kaksifenyylirenkaiden

Kaksifenyylirenkaiden is a Finnish term that translates to "biphenyl rings" in English. It refers to organic molecules containing two phenyl rings. A phenyl ring is a cyclic molecule with the chemical formula C6H5. When two such rings are connected, they form a biphenyl structure.

Biphenyls are a class of aromatic hydrocarbons. The simplest biphenyl has a direct single bond connecting the two phenyl rings. However, substituents can be present on either or both rings, leading to a vast array of substituted biphenyl derivatives. These derivatives can have significantly different physical and chemical properties compared to the parent biphenyl molecule.

The biphenyl structure is planar in the gas phase but can deviate from planarity in the solid state due to steric hindrance between substituents on adjacent rings. This non-planarity can influence the molecule's interactions and reactivity.

Kaksifenyylirenkaiden, or biphenyls, find applications in various fields. They are used as intermediates in the synthesis of other organic compounds, including dyes, pharmaceuticals, and polymers. Some biphenyl derivatives are known for their thermal stability and are employed as heat transfer fluids or as components in liquid crystals used in display technology. Polychlorinated biphenyls (PCBs), a specific class of biphenyls, were widely used as coolants and insulating fluids but are now recognized as persistent organic pollutants and their production and use are heavily restricted due to environmental and health concerns.