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An '''entropic explosion''' is an [[explosion]] in which the [[reactant]]s undergo a large change in volume without releasing a large amount of [[heat]]. The [[chemical decomposition]] of [[acetone peroxide|triacetone triperoxide]] (TATP) may be an example of an entropic explosion.<ref name=pmid15669854>{{cite journal |doi=10.1021/ja0464903 |pmid=15669854 |title=Decomposition of Triacetone Triperoxide is an Entropic Explosion |journal=Journal of the American Chemical Society |volume=127 |issue=4 |pages=1146–59 |year=2005 |last1=Dubnikova |first1=Faina |last2=Kosloff |first2=Ronnie |last3=Almog |first3=Joseph |last4=Zeiri |first4=Yehuda |last5=Boese |first5=Roland |last6=Itzhaky |first6=Harel |last7=Alt |first7=Aaron |last8=Keinan |first8=Ehud }}</ref> It is not a [[thermochemistry|thermochemically]] highly favored event because little energy is generated in [[chemical bond]] formation in reaction products, but rather involves an [[entropy]] burst, which is the result of formation of one [[ozone]] and three [[acetone]] gas phase molecules from every molecule of TATP in the solid state.<ref>{{cite book|last1=Dubnikova|first1=Faina|last2=Kosloff|first2=Ronnie|last3=Yehuda |first3=Zeiri|editor1-last=Schubert|editor1-first=Hitmar|editor2-last=Kuznetsov|editor2-first=Audrey|title=Rational Detection Schemes for TATP NATO Advanced Research Workshop|date=2006|publisher=Springer|location=Netherlands|isbn=978-1402048869|pages=111–112|url=https://books.google.com/books?id=XddB6_Xy9AQC&pg=PA113|accessdate=6 February 2017}}"The calculated thermal decomposition pathway of the TATP molecule was a complicated multistep process with several highly reactive intermediates, including singlet molecular oxygen and various biradicals. Of note, the calculations predict the formation of acetone and ozone as the main decomposition products and not the intuitively expected oxidation products. The key conclusion from this study is that the explosion of TATP is not a thermochemically highly favored event. Rather, the explosion involves entropy burst, which is the result of the formation of 4 gas-phase molecules from every molecule of TATP in the [[solid]] state. Quite unexpectedly, the 3 isopropylidene units of the TATP molecule do not play the role of fuel that can be oxidized and release [[energy]] during the explosion. Instead, these units function as molecular [[scaffolds]] that hold the 3 [[peroxide]] units close together spatially in the appropriate orientation for the decomposition chain reaction."</ref><ref>{{cite web|url=http://www.scripps.edu/news/sk/sk2004/sk04keinan.html |accessdate=July 17, 2005 |url-status=dead |archiveurl=https://web.archive.org/web/20051105140057/http://www.scripps.edu/news/sk/sk2004/sk04keinan.html |archivedate=November 5, 2005 |title=In the Media | Scripps Research }}</ref><ref>{{Cite web |url=http://arutzsheva.com/news.php3?id=75139 |title= | An '''entropic explosion''' is an [[explosion]] in which the [[reactant]]s undergo a large change in volume without releasing a large amount of [[heat]]. The [[chemical decomposition]] of [[acetone peroxide|triacetone triperoxide]] (TATP) may be an example of an entropic explosion.<ref name=pmid15669854>{{cite journal |doi=10.1021/ja0464903 |pmid=15669854 |title=Decomposition of Triacetone Triperoxide is an Entropic Explosion |journal=Journal of the American Chemical Society |volume=127 |issue=4 |pages=1146–59 |year=2005 |last1=Dubnikova |first1=Faina |last2=Kosloff |first2=Ronnie |last3=Almog |first3=Joseph |last4=Zeiri |first4=Yehuda |last5=Boese |first5=Roland |last6=Itzhaky |first6=Harel |last7=Alt |first7=Aaron |last8=Keinan |first8=Ehud |bibcode=2005JAChS.127.1146D }}</ref> It is not a [[thermochemistry|thermochemically]] highly favored event because little energy is generated in [[chemical bond]] formation in reaction products, but rather involves an [[entropy]] burst, which is the result of formation of one [[ozone]] and three [[acetone]] gas phase molecules from every molecule of TATP in the solid state.