STRUCTURALLY AWARE APPROACH TO THE INTERPRETATION OF VIBRATIONAL SPECTRA

transcript

Spectroscopy • Chromatography • PhysChem • Naming • Drawing and Databasing • Enterprise Solutions

STRUCTURALLY AWARE APPROACH

TO THE INTERPRETATIONOF VIBRATIONAL SPECTRA

Eugene Karpushkin,Yury Zhukov,

Andrey Bogomolov

www.acdlabs.com

What makes “manual” IR interpretation challenging?

IR spectral signals are “volatile” due to overlap and influence of chemical environment

Many different factors to take into account simultaneously

Correlation tables and charts take expert’s time and efforts

Structurally aware software required!

ACD/Labs is a structurally aware software

Drawn Structure

Chemicaldatabases

Systematicnaming

Spectra

Chromatograms NMR spectralprediction

Phys-chemproperty

prediction

What does structural awareness mean?

Easy drawing of chemical structures 2D-cleaning/3D-optimization Attaching molecule to a spectrum Fragment structure analysis

Structure/substructure DB search Reporting with structures

Peak-to-fragment assignment

Spectrum Interpretation ChartRaw

Spectrum

Report

Confirmed Structure

Hit List

Peak Table

Possible Fragments

Hypothetic Structures

PeakAnalysis

DB Search

Compare

Knowledge Base

Construct

Verify

Assign

Find Repeating

More Data

Possible Fragments

Searching Database: Example 1Raw

Spectrum

Report

Confirmed Structure

Hit List

Peak Table

PeakAnalysis

DB Search

Compare

Knowledge Base

Construct

Verify

Assign

Find Repeating

More Data

Searching Database: Example 2Raw

Spectrum

Report

Confirmed Structure

Hit List

Peak Table

Possible Fragments

PeakAnalysis

DB Search

Compare

Knowledge Base

Construct

Verify

Assign

Find Repeating

More Data

Candidate fragments:CH3 – 9 hits; NO2 – 7 hits; aromatics - 4 hits

Peak AnalysisRaw

Spectrum

Report

Confirmed Structure

Hit List

Peak Table

Possible Fragments

PeakAnalysis

DB Search

Compare

Knowledge Base

Construct

Verify

Assign

Find Repeating

More Data

Knowledge Base: classes

alkanes, alkenes, alkynes, allenes, alicyclic compounds

alcohols, ethers, aldehydes, ketones, non-carbon acids, peroxy compounds, halogen compounds

carboxylic acids, halogenides, anhydrides, carbonates, carboxylates, esters

aromatic compounds, heterocycles amides, amines, imides, imines,

nitrocompounds, other N compounds B, P, S, Se, Si compounds inorganic ions

Knowledge Base

Knowledge BaseRaw

Spectrum

Report

Confirmed Structure

Hit List

Peak Table

Possible Fragments

PeakAnalysis

DB Search

Compare

Construct

Verify

Assign

Find Repeating

More Data

ACD/Labs Fragment Object

“Atom” descriptors: * A [C,H] AnyC SatC Aryl Hal [N,O,S]Bond descriptors:Ar D Rn Ch

O Aryl

A[N,O]

Powerful means selective

PCA for Fragment FormulationExample set:

15 chloroanhydrides

+19 aldehydes

=34 compounds

*825 wavelengths

PCA for Fragment Formulation:Captured Variance

PCA for Fragment Formulation: Scores Plot – Structure Classes

PCA for Fragment Formulation:Bi-Plot Reveals Spectral Features

1718 cm-1

1742 cm-1

1802 cm-1

PCA for Fragment Formulation

Knowledge Base is Interactive

Structure VerificationRaw

Spectrum

Report

Confirmed Structure

Hit List

Peak Table

Possible Fragments

PeakAnalysis

DB Search

Compare

Knowledge Base

Construct

Verify

Assign

Find Repeating

More Data

Successful Verification is… Failed One

Raw Spectrum

Report

Confirmed Structure

Hit List

Peak Table

Possible Fragments

PeakAnalysis

DB Search

Compare

Knowledge Base

Construct

Verify

Assign

Find Repeating

More Data

Assignment and ReportingRaw

Spectrum

Report

Confirmed Structure

Hit List

Peak Table

Possible Fragments

PeakAnalysis

DB Search

Compare

Knowledge Base

Construct

Verify

Assign

Find Repeating

More Data

Conclusions1. Full qualitative analysis spectral interpretation tools in the same product interface

2. Authentic Fragment Object provides almost unlimited flexibility in specifying group environment

3. Advanced tool for fragmental analysis of molecules

4. Knowledge Base with about 2400 highly selective fragments

5. Facilitated IR spectral interpretation and automated structure verification

Acknowledgements

Yury Zhukov Alexey Pastutsan

STRUCTURALLY AWARE APPROACH TO THE INTERPRETATION OF VIBRATIONAL SPECTRA

Documents