Strong bonds are made by the overlap of closely matched orbitals in size and energy.
Bond cleavage sometimes require catalysts. Due to the high bond energy of C-H of 105.0 kcal/mol (439.32 kJ/mol)[1], it requires a lot of energy to cleave the hydrogen atom and bond a different atom to the carbon[2]. Therefore, a mechanism, such as non-directed C–H functionalization can be used, where 2-pyridone ligand and palladium catalyst in silver acetate allow for the C-H bond cleavage[3].
Ring-opening edit
In a ring-opening, the cleaved molecule remains as a single unit[4]. For example, an epoxide ring is opened by ionic mechanisms, in which the polar carbon–oxygen bond is cleaved.[4]
Applications edit
In biology, cleaving agents are used in proteome analysis where proteins are cleaved into smaller peptide fragments[5]. Examples of cleaving agents used are cyanogen bromide, pepsin, and trypsin[5].
References edit
- ^ Gronert, Scott (February 2006). "An Alternative Interpretation of the C−H Bond Strengths of Alkanes". The Journal of Organic Chemistry. 71 (3): 1209–1219. doi:10.1021/jo052363t.
- ^ Wencel-Delord, Joanna; Colobert, Françoise (2017). "Super-reactive catalyst for bond cleavage". Nature. pp. 447–448. doi:10.1038/d41586-017-07270-0. Retrieved 23 February 2018.
- ^ Wang, Peng; Verma, Pritha; Xia, Guoqin; Shi, Jun; Qiao, Jennifer X.; Tao, Shiwei; Cheng, Peter T. W.; Poss, Michael A.; Farmer, Marcus E.; Yeung, Kap-Sun; Yu, Jin-Quan (22 November 2017). "Ligand-accelerated non-directed C–H functionalization of arenes". Nature. 551 (7681): 489–493. doi:10.1038/nature24632.
{{cite journal}}:|access-date=requires|url=(help) - ^ a b Parker, R. E.; Isaacs, N. S. (1 August 1959). "Mechanisms Of Epoxide Reactions". Chemical Reviews. 59 (4): 737-799. doi:10.1021/cr50028a006.
{{cite journal}}:|access-date=requires|url=(help); More than one of|pages=and|page=specified (help) - ^ a b Mander, Lew; Liu, Hung-Wen (2010). Comprehensive Natural Products II: Chemistry and Biology (1 ed.). Elsevier. pp. 462–463. ISBN 978-0-08-045381-1. Retrieved 23 February 2018.