Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States.
J Am Chem Soc. 2021 Oct 13;143(40):16653-16662. doi: 10.1021/jacs.1c07509. Epub 2021 Oct 4.
The surface activity of ten atmospherically relevant α-pinene-derived dimers having varying terminal functional groups and backbone stereochemistry is reported. We find ∼10% differences in surface activity between diastereomers of the same dimer, demonstrating that surface activity depends upon backbone stereochemistry. Octanol-water () and octanol-ammonium sulfate partitioning coefficient () measurements of our standards align well with the surface activity measurements, with the more surface-active dimers exhibiting increased hydrophobicity. Our findings establish a link between molecular chirality and cloud activation potential of secondary organic aerosol particles. Given the diurnal variations in enantiomeric excess of biogenic emissions, possible contributions of such a link to biosphere:atmosphere feedbacks as well as aerosol particle viscosity and phase separation are discussed.
报告了十种具有不同末端官能团和主链立体化学的大气相关 α-蒎烯衍生二聚体的表面活性。我们发现，相同二聚体的非对映异构体之间的表面活性存在约 10%的差异，这表明表面活性取决于主链立体化学。我们的标准品的辛醇-水（）和辛醇-硫酸铵分配系数（）测量与表面活性测量吻合良好，更具表面活性的二聚体表现出更高的疏水性。我们的发现建立了分子手性与二次有机气溶胶颗粒云激活潜力之间的联系。鉴于生物源排放的对映体过量的日变化，这种联系可能对生物圈-大气反馈以及气溶胶粒子粘度和相分离产生影响。
