What Are the Characteristic Reactions of Haloalkanes

A nucleophile (nucleus-loving reagent) is any reagent that donates an unshared pair of electrons to form a new covalent bond. Nucleophilic substitution is any reaction in which one nucleophile is substituted for another. In the following general equations, Nu is the nucleophile, X is the leaving group, and substitution takes place on an hybridized carbon atom  

Halide ions are among the best and most important leaving groups. Recall from Section 5.7 that nucleophilic substitution occurs in the alkylation of an acetylide ion  

Nucleophile An atom or a group of atoms that donates a pair of electrons to another atom or group of atoms to form a new covalent bond. 

The concern about CFCs prompted two conventions, one in Vienna in 1985 and one in Montreal in 1987, held by the United Nations Environmental Program. The 1987 meeting produced the Montreal Protocol, which set limits on the production and use of ozone-depleting CFCs and urged the complete phaseout of their production by the year 1996. Only two members of the UN have failed to ratify the protocol in its original form. 

Rowland, Molina, and Paul Crutzen (a Dutch chemist at the Max Planck Institute for Chemistry in Germany) were awarded the 1995 Nobel Prize for chemistry. As the Royal Swedish Academy of Sciences noted in awarding the prize, By explaining the chemical mechanisms that affect the thickness of the ozone layer, these three researchers have contributed to our salvation from a global environmental problem that could have catastrophic consequences.  

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