Diamond Crystal Lattice for Representing n -Pentane Conformers (Finding syn-Pentane Interactions): An Auxiliary Tool for Students

Natta projections can make it challenging to observe the syn-pentane interaction. Presenting two partial, predefined conformers of n -butane using the sawhorse formula for n -pentane can be confusing and may lead to errors in identifying specific n -pentane conformers. To address this challenge, undergraduate students were taught how to represent hypothetical conformers of n -pentane using the diamond crystal lattice (DCL) system. Students were provided with rules for representing a predetermined hypothetical conformer of n -pentane in DCL. Since DCL utilizes imaginary chair conformations of the carbon skeleton from cyclohexane, students can apply the stereochemical properties of the chair conformation of cyclohexane alongside symmetrical operations they have previously mastered when comparing two hypothetical conformers of n -pentane. During the theoretical exercises, the lecturer first demonstrated the rules for applying the diamond crystal lattice to represent conformers. After this demonstration, students individually presented their conformers of n -pentane using preprinted DCLs and compared them with molecular models. This was followed by a joint discussion that expanded on the application of DCL to cyclic systems. A short test was conducted comparing a group of students familiar with the DCL system to a control group. The results indicated that the DCL system enhances the likelihood of identifying the syn-pentane interaction and discovering stable conformations.