Multi-faceted Studies on Highly Oxidized Organic Molecules MUSHROOM

“高度氧化的有机分子（HOMs）是大气中的一组关键化合物，最近引起了相当大的关注这些化合物的低挥发性意味着它们对气溶胶的形成和生长具有重要作用，从而对空气质量和气候产生影响。HOMs可以由简单的有机物质通过一种称为自氧化的过程形成。对于丁烷，它可以由以下化学反应组成。初始自由基形成(R)，与氧反应生成CH3CH2CH2CH2O2 （RO2）。现在存在RO2与一系列大气物质（如NO， NO2, HO2, RO2）的双分子反应之间的竞争，以及内部抽象生成羟基自由基CH3CHCH2CH2OOH。然后可以重复这个过程（向碳中心自由基添加O2和内部提取），逐渐将更多的功能引入分子并降低挥发性。提议者很适合研究这种化学反应。自氧化机理是在燃烧化学中发展起来的，Seakins在二甲醚燃烧中研究了这种化学，并带来了燃烧和大气化学的实验室动力学方面的专业知识。2-3该项目的这一部分将着眼于单个或小组的基本反应。这三位提议者都参与了大气化学高仪器化反应器（HIRAC）的操作，这是另一种获得动力学信息的方法，但补充关注整个系统而不是单个反应。希尔德是NERC一项研究RO2化学的提案的PI，斯通和希尔德在监测RO2物种方面具有特别的专长。4-5项目的主要重点将是气相物种的实验室研究，但根据学生的兴趣和项目的发展情况，将有机会获得建模、计算、实地考察和气溶胶化学方面的额外经验。比安奇,f;Kurten t;莉娃,m;莫尔,c;Rissanen, m.p.；Roldin p;Berndt t;克劳斯，j.d.；温伯格，p.o.；门特尔，t.f.；称,j .;Junninen h;Jokinen t;Kulmala m;Worsnop博士；桑顿，j.a.；多纳休:;H. G. kjaergard；涉及过氧自由基的气相自氧化的高氧有机分子（homm）：大气气溶胶的关键贡献者。化学。中国生物医学工程学报，2019,39(6),362 - 362。埃斯科拉，a.j.；卡尔，s.a.；香农，r.j.；王,b;闪电战，文学硕士；皮林，m.j.；p·w·希金斯；(1)在195-650 K温度范围内CH3OCH2 + O2反应的动力学和产率分析：实验和计算研究。期刊。化学。[j] .中国生物医学工程学报，2014,32(4):559 - 563。格洛瓦奇博士；洛克哈特,j .;闪电战，文学硕士；克里彭斯坦，s.j.；皮林，m.j.；罗伯逊，s.h.；Seakins， P. W.，大气结合反应中O2对激发振动量子态的拦截。科学通报，2012,37(6),1066- 1064。Onel l;布伦南,a;p·w·希金斯；沃利,l;赫德，D. E.，一种大气中检测CH3O2自由基的新方法。大气压。量。科技，2017,10(10),3985-4000.5。张志生；刘易斯，t.r.；Onel l;闪电战，文学硕士；p·w·希金斯；Stone， D.， ch220 + ch220和ch220 + i的中间紫外吸收截面和动力学作为压力的函数。PCCP 2020, 22(17), 9448-9459。

"Highly oxidized organic molecules (HOMs) are a key set of compounds in the atmosphere that have attracted considerable recent attention.1 The low volatility of these compounds means that they have an important role in aerosol formation and growth with a consequent impact on air quality and climate.HOMs can be formed from simple organic species by a process known as auto-oxidation. For butane this could consist of the following chemistry. The initial radical formed (R), reacts with oxygen to give CH3CH2CH2CH2O2 (RO2). Now there is a competition between bimolecular reactions of RO2 with a range of atmospheric species (e.g. NO, NO2, HO2, RO2) and an internal abstraction to give a hydroperoxy radical CH3CHCH2CH2OOH. This process can then be repeated (addition of O2 to the carbon centre radical and internal abstraction) gradually introducing more functionality into the molecule and reducing the volatility.The proposers are well-placed to study this chemistry. The mechanism of auto-oxidation was developed within combustion chemistry and Seakins has studied such chemistry in dimethylether combustion, and brings expertise in laboratory kinetics of combustion and atmospheric chemistry.2-3 This component of the project will look at individual or small groups of elementary reactions. All three proposers are involved in the operation of the Highly Instrumented Reactor for Atmospheric Chemistry (HIRAC) which is another approach to obtaining kinetic information but with a complementary focus on the whole system rather than individual reactions. Heard is the PI on a NERC proposal looking at RO2 chemistry and Stone and Heard have particular expertise in monitoring RO2 species.4-5 The main focus of the project will be laboratory studies of gas phase species, but there will be scope to gain additional experience in modelling, calculations, fieldwork and aerosol chemistry depending on the interests of the student and how the project develops.1. Bianchi, F.; Kurten, T.; Riva, M.; Mohr, C.; Rissanen, M. P.; Roldin, P.; Berndt, T.; Crounse, J. D.; Wennberg, P. O.; Mentel, T. F.; Wildt, J.; Junninen, H.; Jokinen, T.; Kulmala, M.; Worsnop, D. R.; Thornton, J. A.; Donahue, N.; Kjaergaard, H. G.; Ehn, M., Highly oxygenated organic molecules (hom) from gas-phase autoxidation involving peroxy radicals: A key contributor to atmospheric aerosol. Chem. Rev. 2019, 119 (6), 3472-3509.2. Eskola, A. J.; Carr, S. A.; Shannon, R. J.; Wang, B.; Blitz, M. A.; Pilling, M. J.; Seakins, P. W.; Robertson, S. H., Analysis of the kinetics and yields of OH radical production from the CH3OCH2 + O2 reaction in the temperature range 195-650 K: An experimental and computational study. J. Phys. Chem. A 2014, 118 (34), 6773-6788.3. Glowacki, D. R.; Lockhart, J.; Blitz, M. A.; Klippenstein, S. J.; Pilling, M. J.; Robertson, S. H.; Seakins, P. W., Interception of excited vibrational quantum states by O2 in atmospheric association reactions. Science 2012, 337 (6098), 1066-1069.4. Onel, L.; Brennan, A.; Seakins, P. W.; Whalley, L.; Heard, D. E., A new method for atmospheric detection of the CH3O2 radical. Atmos. Meas. Tech. 2017, 10 (10), 3985-4000.5. Mir, Z. S.; Lewis, T. R.; Onel, L.; Blitz, M. A.; Seakins, P. W.; Stone, D., CH2OO criegee intermediate UV absorption cross-sections and kinetics of CH2OO + CH2OO and CH2OO + i as a function of pressure. PCCP 2020, 22 (17), 9448-9459."