Benzoyl chloride infrared spectrum

The uniquely distinguished axial alcohol at C5 was activated by triflation and the resultant triflate was displaced by the action of tetra n-butylammonium azide in benzene at room temperature. Compound 25 was thus available in 86% yield from alcohol 24. Hydrogenolysis ((H24 d(OH)2C) followed by acetylation afforded compound 26 in 96% yield. TTie richly detailed NMR spectrum (490 MHz) of 26 was identical in every respect with that of the L-antipode derived from reaction of NeuSAc, first with acidic methanol and then with benzoyl chloride under the influence of DMAP. The infrared and mass spectra, as well as the chromatographic characteristics of the two materials, were identical. 

To a solution of 2.00 grams (0.00454 mole) of K[Cr(HO-A)2] in 200 ml. of water, cooled to 6° C., were added 12.8 grams of benzoyl chloride and a solution of 2.00 grams of potassium bicarbonate in 20 ml. of water. This mixture was stirred in an ice bath for 30 minutes and then for an additional hour out of the bath. The solution was acidified with concentrated nitric acid, and then filtered to remove benzoic acid. From the filtrate only starting material (infrared spectrum ) and its decomposition products could be isolated. 

FIGURE 2.56 The infrared spectrum of benzoyl chloride (neat liquid, KBr plates). 

Another phenomenon which adds to the complexity of an infrared spectrum is known as Fermi resonance. Fermi resonance is the result of an interaction of a fundamental vibration with an overtone or combination band which has nearly the same frequency. It is a consequence of quantum mechanical mixing. The phenomenon was explained by the Italian-American physicist Enrico Fermi. The result is the appearance of two bands equally displaced on both sides of the predicted interacting frequencies. The intensities of the two bands resulting from this interaction are not ordinarily the same. An example of Fermi resonance is the doublet centered at 1,765 cm for benzoyl chloride. 

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