2014英特尔ISEF获奖作品摘要 化学 Intel Finalist Abstract Chemistry

获奖作品基本信息

年份	2014
学科	化学 Chemistry
国家/州	United States of America

获奖作品名称

Factors that Influence Energies of Simple Hydrocarbons

获奖作品摘要

Although several models have been proposed to account for the varying stabilities of alkanes, the ability of these models to fit experimental data remains controversial. The work presented here focuses on evaluating the abilities of three models to describe the energy differences of alkanes, thereby providing insight into the factors that are the most consequential to hydrocarbons' relative stabilities and leading to the proposal of the vicinal interactions model (VIM). In contrast to older models that generally lack theoretical support, the VIM is justified by natural bond orbital (NBO) analysis confirming that vicinal, antiperiplanar bond-bond and bond-antibond interactions are the most consequential. The VIM is a fairly simple additivity scheme based on bond enthalpies and vicinal, antiperiplanar bond pair interactions. The VIM was compared to the localized bond model (LBM) and geminal interactions model (GIM). Energy parameters for each model were fitted to best represent the atomization enthalpies (AE) of the C1-C6 alkanes, calculated by the Gaussian electronic structure program. Parameter fittings yielded chi squared values for the LBM, GIM, and VIM of 15.26, 12.04, 7.68 respectively. As anticipated, the LBM failed to account for differing AEs as it attributed no significance to any factors other than CC and CH bond enthalpies. The GIM, although exhibiting an improvement over the LBM, failed to describe the AEs of alkane conformers. The proposed VIM, on the other hand, generated unique AEs for each C1-C6 alkanes.  The results of this study strongly support the VIM as a new model for understanding the differing stabilities of alkanes.

 

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ISEF 简介

英特尔国际科学与工程大奖赛，简称 "ISEF"，由美国 Society for Science and the Public（科学和公共服务协会）主办，英特尔公司冠名赞助，是全球规模最大、等级最高的中学生的科研科创赛事。ISEF 的学术活动学科包括了所有数学、自然科学、工程的全部领域和部分社会科学。ISEF 素有全球青少年科学学术活动的“世界杯”之美誉，旨在鼓励学生团队协作，开拓创新，长期专一深入地研究自己感兴趣的课题。

学科简介：化学 Chemistry

Studies exploring the science of the composition, structure, properties, and reactions of matter not involving biochemical systems.

Subcategories:

Analytical Chemistry (ANC): The study of the separation, identification, and quantification of the chemical components of materials.

Computational Chemistry (COM): A study that applies the discipline and techniques of computer science and mathematics to solve large and complex problems in Chemistry.

Environmental Chemistry (ENV): The study of chemical species in the natural environment, including the effects of human activities, such as the design of products and processes that reduce or eliminate the use or generation of hazardous substances.

Inorganic Chemistry (INO): The study of the properties and reactions of inorganic and organometallic compounds.

Materials Chemistry (MAT): The chemical study of the design, synthesis and properties of substances, including condensed phases (solids, liquids, polymers) and interfaces, with a useful or potentially useful function, such as catalysis or solar energy.

Organic Chemistry (ORG): The study of carbon-containing compounds, including hydrocarbons and their derivatives.

Physical Chemistry (PHC): The study of the fundamental physical basis of chemical systems and processes, including chemical kinetics, chemical thermodynamics, electrochemistry, photochemistry, spectroscopy, statistical mechanics and astro-chemistry.

Other (OTH): Studies that cannot be assigned to one of the above subcategories. If the project involves multiple subcategories, the principal subcategory should be chosen instead of Other.