Physical properties organic compounds

G. J. Janz, in Thermodymic Properties of Organic Compounds, Physical Chemistry Vol. VI. Academic Press, New York, 1967. 

Compounds, it is now in electronic form as Properties of Organic Compounds. The database includes about 30,000 compounds physical properties and spectral data (mass, infrared, Raman, ultraviolet, and NMR) are covered. It is offered as CDROM [www.crcpress.com] and by Web access [www.chemnetbase.com]. 

PHYSICAL PROPERTIES Appearance and odor vary depending upon the specify organic arsenic compound. Physical properties of specific compounds are provided for illustrative purposes, (arsenic diethyl) liquid or oil BP (185-190 C, 365-374°F) DN (about 1.0 g/mL) SG (about 1.0). (arsenic dimethyl) colorless to yellow oily liquid MP (-6°C, 21.2°F) BP (186°C, 366.8°F) DN (1.15 g/mL) SG (1.15). (arsenoacetic acid) minute yellow needles does not melt below 260 C (500°F) decomposition begins at about 205°C (401 F) readily soluble in pyridine, dilute sodium carbon-ate and dilute sodium hydroxide solutions insoluble in water and common organic solvents. 

Another basic subdivision of discipline of chemistry is physical chemistry. It is to study the physical manifestations of chemical compounds physical properties, interactions of compounds with electromagnetic waves (spectroscopy), and how they react each other, and so on. Therefore, there are physical organic chemistry, which focuses on the organic compounds, and physical inorganic chemistry, if you want to subdivide it. Understanding the physical manifestations of chemicals is based on the principles and theories of physics. Hence physical chemistry is on the borderline between chemistry and physics in a way. If the phasis of an inquiry is placed more on physics, it is called chemical physics. ... 

Location of the compound within a class (or homologous series) of compounds. Reference to the literature or to tables of the physical properties of the class (or classes) of organic compounds to which the substance has been assigned, will generally locate a number of compounds which boil or melt within 6° of the value observed for the unknown. If other physical properties e.g., refractive index and density for a hquid) are available, these will assist in deciding whether the unknown is identical with one of the known compounds. In general, however, it is more convenient in practice to prepare one, but preferably two, crystalhne derivatives of the substance. 

Separations based upon differences in the physical properties of the components. When procedures (1) or (2) are unsatisfactory for the separation of a mixture of organic compounds, purely physical methods may be employed. Thus a mixture of volatile liquids may be fractionally distilled (compare Sections 11,15 and 11,17) the degree of separation may be determined by the range of boiling points and/or the refractive indices and densities of the different fractions that are collected. A mixture of non-volatile sohds may frequently be separated by making use of the differences in solubilities in inert solvents the separation is usually controlled by m.p. determinations. Sometimes one of the components of the mixture is volatile and can be separated by sublimation (see Section 11,45). 

Appendix 1 lists selected physical properties for repre sentative alkanes as well as members of other families of organic compounds... 

TABLE B Selected Physical Properties of Representative Organic Halogen Compounds... 

References D. D. Wagman, et ah, The NBS Tables of Chemical Thermodynamic Properties, in J. Phys. Chem. Ref. Data, 11 2,1982 M. W. Chase, et ah, JANAF Thermochemical Tables, 3rd ed., American Chemical Society and the American Institute of Physics, 1986 (supplements to JANAF appear in J. Phys. Chem. Ref. Data) Thermodynamic Research Center, TRC Thermodynamic Tables, Texas A M University, College Station, Texas I. Barin and O. Knacke, Thermochemical Properties of Inorganic Substances, Springer-Verlag, Berlin, 1973 J. B. Pedley, R. D. Naylor, and S. P. Kirby, Thermochemical Data of Organic Compounds, 2nd ed.. Chapman and Hall, London, 1986 V. Majer and V. Svoboda, Enthalpies of Vaporization of Organic Compounds, International Union of Pure and Applied Chemistry, Chemical Data Series No. 32, Blackwell, Oxford, 1985. 

Physical Properties. Furfural [98-01-1] (2-furancarboxaldehyde), when freshly distilled, is a colorless Hquid with a pungent, aromatic odor reminiscent of almonds. It darkens appreciably on exposure to air or on extended storage. Furfural is miscible with most of the common organic solvents, but only slightly miscible with saturated aHphatic hydrocarbons. Inorganic compounds, generally, are quite insoluble in furfural. 

Physical Properties Electrical. Electrical properties have been the main focus of study of organic semiconductors, and conductivity studies on organic materials have led to the development of materials with extremely low resistivities and large anisotropies. A discussion of conductivity behaviors for various classes of compounds follows. 

Substitution of fluorine for hydrogen in an organic compound has a profound influence on the compound s chemical and physical properties. Several factors that are characteristic of fluorine and that underHe the observed effects are the large electronegativity of fluorine, its small size, the low degree of polarizabiHty of the carbon—fluorine bond and the weak intermolecular forces. These effects are illustrated by the comparisons of properties of fluorocarbons to chlorocarbons and hydrocarbons in Tables 1 and 2. 

In general, the peilluoioepoxides have boiling points that are quite similar to those of the corresponding fluoroalkenes. They can be distinguished easily from the olefins by it spectroscopy, specifically by the lack of olefinic absorption and the presence of a characteristic band between 1440 and 1550 cm . The nmr spectra of most of the epoxides have been recorded. Litde physical property data concerning these compounds have been pubhshed (Table 1). The stmcture of HFPO by electron diffraction (13) as well as its solubility and heats of solution in some organic solvents have been measured (14,15). 

The physical properties of the principal constituents of natural gas are Hsted in Table 5. These gases are odorless, but for safety reasons, natural gas is odorized before distribution to provide a distinct odor to warn users of possible gas leaks in equipment. Sulfur-containing compounds such as organic mercaptans, aUphatic sulfides, and cycHc sulfur compounds are effective odorants at low concentrations and are added to natural gas at levels ranging from 4 to 24mg/m. ... 

Dibasic Acid Esters. Dibasic acid esters (diesters) are prepared by the reaction of a dibasic acid with an alcohol that contains one reactive hydroxyl group (see Esters, organic). The backbone of the stmcture is formed by the acid. The alcohol radicals are joined to the ends of the acid. The physical properties of the final product can be varied by using different alcohols or acids. Compounds that are typically used are adipic, azelaic, and sebacic acids and 2-ethyIhexyl, 3,5,5-trimethyIhexyl, isodecyl, and tridecyl alcohols. 

Beilstein Handbook of Organic Chemistry. This reference (55) is one of the most significant collections of data in organic chemistry. The physical and chemical properties of organic compounds are tabulated in more than 500 fields. Most of these fields are searchable, and a sample of the record for chlorobenzene [108-90-7] is shown in Table 3. 

OtherD t b ses. Available from different vendors (Table 8). For example, the researcher can obtain physical properties by usiag the Merck Index Online or the Dictionary of Organic Compounds available by Chapman and Hall Chemical Database. In DIALOG, numeric databases are collected under the name of CHEMPROP. 

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