论文标题
钛(IV) - 异丙氧化物的热分解的原子尺度建模
Atomic-scale modeling of the thermal decomposition of titanium(IV)-isopropoxide
论文作者
论文摘要
金属有机(MO)化合物钛(IV) - 异丙氧化物(Ti(OIPR)4,TTIP)与薄膜生长和涂层技术具有巨大的技术相关性,为钛和氧化钛基化合物提供了低温沉积途径。通常假定只有通过β-氢化物消除过程进行的任何基于TTIP的合成方法中的关键过程,通过释放有机配体的热分解是一个关键过程。在这里,我们提出了反应性力场分子动力学(RAEXFF-MD)和元动力学模拟,这些动力学通过揭示不同的,能量优先的反应途径来挑战这种常规假定的情况。提出了TTIP热解的完整反应方案,以及不同配体释放步骤的统计数据以及键解离发生事件的相关反应屏障。在稀限中进行的reaxff-MD模拟实际捕获了典型的薄膜沉积条件,该薄膜沉积条件与产生自由能的元动力数据结合使用,它构成了一种非常有力的工具,可以定量分析基于Mo的薄膜生长过程的反应动态,并提供对不同的有机物ligant的理解,从而依赖有机体的titain分支,将其分解不同。此处介绍的方法允许有效且直接地识别ReaxFF-MD中不良温度偏置效应,并代表了一个预测框架,以识别在现实,实验相关条件下与原子量表上膜生长过程相关的化学反应途径。它可以通过定制的分解和反应途径对MO分子进行计算知情的工程,从而在MO分子设计中的快速且具有成本效益的进步,以实现薄膜沉积和涂料过程的现有和未来应用。
The metal-organic (MO) compound titanium(IV)-isopropoxide (Ti(OiPr)4, TTIP) has tremendous technological relevance for thin film growth and coating technologies, offering a low-temperature deposition route for titania and titanium-oxide-based compounds. Thermal decomposition via the release of organic ligands, a key process in any TTIP-based synthesis approach, is commonly assumed to take place only via the beta-hydride elimination process. Here, we present reactive force field molecular dynamics (ReaxFF-MD) and metadynamics simulations that challenge this conventionally assumed scenario by revealing different, energetically preferred reaction pathways. The complete reaction scheme for the TTIP thermolysis, along with the statistics for the different ligand liberation steps and the associated reaction barriers for the bond dissociation events is presented. ReaxFF-MD simulations performed in the dilute limit realistically capture typical thin film deposition conditions, which in combination with metadynamics data, which produces free energies, constitutes a very powerful tool to quantitatively analyze the reaction dynamics of MO-based thin film growth processes and provide an atomic-scale understanding of how the remaining organic ligands detach from different titanium-containing MO fragments. The approach presented here allows for effective and straightforward identification of the undesirable temperature biasing effects in ReaxFF-MD and represents a predictive framework to identify chemical reaction pathways relevant to film growth processes at the atomic scale under realistic, experimentally relevant conditions. It enables computationally informed engineering of MO molecules with tailored decomposition and reaction pathways, and thus rapid and cost-effective advancements in MO molecule design for existing and future applications of thin film deposition and coating processes.