Toluene spectra

Figure 7.57. In situ ATR spectra of P. putida adsorbed at Ge IRE (50 x 20 x 3 mm, with 19 active reflections inside) after lOOh of adsorption (1) biofilm without toluene (2) 5 ppm toluene (3) 15 ppm toluene. Arrows increase of polysaccharide peaks at 5 ppm toluene and of carboxylic group peak at 15 ppm toluene. Spectra were obtained with multichannel ATR/FTIR spectrometer constructed on basis of RFX-30 FT IR interferometer (Laser Precision Analytical). Reprinted, by permission, from J. Schmitt, D. E. Nivens, D. C. White, and H.-C. Flemming, Water Sci. Tech. 32, 149 (1995), p. 154, Fig. 5. Copyright 1996 International Association on Water Quality (lAWQ).

The heights of the steps in the integration curve in the toluene spectrum are in the ratio of 3 5 for peaks at <5 2.13 and <56.98 respectively. It is thus possible to assign the former to the methyl protons and the latter to the protons on the benzene ring. 

Figure 4. Si NMR spectrum of MPTMS SAMMS prepared in refluxing toluene. Spectrum (a) is obtained from a sample after 4 hours of reflux, while spectrum (b) was obtained from a similar sample with the addition of azeotropic removal of water and alcohol from the reaction mixture after the reflux period.

Alkylaromatics form very stable molecular ions which can be detected with very high sensitivity (Figures 3.57-3.65). The tropylium ion occurs at m/z 91 as the base peak, which is, for example, responsible for the uneven base peak in the toluene spectrum (M - 92). The fragmentation of the aromatic skeleton leads to typical series of ions with m/z 38-40, 50-52, 63-67, 77-79 ( aromatic rubble ). Ethylbenzene and the xylenes cannot be differentiated from their spectra because they are isomers. In these cases, the retention times of the components are more meaningful. 

The reaction mixture is diluted with 250 ml of water, the mixture is transferred to a 2 liter flask using methanol as a wash liquid, and the organic solvents are distilled at 20-25 mm using a rotary vacuum evaporator. The product separates as a solid and distillation is continued until most of the residual toluene has been removed. The solid is collected on a 90 cm, medium porosity, fritted glass Buchner funnel and washed well with cold water. After the material has been sucked dry, it is covered with a little cold methanol, the mixture is stirred to break up lumps, and the slurry is kept for 5 min. The vacuum is reapplied, the solid is rinsed with a little methanol followed by ether, and the material is air-dried to give 9.1 g (85%), mp 207-213° after sintering at ca. 198°. Reported mp 212-213°. The crude material contains 1.0-1.5% of unreduced starting material as shown by the UV spectrum. Further purification may be effected by crystallization from methanol. 

In a 250 ml Erlenmeyer flask covered with aluminum foil, 14.3 g (0.0381 mole) of 17a-acetoxy-3j5-hydroxypregn-5-en-20-one is mixed with 50 ml of tetra-hydrofuran, 7 ml ca. 0.076 mole) of dihydropyran, and 0.15 g of p-toluene-sulfonic acid monohydrate. The mixture is warmed to 40 + 5° where upon the steroid dissolves rapidly. The mixture is kept for 45 min and 1 ml of tetra-methylguanidine is added to neutralize the catalyst. Water (100 ml) is added and the organic solvent is removed using a rotary vacuum evaporator. The solid is taken up in ether, the solution is washed with water and saturated salt solution, dried over sodium sulfate, and then treated with Darco and filtered. Removal of the solvent followed by drying at 0.2 mm for 1 hr affords 18.4 g (theory is 17.5 g) of solid having an odor of dihydropyran. The infrared spectrum contains no hydroxyl bands and the crude material is not further purified. This compound has not been described in the literature. 

Fig. 3.2 NMR spectrum for the products of the decomposition of BuN=Se=N Bu in toluene at 20°C after 2 days [Reproduced with permission from Inorg. Chem., 39, 5341 (2000)]...

