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Updated: May 29, 2025

Direct Detection of the Acetate-forming Activity of the Enzyme Acetate Kinase
Published on: December 19, 2011
Low Energy Electron Induced Dissociation of Acetylacetone
Surbhi Sinha1, Vaibhav S Prabhudesai1
1Tata Institute of Fundamental Research, Dr Homi Bhabha Road, Colaba, Mumbai 400005, India.
Abstract:
We report a detailed investigation of the dissociative electron attachment (DEA) to acetylacetone, an important molecule for industrial and atmospheric chemistry. We find that the DEA process leads to several dissociation channels, leading to the formation of and other anions with m/z 39, 41, 43, 57, 83, and 85, with the H- and OH- being the most dominant channels. The absolute cross sections for both of these channels peak around 8.8 and 9 eV with cross-section values of 3.1 × 10-18 and 3.7 × 10-19 cm2, respectively. We also report the DEA dynamics for these channels based on the Velocity Slice Images that were obtained. We also compare the dissociation pattern from DEA with that from photodissociation reported for 248 and 266 nm wavelengths and propose the possibility of the neutral excited state's role as the underlying parent state for the negative ion resonance.
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The acidic strength of hydrocarbons follows the order: Alkynes > Alkenes > Alkanes. The strength of an acid is commonly expressed in units of pKa — the lower the pKa, the stronger the acid. Among the hydrocarbons, terminal alkynes have lower pKa values and are, therefore, more acidic. For example, the pKa values for ethane, ethene, and acetylene are 51, 44, and 25, respectively, as shown here.
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