The Particle in a Box Redux: Improved Experimental Conditions for the Laser Synthesis of Linear Polyynes

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• 作者：Melanie Henry ; Hudson G. Roth ; Bruce D. Anderson
• 刊名：Journal of Chemical Education
• 出版年：2012
• 出版时间：June 12, 2012
• 年：2012
• 卷：89
• 期：7
• 页码：960-961
• 全文大小：134K
• 年卷期：v.89,no.7(June 12, 2012)
• ISSN：1938-1328

文摘

The one-dimensional, particle-in-a-box model is an integral part of most undergraduate physical chemistry courses. Linear polyynes can be synthesized and are found to serve as real-world examples of the particle-in-a-box model. An improved set of experimental conditions for the laser synthesis of linear polyynes has been determined. Specifically, a Nd:YAG laser operating at 532 nm and 20 mJ/pulse for 5 min can produce sufficient polyynes to be detected with a UV鈥搗is spectrophotometer. Students can use the experimental wavelength and the eigenvalue expression for the particle in a box to calculate the length of the box and compare it to the length of the molecule with good results. The lower laser energy used here is important because it enables a less costly laser to be used for the experiment, which will enable more instructors to incorporate the experiment into their curriculum.

Keywords:

Upper-Division Undergraduate; Laboratory Instruction; Physical Chemistry; Hands-On Learning/Manipulatives; Alkynes; Laboratory Equipment/Apparatus; Lasers; Quantum Chemistry; UV鈭扸is Spectroscopy