Synthesis and characterization of 1-methyl-1-silaindane and 1-methyl-1-germaindane

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.     

Theoretical rotational-vibrational spectra of theX 3 B 1,a 1 A 1 andb 1 B 1 states of NH 2 +

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     

The X˜1A1, a˜3B1, a˜1B˜1, and B˜1A1 electronic states of SiH2

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 r_e(SiH)=1.458 and θ_e=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     

2 1 1At-tellurium colloid and Na2 1 1At injections,and their radiobiological effects

Na^{2 1 1}At and^{2 1 1}At–Te colloid injections were prepared. By comparison with tissue distribution of Na^{2 1 1}At and^{2 1 1}At–Te colloid injections it has been demonstrated that the^{2 1 1}At–Te colloid is stable in vivo. It has been shown that the radiohalogen,^{2 1 1}At, 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 of^{2 1 1}At on experimental Ehrlich ascites cells.     

VICINAL DIBROMO-1-HYDROXYPHOSPHOLANE 1-OXIDES

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.     

1H AND 13C NMR SPECTRA OF 1-DEOXY-1-THIOGLYCOPYRANOSIDES

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.     

Angular distributions of photoelectrons in resonantly enhanced multiphoto ionization via the 7s[1 1/2]0 1 and 8s[1 1/2]0 1 states of Xe

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.     

1, 1-Difluoro-1H-cyclopropa[a]naphthalene

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).     

1-Trimethylsilyl-, 1-Trimethylgermyl- und 1-Trimethylstannyl-3,4-dimethylphospholen

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.     

Spin-spin coupling constants of 13C-1H and 1H- 1H in 4-substituted pyridines

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.     

Correlation of the Solubilizing Abilities of 1-Butyl-1-methyl-pyrrolidinium Tris(pentafluoroethyl)trifluorophosphate, 1-Butyl-1-methylpyrrolidinium Triflate and 1-Methoxyethyl-1-methylmorpholinium Tris(pentafluoroethyl)trifluorophosphate

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.     

19F-detected dual-optimized inverted 1JCC 1,n-ADEQUATE

Modification of the recently reported ¹⁹F-detected 1,1-ADEQUATE experiment that incorporates dual-optimization to selectively invert a wide range of ¹J_CC 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 ¹J_CC homonuclear coupling constants of poly- and perfluorinated molecules relative to protonated molecules to allow broadband inversion of the ¹J_CC correlations. The observation and utility of isotope shifts are reported for the first time for 1,1- and 1,n-ADEQUATE correlations.     

1H NMR assignments for t-2-deuterio-r-1-methyl-1-phenylcyclopropane and c-2-deuterio-r-1-methyl-1-phenylcylclopropane. A literature correction

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.     

1-Alkynyl Disulfides and their 1-Thiapropargyl-3-Thiaallenyl Rearrangements

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.     

Lithiation-methylation of thiasilinane 1-oxides

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.     

Structural analysis of 1-vinylbenzazoles by 1H and 13C NMR spectroscopy

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.     

The 1B1u ← 1A1g 0—0 transition in crystal benzene

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 ΔE_o = 50 cm^? at O°K. In C₆H₆ ΔE = (50 + 7T^{$\text{1}\text{2}$}) 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 ¹B_1u(= S₂) decay rate k_H = 9.4 × 10¹² sec^?1, derived from ΔE₀, into S₂S₁ internal conversion (rate ≈ 6.6 × 10¹² sec^?1) and S₂S_x (channel 3) internal conversion (rate ≈ 2.8 × 10¹² sec^?1. A similar value of k_H = 9.9 × 10¹² sec^?1 is obtained from the S₂S_o fluorescence quantum yield of liquid benzene.     

Crystallographic characterization of three cathinone hydrochlorides new on the NPS market: 1-(4-methylphenyl)-2-(pyrrolidin-1-yl)hexan-1-one (4-MPHP), 4-methyl-1-phenyl-2-(pyrrolidin-1-yl)pentan-1-one (α-PiHP) and 2-(methylamino)-1-(4-methylphenyl)pentan-1-one (4-MPD)

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 .     

1H, 13C,and 29Si NMR spectra of 1-methylazasilatrane

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[3.3.3.0^1,5]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 ¹J_CH and ²J_SiH.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1063–1064, August, 1977.