Experimental Chemistry I Curricula
CH 361- 362. Experimental Chemistry I. (3 credits each term). First Integrated Laboratory sequence for majors in chemistry and biochemistry&biophysics majors covering experimental techniques of analytical, inorganic, organic and physical chemistry. Must be taken in order. Enrollment is about 40 students each term. Examples of the project experiments done in this series:
1.Preparation and Characterization of an Unknown Carboxylic Acid.
2. Preparation and Equilibration of Isomeric 2,3-Dimethylbutenes.
1. Strain Energy of the Cyclopropane Ring from Heats of Combustion.
2. Tautomerism and Coordination Chemistry of $-Diketones.
3. NMR Characterization of an Unknown Substituted Benzene or Benzene Derivative.
Experimental Chemistry II Curricula
CH 461- 464. Experimental Chemistry II. (3 credits each term). Second Integrated Laboratory sequence for majors in chemistry and related disciplines, covering experimental techniques of analytical, inorganic, organic and physical chemistry. Must be taken in order. Enrollment is about 18 students each term. Examples of the projects done in this series are:
1. Chemical Instrumentation. A. Electronic Instrumentation. B. Optical Instrumentation.
2.Determination of Riboflavin: A Comparison of Techniques. A. Molecular Absorption Spectrophotometry. B. Molecular Fluorescence Spectroscopy. C. HPLC .
3. Enzyme Kinetics. Yeast Alcohol Dehydrogenase.
4. ICP Atomic Emission and Flame Absorption Spectrometry.
5. Coulometric Titration and Spectrometric Endpoint Detection.
6. Special Project. A real sample is chosen by the student for analysis.
CH 462/462H (WIC)
1. Preparation and Investigation of the Properties of Synthetic Zeolite 4A and 5A.
2. Electrochemical Studies.
3. Preparation and Investigation of Poly(Methyl Methacrylate).
4. Equilibrium and Kinetic Studies of the Ferric Thiocyanate Complex.
CH 463/463H (WIC)
1. Synthesis, Spectroscopy and Photochemistry of Benzophenones.
2. Mass Spectrometry of Synthesized Deuterated Toluenes.
CH 464/464H (WIC)
1. Synthesis and Physical Properties for HCl, DCl, HBr and DBr. Vacuum line techniques, FTIR, index of refraction and dipole moment determination, NMR, ab initio quantum methods for comparison.
Two additional projects from the following list:
2. Synthesis and Spectroscopic Characterization of CdSe Quantum Dots.
4. Preparation of Enantiomers of Tris[ethylenediamine] Cobalt(III) iodide. Resolution, Analysis and Spectra.
5. High Resolution Absorption Spectrum for Iodine and Lifetime Measurement using a Pulsed Laser.
6. Tunable laser experiments.
Details of Projects for Experimental Chemistry I & II
Experimental Chemistry I.
Exp. 1 Preparation and Characterization of an Unknown Carboxylic Acid.
Techniques: Vacuum filtration; determining best solvent for crystallization; mp determination; recrystallization; potentiometric titration.
Chemistry: Acidification of salt to form acid; preparation of an acid chloride, then conversion to the anilide or amide derivative; acid-base equilibria.
Exp. 2 Preparation and Equilibration of Isomeric 2,3-Dimethylbutenes.
Techniques: Controlling a water sensitive reaction; working with a Class B carcinogen; work up of product by extraction using a separatory funnel; fractional distillation; gas chromatography; spinning band column distillation; fraction collecting; sealing ampules with a torch; time course isomerization; computer spreadsheet work with graphing and linear regression to determine thermodynamic parameters of isomerization (Kc, )GE, )SE, )HE); keeping a laboratory notebook; writing formal reports; working in peer groups on a big project.
Chemistry: Grignard reaction between iodomethane and methyl isopropyl ketone to form the alcohol, subsequent elimination using p-toluenesulfonic acid to form a mixture of 2,3-dimethyl-1- and -2-butene; acid catalyzed isomerization at five different temperatures.
Experimental Chemistry I
Exp. 1 Strain Energy of the Cyclopropane Ring from Heats of Combustion.
Techniques: Cyclization reaction in fused alkali; roto-evaporation; vacuum fractional distillation; refractometry and GC; FTIR; oxygen bomb calorimetry for ring strain; graphing and linear regression using a spreadsheet; propagation error analysis; computational chemistry to determine model for ring strain and vibrational spectra.
Chemistry: One half of the class: Conversion of 3 -chlorobutyronitrile to cyclopropane carboxylic acid and subsequent formation of the acid chloride. The acid chloride is then converted to n -butylcyclopropane carboxylate upon reaction with n-butanol. One half of the class: Preparation of the Grignard reagent cyclohexylmagnesiumchloride and reaction with CO2 to form cyclohexanecarboxylic acid, then the acid chloride, and finally condensation with methanol to form methyl cyclohexanecarboxylate.
