Organyl group

In organosilicon and polymer chemistry, a silicone or polysiloxane is a polymer composed of repeating units of siloxane (−O−R₂Si−O−SiR₂−, where "R" stands for an organic group). They are typically colorless oils or rubber-like substances. Silicones are used in sealants, adhesives, lubricants, medicine, cooking utensils, thermal insulation, and electrical insulation. Some common forms include silicone oil, grease, rubber, resin, and caulk.

Silicone is often confused with one of its constituent elements, silicon, but they are distinct substances. Silicon is a pure chemical element, a metalloid, which forms a dark-grey semiconducting crystalline solid. In its crystalline form it is used to make integrated circuits ("electronic chips") and solar cells. In contrast, silicone is formed by the polymerization of the siloxane molecule, which itself is made up of a variable combination of carbon, hydrogen, oxygen and silicon atoms. Depending on the chemical makeup and polymer structure of a particular silicone product, it can possess a variety of physical properties, ranging from an oily liquid to a rubbery resin.

In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group (−C(=O)−OH) attached to an R-group. The general formula of a carboxylic acid is often written as R−COOH or R−CO₂H, sometimes as R−C(O)OH with R referring to an organyl group (e.g., alkyl, alkenyl, aryl), or hydrogen, or other groups. Carboxylic acids occur widely. Important examples include the amino acids and fatty acids. Deprotonation of a carboxylic acid gives a carboxylate anion.

In chemistry, an acyl group is a moiety derived by the removal of one or more hydroxyl groups from an oxoacid, including inorganic acids. It contains a double-bonded oxygen atom and an organyl group (R−C=O) or hydrogen in the case of formyl group (H−C=O). In organic chemistry, the acyl group (IUPAC name alkanoyl if the organyl group is alkyl) is usually derived from a carboxylic acid, in which case it has the formula R−C(=O)−, where R represents an organyl group or hydrogen. Although the term is almost always applied to organic compounds, acyl groups can in principle be derived from other types of acids such as sulfonic acids and phosphonic acids. In the most common arrangement, acyl groups are attached to a larger molecular fragment, in which case the carbon and oxygen atoms are linked by a double bond.

In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a compound with the general formula R−C(=O)−NR′R″, where R, R', and R″ represent any group, typically organyl groups or hydrogen atoms. The amide group is called a peptide bond when it is part of the main chain of a protein, and an isopeptide bond when it occurs in a side chain, as in asparagine and glutamine. It can be viewed as a derivative of a carboxylic acid (R−C(=O)−OH) with the hydroxyl group (−OH) replaced by an amino group (−NR′R″); or, equivalently, an acyl (alkanoyl) group (R−C(=O)−) joined to an amino group.

Common amides are formamide (H−C(=O)−NH₂), acetamide (H₃C−C(=O)−NH₂), benzamide (C₆H₅−C(=O)−NH₂), and dimethylformamide (H−C(=O)−N(−CH₃)₂).

In organosulfur chemistry, a sulfonate is a salt, anion or ester of a sulfonic acid. Its formula is R−S(=O)₂−O, containing the functional group −S(=O)₂−O, where R is typically an organyl group, amino group or a halogen atom. Sulfonates are the conjugate bases of sulfonic acids. Sulfonates are generally stable in water, non-oxidizing, and colorless. Many useful compounds and even some biochemicals feature sulfonates. Most detergents and surfactants are sulfonates. These include alkylbenzene sulfonates, 𝛼-Olefin sulfonates, and paraffin sulfonates.

A silicone or polysiloxane is a polymer composed of repeating units of siloxane (−O−SiR₂−O−SiR₂−, where "R" stands for an organic group). They are typically colorless oils or rubber-like substances. Silicones are used in sealants, adhesives, lubricants, medicine, cooking utensils, thermal insulation, and electrical insulation. Some common forms include silicone oil, grease, rubber, resin, and caulk. From the chemical perspective, silicones are unusual because they feature inorganic backbones, composed only of Si and O, but they have properties of organic polymers. They represent one of the main applications of organosilicon chemistry.

Silicone is often confused with one of its constituent elements, silicon. Silicon, a hard gray solid, is used to make integrated circuits ("electronic chips") and solar cells. In contrast, silicones, which tend to be electrical insulators, are often colorless oils or rubbery resin.