Osmium carbonyl halides


A unique hydrogen bonding arrangement shown m Figure 19 2 contributes to these attractive forces The hydroxyl group of one carboxylic acid molecule acts as a proton donor toward the carbonyl oxygen of a second In a reciprocal fashion the hydroxyl proton of the second carboxyl function interacts with the carbonyl oxygen of the first The result is that the two carboxylic acid molecules are held together by two hydrogen bonds So efficient is this hydrogen bonding that some carboxylic acids exist as hydrogen bonded dimers even m the gas phase In the pure liquid a mixture of hydrogen bonded dimers and higher aggregates is present  [c.794]

Peracids convert ketones into esters in high yield. The peracid adds to the carbonyl group, and one carbon substituent migrates to the positively polarized peroxy oxygen (C.H. Hassall, 1957 W.D. Emmons, 1955 B. Plesnicar, 1978). The migration tendency follows the order f-alkyl > s-alkyl > benzyl > phenyl > /i-alkyl > methyl, if no steric effects are counteracting. This Baeyer-Villiger oxidation is particularly useful with bridged polycyclic ketones. From these compounds lactones are formed, in which the new ester bond replaces a C—C single bond with complete retention of configuration. Thus, upon hydrolysis of the lactone, a cis-disubstituted ring results (J. Meinwald, 1960 R.R. Sauers, 1961). Aldehydes are converted into sensitive formate esters by selenous peracid (F. Nakatsubo, 1970). Ketones may also be converted into amides or lactams via the similar Beckmann rearrangement of ketoximes (W.Z. Heldt, 1960).  [c.136]

The carbon monoxide component of the oxo reactant gases presents the most immediate human health hazard. The OSHA exposure limit for carbon monoxide is 35 ppm (40 mg/m ) and a ceiling of 200 ppm (229 mg/m ). Carbon monoxide iatermpts the body s normal oxygen metaboHc cycle by reacting preferentially with the hemoglobin ia the blood, effectively starving the body of requited oxygen. The cherry red iron carbonyl heme complex formed is much brighter than the corresponding oxygen complex so that someone overcome with carbon monoxide presents a characteristic flushed appearance and bright red Hps. Conventional first-aid procedures requite immediate removal from the source. Appropriate fresh air equipment should be worn ia the presence of high concentrations of the gas. Artificial respitation is appHed if the person overcome has stopped breathing and fresh oxygen is appHed to faciHtate the release of CO. After initial first aid, medical attention must be sought.  [c.473]

A unique hydrogen-bonding aiiangement, shown in Figure 19.2, contributes to these attractive forces. The hydroxyl group of one carboxylic acid molecule acts as a proton donor toward the carbonyl oxygen of a second. In a reciprocal fashion, the hydroxyl proton of the second car boxyl function interacts with the car bonyl oxygen of the first. The result is that the two carboxylic acid molecules are held together by two hydrogen bonds. So efficient is this hydrogen bonding that some carboxylic acids exist as hydrogen-bonded dimers even in the gas phase. In the pure liquid a mixture of hydrogen-bonded dimers and higher aggregates is present.  [c.794]


See pages that mention the term Osmium carbonyl halides : [c.163]   
Chemistry of the elements (1998) -- [ c.1108 ]