Nitrobenzyl alcohols
Nitrobenzyl alcohols | ||||||
Surname | 2-nitrobenzyl alcohol | 3-nitrobenzyl alcohol | 4-nitrobenzyl alcohol | |||
other names | o -nitrobenzyl alcohol | m -nitrobenzyl alcohol | p -nitrobenzyl alcohol | |||
Structural formula | ||||||
CAS number | 612-25-9 | 619-25-0 | 619-73-8 | |||
PubChem | 11923 | 69267 | 69275 | |||
Molecular formula | C 7 H 7 NO 3 | |||||
Molar mass | 153.14 g mol −1 | |||||
Physical state | firmly | |||||
Melting point | 69-72 ° C | 30-32 ° C | 92-94 ° C | |||
boiling point | 270 ° C |
175-180 ° C (3 mmHg ) |
185 ° C (12 mmHg) |
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GHS labeling |
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H and P phrases | no H-phrases | no H-phrases | no H-phrases | |||
no EUH phrases | no EUH phrases | no EUH phrases | ||||
no P-phrases | no P-phrases | no P-phrases |
In chemistry, nitrobenzyl alcohols form a group of substances that are derived from both benzyl alcohol and nitrobenzene . The structure consists of a benzene ring with attached hydroxymethyl (-CH 2 OH) and nitro group (-NO 2 ) as substituents . Their different arrangements ( ortho , meta or para ) result in three constitutional isomers with the empirical formula C 7 H 7 NO 3 .
presentation
The nitrobenzyl alcohols can be prepared from the nitrobenzoyl chlorides in anhydrous dioxane by reduction with sodium borohydride (NaBH 4 ) . They can also be obtained from the nitrobenzaldehydes by means of the Meerwein-Ponndorf-Verley reduction . In the basic medium, the nitrobenzaldehydes disproportionate to nitrobenzoic acids and nitrobenzyl alcohols.
properties
The nitrobenzyl alcohols are solids. The 4-nitrobenzyl alcohol, which has the highest symmetry, has the highest melting point.
use
In mass spectrometry , 3-nitrobenzyl alcohol (often abbreviated as "3-NBA") is used as a liquid matrix for fast atom bombardment and matrix-assisted laser desorption / ionization .
Individual evidence
- ↑ a b c data sheet 2-nitrobenzyl alcohol from Sigma-Aldrich , accessed on March 12, 2017 ( PDF ).
- ↑ a b c data sheet 3-nitrobenzyl alcohol from Sigma-Aldrich , accessed on March 12, 2017 ( PDF ).
- ↑ a b c data sheet 4-nitrobenzyl alcohol from Sigma-Aldrich , accessed on March 12, 2017 ( PDF ).
- ↑ a b c CRC Handbook of Tables for Organic Compound Identification , Third Edition, 1984, ISBN 0-8493-0303-6 .
- ^ Gattermann / Wieland : The practice of organic chemists , 43rd edition, Walter de Gruyter , Berlin · New York 1982, ISBN 3-11-006654-8 , pp. 540-541: " p -nitrobenzyl alcohol".
- ↑ Representation of o -nitrobenzyl alcohol (PDF file; 81 kB).
- ↑ J. Meili, J. Seibl: A new versatile matrix for fast atom bombardment analysis ; in: Organic Mass Spectrometry , 1984 , 19 (11), pp. 581-582 ( doi: 10.1002 / oms.1210191111 ).
- ↑ Shankai Zhao, Kasi V. Somayajula, Andrew G. Sharkey, David M. Hercules, Franz Hillenkamp, Michael Karas, Arndt Ingendoh: Novel Method for Matrix-Assisted Laser Mass Spectrometry of Proteins ; in: Anal. Chem. , 1991 , 63 (5), pp. 450-453 ( doi: 10.1021 / ac00005a012 ).
- ↑ TW. Dominic Chan, AW Colburn, Peter J. Derrick: Matrix-assisted laser desorption / ionization using a liquid matrix: Formation of high-mass cluster ions from proteins ; in: Organic Mass Spectrometry , 1992 , 27 (1), pp. 53-56 ( doi: 10.1002 / oms.1210270114 ).