Figure 13.18 The 1H NMR spectrum of toluene, showing the accidental overlap of the five nonequivaient aromatic ring protons.

The IR spectrum of toluene in figure 15.13 shows these characteristic absorptions. 

Figure 2.33 The ESR spectrum of [Rh(tmpp)2]2+ in CH2Cl2/toluene at 8 K. (Reprinted with permission from J. Am. Chem. Soc., 1991, 111, 5504. Copyright (1991) American Chemical Society.)...

Helf White (Ref 2) interpret the above behavior of the nitrocompds in inhibiting the scintillation process as one of simple light absorption rather than as a true chemical quenching (ae-excitation process). To substantiate this, the UV and near-visible spectrum of each of the light compds in toluene—PPO soln was measured using the 50% extinction concn for each nitrocompd (as determined from Fig 1). 

A with a max at 3800A. The absorption overlap of the nitrocompds is plainly evident. The position and slope of each curve in Fig 1 can be qualitatively correlated with the absorption range and % transmittance at the peak for each compd. Nitro me thane, which absorbs more at shorter wave lengths and exhibits the least overlap of the toluene-PPO emission spectrum, accordingly has the least effect on the count Tate of the pure scintiliator... 

Comparison between flame-sampled PIE curves for (a) m/z = 90 (C H ) and (b) m/z = 92 (C Hg) with the PIE spectra simulated based on a Franck-Condon factor analysis and the cold-flow PIE spectrum of toluene. Calculated ionization energies of some isomers are indicated. (From Hansen, N. et al., /. Phys. Chem. A, 2007. With permission.)... 

In toluene at —60° C the NMR spectrum of a mixture of HjSiBr and 7flMi-(Et3P)2PtHCl showed that all of the H3SiBr is converted into HjSiCl prior to formation of a Si—Pt product. 

Solvent — The transition energy responsible for the main absorption band is dependent on the refractive index of the solvent, the transition energy being lower as the refractive index of the solvent increases. In other words, the values are similar in petroleum ether, hexane, and diethyl ether and much higher in benzene, toluene, and chlorinated solvents. Therefore, for comparison of the UV-Vis spectrum features, the same solvent should be used to obtain all carotenoid data. In addition, because of this solvent effect, special care should be taken when information about a chromophore is taken from a UV-Vis spectrum measured online by a PDA detector during HPLC analysis. 

ESR spectrum of the RjSn radical (R = 2,4,6-triisopropylphenyl), spontaneously generated upon dissolving distannane RBSn-SnRj in deoxygenated toluene, revealed at -140°C in the solid state the Sn hfcc of 163 Such a radical is more planar than the PhjSn radical ( Sn hfcc = 186.6mT) but less planar than the MejSn radical C Snhfcc = 161.1 mT)3° ... 

Sanders (14) has exploited the strong and selective coordination of phosphine donor groups to Ru(II) to construct hetero-dimetallic porphyrin dimers (17, Fig. 5). An alkyne-phosphine moiety introduced on the periphery of a free base or metalloporphyrin (M = Zn or Ni) spontaneously coordinates to a Ru(II)(CO) porphyrin when the two porphyrins are mixed in a 1 1 ratio. Coordination is characterized by a downfield shift of the 31P resonance (A<531P = 19 ppm). There is no evidence of self-coordination of the zinc porphyrin at 10 6 m in toluene, there is no shift in the Soret band in the UV-Vis absorption spectrum. The Ni-Ru dimer was observed by MALDI-TOF mass spectrometry. Heating the Ru(II)CO porphyrin with 2 equivalents of the phosphine porphyrins led to quantitative formation of trimeric assemblies. 

Compound 15a reacts with mesitylazide readily at -80°C in toluene, producing a deep red-purple solution. The 3,P-NMR spectrum of this solution revealed that the adducts 33 and 34 were produced (Eq. II).14... 

Heating (at 100 °C), or photolysis by visible light, of the 1 1 mixture of [IrH3(PPh3)3] C60 in toluene gives a product whose UV-vis spectrum is characteristic of / -coordinated C60.299... 

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