(3):223-227
Photoelectron angular distributions have been measured for the three-photon resonant one-photon ionization, (3+1), of Xe via the 7s[1 1/2]0 1 and 8s[1 1/2]0 1 states. The results are in good agreement with the theoretical predictions of Tang and Lambropoulos [13] for the 8s[1 1/2]0 1, but not for the 7s[1 1/2]0 1 state. Furthermore, the results are compared to those which have been obtained by Blazewicz et al. [1] for the three-photon resonant two-photon ionization, (3+2), of Xe via the 6s[1 1/2]0 1 state. 相似文献
8.
1, 1-Difluorocyclopropa[a]naphthalene ( 1b ) is prepared in three steps from 4-bromo-1,2-dihydronaphthalene ( 7 ) via carbene addition, benzylic bromination and bidehydrohalogenation. Structural evidence for formation of 1b is based on 1H- and 19F-NMR spectroscopy. Compound 1b is stable in solution at ?30°. Upon reaction with MeOH/H+ it is converted to a 1:2 mixture of 1- and 2-methylnaphthoate ( 10 and 11 , respectively). 相似文献
9.
1-Trimethylsilyl-, 1-Trimethylgermyl-, and 1-Trimethylstannyl-3,4-dimethylphospholene 1-Lithium-3,4-dimethylphospholen reacts with Me3SiCl and Me3GeCl yielding 1-trimethylsilyl-3,4-dimethylphospholene ( 1 ) and 1-trimethylgermyl-3,4-dimethylphospholene ( 2 ) respectively. 2 and 1-trimethylstannyl-3,4-dimethylphospholene ( 3 ) are formed using the reaction of 1 with Me3GeCl and Me3SnCl respectively. The 1H, 13C and 31PNMR-spectra as well as the mass spectra of the new compounds are discussed. 相似文献
10.
The spin-spin coupling constants (SSCC) of 13C-1H and 1H-1H in 4-substituted pyridines, C5H4NX [X=,CN, COCH3, COOCH3, N(CH3)2, NO2, OCH3, Cl, Br], were investigated. To determine the constants, the proton-coupled NMR spectra of 13C and 13C-satellites in the PMR spectra of the compounds, recorded for monomolecular solutions of 4-substituted pyridines in DMSO-D6, were analyzed. The interrelationship of the SSCC of 13C-1H and 1H-1H in 4-substituted pyridines with the analogous constants in monosubstittued benzenes were obtained. The correlations of the constants with the F- and R-parameters of the substituents are discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 948–952, July, 1984. 相似文献
11.
Pamela Twu Jared L. Anderson Timothy W. Stephens Anastasia Wilson William E. Acree Jr. Michael H. Abraham 《Journal of solution chemistry》2013,42(4):772-799
Chromatographic retention data were measured for a wide range of organic solutes on 1-butyl-1-methylpyrolidinium tris(pentafluoroethyl)trifluorophosphate ([BMPyrr]+[FAP]?), 1-butyl-1-methylpyrrolidinium triflate, ([BMPyrr]+[Trif]?), and 1-methoxyethyl-1-methylmorpholinium tris(pentafluoroethyl)trifluorophosphate, ([MeoeMMorp]+[FAP]?), stationary phases at (323, 353 and 383) K. The measured retention factors were combined with published infinite dilution activity coefficient and gas-to-water partition coefficient data to yield gas-to-anhydrous ionic liquid (IL) and water-to-anhydrous IL partition coefficients. The three sets of partition coefficients were analyzed using the Abraham model. The derived Abraham model correlations describe the observed gas-to-IL (log10 K) and water-to-IL (log10 P) partition coefficient data to within average standard deviations of about 0.11 and 0.15 log10 units, respectively. 相似文献
12.
Ronald C. Crouch Jeffrey G. Raab Marius Pelmuş Evgeny Tischenko Michael Frey Alexei V. Buevich Mikhail Reibarkh R. Thomas Williamson Gary E. Martin 《Magnetic resonance in chemistry : MRC》2022,60(2):210-220
Modification of the recently reported 19F-detected 1,1-ADEQUATE experiment that incorporates dual-optimization to selectively invert a wide range of 1JCC correlations in a 1,n-ADEQUATE experiment is reported. Parameters for the dual-optimization segment of the pulse sequence were modified to accommodate the increased size of 1JCC homonuclear coupling constants of poly- and perfluorinated molecules relative to protonated molecules to allow broadband inversion of the 1JCC correlations. The observation and utility of isotope shifts are reported for the first time for 1,1- and 1,n-ADEQUATE correlations. 相似文献
13.
The synthesis and 1H NMR spectra of the cis and trans monodeuterated isomers of 2-deuterio-1-methyl-1-phenylcyclopropane have been previously reported. We have prepared one of the isomers, c-2-deuterio-r-1-methyl-1-phenylcyclopropane, by a different, stereospecific, route. We now wish to correct the original 1H NMR assignments which were in error. 相似文献
14.
15.
