Methanol, and deuterated

M. Falk and E. Whalley, Infrared spectra of methanol and deuterated methanols in gas, liquid, and solid phases. J. Chem. Phys. 34, 1554 (1961). 

A. Serrallach, R. Meyer, and H. H. Giinthard, Methanol and deuterated species Infrared data, valence force field, rotamers, and conformation. J. Mol. Spectrosc. 52, 94 129 (1974). 

An examination of the temperature dependence of the fluorescent lifetime of both terbium nitrate and europium nitrate in methanol and deuterated methanol was made. There was little change with temperature for either. 

Um et al. fabricated a tubular DMFC for in situ NMR study of the real-time monitoring of various electrochemical reactions. The tubular DMFC shows improved performance and durability sufficient for its use in an in situ NMR test, but problems with rapid performance decay persist. The tubular DMFC was also installed in an NMR probe to test signal sensitivity and resolution of 2D NMR spectra for deuterated methanol and deuterated water. The spectral resolutions of both species are high, and their signal intensities are strong enough to realize acceptable spectra [177]. 

The capability of methanol in forming hydrogen bonds makes it a protic solvent, suitable for dissolving many inor nic compounds. Data for solubility [37,4244], density [37], and heat of solution [32,44] of many electrolytes in methanol and deuterated methanol have been collected. DiHusivities of selected compounds in liquid methanol can be found in Reference 40. Solubilities of methanol in compressed gases of hydrogen, nitrogen, methane, and carbon... 

Exchange with deuterium oxide-10% deu-teriosulfuric acid in methanol-OD deuteration of estradiol at C-2 and C-4, 157... 

Exchange with deuterium oxide-20 % sodium deuterioxide in methanol-OD deuteration of 5a-pregn-9-en-12-one at C-8 and C-11, 155... 

Exchange with deuterium Oxide-5 % sodium deuterioxide in methanol-OD deuteration of 3/3-hydroxy-5a-androstan-7-one at C-6 and C-8, 151... 

A flow cell-procedure was then applied. The experiment consisted of (a) adsorption of methanol (in a solution containing deuterated methanol and light hydrogen base electrolyte), (b) solution exchange with base electrolyte and (c) application of two potential steps, one of short duration to oxidize the adsorbed residue and then a second one in the negative direction to reduce the ions H+ and/or D+ formed. During this time the mass intensity signals for HD, (m/e = 3) and for COz (m/e = 44) were... 

Samples of both fulvic and humic acids were suspended in methanol and methylated with diazomethane. Both H and spectra of the free acids were obtained, at 299.94 MHz and 75.42 MHz respectively, on a Varian XL-300 spectrometer having a Nicolet TT-100 PET accessory. Spectra were obtained in D2O, in a 12-mm tube, with deuterated TSP (sodium 3-(trimethylsilyl)propionate-, , 3,3- 4) added as internal reference. GC/MS of methylated acids was conducted on a Hewlett-Packard Model No 5995 GC/MS/DA system equipped with a fused silica capillary column (12 m x. 020 mm ID, Hewlett Packard) internally coated with crosslinked methylene silicone. Infrared spectra were obtained with solid samples dispersed in KBr pellets, by using a Beckman IR-33 spectrophotometer. The various absorption peaks in IR and NMR were interpreted conventionally (9-10). 

EF-1 was analyzed by spectrophotometer IH and 13C NMR (Bmker AC 200, 200MHz) using as solvent chloroform (CDCI3) and methanol (CD3OD) deuterated at a ratio of 9 1 to tetrame-thylsilane (TMS) as internal reference standard. An aliquot of EF-1 (5 mg) was methylated with diazomethane and subjected to mass spectrometry (MS Agilent Technologies). The spectral data obtained were compared with the literature [Oliveira et al, 2006]. 

Another example of the separation of isotopomers was observed with deuterated benzoic acid, eluted with acidified 30% aqueous methanol. Deuteration, especially at meta and para positions, decreases retention.136 Ratios of retention times are presented in Table 9, where the IEs of monodeuterated benzoic acid or of benzoic-2,6-% acid are omitted because they are too small to produce resolvable peaks although they do lead to detectable peak broadening. Because the IEs are strongest at positions more distant from the carboxyl group, and because the elution conditions were sufficiently acidic that the benzoic acid was not ionized, an IE on the pKa was rejected as responsible. Instead some sort of lipophilic interaction was suggested, and deuteration at the ortho positions is less effective because the carboxyl group hinders those positions. However, it should be noted that the data in Tables 2 and 3 indicate that the IE on acidity does not fall off at meta and para positions.24,32... 

Shortly afterwards, this work was extended by the incorporation of a mass spectrometer into the system, thus enabling on-line NMR and MS data to be obtained with on-line collection of the eluent for off-line FT-IR spectroscopy [22]. The incorporation of the mass spectrometer required the addition of a small proportion of ammonium acetate, dissolved in methanol, to the deuterated chloroform used as the eluent in order to promote the ionisation of the analytes. The inclusion of methanol and ammonium acetate to the solvent obviously introduced new signals into the NMR spectra, and in addition resulted in the loss of exchangeable protons from the analytes which had been observable when chloroform alone was used as the solvent. This work demonstrated the feasibility of multiple hyphenation ( hypernation ) but the off-line nature of the FT-IR data acquisition, with the inevitable delay inherent in offline analysis, represents a slight disadvantage. In addition, volatile components may well be lost as the solvent is evaporated. This can be a problem that, together with analyte instability, is exacerbated with such interfaces when reversed-phase eluents are used since these require heating in order to ensure removal of the solvent. 

By taking advantage of the keto-enol equilibrium, Yb(hf w/i T was prepared in methanol-rU and its luminescence properties were determined in several solvents, methanol-, thf-cfo, PO(OMe)3, and dmso- 6- Emission intensity is the largest in the latter solvent, by a factor 2.5 with respect to deuterated methanol and the Yb(2F5/2) lifetime reaches 66 ps, as compared to 10 ps in methanol- 4 (Kim and Park, 2003). 

The complexes of general formula [Ln(61)] (Ln = Nd, Er and Yb) (see fig. 60) exhibit the typical NIR luminescence of each Lnm ion upon excitation in the antenna chromophore. The overall quantum yields have been determined in deuterated methanol and by using the Ndm... 

---