Gauche can refer to:
Gauche is an R7RS Scheme implementation. It is designed for scripting in a production environment. It is intended to allow programmers and system administrators to write scripts in support of daily operations. Quick startup, built-in system interface, native multilingual support are some of its key design goals.
Gauche is free software under the BSD License. It is primarily developed by Shiro Kawai.
The term "gauche" refers to conformational isomers (conformers) where two vicinal groups are separated by a 60° torsion angle. IUPAC defines groups as gauche if they have a "synclinal alignment of groups attached to adjacent atoms".
In stereochemistry, gauche interactions hinder bond rotation. For example, sighting along the C2–C3 bond in staggered butane, there are two possible relative potential energies. The two methyl groups can be in an anti-bonding relationship, or offset at sixty degree dihedral angles. In the latter configuration, the two methyls are said to be in a gauche relationship, and the relative potential energy of each methyl-methyl gauche interaction is 0.9 kilocalories per mole (4 kJ/mol). In general a gauche rotamer is less stable than an anti-rotamer.
The Gauche effect characterizes any gauche rotamer which is more stable than the anti rotamer. This effect is present in 1,2-difluoroethane (H2FCCFH2) for which the gauche conformation is more stable by 2.4 to 3.4 kJ/mole in the gas phase. Another example is 1,2-dimethoxyethane.
We were lovers in the past life,
I can see it in your brown eyes.
Baby you were in my lies,
And I was trouble.
I can't believe
Time after time
Time after time