Substituent Effects on Keto-Enol Equilibria Using NMR Spectroscopy

被引：35

作者：

Manbeck, Kimberly A. ^{[1
]}

Boaz, Nicholas C. ^{[1
]}

Bair, Nathaniel C. ^{[1
]}

Sanders, Allix M. S. ^{[1
]}

Marsh, Anderson L. ^{[1
]}

机构：

[1] Lebanon Valley Coll, Dept Chem, Annville, PA 17003 USA

来源：

JOURNAL OF CHEMICAL EDUCATION | 2011年 / 88卷 / 10期

关键词：

Upper-Division Undergraduate; Laboratory Instruction; Physical Chemistry; Hands-On Learning/Manipulatives; Aldehydes/Ketones; Equilibrium; NMR Spectroscopy; TAUTOMERISM;

D O I：

10.1021/ed1010932

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

In this extension to a classic physical chemistry experiment, students record the proton nuclear magnetic resonance spectra of the beta-diketones 2,4-pentanedione, 3-methyl-2,4-pentanedione, and 3-chloro-2,4-pentanedione to investigate the effect of substituents on keto-enol tautomerization equilibria. From the integrated intensities of keto and enol methyl proton peaks, students calculate the equilibrium constant for each 2,4-pentanedione. The students then use the effects of electron-donating and electron-withdrawing substituents to elucidate the nature of keto-enol equilibria.

引用

页码：1444 / 1445

页数：2

共 13 条

[1] KETO-ENOL TAUTOMERISM IN BETA DICARBONYLS STUDIED BY NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY .1. PROTON CHEMICAL SHIFTS + EQUILIBRIUM CONSTANTS OF PURE COMPOUNDS [J].

BURDETT, JL ;

ROGERS, MT .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1964, 86 (11) :2105-&

[2] Determination of Solvent Effects on Keto-Enol Equilibria of 1,3-Dicarbonyl Compounds Using NMR (vol 84, pg 1827, 2007) [J].

Cook, A. Gilbert ;

Feltman, Paul M. .

JOURNAL OF CHEMICAL EDUCATION, 2010, 87 (07) :678-678

[3]

Cook G, 2007, J CHEM EDUC, V84, P1827

[4] NMR-STUDY OF KETO-ENOL TAUTOMERISM IN BETA-DICARBONYL COMPOUNDS [J].

DREXLER, EJ ;

FIELD, KW .

JOURNAL OF CHEMICAL EDUCATION, 1976, 53 (06) :392-393

[5]

GARLAND CW, 2009, EXPT PHYS CHEM, P474

[6]

Grushow A, 2002, J CHEM EDUC, V79, P707

[7] Keto-Enol Equilibrium from NMR Data: A Closer Look at the Laboratory Experiment [J].

Koudriavtsev, Andrei B. ;

Linert, Wolfgang .

JOURNAL OF CHEMICAL EDUCATION, 2009, 86 (10) :1234-1237

[8] Kinetic and Mechanistic Studies of the Deuterium Exchange in Classical Keto-Enol Tautomeric Equilibrium Reactions [J].

Nichols, Michael A. ;

Waner, Mark J. .

JOURNAL OF CHEMICAL EDUCATION, 2010, 87 (09) :952-955

[9] Tautomeric equilibria in relation to Pi-electron delocalization [J].

Raczynska, ED ;

Kosinska, W ;

Osmialowski, B ;

Gawinecki, R .

CHEMICAL REVIEWS, 2005, 105 (10) :3561-3612

[10] An effective synthesis of alkyl β-cyano-α,γ-diketones using chlorosulfonylisocyanate and a representative Cu(II) complex [J].

Silvernail, CM ;

Yap, G ;

Sommer, RD ;

Rheingold, AL ;

Day, VW ;

Belot, JA .

POLYHEDRON, 2001, 20 (26-27) :3113-3117

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