Home » Chemistry » Organic Chemistry Lab » Nuclear Magnetic Resonance (NMR) Spectroscopy, Part II

Dr. Laurie Starkey

Dr. Laurie Starkey

Nuclear Magnetic Resonance (NMR) Spectroscopy, Part II

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Table of Contents

Section 1: Reagent Table
Completing the Reagent Table for Prelab

21m 9s

Intro
0:00
Sample Reagent Table
0:11
Reagent Table Overview
0:12
Calculate Moles of 2-bromoaniline
6:44
Calculate Molar Amounts of Each Reagent
9:20
Calculate Mole of NaNO₂
9:21
Calculate Moles of KI
10:33
Identify the Limiting Reagent
11:17
Which Reagent is the Limiting Reagent?
11:18
Calculate Molar Equivalents
13:37
Molar Equivalents
13:38
Calculate Theoretical Yield
16:40
Theoretical Yield
16:41
Calculate Actual Yield (%Yield)
18:30
Actual Yield (%Yield)
18:31
Section 2: Melting Points
Introduction to Melting Points

16m 10s

Intro
0:00
Definition of a Melting Point (mp)
0:04
Definition of a Melting Point (mp)
0:05
Solid Samples Melt Gradually
1:49
Recording Range of Melting Temperature
2:04
Melting Point Theory
3:14
Melting Point Theory
3:15
Effects of Impurities on a Melting Point
3:57
Effects of Impurities on a Melting Point
3:58
Special Exception: Eutectic Mixtures
5:09
Freezing Point Depression by Solutes
5:39
Melting Point Uses
6:19
Solid Compound
6:20
Determine Purity of a Sample
6:42
Identify an Unknown Solid
7:06
Recording a Melting Point
9:03
Pack 1-3 mm of Dry Powder in MP Tube
9:04
Slowly Heat Sample
9:55
Record Temperature at First Sign of Melting
10:33
Record Temperature When Last Crystal Disappears
11:26
Discard MP Tube in Glass Waste
11:32
Determine Approximate MP
11:42
Tips, Tricks and Warnings
12:28
Use Small, Tightly Packed Sample
12:29
Be Sure MP Apparatus is Cool
12:45
Never Reuse a MP Tube
13:16
Sample May Decompose
13:30
If Pure Melting Point (MP) Doesn't Match Literature
14:20
Melting Point Lab

8m 17s

Intro
0:00
Melting Point Tubes
0:40
Melting Point Apparatus
3:42
Recording a melting Point
5:50
Section 3: Recrystallization
Introduction to Recrystallization

22m

Intro
0:00
Crystallization to Purify a Solid
0:10
Crude Solid
0:11
Hot Solution
0:20
Crystals
1:09
Supernatant Liquid
1:20
Theory of Crystallization
2:34
Theory of Crystallization
2:35
Analysis and Obtaining a Second Crop
3:40
Crystals → Melting Point, TLC
3:41
Supernatant Liquid → Crude Solid → Pure Solid
4:18
Crystallize Again → Pure Solid (2nd Crop)
4:32
Choosing a Solvent
5:19
1. Product is Very Soluble at High Temperatures
5:20
2. Product has Low Solubility at Low Temperatures
6:00
3. Impurities are Soluble at All Temperatures
6:16
Check Handbooks for Suitable Solvents
7:33
Why Isn't This Dissolving?!
8:46
If Solid Remains When Solution is Hot
8:47
Still Not Dissolved in Hot Solvent?
10:18
Where Are My Crystals?!
12:23
If No Crystals Form When Solution is Cooled
12:24
Still No Crystals?
14:59
Tips, Tricks and Warnings
16:26
Always Use a Boiling Chip or Stick!
16:27
Use Charcoal to Remove Colored Impurities
16:52
Solvent Pairs May Be Used
18:23
Product May 'Oil Out'
20:11
Recrystallization Lab

19m 7s

Intro
0:00
Step 1: Dissolving the Solute in the Solvent
0:12
Hot Filtration
6:33
Step 2: Cooling the Solution
8:01
Step 3: Filtering the Crystals
12:08
Step 4: Removing & Drying the Crystals
16:10
Section 4: Distillation
Introduction to Distillation

