R W Grime Ripon Grammar School

Slides:

Advertisements

Similar presentations

Organic Spectroscopy Mass Spectrometry.

Advertisements

Advanced Higher Unit 3 Mass Spectrometry. Mass spectrometry can be used to determine the accurate molecular mass and structural features of an organic.

1 Carboxylic Acids, Esters, Amines and Amides Carboxylic Acids Properties of Carboxylic Acids Esters Esterification and Hydrolysis.

MiniQuiz 6 Answers: Which of the compounds below do you expect to absorb light in the UV-region? (circle) Hexane Ethanol Benzene Naphthalene Explain your.

Mechanism of Phenylurethane

Complete this reaction equation:

Higher Chemistry Unit 2 Multiple Choice Questions Section 6 Esters

Infrared Spectroscopy

Organic Chemistry Naming

Menu A gaseous sample compound is injected into the mass spectrometer.

AS 2.12 Mass spectra a. interpret fragment ion peaks in the mass spectra of simple organic compounds, eg the difference between propanal and propanone.

Mass spectrometry L.O.: Understand how fragmentation can be useful to find the molecular structure.

Menu We will look at some of the major peaks in the mass spectrum of butane.

1.6 Carboxylic Acids and Esters

In MS a molecule is vaporized and ionized by bombardment with a beam of high-energy electrons. E = 1600 kcal (or 70 eV). C-C BDE = 100 kcal Mass Spectrometry.

Created with MindGenius Business 2005® Isotopes (1) Isotopes (1) It is important to use the correct method to calculate molecular weight for MS. Average.

ISOMERISM There are two main types of isomerism Structural i.e.molecular positional functional group Stereoisomerism i.e.Geometric and Optical.

CONTENTS Fragmentation of molecular ions - theory What a mass spectrum tells you Molecular ions Fragmentation Mass spectra of alkanes Mass spectra of halogenoalkanes.

Infra-Red and Mass Spectroscopy Webquest Modern Analytical Techniques.

IR and Mass Spec Webquest Suzanna Newton 12 Fisher.

Demonstrate understanding of spectroscopic data in chemistry Chemistry A.S internal credits.

Chemsheets AS006 (Electron arrangement)

In carbon-13 NMR, what do the number of peaks represent? The number of chemically different carbon atoms present.

Lecture 3 Mass Spectrometry and Infrared Spectroscopy.

12. Structure Determination: Mass Spectrometry

MASS SPECTROSCOPY (with Gas Chromatography). 5 Stages of the process – where do they happen? 1.Sample vaporised 2.Sample ionised 3.Ions accelerated 4.Ions.

IR SPECTROSCOPY R W Grime Ripon Grammar School. Light is one form of electromagnetic radiation. Light is only a very small part of the electromagnetic.

Section Spectroscopic Analysis of Aldehydes and Ketones

Chemical Ideas 6.5 Mass spectrometry.

Atomic structure L.O. To be able to recall definitions of relative atomic, isotopic and molecular mass. To demonstrate an understanding of the basic.

FURTHER MASS SPECTROMETRY KNOCKHARDY PUBLISHING

Carboxylic Acids, Esters, Amines and Amides

Leaving Certificate Chemistry

Atomic structure L.O. 1. To be able to recall definitions of relative atomic, isotopic and molecular mass. 2. To learn about the key principles of mass.

Chapter 15 Structure Determination by Spectroscopy (II): UV-Vis & Mass

IR spectroscopy (review)

MASS SPECTROSCOPY.

Make as many structures as you can from the molecular formula C5H12

Course Evaluation Last semester the average response rate for the on-line form was 54% as compared to about 80% for the old paper forms. Let’s do better.

Lecture 23 Quiz 6 Average = 72% (36 out of 50) Mass Spectrometry

Mass Spectrometry Courtesy

FH2O2Resonance [α]λ SN1E1 ME2SOCl2 TS Enan R. Chem Fall, 2014

Carboxylic Acids, Esters, Amines and Amides

Introduction to Mass Spectrometry (MS)

Organic chemistry Mr G Davies S20

C2.8 Instrumental Analysis

Mass Spectrometry Courtesy

Get your answers out for the challenge we finished with last lesson.

Get your answers out for the challenge we finished with last lesson.

Chemical Reactions 1. H2 + I2 HI S 2. Na + H2O NaOH + H2 SR 3. CO + O2

Chemsheets AS007 (Mass spectroscopy)

Determination of Structure

Functional Group Chemistry

Combined Spectroscopy…

Mass Spectrometry Courtesy

Mass Spectrometry (MS)

Unit Objectives 1)understand the evolution of models of the atom: Dalton, Thomson, Rutherford, Bohr, the ‘quantum model 2) understand the meaning of mass.

Unit 3.4 Structural Analysis

MASS SPECTRA measure a compound’s Mol. Wt.

Mass Spectrometry. 3 The GC-MS => A mixture of compounds is separated by gas chromatography, then identified by mass spectrometry.

Esters and Esterification

FURTHER MASS SPECTROMETRY KNOCKHARDY PUBLISHING

In this lesson you will learn:

Functional Groups.

