Chloroform, deuterated

Characterization. The FT-IR spectra were obtained on a Perkin Elmer 1600 Series machine by coating the samples on a NaCl plate. The purity of BEP was examined by FT-NMR at 400 Mhz in deuterated chloroform on a Varian XL 400. The... 

Proton and carbon-13 nuclear magnetic resonance (NMR) spectra were recorded on a IBM Instruments 270 MHz NMR Spectrometer on 6-8 weight percent solutions in deuterated chloroform. Ultraviolet spectra were recorded on an IBM Ultraviolet Spectropluitometer Model 9420 using chloroform solutions containing 2 x 10-5 g/ml of the copolymers. 

The divalent Co(salen) complex (69a) is one of the most versatile and well-studied Co coordination compounds. It has a long and well-documented history and we shall not restate this here. Recent applications of (69a) as both a synthetic oxygen carrier and as a catalyst for organic transformations are described in Sections 6.1.3.1.2 and 6.1.4.1 respectively. Isotropic shifts in the HNMR spectrum of low-spin Co(salphn) (69b) were investigated in deuterated chloroform, DMF, DMSO, and pyridine.319 Solvent-dependent isotropic shifts indicate that the single unpaired electron, delocalized over the tetradentate 7r-electron system in CHCI3, is an intrinsic property of the planar four-coordinate complex. The high-spin/low-spin equilibrium of the... 

A section of the film was dissolved in 3 parts deuterated chloroform (CDCI3) plus 2 parts 1,1,1-trifluoroethanol (IFF), a known good solvent system for... 

In order to more accurately identify the contaminant, and to determine if the fuel delivery system module filter was the source, both materials were analyzed using 1H NMR spectroscopy Samples were dissolved in a 60 40 mixture of deuterated chloroform/triflouroethanol. It should be noted that the amount of contaminant available for analysis was quite small, so for this sample, the NMR spectral acquisition time was set to 1 h in order to record a spectrum of adequate signal-to-noise ratio. 

The nuclear magnetic resonance spectrum of valproic acid as shown in Figure 4 was obtained on a Varian Associates T-60 NMR Spectrometer as a 10% w/v solution in a solvent of deuterated chloroform. The spectral peak assignments (2) are presented in Table II. 

Proton-decoupled 13C-NMR spectra were recorded on a Varian XL-300 operating at 75.4 MHz. Approximately 250 mg of the sample was dissolved in 3 ml of deuterated chloroform. 13C chemical shifts were referenced internally to CDCL (77 ppm). A delay of 200s was used to ensure relaxation of all the carbon nuclei and 1000 transients were collected to assure a good signal-to-noise ratio. 

Fig. 10.26. ID proton spectrum of dibromopropionic acid in deuterated chloroform.

A popular solvent for the sample is deuterated chloroform, CDC13. The D is the symbol for deuterium, the isotope of hydrogen that has one proton and one neutron. This solvent has no H nuclei and does not absorb RFs. It will therefore not interfere in the analysis. 

H NMR (400 MHz), NMR spectra were recorded on a Varian Mercury-Vx (3000Mx) ve Brucker AC-400L spectrometer using deuterated chloroform solvents and TMS as internal standard. IR spectra were recorded on a Schimadzu Fonrier Transform FTlR-8300 instalment. Mass spectra were recorded on a VG Zap spec instrument (1,000 resolution) (the Chemistry of the Turkish Scientific and Research Institue-Gebze). 

The 90 MHz H-NMR spectrum of benzoic acid shown in Figure 7 was obtained in deuterated chloroform using a Hitachi R-1900 FT-NMR spectrometer. Chemical shifts were measured relative to tetramethylsilane and assignments for the observed bands are found in Table 4. Due to the relatively low resolution of the 90 MHz NMR spectrometer, the only H-H... 

First, second, and third generation dendrimers based on THPE (core) and bis-MPA (repeating unit) have been synthesized and characterized. SEC and NMR analyses verified that the dendrimers were monodisperse. Diffusion NMR was used to determine the dendrimers hydrodynamic radii in deuterated chloroform. First, second, and third generation dendrimers were found to be 7.8, 10.3, and 12.6 A, respectively. These were in agreement with sizes as determined from molecular models (Biichi). 

The absence of an EPR signal in solution or in the solid state is indicative of a singlet ground state for the diradical ( BuBP Pr2)2- An indication of the radical character of this derivative is provided by a variety of facile oxidative addition reactions (Scheme 9.12). " For example, the treatment of ( BuBP Pr2)2 with diphenyl diselenide (or elemental selenium) produces a bicyclic compound in which a selenium atom bridges the two boron atoms. Trimethyl tin hydride reacts rapidly with ( BuBP Pr2)2 to give the trans adduct. Finally, ( BuBP Pr2)2 is slowly oxidised by deuterated chloroform to produce a R,R -dichloro adduct as a mixture of cis and trans isomers. 

