Ethers infrared frequencies

Subsequently, Hiittel and co-workers (303, 306, 307) have described a series of gold(I)-olefin complexes involving both cyclic and acyclic mono- and oligoolefins (Table VI). The 1 1 monoolefin complexes, prepared in almost quantitative yield by reaction of excess olefin with AuCl in ether, are monomolecular and are obtained as colorless crystals. The cyclic olefins, which react as well with aqueous HAUCI4 or NaAuC, form complexes which are more stable than those of the corresponding straight-chain olefins. Formation of the complex results in a low infrared frequency shift in the C=C stretching vibration of 115 cm for the... 

Section 16 18 An H—C—O—C structural unit m an ether resembles an H—C—O—H unit of an alcohol with respect to the C—O stretching frequency m its infrared spectrum and the H—C chemical shift m its H NMR spectrum Because sulfur is less electronegative than oxygen the H and chemical shifts of H—C—S—C units appear at higher field than those of H—C—O—C... 

Triphenylphosphine selenide crystallizes from absolute ethanol as small white needles which melt at 187 to 188°. The compound is very soluble in dichloromethane moderately soluble in hot methanol, hot ethanol, hot acetonitrile, hot benzene, and hot 1-butanol and insoluble in ether and water. The PSe infrared stretching frequency occurs at 562 cm.-1 (Nujol mull). 

The compound is soluble in H20, slightly soluble in acetone, and insoluble in ethanol or ether. The ultraviolet absorption spectrum shows a band at 38,500 cm.-1 with a molar extinction coefficient of 560. The conductivity in aqueous solution is 217 cm.2 ohm-1 mole-1. The linkage properties are determined from the infrared spectrum5 which shows a C—S stretching frequency at 825 cm.-1 for the JV-bonded isomer. 

The infrared spectrum (Nujol mull) of (Et4N)2ReH9 has i (ReH) at 1780(s), (br) and 5(ReH) at ca. 720(sh), 675(s), and ca. 610(sh) cm.-1. In acetonitrile solution, tju-h = 18.5. The compound is soluble in water, acetonitrile, ethanol, 2-propanol, and other alcohols it is insoluble in ether, tetrahydrofuran, and 1,2-dimethoxyethane. The solutions are stabilized by alkali. On heating in a vacuum (2-4°/minute), decomposition occurs at 115-120° with the evolution of hydrogen and ethane. When a ca. 50-mg. sample of (Et4N)2[ReH9] was exposed to the atmosphere at a relative humidity of 19% (25°), it formed moist, brownish clumps within half an hour. An infrared spectrum taken after one hour exposure showed strong (ReO) and 5(OH) bands at 910 and 1630 cm.-1, respectively the j (ReH) and 8 (ReH) frequencies were present but diminished in intensity. 

Infrared studies have shown dependence of the carbonyl absorption value of a series of heteroannularly disubstituted ferrocene carboxylic acids and their methyl ethers on changes in the substituent in the other ring. Nes-meyariov and co-workers (31) have detected a shift to lower frequencies of yc=o values with increasing electron donation. For example, the carbonyl absorption was observed to be 1704 cm for I -sulfuralfluoroferrocene-carboxylic acid, but when the substituent was a methyl or ferf-butyl the... 

Hexaethoxycyclotriphosphazatriene is a colorless, odorless liquid for which n is 1.4522. The compound is soluble in petroleum ether, benzene, diethyl ether, carbon tetrachloride, or chloroform, but almost insoluble in water. The frequencies of the principal absorption maxima in the infrared spectrum are 3000, 1225, 1170, 1036, 972, 899, 813, 800, and 751 cm. The frequency at 1225 cm. is characteristic of a six-membered ring in this case. 

Hyponitrous acid. In contrast to nitrous and nitric acids, hyponitrous acid crystallizes from ether as colourless crystals which easily decompose, explosively if heated. The detailed molecular structure of this acid has not been determined, but it is known that the molecular weights of the free acid and its esters correspond to the double formula, H2N2O2, that it is decomposed by sulphuric acid to N2O, and that it can be reduced to hydrazine, H2N-NH2. Infrared and Raman studies show conclusively that the hyponitrite ion has the trans configuration (a), but the N-N frequency suggests that the central bond has an order of rather less than two. ... 

Although Wittig 170> noted that the reactivity of the ylid in ether was reduced when lithium iodide was added, Daniel and Paetsch 39> observed that the reactivity of the ylid was not reduced when lithium iodide was added to a THF solution of the ylid. In addition, they observed C—Li bond stretching vibrations in the infrared spectrum of a THF solution of the ylid 40h The absorptions at 385, 425, 475, 500 and 580 cm-1, which were attributed to the ylid, disappear on treatment with oxygen. The new band which appears at 450 cm-1 is attributable to an Li—O stretching frequency 40>. 

Of importance in connection with the solubility of the metals in liquid ammonia are ammonia solvates such as the [Na(NH3)4]+ ion which is formed on treatment of Nal with liquid ammonia. [Na(NH3)4]I is a liquid of fair thermal stability. It freezes at 3° and at 25° has an equilibrium pressure of NH3 of 420 mm thus it must be kept in an atmosphere of ammonia with at least this pressure at 25°. The infrared and Raman spectra indicate the complex ion [Na(NH3)4]+ to be tetrahedral with Na—N bonds about as strong as the Zn—N bonds in [Zn(NH3)4]2+ or the Pb—C bonds in Pb(CH3)4. Bending and rocking frequencies, however, are quite low, suggesting that the Na—N bonding is mainly due to ion-dipole forces. Thus it may be assumed that Na+ and other metal ions in the dilute liquid ammonia, amine and ether solutions are strongly solvated in the same way. 

The infrared spectra of n-butyl alcohol in carbon tetrachloride (no hydrogen bonding) and in diethyl ether. The hydrogen bonding with the fatter solvent leads to a shift to lower frequencies and an intensification of the band. 

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