25m 54s

Intro
0:00
Distillation: Purify a Liquid
0:04
Simple Distillation
0:05
Fractional Distillation
0:55
Theory of Distillation
1:04
Theory of Distillation
1:05
Vapor Pressure and Volatility
1:52
Vapor Pressure
1:53
Volatile Liquid
2:28
Less Volatile Liquid
3:09
Vapor Pressure vs. Boiling Point
4:03
Vapor Pressure vs. Boiling Point
4:04
Increasing Vapor Pressure
4:38
The Purpose of Boiling Chips
6:46
The Purpose of Boiling Chips
6:47
Homogeneous Mixtures of Liquids
9:24
Dalton's Law
9:25
Raoult's Law
10:27
Distilling a Mixture of Two Liquids
11:41
Distilling a Mixture of Two Liquids
11:42
Simple Distillation: Changing Vapor Composition
12:06
Vapor & Liquid
12:07
Simple Distillation: Changing Vapor Composition
14:47
Azeotrope
18:41
Fractional Distillation: Constant Vapor Composition
19:42
Fractional Distillation: Constant Vapor Composition
19:43
Distillation Lab

24m 13s

Intro
0:00
Glassware Overview
0:04
Heating a Sample
3:09
Bunsen Burner
3:10
Heating Mantle 1
4:45
Heating Mantle 2
6:18
Hot Plate
7:10
Simple Distillation Lab
8:37
Fractional Distillation Lab
17:13
Removing the Distillation Set-Up
22:41
Section 5: Chromatography
Introduction to TLC (Thin-Layer Chromatography)

28m 51s

Intro
0:00
Chromatography
0:06
Purification & Analysis
0:07
Types of Chromatography: Thin-layer, Column, Gas, & High Performance Liquid
0:24
Theory of Chromatography
0:44
Theory of Chromatography
0:45
Performing a Thin-layer Chromatography (TLC) Analysis
2:30
Overview: Thin-layer Chromatography (TLC) Analysis
2:31
Step 1: 'Spot' the TLC Plate
4:11
Step 2: Prepare the Developing Chamber
5:54
Step 3: Develop the TLC Plate
7:30
Step 4: Visualize the Spots
9:02
Step 5: Calculate the Rf for Each Spot
12:00
Compound Polarity: Effect on Rf
16:50
Compound Polarity: Effect on Rf
16:51
Solvent Polarity: Effect on Rf
18:47
Solvent Polarity: Effect on Rf
18:48
Example: EtOAc & Hexane
19:35
Other Types of Chromatography
22:27
Thin-layer Chromatography (TLC)
22:28
Column Chromatography
22:56
High Performance Liquid (HPLC)
23:59
Gas Chromatography (GC)
24:38
Preparative 'prep' Scale Possible
28:05
TLC Analysis Lab

20m 50s

Intro
0:00
Step 1: 'Spot' the TLC Plate
0:06
Step 2: Prepare the Developing Chamber
4:06
Step 3: Develop the TLC Plate
6:26
Step 4: Visualize the Spots
7:45
Step 5: Calculate the Rf for Each Spot
11:48
How to Make Spotters
12:58
TLC Plate
16:04
Flash Column Chromatography
17:11
Section 6: Extractions
Introduction to Extractions

34m 25s

Intro
0:00
Extraction Purify, Separate Mixtures
0:07
Adding a Second Solvent
0:28
Mixing Two Layers
0:38
Layers Settle
0:54
Separate Layers
1:05
Extraction Uses
1:20
To Separate Based on Difference in Solubility/Polarity
1:21
To Separate Based on Differences in Reactivity
2:11
Separate & Isolate
2:20
Theory of Extraction
3:03
Aqueous & Organic Phases
3:04
Solubility: 'Like Dissolves Like'
3:25
Separation of Layers
4:06
Partitioning
4:14
Distribution Coefficient, K
5:03
Solutes Partition Between Phases
5:04
Distribution Coefficient, K at Equilibrium
6:27
Acid-Base Extractions
8:09
Organic Layer
8:10
Adding Aqueous HCl & Mixing Two Layers
8:46
Neutralize (Adding Aqueous NaOH)
10:05
Adding Organic Solvent Mix Two Layers 'Back Extract'
10:24
Final Results
10:43
Planning an Acid-Base Extraction, Part 1
11:01
Solute Type: Neutral
11:02
Aqueous Solution: Water
13:40
Solute Type: Basic
14:43
Solute Type: Weakly Acidic
15:23
Solute Type: Acidic
16:12
Planning an Acid-Base Extraction, Part 2
17:34
Planning an Acid-Base Extraction
17:35
Performing an Extraction
19:34
Pour Solution into Sep Funnel
19:35
Add Second Liquid
20:07
Add Stopper, Cover with Hand, Remove from Ring
20:48
Tip Upside Down, Open Stopcock to Vent Pressure
21:00
Shake to Mix Two Layers
21:30
Remove Stopper & Drain Bottom Layer
21:40
Reaction Work-up: Purify, Isolate Product
22:03
Typical Reaction is Run in Organic Solvent
22:04
Starting a Reaction Work-up
22:33
Extracting the Product with Organic Solvent
23:17
Combined Extracts are Washed
23:40
Organic Layer is 'Dried'
24:23
Finding the Product
26:38
Which Layer is Which?
26:39
Where is My Product?
28:00
Tips, Tricks and Warnings
29:29
Leaking Sep Funnel
29:30
Caution When Mixing Layers & Using Ether
30:17
If an Emulsion Forms
31:51
Extraction Lab

