Carbonyl compounds physical properties

Electronically excited states of organic molecules, acid-base properties of, 12,131 Energetic tritium and carbon atoms, reactions of, with organic compounds, 2, 201 Enolisation of simple carbonyl compounds and related reactions, 18,1 Entropies of activation and mechanisms of reactions in solution, 1,1 Enzymatic catalysis, physical organic model systems and the problem of, 11, 1 Enzyme action, catalysis of micelles, membranes and other aqueous aggregates as models of, 17. 435... 

During occupational exposure, respiratory absorption of soluble and insoluble nickel compounds is the major route of entry, with gastrointestinal absorption secondary (WHO 1991). Inhalation exposure studies of nickel in humans and test animals show that nickel localizes in the lungs, with much lower levels in liver and kidneys (USPHS 1993). About half the inhaled nickel is deposited on bronchial mucosa and swept upward in mucous to be swallowed about 25% of the inhaled nickel is deposited in the pulmonary parenchyma (NAS 1975). The relative amount of inhaled nickel absorbed from the pulmonary tract is dependent on the chemical and physical properties of the nickel compound (USEPA 1986). Pulmonary absorption into the blood is greatest for nickel carbonyl vapor about half the inhaled amount is absorbed (USEPA 1980). Nickel in particulate matter is absorbed from the pulmonary tract to a lesser degree than nickel carbonyl however, smaller particles are absorbed more readily than larger ones (USEPA 1980). Large nickel particles (>2 pm in diameter) are deposited in the upper respiratory tract smaller particles tend to enter the lower respiratory tract. In humans, 35% of the inhaled nickel is absorbed into the blood from the respiratory tract the remainder is either swallowed or expectorated. Soluble nickel compounds... 

The structure of the labile intermediate compound "Y" is uncertain. On the basis of its physical properties and chemical behaviour (which cannot be detailed here), possible formulations that were originally (485) considered included a six-membered bridged carbonyl-structure, as well as seven- or five-membered rings. The Italian group of workers (536) favoured the seven-membered ring-structure (CXVI) for the intermediate "Y", and 5-phenylguanamine structures (CXXI) for the final stable products. 

The physical and chemical properties of the X -phosphorins 118 and 120 are comparable to those of phosphonium ylids which are resonance-stabilized by such electron-pulling groups as carbonyl or nitrile substituents Thus they can be viewed as cyclic resonance-stabilized phosphonium ylids 118 b, c, d). As expected, they do not react with carbonyl compounds giving the Wittig olefin products. However, they do react with dilute aqueous acids to form the protonated salts. Similarly, they are attacked at the C-2 or C-4 positions by alkyl-, acyl- or diazo-nium-ions Heating with water results in hydrolytic P—C cleavage, phosphine oxide and the hydrocarbon being formed. 

The polarity of the carbonyl group is manifest in the physical properties of carbonyl compounds. Boiling points for the lower members of a series of aldehydes and ketones are 50-80° higher than for hydrocarbons of the same molecular weight this may be seen by comparing the data of Table 16-2 (physical... 

Organic constituents that may be found in ppb levels in WP/F smoke include methane, ethylene, carbonyl sulfide, acetylene, 1,4-dicyanobenzene, 1,3-dicyanobenzene, 1,2-dicyanobenzene, acetonitrile, and acrylonitrile (Tolle et al. 1988). Since white phosphorus contains boron, silicon, calcium, aluminum, iron, and arsenic in excess of 10 ppm as impurities (Berkowitz et al. 1981), WP/F smoke also contains these elements and possibly their oxidation products. The physical properties of a few major compounds that may be important for determining the fate of WP/F smoke in the environment are given in Table 3-3. 

Structure and Classification of Alcohols 425 10-3 Nomenclature of Alcohols and Phenols 427 10-4 Physical Properties of Alcohols 430 10-5 Commercially Important Alcohols 433 10-6 Acidity of Alcohols and Phenols 435 10-7 Synthesis of Alcohols Introduction and Review 438 Summary Previous Alcohol Syntheses 438 10-8 Organometallic Reagents for Alcohol Synthesis 440 10-9 Addition of Organometallic Reagents to Carbonyl Compounds 443... 

There are two distinct types of electronic excitation which occur in carbonyl compounds and which produce excited states with quite different physical and chemical properties. In aliphatic ketones and aldehydes, the weak absorption with /lmax at 280—300 nm represents an transition, in which a nonbonding... 

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