<ref>{{cite book|last1=Dubnikova|first1=Faina|last2=Kosloff|first2=Ronnie|last3=Yehuda |first3=Zeiri|editor1-last=Schubert|editor1-first=Hitmar|editor2-last=Kuznetsov|editor2-first=Audrey|title=Rational Detection Schemes for TATP NATO Advanced Research Workshop|date=2006|publisher=Springer|location=Netherlands|isbn=978-1402048869|pages=111–112|url=https://books.google.com/books?id=XddB6_Xy9AQC&pg=PA113|accessdate=6 February 2017}}"The calculated thermal decomposition pathway of the TATP molecule was a complicated multistep process with several highly reactive intermediates, including singlet molecular oxygen and various biradicals. Of note, the calculations predict the formation of acetone and ozone as the main decomposition products and not the intuitively expected oxidation products. The key conclusion from this study is that the explosion of TATP is not a thermochemically highly favored event. Rather, the explosion involves entropy burst, which is the result of the formation of 4 gas-phase molecules from every molecule of TATP in the [[solid]] state. Quite unexpectedly, the 3 isopropylidene units of the TATP molecule do not play the role of fuel that can be oxidized and release [[energy]] during the explosion. Instead, these units function as molecular [[scaffolds]] that hold the 3 [[peroxide]] units close together spatially in the appropriate orientation for the decomposition chain reaction."</ref><ref>{{cite web|url=http://www.scripps.edu/news/sk/sk2004/sk04keinan.html |accessdate=July 17, 2005 |url-status=dead |archiveurl=https://web.archive.org/web/20051105140057/http://www.scripps.edu/news/sk/sk2004/sk04keinan.html |archivedate=November 5, 2005 |title=In the Media | Scripps Research }}</ref><ref>{{Cite web |url=http://arutzsheva.com/news.php3?id=75139 |title=Arutz Sheva - Israel National News |access-date=2005-07-17 |archive-date=2005-02-15 |archive-url=https://web.archive.org/web/20050215104455/http://www.arutzsheva.com/news.php3?id=75139 |url-status=dead }}{{full citation needed|date=December 2017}}</ref><ref>{{cite web |url=http://www.technion.ac.il/~keinanj/pub/122a.pdf |title=Archived copy |accessdate=2005-07-17 |url-status=dead |archiveurl=https://web.archive.org/web/20110514040309/http://www.technion.ac.il/~keinanj/pub/122a.pdf |archivedate=2011-05-14 }}{{full citation needed|date=December 2017}}</ref> | ||
This hypothesis has been questioned as opposing to other theoretical investigations as well as actual measurements of the detonation heat of TATP. Experiments have shown that the explosion heat of TATP is about 2800 kJ/kg (about 70% of TNT) and that it acts as a usual explosive, producing a mix of hydrocarbons, water and carbon oxides upon detonation.<ref>{{cite journal |doi=10.1016/j.tca.2014.03.046 |title=Thermochemistry of cyclic acetone peroxides |journal=Thermochimica Acta |volume=585 |pages=10–15 |year=2014 |last1=Sinditskii |first1=V.P |last2=Kolesov |first2=V.I |last3=Egorshev |first3=V.Yu |last4=Patrikeev |first4=D.I |last5=Dorofeeva |first5=O.V }}</ref> | This hypothesis has been questioned as opposing to other theoretical investigations as well as actual measurements of the detonation heat of TATP. Experiments have shown that the explosion heat of TATP is about 2800 kJ/kg (about 70% of TNT) and that it acts as a usual explosive, producing a mix of hydrocarbons, water and carbon oxides upon detonation.<ref>{{cite journal |doi=10.1016/j.tca.2014.03.046 |title=Thermochemistry of cyclic acetone peroxides |journal=Thermochimica Acta |volume=585 |pages=10–15 |year=2014 |last1=Sinditskii |first1=V.P |last2=Kolesov |first2=V.I |last3=Egorshev |first3=V.Yu |last4=Patrikeev |first4=D.I |last5=Dorofeeva |first5=O.V |bibcode=2014TcAc..585...10S }}</ref> | ||