14m 49s

Intro
0:00
Step 1: Preparing the Separatory Funnel
0:03
Step 2: Adding Sample
1:18
Step 3: Mixing the Two Layers
2:59
Step 4: Draining the Bottom Layers
4:59
Step 5: Performing a Second Extraction
5:50
Step 6: Drying the Organic Layer
7:21
Step 7: Gravity Filtration
9:35
Possible Extraction Challenges
12:55
Section 7: Spectroscopy
Infrared Spectroscopy, Part I

1h 4m

Intro
0:00
Infrared (IR) Spectroscopy
0:09
Introduction to Infrared (IR) Spectroscopy
0:10
Intensity of Absorption Is Proportional to Change in Dipole
3:08
IR Spectrum of an Alkane
6:08
Pentane
6:09
IR Spectrum of an Alkene
13:12
1-Pentene
13:13
IR Spectrum of an Alkyne
15:49
1-Pentyne
15:50
IR Spectrum of an Aromatic Compound
18:02
Methylbenzene
18:24
IR of Substituted Aromatic Compounds
24:04
IR of Substituted Aromatic Compounds
24:05
IR Spectrum of 1,2-Disubstituted Aromatic
25:30
1,2-dimethylbenzene
25:31
IR Spectrum of 1,3-Disubstituted Aromatic
27:15
1,3-dimethylbenzene
27:16
IR Spectrum of 1,4-Disubstituted Aromatic
28:41
1,4-dimethylbenzene
28:42
IR Spectrum of an Alcohol
29:34
1-pentanol
29:35
IR Spectrum of an Amine
32:39
1-butanamine
32:40
IR Spectrum of a 2° Amine
34:50
Diethylamine
34:51
IR Spectrum of a 3° Amine
35:47
Triethylamine
35:48
IR Spectrum of a Ketone
36:41
2-butanone
36:42
IR Spectrum of an Aldehyde
40:10
Pentanal
40:11
IR Spectrum of an Ester
42:38
Butyl Propanoate
42:39
IR Spectrum of a Carboxylic Acid
44:26
Butanoic Acid
44:27
Sample IR Correlation Chart
47:36
Sample IR Correlation Chart: Wavenumber and Functional Group
47:37
Predicting IR Spectra: Sample Structures
52:06
Example 1
52:07
Example 2
53:29
Example 3
54:40
Example 4
57:08
Example 5
58:31
Example 6
59:07
Example 7
1:00:52
Example 8
1:02:20
Infrared Spectroscopy, Part II

48m 34s

Intro
0:00
Interpretation of IR Spectra: a Basic Approach
0:05
Interpretation of IR Spectra: a Basic Approach
0:06
Other Peaks to Look for
3:39
Examples
5:17
Example 1
5:18
Example 2
9:09
Example 3
11:52
Example 4
14:03
Example 5
16:31
Example 6
19:31
Example 7
22:32
Example 8
24:39
IR Problems Part 1
28:11
IR Problem 1
28:12
IR Problem 2
31:14
IR Problem 3
32:59
IR Problem 4
34:23
IR Problem 5
35:49
IR Problem 6
38:20
IR Problems Part 2
42:36
IR Problem 7
42:37
IR Problem 8
44:02
IR Problem 9
45:07
IR Problems10
46:10
Nuclear Magnetic Resonance (NMR) Spectroscopy, Part I

