Azobenzene question?

Question

In Azobenzene, what does "Azo" means?

Answer 1

azobenzne is the core molecule of the azobenzene class of compounds. The azo refers to the two benzene rings being linked by a N=N bond.

Answer 2

Azobenzene is a chemical compound composed of two phenyl rings linked by a N=N double bond. The term 'azobenzene' or simply 'azo' is often used to refer to a wide class of molecules that share the core azobenzene structure, with different chemical functional groups extending from the phenyl rings (technically, these compounds should be referred to as 'diazenes'). The azobenzene compounds strongly absorb light, and were historically used as dyes in a variety of industries. One of the most intriguing properties of azos is photoisomerization behavior between two isomers, the trans- and cis- configurations. The two isomers can be switched with particular wavelengths of light: ultraviolet light, which corresponds to the energy gap of the π-π* (S2 state) transition, for trans-to-cis conversion, and blue light, which is equivalent to that of the n-π* (S1 state) transition, for cis-to-trans isomerization. For a variety of reasons, the cis- isomer is less stable than the trans (for instance, it has a distorted configuration and breaks the aromaticity of the trans configuation). Thus, cis-azobenzene will thermally relax back to the trans via cis-to-trans isomerization. The trans isomer is more stable by approximately 50 kJ/mol, and the barrier to photo-isomerization is on the order of 200 kJ/mol. Azobenzene molecules can be incorporated into polymer matrices in order to stabilize them. It is also interesting to note that the rigid rod-like structure of azo molecules makes them behaves as liquid-crystal mesogens in many materials.