SDBS Integrated Spectral Database for Organic Compounds Sample Search for Chemistry 130 Grace Baysinger and Dr. Dave Keller

2 SDBS – URL and Description SDBS includes 6 different types of spectra under a directory of the compounds. The six spectra are:  Electron impact Mass spectrum (EI-MS),  Fourier transform infrared spectrum (FT-IR)  1 H nuclear magnetic resonance (NMR) spectrum  13 C NMR spectrum  Laser Raman spectrum  Electron spin resonance (ESR) spectrum It is possible to search by number of atoms, spectral peaks, plus compound name, molecular formula, molecular weight, and CAS Registry Number.

3 SDBS Welcome Page

4 SDBS - Search Form Note: for each peak, a range of values is actually being searched

5 Spectra Data Search Tips 13 C NMR  Search 13 C spectral peaks first as they most closely match your lab data 1 H NMR  Use midpoints of multiplets as spectral peak values  OH peaks for alcohols and acids, and NH peaks for amines may “wander” so your values may not agree with the database IR  Only include major peaks in IR search; usually < 2800 cm -1

6 Spectra Data Search Tips Be sure to omit any peaks due to solvent For Chem 130, the complete range for a spectral diagram is about :  13 C NMR: 0 to ~220 ppm  IR:~700 to ~4000 cm -1  1 H NMR: 0 to ~12 ppm Add no shift regions (i.e. no peak present) to refine a 13 C or 1 H NMR search Review of General Search Strategy  Search spectral peaks using conventions required by search interface  Search 13 C NMR first, IR second, and 1 H NMR last  Refine using no shift regions for 13 C and 1 H NMR data  Further refine using heteroatom and/or hydrogen data

7 SDBS - Tips for Converting Selected Lab Data to Search Strategies

8 13 C NMR Spectrum of Unknown

9 SDBS 13 C NMR Search – Peaks, No Shift Regions, and Number of Atoms Use comma with no spaces for multiple peaks. For ranges use space between upper and lower values. Use comma with no spaces for multiple ranges. Peaks=128,129,130,172. No peak region= ,110 5 N, F, Cl, Br, I, S, P, Si not present

10 SDBS - Brief Display of Results Summary of available spectra (Yes/No) Review molecular formulas and eliminate some compounds from further consideration based on heteroatoms present. Remaining compounds can be quickly compared to unknown using 1 H, 13 C,and IR spectra as well as functional groups listed in name

11 SDBS – View 13 C NMR in CDCl 3 for Benzoic Acid (=Unknown)

12 IR Spectrum of Unknown

13 SDBS IR Search – Peaks and Number of Atoms Peaks = 1688,1454,1327,1 294,936,708 N, F, Cl, Br, I, S, P, Si not present

14 IR Search Results Results on each page are sorted by MW. Use heteroatoms and functional groups in chemical name of to help eliminate candidates.

15 SDBS - Viewing IR Spectra for Benzoic Acid

16 1 H NMR Spectrum of Unknown For multiplets, use midpoints as spectral peak values

17 SDBS 1 H NMR Search – Peaks, No Shift Regions, and Number of Atoms Peaks = 8.12,7.6,7.46 No shift Regions = , N, F, Cl, Br, I, S, P, Si not present

18 SDBS - 1 H NMR Search Results

19 SDBS – Viewing 1 H NMR (90 MHz in CDCl 3 ) for Benzoic Acid Each hydrogen is labeled and assigned to a peak with a given chemical shift in ppm. Click on peak data button for list of individual peaks.

20 SDBS – 1 H NMR Peak Data for Benzoic Acid