1h 32m 14s

Intro
0:00
Purpose of NMR
0:14
Purpose of NMR
0:15
How NMR Works
2:17
How NMR Works
2:18
Information Obtained From a ¹H NMR Spectrum
5:51
# of Signals, Integration, Chemical Shifts, and Splitting Patterns
5:52
Number of Signals in NMR (Chemical Equivalence)
7:52
Example 1: How Many Signals in ¹H NMR?
7:53
Example 2: How Many Signals in ¹H NMR?
9:36
Example 3: How Many Signals in ¹H NMR?
12:15
Example 4: How Many Signals in ¹H NMR?
13:47
Example 5: How Many Signals in ¹H NMR?
16:12
Size of Signals in NMR (Peak Area or Integration)
21:23
Size of Signals in NMR (Peak Area or Integration)
21:24
Using Integral Trails
25:15
Example 1: C₈H₁₈O
25:16
Example 2: C₃H₈O
27:17
Example 3: C₇H₈
28:21
Location of NMR Signal (Chemical Shift)
29:05
Location of NMR Signal (Chemical Shift)
29:06
¹H NMR Chemical Shifts
33:20
¹H NMR Chemical Shifts
33:21
¹H NMR Chemical Shifts (Protons on Carbon)
37:03
¹H NMR Chemical Shifts (Protons on Carbon)
37:04
Chemical Shifts of H's on N or O
39:01
Chemical Shifts of H's on N or O
39:02
Estimating Chemical Shifts
41:13
Example 1: Estimating Chemical Shifts
41:14
Example 2: Estimating Chemical Shifts
43:22
Functional Group Effects are Additive
45:28
Calculating Chemical Shifts
47:38
Methylene Calculation
47:39
Methine Calculation
48:20
Protons on sp³ Carbons: Chemical Shift Calculation Table
48:50
Example: Estimate the Chemical Shift of the Selected H
50:29
Effects of Resonance on Chemical Shifts
53:11
Example 1: Effects of Resonance on Chemical Shifts
53:12
Example 2: Effects of Resonance on Chemical Shifts
55:09
Example 3: Effects of Resonance on Chemical Shifts
57:08
Shape of NMR Signal (Splitting Patterns)
59:17
Shape of NMR Signal (Splitting Patterns)
59:18
Understanding Splitting Patterns: The 'n+1 Rule'
1:01:24
Understanding Splitting Patterns: The 'n+1 Rule'
1:01:25
Explanation of n+1 Rule
1:02:42
Explanation of n+1 Rule: One Neighbor
1:02:43
Explanation of n+1 Rule: Two Neighbors
1:06:23
Summary of Splitting Patterns
1:06:24
Summary of Splitting Patterns
1:10:45
Predicting ¹H NMR Spectra
1:10:46
Example 1: Predicting ¹H NMR Spectra
1:13:30
Example 2: Predicting ¹H NMR Spectra
1:19:07
Example 3: Predicting ¹H NMR Spectra
1:23:50
Example 4: Predicting ¹H NMR Spectra
1:29:27
Nuclear Magnetic Resonance (NMR) Spectroscopy, Part II

2h 3m 48s

Intro
0:00
¹H NMR Problem-Solving Strategies
0:18
Step 1: Analyze IR Spectrum (If Provided)
0:19
Step 2: Analyze Molecular Formula (If Provided)
2:06
Step 3: Draw Pieces of Molecule
3:49
Step 4: Confirm Piecs
6:30
Step 5: Put the Pieces Together!
7:23
Step 6: Check Your Answer!
8:21
Examples
9:17
Example 1: Determine the Structure of a C₉H₁₀O₂ Compound with the Following ¹H NMR Data
9:18
Example 2: Determine the Structure of a C₉H₁₀O₂ Compound with the Following ¹H NMR Data
17:27
¹H NMR Practice
20:57
¹H NMR Practice 1: C₁₀H₁₄
20:58
¹H NMR Practice 2: C₄H₈O₂
29:50
¹H NMR Practice 3: C₆H₁₂O₃
39:19
¹H NMR Practice 4: C₈H₁₈
50:19
More About Coupling Constants (J Values)
57:11
Vicinal (3-bond) and Geminal (2-bond)
57:12
Cyclohexane (ax-ax) and Cyclohexane (ax-eq) or (eq-eq)
59:50
Geminal (Alkene), Cis (Alkene), and Trans (Alkene)
1:02:40
Allylic (4-bond) and W-coupling (4-bond) (Rigid Structures Only)
1:04:05
¹H NMR Advanced Splitting Patterns
1:05:39
Example 1: ¹H NMR Advanced Splitting Patterns
1:05:40
Example 2: ¹H NMR Advanced Splitting Patterns
1:10:01
Example 3: ¹H NMR Advanced Splitting Patterns
1:13:45
¹H NMR Practice
1:22:53
¹H NMR Practice 5: C₁₁H₁₇N
1:22:54
¹H NMR Practice 6: C₉H₁₀O
1:34:04
¹³C NMR Spectroscopy
1:44:49
¹³C NMR Spectroscopy
1:44:50
¹³C NMR Chemical Shifts
1:47:24
¹³C NMR Chemical Shifts Part 1
1:47:25
¹³C NMR Chemical Shifts Part 2
1:48:59
¹³C NMR Practice
1:50:16
¹³C NMR Practice 1
1:50:17
¹³C NMR Practice 2
1:58:30
Mass Spectrometry

