报告题目：Chemistry Among the Stars - Molecular Complexity in Interstellar Space
报告人：Ralf I. Kaiser 教授 美国夏威夷大学
时间：2026年5月29日（周五），下午2:00
地点：光电大楼1楼党员活动室
联系人：刘一 教授
报告简介：
Over the past decade, astrochemistry has undergone a paradigm shift: complex organic molecules can form efficiently in the coldest regions of space. Ice-coated interstellar grains are now understood as molecular factories that synthesize biorelevant species within cold molecular clouds and star-forming regions—environments once thought chemically inert. Understanding this reactivity requires bridging gas-phase and condensed-phase chemistry. In this talk, we present molecular beam and surface science experiments that resolve the underlying reaction dynamics and kinetics. In the gas phase, we identify pathways to polycyclic aromatic hydrocarbons (PAHs), key building blocks of carbonaceous nanoparticles. On icy grains, we demonstrate the formation of complex organics—including amino acids, sugars, and polyalcohols—under conditions that challenge conventional assumptions about low-temperature chemistry. Our approach combines isomer-selective vacuum ultraviolet (VUV) photoionization with reflectron time-of-flight mass spectrometry (ReTOF-MS) and infrared (FTIR) spectroscopy, enabled by advanced VUV light sources. These techniques provide molecular-level insight into reaction mechanisms. The results reveal efficient low-temperature routes to aromatic and complex organic molecules via non-classical pathways involving radical–radical reactions, submerged barriers, and excited-state dynamics. Together, these findings redefine how chemical complexity emerges in space and reshape our understanding of molecular evolution in the universe.
报告人简介：
Ralf I. Kaiser 教授现任美国夏威夷大学马诺阿分校化学系教授，兼任 W.M. Keck 天体化学研究实验室主任。他在德国明斯特大学获得化学博士学位，并曾在加州大学伯克利分校从事博士后研究 。Kaiser 教授的研究领域广泛涵盖天体化学、反应动力学和行星科学等交叉学科，在Science, Nature Astronomy等期刊发表论文600余篇，论文被引超过2.2万次，H因子高达78 。凭借在气相、凝聚相化学反应及星际复杂分子形成机制等领域的开创性贡献，Kaiser 教授当选为美国化学会（ACS）、美国物理学会（APS）、美国科学促进会（AAAS）、英国皇家化学会（RSC）等六大国际学术组织的会士。
Professor Ralf I. Kaiser is currently a Professor in the Department of Chemistry at the University of Hawaii at Manoa and serves as the Director of the W.M. Keck Research Laboratory in Astrochemistry. He received his Ph.D. in Chemistry from the University of Münster in Germany and completed his postdoctoral research at the University of California, Berkeley. Professor Kaiser's research interests broadly encompass interdisciplinary fields such as astrochemistry, reaction dynamics, and planetary sciences. He has published over 600 papers in journals including Science and Nature Astronomy, with his work being cited over 22,000 times and achieving an H-index of 78. In recognition of his pioneering contributions to the understanding of chemical reactions in the gas and condensed phases, as well as the formation mechanisms of complex interstellar molecules, Professor Kaiser has been elected as a Fellow of six major international academic organizations, including the American Chemical Society (ACS) , the American Physical Society (APS) , the American Association for the Advancement of Science (AAAS) , and the Royal Society of Chemistry (RSC).
