In chemistry, a chemical trap is a chemical compound that is used to detect unstable compounds.[1] The method relies on efficiency of bimolecular reactions with reagents to produce a more easily characterize trapped product. In some cases, the trapping agent is used in large excess.
A famous example is the detection of cyclobutadiene released upon oxidation of cyclobutadieneiron tricarbonyl. When this degradation is conducted in the presence of an alkyne, the cyclobutadiene is trapped as a bicyclohexadiene. The requirement for this trapping experiment is that the oxidant (ceric ammonium nitrate) and the trapping agent be mutually compatible.[2]
Diphosphorusedit
Diphosphorus is an old target of chemists since it is the heavy analogue of N2. Its fleeting existence is inferred by the controlled degradation of certain niobium complexes in the presence of trapping agents. Again, a Diels-Alder strategy is employed in the trapping:[3]
This inference is supported by conducting the dechlorination in the presence of trimethylsilane, the trapped product being pentamethyldisilane:
Si(CH3)2 + HSi(CH3)3 → (CH3)2Si(H)-Si(CH3)3
Not that the trapping agent does not react with dimethyldichlorosilane or potassium metal.
Related meaningsedit
In some cases, chemical trap is used to detect or infer a compound when present at concentrations below its detection limit or is present in a mixture, where other components interfere with its detection. The trapping agent, for example a dye, reacts with the chemical to be detected, giving a product that is more easily detected.
Referencesedit
^March, Jerry (1985), Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 3rd edition, New York: Wiley, ISBN9780471854722, OCLC 642506595
^G. F. Emerson; L. Watts; R. Pettit (1965). "Cyclobutadiene- and Benzocyclobutadiene-Iron Tricarbonyl Complexes". J. Am. Chem. Soc. 87: 131–133. doi:10.1021/ja01079a032.
^Piro, Nicholas A.; Figueroa, Joshua S.; McKellar, Jessica T.; Cumnins, Christopher C. (1 September 2006). "Triple-Bond Reactivity of Diphosphorus Molecules". Science. 313 (5791): 1276–1279. Bibcode:2006Sci...313.1276P. doi:10.1126/science.1129630. PMID 16946068. S2CID 27740669.
^Skell, P. S.; Goldstein, E. J. (1964). "Dimethylsilene: CH3SiCH3". Journal of the American Chemical Society. 86 (7): 1442–1443. doi:10.1021/ja01061a040.
January 01, 1970
chemical, trap, chemistry, chemical, trap, chemical, compound, that, used, detect, unstable, compounds, method, relies, efficiency, bimolecular, reactions, with, reagents, produce, more, easily, characterize, trapped, product, some, cases, trapping, agent, use. In chemistry a chemical trap is a chemical compound that is used to detect unstable compounds 1 The method relies on efficiency of bimolecular reactions with reagents to produce a more easily characterize trapped product In some cases the trapping agent is used in large excess Contents 1 Case studies 1 1 Cyclobutadiene 1 2 Diphosphorus 1 3 Silylene 2 Related meanings 3 ReferencesCase studies editCyclobutadiene edit A famous example is the detection of cyclobutadiene released upon oxidation of cyclobutadieneiron tricarbonyl When this degradation is conducted in the presence of an alkyne the cyclobutadiene is trapped as a bicyclohexadiene The requirement for this trapping experiment is that the oxidant ceric ammonium nitrate and the trapping agent be mutually compatible 2 nbsp Diphosphorus edit Diphosphorus is an old target of chemists since it is the heavy analogue of N2 Its fleeting existence is inferred by the controlled degradation of certain niobium complexes in the presence of trapping agents Again a Diels Alder strategy is employed in the trapping 3 nbsp Silylene edit Another classic but elusive family of targets are silylenes analogues of carbenes It was proposed that dechlorination of dimethyldichlorosilane generates dimethylsilylene 4 SiCl2 CH3 2 2 K Si CH3 2 2 KCl This inference is supported by conducting the dechlorination in the presence of trimethylsilane the trapped product being pentamethyldisilane Si CH3 2 HSi CH3 3 CH3 2Si H Si CH3 3 Not that the trapping agent does not react with dimethyldichlorosilane or potassium metal Related meanings editIn some cases chemical trap is used to detect or infer a compound when present at concentrations below its detection limit or is present in a mixture where other components interfere with its detection The trapping agent for example a dye reacts with the chemical to be detected giving a product that is more easily detected References edit March Jerry 1985 Advanced Organic Chemistry Reactions Mechanisms and Structure 3rd edition New York Wiley ISBN 9780471854722 OCLC 642506595 G F Emerson L Watts R Pettit 1965 Cyclobutadiene and Benzocyclobutadiene Iron Tricarbonyl Complexes J Am Chem Soc 87 131 133 doi 10 1021 ja01079a032 Piro Nicholas A Figueroa Joshua S McKellar Jessica T Cumnins Christopher C 1 September 2006 Triple Bond Reactivity of Diphosphorus Molecules Science 313 5791 1276 1279 Bibcode 2006Sci 313 1276P doi 10 1126 science 1129630 PMID 16946068 S2CID 27740669 Skell P S Goldstein E J 1964 Dimethylsilene CH3SiCH3 Journal of the American Chemical Society 86 7 1442 1443 doi 10 1021 ja01061a040 Retrieved from https en wikipedia org w index php title Chemical trap amp oldid 1160043192, wikipedia, wiki, book, books, library,
