cyanogroep

The cyanogroep, also known as the cyano group, is a functional group in organic chemistry consisting of a carbon triple-bonded to a nitrogen, written as -C≡N. When attached to a carbon skeleton, it forms a nitrile, with the general formula R-CN for an organic substituent R.

The cyano group is linear and the carbon atom is sp-hybridized, giving a nearly 180-degree arrangement around the group. It is moderately polar, with the carbon bearing a partial positive charge and the nitrogen a partial negative charge. This polarity withdraws electron density from neighboring carbons, influencing acidity and reactivity of adjacent substituents. The cyano group is relatively stable under many conditions, but can undergo hydrolysis to give carboxylic acids under acidic or basic conditions, and it can participate in a variety of nucleophilic additions and reductions.

Nomenclature commonly treats the cyano group as a substituent, named as -cyano, or as the nitrile functional group in the parent compound, yielding names such as benzonitrile or acetonitrile. Common examples include acetonitrile (CH3CN) and benzonitrile (C6H5CN), both widely used as solvents and chemical intermediates.

Synthesis routes for nitriles include dehydration of amides, conversion of aldehydes or ketones via oximes followed by dehydration, and substitution reactions where a leaving group is replaced by cyanide (for example, using NaCN or KCN). Nitriles occur in many natural products and are key intermediates in pharmaceuticals, agrochemicals, and polymers. Polyacrylonitrile is a prominent example in the field of synthetic fibers and carbon materials.

Safety considerations: nitriles can be toxic and may release cyanide under certain conditions, so proper handling, ventilation, and waste management are essential.