Mass spectrometry parent peak

Triaziane XIV. 10.0 g of residue XIII and 21.6 g of octadecanol were heated at 150 °C, while tetraisopropyl-o-titanate was added as a catalyst. After destination of the methanol, the residue was recrystallized from methylisobutyl ketone, which gave 23.1 g of triazine XIV, 87%, mp 68.8-69.7°C. Mass spectrometry parent peak m/E 1149. The identity and purity of the / -activated thioethers followed from spectroscopic data (ir, NMR, and mass spectrometry). 

Thermal Decomposition of Sulfinate (XVI). A solution of 0.12 mmol of sulfinate (XVI) in 1 mL of o-dichlorobenzene was heated at 150°C. In the liquid chromatograms several peaks rose and disappeared during the reaction. Three main products were isolated 4-methoxy-2,6-diphenyl-phenol (Vila) was identified by its ir spectrum thiosulfonate (IXVIII), the vmax 1200 s (S02), 750 s, and 700 s cm-1 (aromatic monosubstitution), (mass spectrometry parent peak (M) m/e 306, peak m/e 242 (M-S02), m/e 105 (CeH5C2H4 fragment), and a molecule ion peak m/e 136, which was assigned to sulfide XX) and sulfonate XIX (the vmax 2830 w (OCH3), 1200 s (S02), and strong bands between 700 and 800 cm-1 (two types of aromatic substitution) mass spectrometry parent peak (M) m/e 444, peak m/e 380 (M-S02)). 

The combined techniques of gas chromatography/mass spectrometry (gc/ms) are highly effective in identifying the composition of various gc peaks. The individual peaks enter a mass spectrometer in which they are analyzed for parent ion and fragmentation patterns, and the individual components of certain resoles are completely resolved. 

The chromatograms of the liquid phase show the presence of smaller and larger hydrocarbons than the parent one. Nevertheless, the main products are n-alkanes and 1-alkenes with a carbon number between 3 to 9 and an equimolar distribution is obtained. The product distribution can be explained by the F-S-S mechanism. Between the peaks of these hydrocarbons, it is possible to observe numerous smaller peaks. They have been identified by mass spectrometry as X-alkenes, dienes and also cyclic compounds (saturated, partially saturated and aromatic). These secondary products start to appear at 400 °C. Of course, their quantities increase at 425 °C. As these hydrocarbons are not seen for the lower temperature, it is possible to imagine that they are secondary reaction products. The analysis of the gaseous phase shows the presence of hydrogen, light alkanes and 1-alkenes. 

Tandem mass spectrometry (70eVEI) performed on 5-amino-l,3,4-thiadiazole-2-thiol 26 gave a weak abundance peak at m/z 78 Da (2%) corresponding to the [CH2S2]+ ion (Equation 1) <1999PCA5123>. The linked-scan spectra of the parent ion (M+) and the ion at mfz 106 showed that loss of HNC followed by N2 elimination accounted for the... 

A look at Table IV will show the general simplicity of the spectra. This is due to the fact that ionization occurs by electron tunneling, which does not excite the ions vibrationally, as is the case with impact ionization. Thus the combination of field ionization and mass spectrometry has considerable analytical potentialities, when it is considered that acetone, for example, gives rise to 19 peaks of comparable intensity by impact ionization and shows no peaks over 0.1% except the parent in field ionization. 

The existence of interlocked molecules such as 10.95 can be established by a variety of spectroscopic techniques. Most importantly, mass spectrometry provides very characteristic patterns for catenanes. The mass spectra for catenated species are very different from those of covalently linked precursors (such as 10.94) but are more than the sum of their two individual components. Catenane mass spectra are characterised by the appearance of peaks at high mlz corresponding to the parent species as well as fragments corresponding to the transfer of hydrogen atoms from one macrocycle to the functional... 

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry MALDI-TOF appears the newest technique particularly suitable for the study of oligomers and dendrimers because, under appropriate conditions, the parent peak is obtained uncontaminated by fragmentation species. However, in some cases supramolecular clusters have been observed which could be misinterpre-tated as dimers and higher multiplets [13]. The molecular weight range available reaches 50,000 D with a potential resolution between 0.01 and 0.05%. 

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