Chemical Synthesis Accelerated by Paper Spray: The Haloform Reaction

• Published in: Journal of chemical education Vol. 93; no. 2; pp. 340 - 344
• Main Authors: Bain, Ryan M, Pulliam, Christopher J, Raab, Shannon A, Cooks, R. Graham
• Format: Journal Article
• Language: English
• Published: Easton American Chemical Society and Division of Chemical Education, Inc 09-02-2016; Division of Chemical Education, Inc and ACS Publications Division of the American Chemical Society; American Chemical Society
• Subjects: Chemical analysis; Chemical reactions; Chemical synthesis; Chemistry; Hands on Science; Ionization; Laboratory Experiments; Mass spectrometry; Organic Chemistry; Oxidation; Pretests Posttests; Qualitative Research; Science Achievement; Science education; Spectroscopy; Students; Synthesis; Undergraduate Students; Hands-On Learning/Manipulatives; Instrumental Methods; Upper-Division Undergraduate; Synthesis; Laboratory Instruction; Qualitative Analysis; Mass Spectrometry; Second-Year Undergraduate; Organic Chemistry
• ISSN: 0021-9584; 1938-1328
• DOI: 10.1021/acs.jchemed.5b00263

In this laboratory, students perform a synthetic reaction in two ways: (i) by traditional bulk-phase reaction and (ii) in the course of reactive paper spray ionization. Mass spectrometry (MS) is used both as an analytical method and a means of accelerating organic syntheses. The main focus of this laboratory exercise is that the same ionization source can be operated to perform chemical analysis or to accelerate synthesis. More specifically, students explore the effect on reaction progress of operating in one of two modes of paper spray ionization. The modes relate to droplet size that changes as the solvent is depleted from the paper over time. The online mass spectral data for the two modes allow students to see the differences that small changes to spray conditions can have on the MS of a reaction mixture, allowing transition from traditional analysis to accelerated chemical synthesis by simply allowing the paper to partially dry. Chemical analysis and accelerated synthesis can be performed sequentially in one simple, 2 min paper spray experiment with the haloform oxidation.