Proton nuclear magnetic resonance spectra

Nuclear magnetic resonance spectra Proton magnetic resonance spectroscopy. See Nuclear magnetic resonance spectroscopy... 

Nuclear magnetic resonance spectra Proton NMR spectra have been measured for many lanthanide macrocycles carbon-13 spectra have been reported for selected species. Information on all reported NMR spectra is included in the tables under the individual complexes. 

Spectra. The UV spectra in w, acid, and base are given in Ref 5. The proton nuclear magnetic resonance spectrum shows a sharp singlet at 3.90ppm from te tram ethyl silane (Ref 15)... 

Carborane, Bk>C2Hi2, is quite soluble in aromatic solvents and is sparingly soluble in aliphatic solvents. The infrared spectrum has been previously reported.25 The proton nuclear magnetic resonance spectrum of a chloroform-d3 solution of carborane contains a broad CH resonance at 6.46 t. 

Methylcarborane is an air-stable, white crystalline solid which is soluble in common organic solvents. The infrared spectrum (Nujol mull) contains major absorption bands at 3.90 (s), 8.83 (w), 9.12 (w), 9.69 (w), 9.83 (w), 10.03 (w), and 13.85 (s) p. The proton nuclear magnetic resonance spectrum of a carbon tetrachloride solution of methylcarborane contains a broad —CH resonance of intensity 1 at 6.52 r and a —CH3 resonance of intensity 3 at 8.02 r. 

Tris(dimethylamino)arsine (d2o 1.1248 nd 1.4848)3 is a colorless liquid which is readily hydrolyzed to form arsenic (III) oxide and dimethylamine when brought into contact with water. The compound is soluble in ethers and hydrocarbons. The product is at least 99.5% pure (with respect to hydrogen-containing impurities) as evidenced by the single sharp peak at —2.533 p.p.m. (relative to tetramethylsilane) seen in the proton nuclear magnetic resonance spectrum of the neat liquid. 

Diethylamino)trimethylstannane is a colorless liquid which boils at 36°/6 mm. The compound is quickly hydrolyzed by moisture. The proton nuclear magnetic resonance spectrum of a neat sample shows a CH3—Sn resonance at 9.92 r with HChs—Sn119 splitting of 56.5 cycles and HCh,—Sn117 splitting of 54.0 cycles. The ethyl resonance consists of a triplet at 9.10 r... 

Since the product slowly darkens on exposure to air, it should be stored under nitrogen in a refrigerator. The compound solidifies on cooling m.p. 16.0-16.5°. Nuclear magnetic resonance spectrum (neat, tetramethylsilane internal standard) singlets at d 7.00 (aromatic protons), 3.93 (CH2), and 2.24 p.p.m. (NH). 

The infrared spectrum of y-crotonolactone shows two bands in the carbonyl r on at 5.60 and 5.71 fi in carbon tetrachloride (5%) [shifted to 5.61 and 5.71 fi in chloroform (5%)] and carbon-carbon stretching absorption at 6.23 fjt. The nuclear magnetic resonance spectrum shows olefinic peaks centered at 2.15r (pair of triplets) and 3.85r (pair of triplets), each due to one proton, and a two-proton triplet centered at 5.03t (in CCU). 

The pentacyanocobalt(II) ion reacts with acetylene to form a yellow crystalline salt K6[Co2(CN)io(C2H2)HH20 108). The nuclear magnetic resonance spectrum of the ion shows a single proton resonance line in the... 

Figure 9-37 Nuclear magnetic resonance spectrum of C9H10 at 60 MHz. The calibrations are relative to the protons of TMS. The insets show the peaks centered on 321, 307, and 119 Hz with an expanded scale. The spacing between the peaks is 1.5 Hz for Group B at 307 Hz, and 0.75 Hz for Groups A and C at 321 and 119 Hz. The C6H5 protons are coupled to each other, not to A, B, or C.

The proton nuclear magnetic resonance spectrum of ethynylbenzene is shown in Figure 10-5. The peaks near 435 Hz and 185 Hz correspond to resonances of the phenyl and =C—H protons, respectively. The difference... 

Fig. 3.41 Proton magentic resonance spectrum (top) and, 3C nuclear magnetic resonance spectrum (bottom) of 3-methylheptane. Data reproduced from G. C. Levy and C. L. Nelson (1972). Carbon-13 Nuclear Magnetic Resonance for Organic Chemists. New York Wiley-Interscience, p. 39.

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. 

Assignments for the Proton Nuclear Magnetic Resonance Spectrum of Benazepril Hydrochloride... 

Acid hydrolysis of 5-amino-5-deoxy-l,2-0-isopropylidene-o -D-xy-lofuranose (15) might be expected to afiFord 5-amino-5-deoxy-D-xylose, but instead, at 70 , 3-pyridinol (21) is the main product. If the acid hydrolysis of compound 15 is conducted at room temperature, there is obtained, besides 3-pyridinol (21), the crystalline hydrochloride of l-amino-l,5-anhydro-l-deoxy-D-fhreo-pentulose hydrate (22). The crystalline hydrate exhibits no carbonyl band in its infrared and ultraviolet spectra. The water content cannot be removed without decomposition of the compound, and is, therefore, water of constitution. The nuclear magnetic resonance spectrum of 22 lacks the signal characteristic of an anomeric proton. The free ketone group is, however, detectable by the preparation of a (2,4-dinitrophenyl)-hydrazone. 

Fig. 1. —Nuclear Magnetic Resonance Spectrum of lA3,4-Tetra-0-acetyl-5-[(ben-zyloxycarbonyI)amino]-5-deoxy-a-D-xylopyranose (207). (Taken at 100 MHz in chloroform at 35° acetyl protons omitted the decoupled signals are indicated above tetra-methylsilane as internal standard.)...

The behavior associated with hindered rotation is seen in the nuclear magnetic resonance spectrum of methyl 5-acetamido-5-deoxy-2,3,4-tri-O-methyl-a-D-xylopyranoside (210) (see Fig. S). - In this compound, widely separated signals for the two anomeric protons of the rotamers A and B appear especially well at lower field. The ratio of forms B to A is about 1.5 to 1 at 110° (upper curve), the signals coalesce, as a result of more-rapid rotations, into one signal (which is the average of the separate signals). 

At pH 4.4, 5-thio-D-xylopyranose (215) shows a slow mutarotation, namely, [a]p +202 - +178° (half-time, 10 hours). At pH 6.6, however, the half-time is only about 10 minutes. The direction of the rotation shows that 215 crystallizes in the a-D form. The nuclear magnetic resonance spectrum of 215 in deuterium oxide shows the presence of the H-1 proton of both anomers. The diaxial coupling of 8.2 Hz for the H-1 proton at the higher field (t 5.25) corresponds to the )8-D anomer in the CJ(d) conformation of the molecule having a sulfur-containing ring. 

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