A round dance of acetaldehyde molecular ensembles on Rh(111) surface; formation and decomposition of various paraldehyde conformers

•The single molecule itself may have at least two possibilities for adsorption on Rh(111) surfaces, namely η1−(O)−CH3CHOa and η2−(O,C)−CH3CHOa adsorption forms are considered.•η1−(O)−CH3CHOa aldehyde decomposes, η1−(O)−CH3CHOa molecules reacting with each other can form oligomers or even longer polymers.•The stable type I (eee), type II (aee), as well as the “on surface born” type IV (aaa) paraldehyde conformers are presented and discussed.•During inversion on the surface, paraldehyde and monomer acetaldehyde lives the surface.