The authors of the 2005 Dubnikova et al. study confirm that a final redox reaction (combustion) of ozone, oxygen and reactive species into water, various oxides and hydrocarbons takes place within about 180 ps after the initial reaction - within about a micron of the detonation wave. Crystals of TATP ultimately reach a temperature of 2300 K and pressure of 80 kbar.<ref>{{cite journal | doi = 10.1021/ja052067y| pmid = 16076213| title = Atomistic-Scale Simulations of the Initial Chemical Events in the Thermal Initiation of Triacetonetriperoxide| journal = Journal of the American Chemical Society| volume = 127| issue = 31| pages = 11053–62| year = 2005| last1 = Van Duin| first1 = Adri C T| last2 = Zeiri| first2 = Yehuda| last3 = Dubnikova| first3 = Faina| last4 = Kosloff| first4 = Ronnie| last5 = Goddard| first5 = William A}}</ref> | The authors of the 2005 Dubnikova et al. study confirm that a final redox reaction (combustion) of ozone, oxygen and reactive species into water, various oxides and hydrocarbons takes place within about 180 ps after the initial reaction - within about a micron of the detonation wave. Crystals of TATP ultimately reach a temperature of 2300 K and pressure of 80 kbar.<ref>{{cite journal | doi = 10.1021/ja052067y| pmid = 16076213| title = Atomistic-Scale Simulations of the Initial Chemical Events in the Thermal Initiation of Triacetonetriperoxide| journal = Journal of the American Chemical Society| volume = 127| issue = 31| pages = 11053–62| year = 2005| last1 = Van Duin| first1 = Adri C T| last2 = Zeiri| first2 = Yehuda| last3 = Dubnikova| first3 = Faina| last4 = Kosloff| first4 = Ronnie| last5 = Goddard| first5 = William A| bibcode = 2005JAChS.12711053V}}</ref> | ||
==References== | ==References== | ||
Latest revision as of 12:09, 27 June 2025
An entropic explosion is an explosion in which the reactants undergo a large change in volume without releasing a large amount of heat. The chemical decomposition of triacetone triperoxide (TATP) may be an example of an entropic explosion.[1] It is not a thermochemically highly favored event because little energy is generated in chemical bond formation in reaction products, but rather involves an entropy burst, which is the result of formation of one ozone and three acetone gas phase molecules from every molecule of TATP in the solid state.[2][3][4][5]
This hypothesis has been questioned as opposing to other theoretical investigations as well as actual measurements of the detonation heat of TATP. Experiments have shown that the explosion heat of TATP is about 2800 kJ/kg (about 70% of TNT) and that it acts as a usual explosive, producing a mix of hydrocarbons, water and carbon oxides upon detonation.[6]
The authors of the 2005 Dubnikova et al. study confirm that a final redox reaction (combustion) of ozone, oxygen and reactive species into water, various oxides and hydrocarbons takes place within about 180 ps after the initial reaction - within about a micron of the detonation wave. Crystals of TATP ultimately reach a temperature of 2300 K and pressure of 80 kbar.[7]
References
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- ↑ Script error: No such module "citation/CS1"."The calculated thermal decomposition pathway of the TATP molecule was a complicated multistep process with several highly reactive intermediates, including singlet molecular oxygen and various biradicals. Of note, the calculations predict the formation of acetone and ozone as the main decomposition products and not the intuitively expected oxidation products. The key conclusion from this study is that the explosion of TATP is not a thermochemically highly favored event. Rather, the explosion involves entropy burst, which is the result of the formation of 4 gas-phase molecules from every molecule of TATP in the solid state. Quite unexpectedly, the 3 isopropylidene units of the TATP molecule do not play the role of fuel that can be oxidized and release energy during the explosion. Instead, these units function as molecular scaffolds that hold the 3 peroxide units close together spatially in the appropriate orientation for the decomposition chain reaction."
- ↑ Script error: No such module "citation/CS1".
- ↑ Script error: No such module "citation/CS1".Template:Full citation needed
- ↑ Script error: No such module "citation/CS1".Template:Full citation needed
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "Citation/CS1".