1h 28m 35s

Intro
0:00
Introduction to Mass Spectrometry
0:37
Uses of Mass Spectrometry: Molecular Mass
0:38
Uses of Mass Spectrometry: Molecular Formula
1:04
Uses of Mass Spectrometry: Structural Information
1:21
Uses of Mass Spectrometry: In Conjunction with Gas Chromatography
2:03
Obtaining a Mass Spectrum
2:59
Obtaining a Mass Spectrum
3:00
The Components of a Mass Spectrum
6:44
The Components of a Mass Spectrum
6:45
What is the Mass of a Single Molecule
12:13
Example: CH₄
12:14
Example: ¹³CH₄
12:51
What Ratio is Expected for the Molecular Ion Peaks of C₂H₆?
14:20
Other Isotopes of High Abundance
16:30
Example: Cl Atoms
16:31
Example: Br Atoms
18:33
Mass Spectrometry of Chloroethane
19:22
Mass Spectrometry of Bromobutane
21:23
Isotopic Abundance can be Calculated
22:48
What Ratios are Expected for the Molecular Ion Peaks of CH₂Br₂?
22:49
Determining Molecular Formula from High-resolution Mass Spectrometry
26:53
Exact Masses of Various Elements
26:54
Fragmentation of various Functional Groups
28:42
What is More Stable, a Carbocation C⁺ or a Radical R?
28:43
Fragmentation is More Likely If It Gives Relatively Stable Carbocations and Radicals
31:37
Mass Spectra of Alkanes
33:15
Example: Hexane
33:16
Fragmentation Method 1
34:19
Fragmentation Method 2
35:46
Fragmentation Method 3
36:15
Mass of Common Fragments
37:07
Mass of Common Fragments
37:08
Mass Spectra of Alkanes
39:28
Mass Spectra of Alkanes
39:29
What are the Peaks at m/z 15 and 71 So Small?
41:01
Branched Alkanes
43:12
Explain Why the Base Peak of 2-methylhexane is at m/z 43 (M-57)
43:13
Mass Spectra of Alkenes
45:42
Mass Spectra of Alkenes: Remove 1 e⁻
45:43
Mass Spectra of Alkenes: Fragment
46:14
High-Energy Pi Electron is Most Likely Removed
47:59
Mass Spectra of Aromatic Compounds
49:01
Mass Spectra of Aromatic Compounds
49:02
Mass Spectra of Alcohols
51:32
Mass Spectra of Alcohols
51:33
Mass Spectra of Ethers
54:53
Mass Spectra of Ethers
54:54
Mass Spectra of Amines
56:49
Mass Spectra of Amines
56:50
Mass Spectra of Aldehydes & Ketones
59:23
Mass Spectra of Aldehydes & Ketones
59:24
McLafferty Rearrangement
1:01:29
McLafferty Rearrangement
1:01:30
Mass Spectra of Esters
1:04:15
Mass Spectra of Esters
1:01:16
Mass Spectrometry Discussion I
1:05:01
For the Given Molecule (M=58), Do You Expect the More Abundant Peak to Be m/z 15 or m/z 43?
1:05:02
Mass Spectrometry Discussion II
1:08:13
For the Given Molecule (M=74), Do You Expect the More Abundant Peak to Be m/z 31, m/z 45, or m/z 59?
1:08:14
Mass Spectrometry Discussion III
1:11:42
Explain Why the Mass Spectra of Methyl Ketones Typically have a Peak at m/z 43
1:11:43
Mass Spectrometry Discussion IV
1:14:46
In the Mass Spectrum of the Given Molecule (M=88), Account for the Peaks at m/z 45 and m/z 57
1:14:47
Mass Spectrometry Discussion V
1:18:25
How Could You Use Mass Spectrometry to Distinguish Between the Following Two Compounds (M=73)?
1:18:26
Mass Spectrometry Discussion VI
1:22:45
What Would be the m/z Ratio for the Fragment for the Fragment Resulting from a McLafferty Rearrangement for the Following Molecule (M=114)?
1:22:46
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Lecture Comments (57)

