Vernier Software and Technology
Vernier Software & Technology

Grignard Formation of Crystal Violet

Introduction

An organometallic compound is one that contains a carbon-metal bond. The key feature of many of these compounds is that the carbon on the carbon-metal bond carries a partial negative charge. The partial negative charge on carbon makes it basic and nucleophilic; this latter property can be exploited in organic synthesis to help construct carbon-carbon bonds. Organomagnesium compounds are referred to as Grignard reagents.

Crystal violet is a triarylmethane dye which is commonly used in general chemistry classrooms to study spectrophotometry and basic chemical kinetics. Here, you will synthesize crystal violet by preparing a Grignard reagent from the bromine-containing compound 4-bromo-N,N-dimethylaniline. Addition of this Grignard to diethyl carbonate followed by acid hydrolysis ultimately leads to the triarylmethane dye.

Objectives

In this experiment, you will

  • Prepare a Grignard reagent from 4-bromo-N,N-dimethylaniline, illustrating the synthetic process of carbon-carbon bond formation.
  • Synthesize crystal violet from this Grignard reagent.
  • Analyze the purity of the synthesized crystal violet spectrophotometrically.

Sensors and Equipment

This experiment features the following Vernier sensors and equipment.

Option 1

Option 2

Option 3

Additional Requirements

You may also need an interface and software for data collection. What do I need for data collection?

Organic Chemistry with Vernier

See other experiments from the lab book.

1Determining Melting Temperature
2Recrystallization of Benzoic Acid and Aspirin
3Determination of a Boiling Point: Simple and Fractional Distillation
4Identifying an Unknown Analgesic by Melting Temperature and Thin-Layer Chromatography
5Separation of Organic Compounds by Acid-Base Extraction Techniques
6Understanding Polarimetry
7Identification of Organic Unknowns Using Polarimetry
8Investigating Gas Chromatography
9Fractional Distillation of Esters
10Understanding Intermolecular Forces Using a Gas Chromatograph: Enthalpy of Vaporization
11Investigating Thermodynamic Relationships of Substituted Hydrocarbons
12Extraction of Spinach Pigments and Analysis by Electronic Absorption Spectroscopy
13SN1: Synthesis of t-butyl chloride
14SN2: Synthesis of 1-bromobutane
15Observing the Reaction Kinetics of Sucrose with Polarimetry
16The Synthesis and Analysis of Aspirin
17Isolation and Epoxidation of a Natural Product: Limonene
18Synthesizing Ethyl Acetate by Fisher Esterification
19Synthesis of Dibenzalacetone by Aldol Condensation
20The Diels-Alder Reaction of Anthracene with Maleic Anhydride
21Friedel-Crafts Acylation of Ferrocene
22Grignard Formation of Crystal Violet
23Synthesis of Fluorescein
24Synthesis of Methyl Orange and Its Application to Textiles
25Analysis of Natural Products
26Using a Gas Chromatograph: Identifying an Unknown Compound

Experiment 22 from Organic Chemistry with Vernier Lab Book

<i>Organic Chemistry with Vernier</i> book cover

Included in the Lab Book

Vernier lab books include word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.

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