Influence of the chemical environment on metolachlor conformations

Metolachlor exists in multiple, different stable conformations in solution. Assignment of the NMR frequencies to chemical structure is a prerequisite to understanding the behavior of individual conformations. H-1 NMR experime nts of metolachlor in different chemical environments identified the labile sites of metolachlor and environments that influence conformational/config urational changes. Within very specific chemical environments, metolachlor atropisomers aS,12S (aR,12R) and aR,12S (aS,12R) freely interchange, and co nsequently, the multiple conformations also interchange. The changes in che mical environments, which most alter the conformations and molecular dynami cs of metolachlor, identify the most critical components affecting its envi ronmental fate. These results enable a structural interpretation of conform ational changes that can influence the environmental fate of metolachlor.