SDBS Integrated Spectral Database for Organic Compounds
Transcription
SDBS Integrated Spectral Database for Organic Compounds
SDBS Integrated Spectral Database for Organic Compounds Sample Search for Chemistry 130 Grace Baysinger and Dr. Dave Keller SDBS – URL and Description http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/cre_index.cgi?lang=eng 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) 1H nuclear magnetic resonance (NMR) spectrum 13C 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. 2 SDBS Welcome Page 3 SDBS - Search Form Note: for each peak, a range of values is actually being searched 4 Spectra Data Search Tips 13C 1H NMR Search 13C spectral peaks first as they most closely match your lab data 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 5 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: 13C NMR: IR: 1H NMR: 0 to ~220 ppm ~600 to ~4000 cm-1 0 to ~12 ppm Add no shift regions (i.e. no peak present) to refine a 13C or 1H NMR search Review of General Search Strategy Search spectral peaks using conventions required by search interface Search 13C NMR first, IR second, and 1H NMR last Refine using no shift regions for 13C and 1H NMR data Further refine using heteroatom and/or hydrogen data 6 SDBS - Tips for Converting Selected Lab Data to Search Strategies Type of Search Lab Data Values Searched CAS Registry Number Not available from lab data 68-85-0 Molecular Formula C6H5Br C6H5Br Number of Atoms 5-6 Hydrogens, 1-4 Oxygens, No Nitrogen present Hydrogen 5 to 6, Oxygen 1 to 4, Nitrogen 0 to 0 13 C Peaks IR Peaks 1 H-NMR Peaks 128, 129, 130, 133, 172 No Shift Region 165-140 and 125-5 1688, 1454, 1327, 1294, 936, 708 8.12, 7.6, 7.46 No Shift Region 11-8.5 and 7-0.5 128,129,130,133,172 No Shift Regions 165 140,125 5 1688,1454,1327,1294,936,708 8.12,7.6,7.46 No Shift Region 11.0 8.5,7.0 0.5 Error Range Caveats Use CAS RN to find/confirm physical properties info and view spectral diagram. Element symbols are case sensitive in many resources but not in SDBS. Put MF in Hill System Order (Carbon 1st, Hydrogen 2nd, and then all other elements in alphabetical order). +/- 2.0 +/-10 Comma is the separator for multiple shifts. Range is defined by two numbers separated by a space. Ranges for multiple peaks – put space between upper and lower range of each peak, use comma between each range with no space between comma and values. Complete range for Chem 130 is 0 to ~220 ppm. Use either a space or a comma as the separator for multiple peaks. Use a hyphen to search a range of values (e.g. 700-750). Only include major peaks, usually < 2800 cm-1 Complete range for Chem 130 is ~700 to ~4000 cm-1 Use midpoints of multiplets as spectral peak values. Comma is the separator for multiple shifts. Range is defined by two numbers separated by a space. Ranges for multiple peaks – put space +/- 0.2 ppm between upper and lower range of each peak, use comma between each range with no space between comma and values. Complete range for Chem 130 is 0 to ~12 ppm. Don't use peaks from solvent! revised 8 November 2009 7 13C NMR Spectrum of Unknown 8 SDBS 13C 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=220 180,110 5 N, F, Cl, Br, I, S, P, Si not present 9 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 1H, 13C,and IR spectra as well as functional groups listed in name 10 SDBS – View 13C NMR in CDCl3 for Benzoic Acid (=Unknown) 11 IR Spectrum of Unknown 12 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 13 IR Search Results Results on each page are sorted by MW. Use heteroatoms and functional groups in chemical name of to help eliminate candidates. 14 SDBS - Viewing IR Spectra for Benzoic Acid 15 1H NMR Spectrum of Unknown For multiplets, use midpoints as spectral peak values 16 SDBS 1H NMR Search – Peaks, No Shift Regions, and Number of Atoms Peaks = 8.12,7.6,7.46 No shift Regions = 11.0 8.5,7.0 0.5 N, F, Cl, Br, I, S, P, Si not present 17 SDBS - 1H NMR Search Results 18 SDBS – Viewing 1H NMR (90 MHz in CDCl3) 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. 19 SDBS – 1H NMR Peak Data for Benzoic Acid 20