polyhalogenated compounds

(noun)

Compounds with multiple halogen atoms.

Related Terms

Examples of polyhalogenated compounds in the following topics:

  • Halogen Compounds

    • Halogens are highly reactive and can form hydrogen halides, metal halides, organic halides, interhalogens, and polyhalogenated compounds.
    • These include highly ionic compounds such as sodium chloride, monomeric covalent compounds such as uranium hexafluoride, and polymeric covalent compounds such as palladium chloride.
    • Many synthetic organic compounds, such as plastic polymers, as well as a few natural organic compounds, contain halogen atoms; these are known as halogenated compounds, or organic halides.
    • Polyhalogenated compounds are industrially created compounds substituted with multiple halogens.
    • Polyhalogenated compounds include the much publicized PCBs, PBDEs, and PFCs, as well as numerous other compounds.

  • Halogen Uses

    • Although halogens and their compounds can be toxic, some are essential for the human body's functioning and are used in everyday products.
    • Polyhalogenated compounds (PHCs) are of particular interest and importance because halogens are generally highly reactive and bioaccumulate in humans.
    • Halogens are also part of a superset that includes many toxic and carcinogenic industrial chemicals -- PBDEs, PCBs, dioxins (PCDDs), and PFCs are all polyhalogenated compounds.
    • DDT (dichlorodiphenyltrichloroethane) is a polyhalogenated pesticide that was banned in the United States in 1972 because of the potential harmful effects on human health.

  • Five-Membered Rings

    • It is the "aromatic" unsaturated compounds, furan, thiophene and pyrrole that require our attention.
    • Whereas simple cycloalkenes generally give addition reactions, aromatic compounds tend to react by substitution.
    • All these aromatic heterocycles react vigorously with chlorine and bromine, often forming polyhalogenated products together with polymers.
    • Such functions are known to undergo acid-catalyzed hydrolysis to carbonyl compounds and alcohols or amines.
    • As noted in the upper example, furans may indeed be hydrolyzed to 1,4-dicarbonyl compounds, but pyrroles and thiophenes behave differently.

  • Simple and Compound Sentences

  • Types of Leaf Forms

    • Leaves may be simple or compound .
    • In a pinnately compound leaf, the middle vein is called the midrib.
    • Leaves may be simple or compound.
    • In compound leaves, the lamina is separated into leaflets.
    • Compound leaves may be palmate or pinnate.

  • Naming Organic Compounds

    • The increasingly large number of organic compounds identified with each passing day, together with the fact that many of these compounds are isomers of other compounds, requires that a systematic nomenclature system be developed.
    • Just as each distinct compound has a unique molecular structure which can be designated by a structural formula, each compound must be given a characteristic and unique name.
    • As organic chemistry grew and developed, many compounds were given trivial names, which are now commonly used and recognized.
    • Second, it should identify and locate any functional groups present in the compound.
    • A suffix or other element(s) designating functional groups that may be present in the compound.

  • Naming Molecular Compounds

    • Molecular compounds are named using a systematic approach of prefixes to indicate the number of each element present in the compound.
    • Molecular compounds are made when two or more elements share electrons in a covalent bond to connect the elements.
    • Typically, non-metals tend to share electrons, make covalent bonds, and thus, form molecular compounds.
    • Remove the ending of the second element, and add "ide" just like in ionic compounds.
    • This video explains how to use a chemical name to write the formula for that compound.

  • Calculating Values for Different Durations of Compounding Periods

    • Since interest generally compounds, it is not as simple as multiplying 1% by 12 (1% compounded each month).
    • This atom will discuss how to handle different compounding periods.
    • The EAR can be found through the formula in where i is the nominal interest rate and n is the number of times the interest compounds per year (for continuous compounding, see ).
    • The equation follows the same logic as the standard formula. r/n is simply the nominal interest per compounding period, and nt represents the total number of compounding periods.
    • The effective annual rate for interest that compounds more than once per year.

  • Properties of Aromatic Compounds

    • Aromatic compounds are ring structures with delocalized $\pi$ electron density that imparts unusual stability.
    • Aromatic compounds are generally nonpolar and immiscible with water.
    • As they are often unreactive, they are useful as solvents for other nonpolar compounds.
    • Due to their high ratio of carbon to hydrogen, aromatic compounds are characterized by a sooty yellow flame.
    • Aromatic compounds are produced from a variety of sources, including petroleum and coal tar.

  • Percent Composition of Compounds

    • The percent composition (by mass) of a compound can be calculated by dividing the mass of each element by the total mass of the compound.
    • Another convenient way to describe atomic composition is to examine the percent composition of a compound by mass.
    • Percent composition is calculated from a molecular formula by dividing the mass of a single element in one mole of a compound by the mass of one mole of the entire compound.
    • This video shows how to calculate the percent composition of a compound.
    • Translate between a molecular formula of a compound and its percent composition by mass