# Why can't this be another structural isomer of ethanol?

Are the two structures depicting the same molecule? Why? Why not?

• If ethanol was flat, it would make sense, but it isn't. – Mithoron Mar 3 '16 at 12:29
• They can be stereo isomers instead. See upload.wikimedia.org/wikipedia/commons/thumb/1/11/… for 3d structure of ethanol. – another 'Homo sapien' Mar 3 '16 at 12:33
• If ethanol was static, this would be true, but it isn't. – jerepierre Mar 3 '16 at 16:12
• There could be atropoisomers if rotation was blocked but it would need very low temperature to try to separate what is normally rotamers of ethanol. – Mithoron Mar 3 '16 at 22:17

Try to imagine it in a 3D fashion. You can look it at molcalc.org. The molecule rotates around the $\ce{C-C}$ bond converting one structure into the other. These rotations are very fast.