Exp. 2 Tautomerism and Coordination Chemistry of $ -Diketones.
Techniques: Keto -enol equilibrium constant determined for 2,4-pentandione in several solvents using 400 MHZ FT-NMR; paramagnetic susceptibility for Fe(acac)3 by Evans method using 60 MHZ CW-NMR; FTIR analysis for liquid solution and KBr pellet samples.
Chemistry: Preparation of organometallic tris -(acetylacetonato)
iron(III) from iron(III)chloride, 2,4-pentandione, and buffer; recrystallization and mp.
Exp. 3 NMR Characterization of an Unknown Substituted Benzene or Benzene Derivative.
Techniques: Interpretation of FT-NMR proton, 13C, and subsequent 2 -D HSQC, Dept 90 and 135 and CoSY for unknown compounds. Hands-on GC/MS analysis for the empirical formula for the same unknown.
Experimental Chemistry II (4 terms)
Use of volumetric glassware to prepare solutions is required throughout. Six modular electro-optic stations are each interfaced with a PC for data collection and analysis.
Exp. 1 Electronic Instrumentation.
Techniques: Learning about design features and principles in chemical instrumentation: servo recorders; digital multimeters; voltage sources; operational amplifiers (voltage amplifier, response time, voltage follower, integrator); signal conditioning circuits; microcomputers for data acquisition.
Exp. 2 Optical Instrumentation.
Techniques: Learning about characteristics and operation of wavelength selection devices (monochromators, filters), optical transducers (PMT, silicon photodiodes), and excitation sources (tungsten and mercury lamps); resolution, spectral bandpass, frequency response and noise.
Exp. 3 Molecular Absorption Spectrophotometry.
Techniques: Construction of a single beam spectrophotometer with log and linear outputs; use of Beer's law in quantitative analysis; learning about precision, detection limits, stray light and effects of slit width on absorbance.
Chemistry: Analysis for vitamin B2 in a commercial vitamin tablet.
Exp. 4 Molecular Fluorescence Spectroscopy.
Techniques: Construction of a fluorimeter; computer controlled acquisition of emission and excitation spectra; calibration plots, and causes of non-linearity. Vitamin B2 in a commercial vitamin tablet is determine.
Exp. X High Performance Liquid Chromatography.
Techniques: Hands-on operation of HPLC system using diode array detection. Reverse phase LC is used to determine the vitamin B1 and B2 content of a commercial vitamin tablet. Two mobile phases are used to contrast resolution.
Exp. A Enzyme Kinetics. Yeast Alcohol Dehydrogenase.
Techniques: Working with small easily contaminated samples of biologically active chemicals; use of Eppendorf automatic pipettor; saturation kinetics and the Michaelis Menton constant; treatment of two real samples: beer and horse blood inoculated with ethanol.
Exp. 5 Absorption Spectroscopy and Inductively Coupled Plasma Atomic Emission.
Techniques: Preparation and analysis of milk for calcium content and of a commercial mineral tablet for Cu, Zn, Se, Mg and Ca. Digestion of milk done by microwave acid digestion and dry ashing in a muffle furnace of a bovine liver sample.
Exp. 6 Coulometric Titration and Spectrometric Endpoint Detection.
Techniques: Construction of a visible molecular absorption spectrophotometer to carry out the coulometric titration of AsO33- with known amount of iodine generated at a platinum anode in an iodide solution. A constant current generator is constructed to measure the number of coulombs consumed (iodine produced) over a given (measured) time. Spectrophotometric endpoint detection of the blue starch is used to automatically turn off the current generator and timer.
Exp. B Special Project.
A real sample is chosen by the student for analysis. A literature search is done, the feasibility of the project is discussed with the instructor, and afterwards, each student writes a formal report and gives an oral presentation of the project to the rest of the class.
Experimental Chemistry II
CH 462/462H (WIC)
Exp. 1 Preparation and Investigation of the Properties of a Synthetic Zeolite.
Techniques: X-ray crystallography of a powder sample and unit cell structure determination; neutron activation analysis (NAA) for sodium, calcium, and aluminum; nitrogen sorption using a McBain balance to determine surface area; thermogravimetric analysis to find the degree of hydration for zeolite.
Chemistry: Synthesis of 4A zeolite and partial calcium ion exchange to make 5A zeolite.
Exp. 2 Electrochemical Studies.
Techniques: Potentiometry using Ag/AgCl electrode vs. SCE to determine the solubility product for silver chloride; Voltammetry using a static mercury drop working electrode (SDME) and PAR polarographic analyzer/stripping voltammeter equipped with a Ag/AgCl reference electrode for dc polarography, sampled dc polarography, differential pulse polarography of cadmium ion and thallium ion plus ethylenediamine as the chelating agent; Anodic stripping voltammetry using the HDME and differential pulse waveform to demonstrate the technique of standard addition for solutions of cadmium, copper and zinc.