1 answer

Last reply by: Professor Starkey
Wed Sep 12, 2018 5:05 PM

Post by Zohair Badawi on August 30, 2018

What would the degree of unsaturation formula be if there was a Nitrogen or a Halogen in the molecule we're analyzing in the NMR?

1 answer

Last reply by: Professor Starkey
Fri Mar 31, 2017 10:06 PM

Post by Ay Ayy on March 28, 2017

Hello Dr.
I have question  why for 13C there are not integration and splitting?

thank you

1 answer

Last reply by: Professor Starkey
Wed Mar 22, 2017 11:55 AM

Post by Ay Ayy on March 21, 2017

Hi Dr.
Thank you so much,
I have question, in the last practice, in the ring,why carbon double bond attached with ch2 and there are not close together in chemical shift?  
Thanks  

1 answer

Last reply by: Professor Starkey
Thu Mar 31, 2016 2:11 PM

Post by Adiam Ghebre on March 28, 2016

Good lecture! Is it possible for you to do an example with alkenes and the double bond is between two carbons?

1 answer

Last reply by: Professor Starkey
Mon Oct 12, 2015 1:14 AM

Post by sania sarwar on October 10, 2015

Hi Dr Starkey,
thanks for the lectures, they are really helpful.A question that I wasn't sure of is that in example 2 the benzene ring is a singlet so if CH2 is attached to it, wouldn't that make it a triplet?

1 answer

Last reply by: Professor Starkey
Sat Jul 19, 2014 10:28 PM

Post by John Subaitani on July 17, 2014

So are we saying that the H-NMR for C10 H14 is para or can it be para, meta. or ortho?

2 answers

Last reply by: Professor Starkey
Sat Jul 12, 2014 10:32 AM

Post by Francesco Frigo on July 10, 2014

Hello dr. Starkey, at minute 93:41 you define the signal given by proton A as a "clear triplet". But wouldn't proton A couple with Hb with some J value and with Hc with some different J value (since Hb and Hc are chemically different)? So in the end wouldn't this signal look like a doublet of triplets ? Maybe it wouldn't actually be easy to notice since the J values are so similiar but at least we could see some jagged peaks, right?

1 answer

Last reply by: Professor Starkey
Sat Mar 22, 2014 12:08 AM

Post by in gi seo on March 20, 2014

Are we not going to cover DEPT NMR????

1 answer

Last reply by: Professor Starkey
Fri Mar 14, 2014 11:59 AM

Post by saima khwaja on March 13, 2014

Hello Dr. Starkey,

If it wasn't for your lectures there is no way I would understand this part of organic chemistry.  My professor goes really fast and these lectures help me to clarify things in my head.  Thank You!

2 answers

Last reply by: Calin Cochran
Sun Mar 9, 2014 8:40 PM

Post by Calin Cochran on March 4, 2014

Hi Professor Starkey!

I know I've told you before, but your lecturing abilities are phenomenal! I can't thank you enough for all the help you have given me!

I do have a quick question. My professor for Organic 2 has clumped the second half of NMR, Ketones, Aldehydes, Carbohydrates, and Carboxylic Acids together for our upcoming exam. Your lectures have helped tremendously with all, but I'm a little lacking on the carbohydrates. I wasn't sure if I may have missed it somewhere on this website or we just don't cover it on here.

If you have any guidance, I would appreciate it tremendously! Thanks so much!