FURTHER MASS SPECTROMETRY KNOCKHARDY PUBLISHING

Organic Models and Worksheet

TOPIC 9. STRUCTURE DETERMINATION (chapter 9 and part of chapter 2)

Presentation transcript:

R W Grime Ripon Grammar School 18/06/2018 MASS SPECTROSCOPY R W Grime Ripon Grammar School

HIGH RESOLUTION MASS SPECTROSCOPY Molecular ion formed: M → [M]+. + e– m/z value for [M]+. gives the Mr. High resolution measures m/z to enough accuracy to find the molecular formula. e.g. Mr = 60 CH3COOH 60.02112 molecular formula = C2H4O2 NH2CONH2 60.03235 molecular formula = CH4N2O CH3CH2CH2OH 60.05751 molecular formula = C3H8O CH3CH(OH)CH3 60.05751 molecular formula = C3H8O

FRAGMENTATION Molecular ion fragments due to covalent bonds breaking: [M]+. → X+ + Y. Much information from fragmentation patterns – can often work out structure. Relatively stable ions such as carbocations R+ and acylium ions [R-C=O]+ are common. The more stable the ion, the greater the peak intensity. m/z 15 29 31 43 57 fragment CH3+ CH3CH2+ CH2OH+ CH3CH2CH2+ (CH3)2CH+ CH3CO+ CH3CH2CO+

butane CH3CH2CH2CH3 C4H10  [C4H10]+. + e– m/z 58 [C4H10]+.  [CH3CH2CH2]+ + .CH3 m/z 43 [CH3CH2CH2]+ [C4H10]+.  [CH3CH2]+ + .CH2CH3 m/z 29 [CH3CH2]+ [C4H10]+.

ISOTOPES Ions with different isotopes produce different signals. Most important for Br and Cl. Br: 50% 79Br 50% 81Br Cl: 75% 35Cl 25% 37Cl If two or more Br/Cl atoms, then spectrum is more complicated. Often small peaks at m/z + 1 due to 2H and 13C.

bromomethane CH3Br CH381Br  [CH381Br]+. + e– m/z 96 CH379Br  [CH379Br]+. + e– m/z 94 [CH3Br]+.  [CH3]+ + .Br m/z 15 [CH3]+ [CH379Br]+. [CH381Br]+.

chloroethane CH3CH2Cl CH3CH237Cl  [CH3CH237Cl]+. + e– m/z 66 CH3CH235Cl  [CH3CH235Cl]+. + e– m/z 64 [CH3CH237Cl]+.  [CH237Cl]+ + .CH3 m/z 51 [CH3CH2]+ [CH3CH235Cl]+.  [CH235Cl]+ + .CH3 m/z 49 [CH3CH235Cl]+. [CH3CH2Cl]+.  [CH3CH2]+ + .Cl m/z 29 [CH237Cl]+ [CH235Cl]+ [CH3CH237Cl]+.

dichloromethane CH2Cl2 37Cl : 35Cl = 1 : 3 37Cl2 : 35Cl37Cl : 35Cl2 = 1 : 6 : 9 [CH235Cl]+ [CH235Cl2]+. [CH237Cl35Cl]+. [CH237Cl]+ [CH237Cl2]+.

dibromomethane CH2Br2 81Br : 79Br = 1 : 1 81Br2 : 81Cl79Br : 79Br2 = 1 : 2 : 1 174 [CH281Br79Br]+. 93 [CH279Br]+ 95 [CH281Br]+ 172 [CH279Br2]+. 176 [CH281Br2]+.

butanone CH3CH2COCH3 CH3CH2COCH3  [CH3CH2COCH3]+. + e– m/z 72 [CH3CH2COCH3]+.  [CH3CH2CO]+ + .CH3 m/z 57 [CH3CH2COCH3]+.  [CH3CO]+ + .CH2CH3 m/z 43 [CH3CO]+ [CH3CH2COCH3]+.  [CH3CH2]+ + .COCH3 m/z 29 [CH3CH2]+ [COCH2CH3]+ [CH3COCH2CH3]+.

methyl butanoate CH3CH2CH2COOCH3 CH3CH2CH2COOCH3  [CH3CH2CH2COOCH3]+. + e– m/z 102 methyl butanoate CH3CH2CH2COOCH3 [CH3CH2CH2COOCH3]+.  [CH3CH2CH2COO]+ + .CH3 m/z 87 [CH3CH2CH2COOCH3]+.  [CH3CH2CH2CO]+ + .OCH3 m/z 71 [CH3CH2CH2COOCH3]+.  [COOCH3]+ + .CH2CH2CH3 m/z 59 [CH3CH2CH2]+ [CH3CH2CH2COOCH3]+.  [CH3CH2CH2]+ + .COOCH3 m/z 43 [CH3CH2CH2COOCH3]+.  [CH3CH2]+ + .CH2COOCH3 m/z 29 [CH3CH2CH2CO]+ [COOCH3]+. [CH3CH2CH2COO]+ [CH3CH2]+ [CH3CH2CH2COOCH3]+.

propyl methanoate methylethyl methanoate ethyl ethanoate methyl propanoate

propyl methanoate [OCH2CH2CH3]+ m/z 59 [HCO]+ m/z 29 [CH2CH2CH3]+ [HCOO]+ m/z 45

methylethyl methanoate [OCH2(CH3)2]+ m/z 59 [HCO]+ m/z 29 [CH2(CH3)2]+ m/z 43 [HCOO]+ m/z 45

ethyl ethanoate [OCH2CH3]+ m/z 45 [CH3CO ]+ m/z 43 [CH2CH3]+ m/z 29 [CH3COO ]+ m/z 59

methyl propanoate [OCH3]+ m/z 31 [CH3CH2CO ]+ m/z 57 [CH2CH3]+ m/z 29 [CH3OCO ]+ m/z 59