Exp. 3 Synthesis and Electrochemistry of a Model for Iron-Sulfur Proteins
Techniques: Laboratory work in a glove bag to prepare the air and water sensitive [Bu4N]2[Fe4S4(SC6H5)4]; preparation of dry solvents by distillation; transfer of solutions by cannulation. Cyclic voltammetry to determine oxidation states of iron in the feridoxin model complex.
Exp. 4 Equilibrium and Kinetic Studies of the Ferric Thiocyanate Complex.
Techniques: Job's method to determine stoichiometry of complex; potentiometric titration using gold foil indicator electrode v. SSCE to determine the complex equilibrium constant; flash photolysis relaxation method to determine the rate of the complexation using computer assisted operation of a modular spectrometer.
Exp. 2 Preparation and Characterization of a Polymer.
Techniques: Working with polymer solutions; making thin films for FTIR work; viscosity measurements using an Ostwald viscometer to determine viscosity average MW; light scattering measurements to detemine mass average MW; GPC measurements to determine the number average MW. DSC to determine crystallinity of polymer. Optional light scattering.
Chemistry: Either Polyvinylalcohol is prepared by methanolysis of polyvinylacetate and recrystallized from PVOH from acetone, or polymethmethacrylate is made free radical polymerization. Optional: Monodispersed PMMA is prepared by anionic polymerization.
Experimental Chemistry II
CH 463/463H (WIC)
Exp. 1 Synthesis, Spectroscopy and Photochemistry of Benzophenones.
Techniques: Primary literature search starting with secondary sources such as Beilstein, Chemisty Abstracts, Citation Index at the main campus library. UV absorption, excitation and emission spectroscopy with computer assisted data collection. Data analysis using computer spreadsheets and peak fitting programs to determine the oscillator strengths by Gaussian fitting of peaks. Computer assisted phosphorescence lifetime measurements. Photochemical reduction of the substituted benzophenone to a substituted benzopinacol by irradiation at 254 nm. Time course analysis using FTIR to determine the photochemical quantum efficiency.
Chemistry: Friedel Crafts alkylation or acylation method to prepare an assigned substituted benzophenone.
Exp. 2 Mass Spectrometry of Synthesized Deuterated Toluenes. (not done every year)
Techniques: Challenges skill in retrieving a precious sample; freeze drying solvent; use of a microscale Hickman still. GCMS analysis using SIM to observe the fundamental fragmentation and rearrangement processes. The analysis involves a review of free radicals and carbocations, including the tropylium ion.
Chemistry: Half the class prepares 2,4,6-trideuterotoluene from m-toluidine and the other half 3,5-dideuterotoluene from p-toluidine. Each toluidine is first converted to the HBr salt. A time course is conducted to observe the completion of the electrophilic aromatic substitution isotopic exchange with D2O. The deamination by diazotization and subsequent reduction is accomplished using hypophosphorous acid.
Experimental Chemistry II
Project 1 Synthesis and Spectroscopic Characterization of CdSe Quantum Dots (approximately 2 weeks)
a) Synthesis of CdSe nanoparticles of various sizes.
b) Absorption/emission spectroscopy measurements.
c) Comparison of theoretical models of the spectra of quantum dots with experiment.
Project 2 Synthesis and Equilibrium Dynamics of HCl, DCl, DBr, and HBr (approximately 4 weeks)
a) Preparation of DCl, DBr using vacuum‑line techniques.
b) Refraction index and dipole moment determination for HCl.
c) High resolution vibrational-rotational FTIR spectra of HCl, DCl, DBr, and HBr.
d) Raman determination of Kp for the H/D exchange reaction of HBr with DCl.
e) Comparison of measured values of HCl properties with those from computational chemistry determined by ab initio quantum methods (Gaussian calculations).
Project 3 Microlithography
a) Fabrication of lithography masters.
b) Preparation of PDMS stamps.
c) Soft lithography by replica molding and micromolding in capillaries.
d) Microcontact printing and etching.
Exp. 1 Preparation of Enantiomers of Tris[ethylenediamine] Cobalt(III) iodide. Resolution, Analysis and Spectra.
Techniques: Preparation of a racemic mixture and resolution of optical isomers; polarimetry; visible spectroscopy; iodometric titration.
Chemistry: Formation of a thermodynamically stable complex by in situ oxidation and complexation.
Exp. 2 Absorption Spectrum and Sublimation Pressure of Iodine.(replaced by tunable dye laser experiments)
Techniques: High resolution electronic spectroscopy and analysis of the vibrational fine structure to determine thermodynamic parameters for iodine (dissociation energies, bond force constants, etc.); measurement of vapor pressure as a function of temperature for solid iodine to determine the sublimation energy, crystal entropy and mean vibrational frequency for comparison with that reported from neutron inelastic scattering measurements of phonon modes.