Chemistry in Nanometer Particles: Unique breeding sites for oligomers?

了解对流层中新粒子的形成及其随后的增长，对我们预测大气成分和全球气候变化的能力具有至关重要的影响。纳米粒子通过成核形成后，其生长受有机分子的控制。今天，生长纳米颗粒所需的极低挥发性化合物的形成仅基于气相化学进行讨论。然而，颗粒胚胎本身提供了一个独特的纳米级化学环境，影响新形成的凝聚相内的化学反应。较小颗粒的一个物理化学特性是内部压力(拉普拉斯压力)增加。由于形成键的化学反应(例如齐聚反应)在较高的压力下更受欢迎，因此这种反应在最小的颗粒中变得重要，因此正是那些需要生长的物质的颗粒不会因凝聚而丢失。因此，依赖于颗粒大小的化学反应可以在大气气溶胶的生命周期中发挥决定性作用，在颗粒胚胎的最初形成和它们成长到其生存概率更大且最终可能形成云滴的尺寸之间架起一座桥梁。虽然是从大气化学中获得的关于颗粒大小相关化学的知识，但也将有助于更好地理解有机纳米反应器中的平衡反应，这是合成有机化学中的一个新兴研究领域，在非常一般的意义上也可能为理解生命的起源做出贡献。

Understanding new particle formation and their subsequent growth in the troposphere has a critical impact on our ability to predict atmospheric composition and global climate change. After nanometer particles are formed by nucleation, their growth is governed by organic molecules. Today the formation of the extremely low volatile compounds needed to grow nanometer particles is discussed exclusively based on gas phase chemistry. However, the particle embryos itself offer a unique nanoscale chemical environment influencing chemical reactions within the newly formed condensed phase. One physicochemical peculiarity of smaller particles is the increasing internal pressure (Laplace pressure). Since bond-forming chemical reactions (e.g. oligomerization) are favored at higher pressures, such reactions gain importance in the smallest particles, so exactly those particles that need matter for growth to not get lost by coagulation. Therefore, particle size-dependent chemical reactions can play a decisive role in the lifecycle of atmospheric aerosols, bridging the gap between the initial formation of particle embryos and their growth into sizes where their survival probability is larger and on which cloud droplets may eventually form. Although motivated from atmospheric chemistry, the acquired knowledge about particle size-dependent chemistry will also result in a better understanding of equilibrium reactions in organic nanoreactors, an emerging research field in synthetic organic chemistry, and in a very general sense might as well deliver contributions to understand the origin of life.