Kim N⊘rkjær Alexander Senning 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):369-370
Abstract Twelve new 1-alkynyl disulfides,1 R1-C≡C-S-S-R2, 1, for the first time including aromatic examples, have been prepared according eqns. (1/2) and/or (3) and characterized. 相似文献
16.
Lithiation-methylation of 3,3-dimethyl-1λ4,3-thiasilinane 1-oxide and 4,4-dimethyl-1λ4,4-thiasilinane 1-oxide under the action of butyllithium or lithium diisopropylamide and methyl iodide was studied. In both cases, monomethylation proceeds selectively α to the sulfoxide group to form 2,3,3-trimethyl-1λ4,3-thiasilinane 1-oxide and 2,4,4-trimethyl-1λ4,4-thiasilinane 1-oxide, respectively. Subsequently, 2,3,3-trimethyl-1λ4,3-thiasilinane 1-oxide undergoes monomethylation into the same α position to give 2,2,3,3-tetramethyl-1λ4,3-thiasilinane 1-oxide, while 4,4-dimethyl-1λ4,4-thiasilinane 1-oxide is dimethylated into the neighboring α’ position to form two stereoisomers of 2,4,4,6-tetramethyl-1λ4,4-thiasilinane 1-oxide with axial-equatorial or equatorial-equatorial methyl groups in the 2 and 6 positions. 相似文献
17.
A. V. Afonin L. A. Es'kova V. K. Voronov E. S. Domnina L. V. Baikalova E. V. Petrova 《Chemistry of Heterocyclic Compounds》1988,24(4):410-412
Analysis of 1H and 13C NMR spectral parameters for 1-vinylbenzazoles has shown that the vinyl group has a predominantly trans orientation with respect to the condensed benzene ring. Additional evidence is given for a long range effect of the nitrogen lone pair electrons on the one bond 13C-1H and 1H-1H spin-spin couplings and on the 1H chemical shifts.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 499–501, April, 1988. 相似文献
18.
The transition linewidth ΔE in crystal C6H6, C6D6 and sym-C6H3D3 has been measured as a function of temperature T from 4.2 to 135°K, and it extrapolates to a common value of ΔEo = 50 cm? at O°K. In C6H6 ΔE = (50 + 7T) cm?1, indicative of strong exciton—phonon coupling, and there is a line shift of +40 cm?1 per substituent deuteron. Fluorescence excitation spectral data are used to separate the 1B1u(= S2) decay rate kH = 9.4 × 1012 sec?1, derived from ΔE0, into S2S1 internal conversion (rate ≈ 6.6 × 1012 sec?1) and S2Sx (channel 3) internal conversion (rate ≈ 2.8 × 1012 sec?1. A similar value of kH = 9.9 × 1012 sec?1 is obtained from the S2So fluorescence quantum yield of liquid benzene. 相似文献
19.
Marcin Rojkiewicz Piotr Ku Maria Ksiek Joachim Kusz 《Acta Crystallographica. Section C, Structural Chemistry》2022,78(1):56-62
Cathinones belong to a group of compounds of great interest in the new psychoactive substances (NPS) market. Constant changes to the chemical structure made by the producers of these compounds require a quick reaction from analytical laboratories in ascertaining their characteristics. In this article, three cathinone derivatives were characterized by X-ray crystallography. The investigated compounds were confirmed as: 1-[1-(4-methylphenyl)-1-oxohexan-2-yl]pyrrolidin-1-ium chloride ( 1 , C17H26NO+·Cl?, the hydrochloride of 4-MPHP), 1-(4-methyl-1-oxo-1-phenylpentan-2-yl)pyrrolidin-1-ium chloride ( 2 ; C16H24NO+·Cl?, the hydrochloride of α-PiHP) and methyl[1-(4-methylphenyl)-1-oxopentan-2-yl]azanium chloride ( 3 ; C13H20NO+·Cl?, the hydrochloride of 4-MPD). All the salts crystallize in a monoclinic space group: 1 and 2 in P21/c, and 3 in P21/n. To the best of our knowledge, this study provides the first detailed and comprehensive crystallographic data on salts 1 – 3 . 相似文献
20.
S. N. Tandura V. A. Pestunovich M. G. Voronkov G. I. Zelchan I. I. Solomennikova É. Ya. Lukevits 《Chemistry of Heterocyclic Compounds》1977,13(8):854-855
Considerable shielding of the 1H and 29Si nuclei due to transannular nitrogen-silicon coupling, which is expressed more clearly than in the case of silatranes, was established on the basis of 1H, 13C, and 29Si NMR data for the methylsilyl group in 1-methyl-2,5,8,9-tetraaza-1-silatricyclo[3.3.3.01,5]undecane (1-methylazasilatrane) and a comparison of these data with the data for the methyl[tris(dimethylamino)]silane model. It is shown that the change in the hybridization of the silicon atom associated with the increase in its coordination number is not only reflected in the chemical shifts but also leads to an increase in 1JCH and 2JSiH.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1063–1064, August, 1977. 相似文献