Structural characteristics of formic acid dodecamers,

Exploratory ab initio and density functional theory calculations are used to locate low-energy minima on the potential energy surface of the formic acid dodecamer (HCOOH)₁₂. The lowest-energy structures are folded rings, some with a crown-like structure, stabilized by π–π interactions. There are many more C–HO interactions than in smaller oligomers. Unlike in tetramers and pentamers, ring structures with one or more monomers in the E (cis) conformation are not significant for dodecamers.