Calin Cochran

1 answer

Last reply by: Professor Starkey
Sun Feb 23, 2014 5:27 PM

Post by Jia Cheong on February 22, 2014

You are the best!!!!! Be my lecturer! :)

3 answers

Last reply by: Professor Starkey
Mon Feb 17, 2014 11:37 PM

Post by Udoka Ofoedu on February 17, 2014

hey dr. starkey ,
Why did u choose hb for only a germinal j value. it has a vicinal j value too ? Please why did u not split that ? Thanks

1 answer

Last reply by: Professor Starkey
Sun Jan 12, 2014 12:23 AM

Post by Mike Anderson on January 11, 2014

Is there a way to select a lecture and be able to listen to just a part of it?  For example it seems if I want to go back the next day and listen to the second part of a lecture, I have to listen to the whole first half of it first.

Thanks

Mike Anderson

1 answer

Last reply by: Professor Starkey
Tue Oct 29, 2013 10:30 PM

Post by Joel Barrett on October 28, 2013

Professor Starkey, you are wonderful. I saw your YouTube videos as well. Your hard work is appreciated. I love o-chem just a little bit more because of your videos ;)

1 answer

Last reply by: Professor Starkey
Sun Jul 21, 2013 10:52 PM

Post by Amy Lin on July 21, 2013

Hi Dr Starkey,  I don't have a question. I finished all the lectures and I can't express how much of a help it has been. Your lectures have been really concise and you break it down in a way I can finally understand and work through. I have always had a horrible time with Chemistry and this is the first time I actually feel like I can do this.  (And that is a lot given how many times I had to retake Chem...) I am done my subscription and I just wanted to tell you what a big help you have been.  Thank you so much.  !!!

1 answer

Last reply by: Professor Starkey
Wed Jun 5, 2013 10:44 PM

Post by Heidi Schmeck on June 5, 2013

Dr. Starkey:

Just a quick note to thank you for your informative and engaging lectures. I used educator.com and your lab tutorials (Cal Poly Pomona) as supplemental sources to reinforce my understanding of my Organic Chemistry II coursework. Your detailed and clear explanations of complex concepts helped me earn an "A" in both lecture and lab. Thank you! :)

1 answer

Last reply by: Professor Starkey
Mon Feb 25, 2013 10:24 PM

Post by Ryan Rod on February 25, 2013

Hi, did you also cover(including IR and NMR of them), Ethers , Epoxides, and Sulfides? how about Aromatic compounds?
Sorry I have an exam and panicking!

1 answer

Last reply by: Professor Starkey
Wed Feb 20, 2013 9:42 PM

Post by José Menéndez on February 19, 2013

Hello Dr. Starkey, I wanted to know if you have a mass spectrometry lecture? Thanks.

1 answer

Last reply by: Professor Starkey
Wed Feb 20, 2013 9:44 PM

Post by Ryan Rod on February 18, 2013

What about Carbon NMR?? did I miss it, or have you not covered it?

BTW,

Your are a AMAZING!!

1 answer

Last reply by: Professor Starkey
Sun Feb 17, 2013 5:35 PM

Post by Amirnikan Eghbali on February 17, 2013

Thanks and a suggestion, it's better if you label doublet triplet etc with small letters (s,d,t) and the other A, B, C, D... that you use for identification with capital letters to avoid confusion.

1 answer

Last reply by: Professor Starkey
Fri Dec 14, 2012 11:23 AM

Post by Marina Bossi on December 12, 2012

Hi Professor Starkey,
I am confused about labelling some functional groups in certain areas of the spectrum where multiple groups can be found. For instance, methyl groups are found at 10-30 and methylene groups at 15-55. How would I know the difference?

Thanks

2 answers

Last reply by: alister guerrero
Wed Nov 7, 2012 4:02 PM

Post by alister guerrero on November 4, 2012

Hi, I just got my account. i was wondering if there is a way to download all the slides together? Thank You

1 answer

Last reply by: Professor Starkey
Fri Jul 13, 2012 1:33 PM

Post by Gabriella Kaminer-Levin on July 5, 2012

Dear Dr. Starkey:

How can one distinguish between two closely spaced singlets, and a doublet with a large coupling constant (J value)? At 73:30 you examine a doublet with a large coupling constant, but how can one be certain that it is a doublet with a large coupling constant rather than two closely spaced singlets (since in this case examining the ratios does not help)?
Also, do you have any lectures on Mass Spectrometry? I wasn't sure whether they are included in the course and I just wasn't able to locate it in the Table of Contents.
Thank you again for your clear presentation of the material!

