[{"from": "human", "value": "Provide a description of this molecule. [C][Branch1][S][C][Branch1][=Branch2][C][Branch1][C][F][Branch1][C][F][F][Branch1][C][F][F][Branch1][=Branch2][C][Branch1][C][F][Branch1][C][F][F][Branch1][C][F][F]"}, {"from": "gpt", "value": "The molecule is a fluorocarbon that is butane in which all of the hydrogens have been replaced by fluorines. Microbubbles of preflubutane are used in the ultrasound contrast agent BR14. It has a role as an ultrasound contrast agent. It is a gas molecular entity, a fluorocarbon and a fluoroalkane."}]