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Intensity characteristic

The molecular ion typically is not observed but can be deduced by adding 31 to the highest-mass peak observed (even in the case of methyl cyanoacetate). An intense ion in the mass spectra of methyl esters is m/z 74, formed in a McLafferty rearrangement. Also present is m/z 87, but it is of low intensity. Characteristic losses from the molecular ion are 31, 40 (small), 59, and 73 Daltons. [Pg.66]

Molecular ion Molecular ions of cyclic ketones are relatively intense. Characteristic fragment ions of cyclic ketones occur ai m/z 28, 29, 41, and 55. Cyclic ketones also lose CO and/or C>H (m/z 28) from the molecular ion (Q and higher). Low-abundance ions corresponding to loss of H20 are frequently observed. Keto-steroids are a special class of cyclic ketones and have abundani molecular ions. [Pg.90]

Evaluate location, intensity, characteristics, and aggravating/alleviating factors... [Pg.73]

Bistability controlled by input intensity (wavelength fixed) can also be observed. Figure 3 shows input-output intensity characteristics (yt = 2 tr being the normalised intensity of transmitted wave) when A > Ao and demonstrates that the use of slow-wave structures significantly affects appearance of bistability and its threshold. [Pg.144]

The (n, it ) state plays a very important role in the photochemistry of carbonyl compounds and many heterocyclic systems. In conjugated hydrocarbons (it -> it ) transitions are most important and give intense characteristic absorption bands. Because of some overlap forbidden character, the (n - it ) transitions have low probability and hence weak absorption bands. [Pg.41]

The fluorescence spectrum is made up of radiation with frequencies and intensities characteristic of the composition of the sample, allowing its qualitative or quantitative analysis. [Pg.238]

The reaction of the fully reduced enzyme with 02 does not follow the pathway described above. Instead, loss of compound A is followed by the production of compound B through the intermediate formation of another compound (II), which may be equivalent to the peroxo compound C, but having reduced cytochrome a and CuA. The transient nature of this species II compared to compound C would result from the possibility of electron transfer from cytochrome a and CuA, to give compound B. The fact that cytochrome a and CuA are at least partially oxidized in compound B is shown by the appearance of the ESR signal (in 30-50% intensity) characteristic of the fully oxidized enzyme. Intermediates beyond compound B in the oxidation sequence have also been described. In one of these, the CuB2+ is ESR-detectable. [Pg.695]

If the unknown, neutral, oxygen-containing compound does not give the class reactions for aldehydes, ketones, esters and anhydrides, it is probably either an alcohol or an ether. Alcohols are readily identified by the intense characteristic hydroxyl adsorption which occurs as a broad band in the infrared spectrum at 3600-3300 cm-1 (O—H str.). In the nuclear magnetic resonance spectrum, the adsorption by the proton in the hydroxyl group gives rise to a broad peak the chemical shift of which is rather variable the peak disappears on deuteration. [Pg.1223]

Low intensity characteristic isotope cluster Low intensity characteristic isotope cluster Higher than other halides Rather high intensity (loss of 7i-electron)... [Pg.460]

Because the picosecond continuum is generated through a highly nonlinear process, its detailed spatial, spectral, and intensity characteristics vary from shot to shot more severely than do the laser pulses used to generate it. In order to achieve a high degree of reliability in our spectral measurements, it is therefore necessary to obtain double beam spectra in which the data are corrected for continuum fluctuations for every shot. [Pg.230]

The method consists of examining the spectrum of the compound that must be measured in order to select an intense characteristic peak which is used to measure the analyte. A known, exact quantity of labelled internal standard is added to the sample with an unknown concentration. When the labelled internal standard is added, the peak corresponding to the characteristic peak is moved to a different position in the spectrum, according to the number and nature of the atoms that were used in the labelling. The ratio of these two signal intensities is used to measure their relative proportion. [Pg.268]

Figure 23. Schematic volt-intensity characteristics of a gas discharge between... Figure 23. Schematic volt-intensity characteristics of a gas discharge between...
Yang, H. H.-L., and Lawless, H.T. (2006). Time-intensity characteristics of iron compounds. FoodQual. Prefer. 17,337-343. [Pg.602]

The copper(I) alkynyls displayed rich photochemistry and particularly strong photoreducing properties. The transient absorption difference spectrum of [Cu3(dppm)3(/X3-) -C=CPh)2]+ and the electron acceptor 4-(methoxycarbonyl)-A-methylpyridinium ion showed an intense characteristic pyridinyl radical absorption band at ca. 400 nm. An additional broad near-infrared absorption band was also observed and it was assigned as an intervalence-transfer transition of the mixed-valence transient species [Cu Cu Cu (dppm)3(/x3- -C=CPh)2] +. The interesting photophysical and photochemical properties of other copper(I) alkynyl complexes such as [Cu(BTA)(hfac)], 2 [Cui6(hfac)8(C=C Bu)8], and [Cn2o(hfac)8(CsCCH2Ph)i2] have also been studied. [Pg.5430]

All the compounds lose olefin when exposed to air. They should be stored in tightly closed containers and kept in a refrigerator. The compounds are soluble in halogenated solvents. Nmr data are given in Table I. Infrared spectra have two intense characteristic absorptions in the region 1610-1680 cm i (one may be a shoulder). [Pg.119]

The Powder Diffraction File ° contains data on single-phase X-ray powder diffraction patterns. These are stored as lists of interplanar spacings dhki and relative intensities characteristic of each compound, as shown in Figure 16.5. Unit cell dimensions, space groups and densities are also listed. [Pg.699]


See other pages where Intensity characteristic is mentioned: [Pg.469]    [Pg.2961]    [Pg.57]    [Pg.168]    [Pg.65]    [Pg.35]    [Pg.190]    [Pg.57]    [Pg.373]    [Pg.19]    [Pg.204]    [Pg.490]    [Pg.711]    [Pg.7]    [Pg.407]    [Pg.67]    [Pg.711]    [Pg.450]    [Pg.465]    [Pg.120]    [Pg.120]    [Pg.438]    [Pg.245]    [Pg.572]    [Pg.214]    [Pg.115]    [Pg.9]    [Pg.9]    [Pg.438]    [Pg.59]    [Pg.59]    [Pg.190]   
See also in sourсe #XX -- [ Pg.269 , Pg.270 ]




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