We have used the VARIAN XL 100 (100 MHz), VARIAN DA 60 IL (60MHz) and CAMECA (350 MHz) as apparatus. The spectra have been obtained In deuterated chloroform at room temperature with tetramethylsilane as an Internal reference. We cannot work at elevated temperatures to reduce the broadening of the bands because polyacrolelns are very sensitive to heat. 

This does not include the use of deuterated chloroform, which of course is widely used on a small scale for NMR measurement. 

The H NMR spectra of organic compounds are usually obtained in an aprotic solvent at concentration levels of a few percent. The most widely used solvent is deuterated chloroform (CDC13), sufficiently polar to dissolve most organic compounds. Acetone-r/6 (C3D60), methanol-e 4 (CD3OD), pyridinc-r/5 (C5D5N) and heavy water (D20) are also used. 

The infrared spectra of the coal and the various extracts were recorded on a Baird, Model GY-1 (Ireland Mine vitrain concentrate) and on a Perkin Elmer Model 337 spectrophotometer (Bruceton coal). The samples were prepared by the potassium bromide pellet technique. The high resolution proton NMR spectrum of the benzene soluble extract from Ireland Mine vitrain concentrate was recorded on a Varian A-60 spectrometer in 10% deuterated chloroform (CDCh) solution, using tetrametnylsilane internal standard. 

All NMR spectra were recorded on a Varian A-60 spectrometer at room temperature by Nuclear Magnetic Resonance Specialties, Inc., New Kensington, Pa. Benzene soluble fractions were recorded in deuterated chloroform solution (CDCls) while dimethyl sulfoxide-dc (DMSO-dr.) was the solvent employed for other fractions. (Deuterated chloroform with enrichment of 99.8% was purchased from Bio-Rad Laboratories and dimethyl sulfoxide-dr, with enrichment of 99.6% from Merck, Sharp, and Dohme of Canada.) The internal standard used with the CDCla solutions was tetramethvlsilane and hexamethyl-disiloxane (chemical shift 7 c.p.s.) with DMSO-d . Prior to preparation for NMR recording, the samples were thoroughly dried in a vacuum at 110°C. The NMR tubes were sealed to minimize the absorption of atmospheric moisture. The chemical shifts given in c.p.s. are referred to tetramethylsilane. 

C NMR spectra of poly(3-methyl-1-butene) and poly(4-methyl-1-pentene) were determined with a Varian CFT-20 spectrometer operated at ambient probe temperature ( 35° C) using 20-30% solutions of polymer in deuterated chloroform. Spectra were obtained utilizing off-resonance coupling and white noise decoupling techniques for both poly(3-methyl-l-butene) and poly(4-methyl-l-pentene). 

The exchange procedure described was developed in the submitter s laboratories for the preparation of dideuteriodia-zomethane for labeling studies. It is basically a modification of a procedure that has been used extensively in the literature.7 However, the literature procedures give relatively little detail. This modified procedure permits the synthesis of fairly large amounts of high-purity dideuteriodiazomethane. Dideuterio-diazomethane has also been prepared from N-nitroso methyl-dg-urea and related trideuterated diazomethane precursors.8 Deuterated chloroform and hydrazine hydrate have also been used to prepare dideuteriodiazomethane.9... 

Materials and Apparatus. Hexafluorobutadiene, hexafluoropropane, and l, 2-di ch 1 oro-1,1-di fl uoroethane were purchased from PCR, methyl disulfide and chloroform from Aldrich, and deuterated chloroform from Stohler. These reagents were checked by infrared spectroscopy and used as received, except for the methyl disulfide, which was redistilled. 

C Spin-lattice relaxation times T at 25 and 50 MHz have been determined for PMMA and CMIM20 in deuterated chloroform solution over a temperature range of - 50 to 50 °C. 

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. 

The proton MR spectra (Jeol FX-loo Spectrometer) were recorded in different solvents that of ketotifen base in deuterated chloroform, and that of ketotifen hydrogen fumarate in deuterated dimethyl sulphoxide (in either case against TMS as internal standard) (5). These spectra are presented in Figs. 4. and 5. Characteristic features of the spectra are given separately in Tables 3 and 4. 

The C-NMR noise decoupled and off resonance spectra are presented in Fig. 2 and Fig. 3 respectively. Both were recorded over 1+000 Hz range in deuterated chloroform on a Varian FT80 A-80 MHz spectrometer, using 10 mm. sample tube and tetramethyl silane... 

---