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1.
3-Methyl-2-butenenitrile (1) cyclodimerised on treatment with lithium diisopropylamide in dimethoxyethane at temperatures between ?78°C and 0°C to 3-amino-4-cyano-1,5,5-trimethyl-1,3-cyclohexadiene (2) the structure of which was established by acid hydrolysis to the known 4-cyano-1,5,5-trimethyl-1-cyclohexene-3-one (3). 相似文献
2.
Richard Le Sueur Matt Guest Lee Belding Melanie Pilkington Travis Dudding 《Tetrahedron letters》2019,60(32):150928
This work demonstrates how modulating hydrogen bonding between intermolecular, bifurcated, and intramolecular interactions can be used to tune the structural, electronic, and photophysical properties of cyclopropenium ions and their respective fluorophores. The basis of this switchability was examined using X-ray diffraction analysis, 1H NMR spectroscopy, DFT calculations, and fluorescence spectroscopy. 相似文献
3.
Synthesis and Theoretical Investigation of a 1,8‐Bis(bis(diisopropylamino)cyclopropeniminyl)naphthalene Proton Sponge Derivative
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Lee Belding Prof. Travis Dudding 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(4):1032-1037
We report herein the synthesis and characterization of a new proton sponge derivative, 1,8‐bis(bis(diisopropylamino)cyclopropeniminyl)naphthalene 4 (DACN), as well as its bis‐protonated counterpart 6 . A crystal structure of 6 is presented, along with variable temperature 1H NMR data on the BF4? salt ( 6?BF4 ). DFT calculations were performed to investigate the structure of the monoprotonated species 7 and to gain insight into the structural and electronic nature of all three species. The proton affinity (PA) of 4 , calculated at the B3LYP/6‐311G++(d,p)//B3LYP/6‐31G(d,p) level, taking into account thermal corrections from the B3LYP/6‐31G(d,p) method, was 282.3 kcal mol?1, while its pKa was estimated at 27.0. NICS calculations were performed to examine the changes in aromaticity within these systems upon each successive protonation. Lastly, homodesmotic reaction schemes were used in order to estimate the factors contributing to the strong PA predicted for 4 . 相似文献
4.
M.H. Majles Ara SR. Hosseini M.H. Rezvani M. Abolhassani 《Journal of Physics and Chemistry of Solids》2011,72(11):1367-1372
In this paper, the parametric scattering of a single extraordinary polarized beam of laser in BaTiO3 photorefractive crystal has been investigated experimentally and theoretically. The resulting pattern consists of beam fanning, isotropic ring, and anisotropic one. Among all parts of scattering pattern, isotropic ring has not been studied as much as beam fanning and anisotropic ring, and there still are some differences in reports about it. Therefore, the study has mainly focused on this part. In this experimental configuration, isotropic ring is just visible in positive angles although the other parts of parametric scattering pattern can be visible from behind and in front of the crystal. In addition to steady state pattern in forward and backward directions, its transient behavior with the rotation of crystal has been studied. The results of experiments have been analyzed carefully, and their theoretical explanations have been presented based on the standard theory of parametric scattering in photorefractive crystals. It has been shown that this configuration corresponds to the so called parametric B-process scattering. 相似文献
5.
MA Freitas SR Dillon RC Dougherty AG Marshall 《Rapid communications in mass spectrometry : RCM》1999,13(15):1622-1625
The self-chemical ionization of diethylzinc is examined by Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry and semiempirical molecular orbital calculations. Electron impact of diethylzinc neutral produces the radical cation, C(4)H(15)Zn(+) (m/z x 122), which reacts further with the neutral (C(2)H(5))(2)Zn to give the following product ions: Zn(+) (m/z x 64), C(2)H(5)Zn(+) (m/z x 93), C(4)H(9)Zn(+) (m/z x 121), C(4)H(11)Zn(2)(+) (m/z x 187), and C(6)H(15)Zn(2)(+) (m/z x 215). To determine the structure and pathways for production of these ions, monoisotopic (12)C(4)H(15)(64)Zn(+), (64)Zn(+) and (12)C(2)H(5)(64)Zn(+) were individually isolated and reacted with the neutral background. We also performed semiempirical molecular orbital calculations (ZINDO/1). The molecular orbital calculations and experimental data are consistent in predicting that the ethyl group on the diethylzinc cation carries the positive charge. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
6.
Terry Chu Lee Belding Prof. Dr. Art van der Est Prof. Dr. Travis Dudding Dr. Ilia Korobkov Dr. Georgii I. Nikonov 《Angewandte Chemie (International ed. in English)》2014,53(10):2711-2715
Reduction of the cationic GeII complex [dimpyrGeCl][GeCl3] (dimpyr=2,6‐(ArN=CMe)2NC5H3, Ar=2,6‐iPr2C6H3) with potassium graphite in benzene affords an air sensitive, dark green compound of Ge0, [dimpyrGe], which is stabilized by a bis(imino)pyridine platform. This compound is the first example of a complex of a zero‐valent Group 14 element that does not contain a carbene or carbenoid ligand. This species has a singlet ground state. DFT studies revealed partial delocalization of one of the Ge lone pairs over the π*(C?N) orbitals of the imines. This delocalization results in a partial multiple‐bond character between the Ge atom and imine nitrogen atoms, a fact supported by the X‐ray crystallography and IR spectroscopy data. 相似文献
7.
Pairing effect: Varying the concentration of support electrolyte in the electrochemical EC(2) reduction of 2,6-diphenylpyrylium reveals the presence of ion pairing between the electroactive species and BF(4)(-). Experiment and theory are shown to be in good agreement only if ion pairing is included in the simulations. This previously unanticipated effect is only observable if voltammetry is performed under conditions of weak support. 相似文献
8.
Greggory M. Wells Travis Dudding Lee Belding Jeffery A. Frick Abhijit Nayek Junfeng Huang Steven J. Katz Stephen C. Bergmeier 《Tetrahedron》2012,68(21):3980-3987
The reaction of fused ring aziridines, 3-oxa-1-azabicyclo[3.1.0]hexan-2-ones, with amine nucleophiles can provide either an aminomethyl oxazolidinone or an aziridinyl urea. The amine, reaction solvent, and aziridine substitution have been examined with the aid of computational studies to identify reaction conditions that provide a single product. Polar solvents provided only the aminomethyl oxazolidinone products. Formation of aziridinyl ureas required control of aziridine substitution, solvent, and reactant stoichiometry. 相似文献
9.
Belding SR Limon-Petersen JG Dickinson EJ Compton RG 《Angewandte Chemie (International ed. in English)》2010,49(48):9242-9245
10.
Meng Y Aldous L Belding SR Compton RG 《Chemical communications (Cambridge, England)》2012,48(45):5572-5574
The Hydrogen evolution reaction has been quantitatively investigated at a Pt electrode in series of room temperature ionic liquids vs. Ag/Ag(+) redox couple. The measured formal potentials of the H(2)/H(+) (HNTf(2)) redox couple in each RTIL reveals a dependence on the nature of anion, suggesting significant interaction between proton and anion. 相似文献