Browse reference spectra from the USGS Spectral Library Version 7 and other curated sources. Each spectrum includes interactive plots, metadata, and downloadable data.
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| Formula | Modality | Category | Source | ||
|---|---|---|---|---|---|
| 4-PYRIDINECARBOXYLIC ACID METHYL ESTER | C7H7NO2 | Mass Spec | Chemical | MassBank | |
| 4-PYRIDINONE | C5H5NO | Mass Spec | Chemical | MassBank | |
| 4-PYRIDYL ACETATE | C7H7NO2 | Mass Spec | Chemical | MassBank | |
| 4-PYRIMIDINONE | C4H4N2O | Mass Spec | Chemical | MassBank | |
| 4-PYRONE | C5H4O2 | Mass Spec | Chemical | MassBank | |
| 4-Pentylaniline | C11H17N | Mass Spec | Chemical | MassBank | |
| 4-Phenoxyphenol | C12H10O2 | Mass Spec | Chemical | MassBank | |
| 4-Phenylphenol | C12H10O | Mass Spec | Chemical | MassBank | |
| 4-Piperidinecarboxamide | C6H12N2O | Mass Spec | Environmental | MassBank | |
| 4-Propylaniline | C9H13N | Mass Spec | Chemical | MassBank | |
| 4-Propylphenol | C9H12O | Mass Spec | Chemical | MassBank | |
| 4-Pyridinol | C5H5NO | Mass Spec | Chemical | MassBank | |
| 4-Pyridoxate | C8H9NO4 | Mass Spec | Chemical | MassBank | |
| 4-Pyridoxic acid | C8H9NO4 | Mass Spec | Natural product | MassBank | |
| 4-QUINAZOLINONE | C8H6N2O | Mass Spec | Chemical | MassBank | |
| 4-QUINOLINONE | C9H7NO | Mass Spec | Chemical | MassBank | |
| 4-QUINOLYLMETHYL 2-METHYLBENZOATE | C18H15NO2 | Mass Spec | Chemical | MassBank | |
| 4-SEC-BUTYLCYCLOHEXANOL | C10H20O | Mass Spec | Chemical | MassBank | |
| 4-SEC-BUTYLPHENOL | C10H14O | Mass Spec | Chemical | MassBank | |
| 4-Sulfobenzoate | C7H6O5S | Mass Spec | Chemical | MassBank | |
| 4-Sulfophthalic acid | C8H6O7S | Mass Spec | Chemical | MassBank | |
| 4-TERPINENOL | C10H18O | Mass Spec | Chemical | MassBank | |
| 4-TERPINEOL | C10H18O | Mass Spec | Chemical | MassBank | |
| 4-TERPINYL ACETATE | C12H20O2 | Mass Spec | Chemical | MassBank | |
| 4-TERT-AMYLCYCLOHEXANONE | C11H20O | Mass Spec | Chemical | MassBank | |
| 4-TERT-BUTYLBENZOIC ACID | C11H14O2 | Mass Spec | Chemical | MassBank | |
| 4-TERT-BUTYLBENZOIC ACID METHYL ESTER | C12H16O2 | Mass Spec | Chemical | MassBank | |
| 4-TERT-BUTYLBENZOIC ACID TRIMETHYLSILYL ESTER | C14H22O2Si | Mass Spec | Chemical | MassBank | |
| 4-TERT-BUTYLBENZYL BENZOATE | C18H20O2 | Mass Spec | Chemical | MassBank | |
| 4-TERT-BUTYLCYCLOHEXANOL | C10H20O | Mass Spec | Chemical | MassBank | |
| 4-TERT-BUTYLCYCLOHEXANONE | C10H18O | Mass Spec | Chemical | MassBank | |
| 4-TERT-BUTYLCYCLOHEXYL ACETATE(EQUATORIAL-AXIAL) | C12H22O2 | Mass Spec | Chemical | MassBank | |
| 4-TERT-BUTYLCYCLOHEXYL ACETATE(EQUATORIAL-EQUATORIAL) | C12H22O2 | Mass Spec | Chemical | MassBank | |
| 4-TERT-BUTYLCYLOHEXYL ACETATE(EQUATORIAL-EQUATORIAL) | C12H22O2 | Mass Spec | Chemical | MassBank | |
| 4-TERT-BUTYLMERCAPTOPYRIDINECAPTOPYRIDINE | C9H13NS | Mass Spec | Chemical | MassBank | |
| 4-TERT-BUTYLPHENYL METHYL KETONE | C12H16O | Mass Spec | Chemical | MassBank | |
| 4-TERT-BUTYLPYROCATECHOL | C10H14O2 | Mass Spec | Chemical | MassBank | |
| 4-TERT-BUTYLSTYLENE | C12H16 | Mass Spec | Chemical | MassBank | |
| 4-TOLUIC ACID | C8H8O2 | Mass Spec | Chemical | MassBank | |
| 4-TOLYL ISOCYANATE | C8H7NO | Mass Spec | Chemical | MassBank | |
| 4-TRIMETHYLSILYLMETHYL-3-CYCLOHEXENEC-1-ARBALDEHYDE | C11H20OSi | Mass Spec | Chemical | MassBank | |
| 4-TRIMETHYLSILYLMETHYL-3-CYCLOHEXENYL 4-METHYL-3-PENTENYL KETONE | C17H30OSi | Mass Spec | Chemical | MassBank | |
| 4-TRIMETHYLSILYLMETHYL-6-(2-PHENYLETHYL)-5,6-DIHYDRO-2H-PYRAN | C17H26OSi | Mass Spec | Chemical | MassBank | |
| 4-TRIMETHYLSILYLMETHYL-6-PHENYL-5,6-DIHYDRO-2H-PYRAN | C15H22OSi | Mass Spec | Chemical | MassBank | |
| 4-TRIMETHYLSILYLOXYBENZOIC ACID TRIMETHYLSILYL ESTER | C13H22O3Si2 | Mass Spec | Chemical | MassBank | |
| 4-TRIMETHYLSILYLPHENOL | C9H14OSi | Mass Spec | Chemical | MassBank | |
| 4-Toluenesulfonamide | C7H9NO2S | Mass Spec | Environmental | MassBank | |
| 4-Toluenesulfonic acid | C7H8O3S | Mass Spec | Chemical | MassBank | |
| 4-Trifluoromethylphenol | C7H5F3O | Mass Spec | Environmental | MassBank | |
| 4-UNDECANONE | C11H22O | Mass Spec | Chemical | MassBank |