Spectroscopy electronic absorption

The UV absorption spectra of 3-alkyl-2//-azirines show a weak absorption at about 230 nm (e ca. 100), while 3-aryl-2//-azirines exhibit a stronger absorption at about 245 nm (e ca. 13000-20000) with an inflection at about 285 nm for the n- 7t transition (e ca. 1000) B-83Mi 101-02, 84CHEC-1(7)47). The parent compound 2//-azirine shows an absorption at 229 nm 88T4447 . 

Electronic Absorption Spectroscopy. Absorption spectra have been obtained for radical cations and anions generated from a number of carotenoids [phytoene (7,8,ll,12,7, 8, ll, 12 -octahydro-i//,i/ -carotene) (135) and canthaxanthin ()3,/3-carotene-4,4 -dione) (130)] and related polyenes [7,7 -dihydro- -carotene (131), 

Englert, F. Kienzie, and K. Noack, Helv. Chim. Acta, 1977, 60, 1209. 

spectra have been reported for the 9-cis- and aM-trans-C and -Q7, and the all-trans-C22 and -C24 homologues of retinol.187 Several retinaldehyde isomers in iso-octane solution with [Eu(fod)3] gave a new characteristic absorption band.188 

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Perhaps the more conventional approach to electronic absorption spectroscopy is cast in the energy, rather than in the time domain. It is straightforward to show that equation (Al.6.87) can be rewritten as... 

GUlam and Stem, An Introduction to Electronic Absorption Spectroscopy in Organic Chemistry, 1954 (Arnold). 

Electronic absorption spectroscopy, UV and visible, has been covered extensively by (63PMH(2)l) and (71PMH(3)67). Table A2 of (B-76MI40402) contains UV absorption data for nearly 70 pyrazoles and pyrazolones. 

Explain why, in the study of an acid-base equilibrium, we observe absorption peaks of both species (conjugate acid and base) when using electronic absorption spectroscopy, but only a single peak by NMR. 

Electronic absorption spectroscopy (ABS) Magnetic circular dichroism (MCD)... 

Yordanov, A. T. Roundhill, D. M. Electronic absorption spectroscopy for the investigation of the solution binding of gold, palladium, mercury and silver salts to the lower rim substituted calix[4]arenes 25,26,27,28-(2-N,N-dimethyl-dithiocarbamoylethoxy)calix[4]arene and 25,26,27,28-(2-methylthioethoxy)calix[4]arene. Inorg. Chim. Acta 1998, 270, 216-220. 

No significant IR data and electronic absorption spectroscopy have been reported. 

Electronic Absorption Spectroscopy. For comparison purposes, Table I presents spectroscopic data for Linstead s unsubstituted pz (1), pc (44), and... 

P.E. Spectroscopy, Electronic Absorption Spectroscopy and Ligand Field Theory.124... 

Polymers with chromophores exhibiting mt transitions (e.g., C=0) exhibit weaker UV-absorption and these groups together with unsaturated carbon-carbon bonds which develop during radiation damage can be detected by electronic absorption spectroscopy. 

The addition of hydroxyde ion to nitrosobenzene produces azoxybenzene186. Three techniques (electronic absorption spectroscopy, linear sweep voltammetry and d.c. polarography) have been used to study the equilibrium between nitrosobenzene and hydroxyde ions. The probable reaction pathway to obtain azoxybenzene is indicated by Scheme 4. The importance of the nitroso group in the reduction of nitro derivatives by alkoxide ions, when the electron-transfer mechanism is operating, has been explained187. 

The purity of the terminal Au-oxo complexes, 3 and 4, was established by several methods including P NMR (3 and 4 have only one phosphorus peak at —8.55 and —13.15 ppm, respectively), cyclic voltammetry, electronic absorption spectroscopy, vibrational spectroscopy, detailed magnetic measurements and elemental analysis on all elements (triplicate analyses for Au) (44). The single peak in the PNMR spectra is consistent with the C2V symmetry of 3 and 4 established by multiple X-ray crystallographic structure determinations and a neutron diffraction study on 3 at liquid He... 

T.J. Thurston, R.G. Brererton, D.J. Foord, R.E.A. Escott, Monitoring of a second-order reaction by electronic absorption spectroscopy using combined chemometric and kinetic models, J. Chemom., 17, 313-322 (2003). 

Probing Metalloproteins Electronic absorption spectroscopy of copper proteins, 226, 1 electronic absorption spectroscopy of nonheme iron proteins, 226, 33 cobalt as probe and label of proteins, 226, 52 biochemical and spectroscopic probes of mercury(ii) coordination environments in proteins, 226, 71 low-temperature optical spectroscopy metalloprotein structure and dynamics, 226, 97 nanosecond transient absorption spectroscopy, 226, 119 nanosecond time-resolved absorption and polarization dichroism spectroscopies, 226, 147 real-time spectroscopic techniques for probing conformational dynamics of heme proteins, 226, 177 variable-temperature magnetic circular dichroism, 226, 199 linear dichroism, 226, 232 infrared spectroscopy, 226, 259 Fourier transform infrared spectroscopy, 226, 289 infrared circular dichroism, 226, 306 Raman and resonance Raman spectroscopy, 226, 319 protein structure from ultraviolet resonance Raman spectroscopy, 226, 374 single-crystal micro-Raman spectroscopy, 226, 397 nanosecond time-resolved resonance Raman spectroscopy, 226, 409 techniques for obtaining resonance Raman spectra of metalloproteins, 226, 431 Raman optical activity, 226, 470 surface-enhanced resonance Raman scattering, 226, 482 luminescence... 

Electronic absorption spectroscopy charge transfer transitions, 19 71 d-d transitions, 19 70, 71 flavocytochrome b, 36 269-271 intraligand transitions, 19 71-80 of organometallics, 19 69-80 Electronic coupling, between donor and acceptor wave functions, 41 278 Electronic nuclear double resonance spectroscopy, molybdenum center probes, 40 13... 

The electronic structures of polysilane radical ions have also been studied by pulse radiolysis of the liquid solution [35-40]. However, due to short lifetime of the radical ions, the measurement is limited to electronic absorption spectroscopy. 

Zsila, F., Bikadi, Z., and Simonyi, M., Probing the binding of the flavonoid, quercetin to human serum albumin by circular dichroism, electronic absorption spectroscopy and molecular modelling methods, Biochem. Pharmacol, 65, 447, 2003. 

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