Gabriella

1 answer

Last reply by: Professor Starkey
Mon Apr 9, 2012 11:34 PM

Post by Ghazal Fata on April 7, 2012

Dear Professor,
First of all, I wanted to thank you for the great lectures you provide.
Second, I was wondering if the 13C-NMR is going to be thought in a more complex way in Educator. The organic chem I am enrolled in emphasizes a lot more on how to read 13C-NMR without the help of IR or 1H-NMR and it's really complicated and I'd appreciate it if you provide more videos for us, or just refer me to a place which I can find helpful information.
My course actually emphasizes on how different fragments of molecules appear on NMR and which bonds are cleaved and molecular ions are created.
Thank you so much,
Ghazal F

1 answer

Last reply by: Professor Starkey
Tue Mar 27, 2012 11:23 PM

Post by Robert Shaw on March 23, 2012

Dr Starkey, My NMR table has aldehydes listed as 9.5 to 9.9 yet yours shows it at just over 8. Which is correct?

1 answer

Last reply by: Professor Starkey
Sat Jan 21, 2012 1:06 PM

Post by Jason Jarduck on January 20, 2012

Hi DR starkey,

I have a question about an NMR.

I only have hydrogen NMR with a d20 shake.
The question is stating that 3200 - 3500 which specifies an alcohol group.
NO OTHER IR INFO.
NO C NMR spcetrum is given
Find compound A, only H NMR spectrum
ION IS 84M/Z
USED SULFURIC ACID IN AN ELIMANTION REACTION to form an alkene
FIND COMPUND B, only H NMR spectrum
This is an assignment question!!!

I also have the multiplicities for the hydrogens for compound A and B. How many carbons?

I'M CURRENTLY TAKING ORGANIC CHEMISTRY 2 AND THAN I WILL BE TAKING ORGANIC CHEMISTRY 3 LATER.

What would be the best strategy to solve this problem!!! Also where can I find a chart with all energy levels in Joules.

I enjoy your lecture alot and I'm in a hurry because I have a lab to do for Wensday and I must have this question done for Monday.

Thank you

Jason Jarduck

Nuclear Magnetic Resonance (NMR) Spectroscopy, Part II

Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.

  • Intro 0:00
  • ¹H NMR Problem-Solving Strategies 0:18
    • Step 1: Analyze IR Spectrum (If Provided)
    • Step 2: Analyze Molecular Formula (If Provided)
    • Step 3: Draw Pieces of Molecule
    • Step 4: Confirm Piecs
    • Step 5: Put the Pieces Together!
    • Step 6: Check Your Answer!
  • Examples 9:17
    • Example 1: Determine the Structure of a C₉H₁₀O₂ Compound with the Following ¹H NMR Data
    • Example 2: Determine the Structure of a C₉H₁₀O₂ Compound with the Following ¹H NMR Data
  • ¹H NMR Practice 20:57
    • ¹H NMR Practice 1: C₁₀H₁₄
    • ¹H NMR Practice 2: C₄H₈O₂
    • ¹H NMR Practice 3: C₆H₁₂O₃
    • ¹H NMR Practice 4: C₈H₁₈
  • More About Coupling Constants (J Values) 57:11
    • Vicinal (3-bond) and Geminal (2-bond)
    • Cyclohexane (ax-ax) and Cyclohexane (ax-eq) or (eq-eq)
    • Geminal (Alkene), Cis (Alkene), and Trans (Alkene)
    • Allylic (4-bond) and W-coupling (4-bond) (Rigid Structures Only)
  • ¹H NMR Advanced Splitting Patterns 1:05:39
    • Example 1: ¹H NMR Advanced Splitting Patterns
    • Example 2: ¹H NMR Advanced Splitting Patterns
    • Example 3: ¹H NMR Advanced Splitting Patterns
  • ¹H NMR Practice 1:22:53
    • ¹H NMR Practice 5: C₁₁H₁₇N
    • ¹H NMR Practice 6: C₉H₁₀O
  • ¹³C NMR Spectroscopy 1:44:49
    • ¹³C NMR Spectroscopy
  • ¹³C NMR Chemical Shifts 1:47:24
    • ¹³C NMR Chemical Shifts Part 1
    • ¹³C NMR Chemical Shifts Part 2
  • ¹³C NMR Practice 1:50:16
    • ¹³C NMR Practice 1
    • ¹³C NMR Practice 2
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