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Biswas S, Antonov I, Fujioka K, Rizzo GL, Chambreau SD, Schneider S, Sun R, Kaiser RI. Unraveling the initial steps of the ignition chemistry of the hypergolic ionic liquid 1-ethyl-3-methylimidazolium cyanoborohydride ([EMIM][CBH]) with nitric acid (HNO 3) exploiting chirped pulse triggered droplet merging. Phys Chem Chem Phys 2023; 25:6602-6625. [PMID: 36806836 DOI: 10.1039/d2cp05943f] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
The composition of the products and the mechanistic routes for the reaction of the hypergolic ionic liquid (HIL) 1-ethyl-3-methylimidazolium cyanoborohydride ([EMIM][CBH]) and nitric acid (HNO3) at various concentrations from 10% to 70% were explored using a contactless single droplet merging within an ultrasonic levitation setup in an inert atmosphere of argon to reveal the initial steps that cause hypergolicity. The reactions were initiated through controlled droplet-merging manipulation triggered by a frequency chirp pulse amplitude modulation. Utilizing the high-speed optical and infrared cameras surrounding the levitation process chamber, intriguing visual images were unveiled: (i) extensive gas release and (ii) temperature rises of up to 435 K in the merged droplets. The gas development was validated qualitatively and quantitatively with Fourier Transform Infrared Spectroscopy (FTIR) indicating the major gas-phase products to be hydrogen cyanide (HCN) and nitrous oxide (N2O). The merged droplet was also probed by pulsed Raman spectroscopy which deciphered features for key functional groups of the reaction products and intermediates (-BH, -BH2, -BH3, -NCO); reaction kinetics revealed that the reaction was initiated by the interaction of the [CBH]- anion of the HIL with the oxidizer (HNO3) through proton transfer. Computations indicate the formation of a van-der-Waals complex between the [CBH]- anion and HNO3 initially, followed by proton transfer from the acid to the anion and subsequent extensive isomerization; these rearrangements were found to be essential for the formation of HCN and N2O. The exoergicity observed during the merging process provides a molar enthalpy change up to 10 kJ mol-1 to the system, which could be sufficient for a significant fraction of the reactants of about 11% to overcome the reaction barriers in the individual steps of the computationally determined minimum energy pathways.
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Affiliation(s)
- Souvick Biswas
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Ivan Antonov
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Kazuumi Fujioka
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Grace L Rizzo
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | | | - Stefan Schneider
- Air Force Research Laboratory, Edwards Air Force Base, California 93524, USA
| | - Rui Sun
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Ralf I Kaiser
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
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2
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Vogelhuber KM, Booth RS, Annesley CJ. Theoretical Investigation of the Reactivity of Sodium Dicyanamide with Nitric Acid. J Phys Chem A 2018; 122:1954-1959. [PMID: 29384671 DOI: 10.1021/acs.jpca.7b11661] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
There is a need to replace current hydrazine fuels with safer propellants, and dicyanamide (DCA-)-based systems have emerged as promising alternatives because they autoignite when mixed with some oxidizers. Previous studies of the hypergolic reaction mechanism have focused on the reaction between DCA- and the oxidizer HNO3; here, we compare the calculated pathway of DCA- + HNO3 with the reaction coordinate of the ion pair sodium dicyanamide with nitric acid, Na[DCA] + HNO3. Enthalpies and free energies are calculated in the gas phase and in solution using a quantum mechanical continuum solvation model, SMD-GIL. The barriers to the Na[DCA] + HNO3 reaction are dramatically lowered relative to those of the reaction with the bare anion, and an exothermic exit channel to produce NaNO3 and the reactive intermediate HDCA appears. These results suggest that Na[DCA] may accelerate the ignition reaction.
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Affiliation(s)
- Kristen M Vogelhuber
- Space Vehicles Directorate, Air Force Research Laboratory , Kirtland AFB, New Mexico 87117, United States.,Institute for Scientific Research, Boston College , Chestnut Hill, Massachusetts 02467, United States
| | - Ryan S Booth
- Space Vehicles Directorate, Air Force Research Laboratory , Kirtland AFB, New Mexico 87117, United States.,Institute for Scientific Research, Boston College , Chestnut Hill, Massachusetts 02467, United States
| | - Christopher J Annesley
- Space Vehicles Directorate, Air Force Research Laboratory , Kirtland AFB, New Mexico 87117, United States
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3
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Tian T, Hu X, Guan P, Wang S, Ding X. Density and thermodynamic performance of energetic ionic liquids based on 1-alkyl/esteryl-4-amino-1,2,4-triazolium. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.09.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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4
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Schmidt MW, Gordon MS. Effect of Boron Clusters on the Ignition Reaction of HNO 3 and Dicynanamide-Based Ionic Liquids. J Phys Chem A 2017; 121:8003-8011. [PMID: 28922914 DOI: 10.1021/acs.jpca.7b07996] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Many ionic liquids containing the dicynamide anion (DCA-, formula N(CN)2-) exhibit hypergolic ignition when exposed to the common oxidizer nitric acid. However, the ignition delay is often about 10 times longer than the desired 5 ms for rocket applications, so that improvements are desired. Experiments in the past decade have suggested both a mechanism for the early reaction steps and also that additives such as decaborane can reduce the ignition delay. The mechanisms for reactions of nitric acid with both DCA- and protonated DCAH are considered here, using accurate wave function methods. Complexation of DCA- or DCAH with borane clusters B10H14 or B9H14- is found to modify these mechanisms slightly by changing the nature of some of the intermediate saddle points and by small reductions in the reaction barriers.
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Affiliation(s)
- Michael W Schmidt
- Department of Chemistry, Iowa State University , Ames, Iowa 50014, United States
| | - Mark S Gordon
- Department of Chemistry, Iowa State University , Ames, Iowa 50014, United States
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5
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Protein remains stable at unusually high temperatures when solvated in aqueous mixtures of amino acid based ionic liquids. J Mol Model 2016; 22:258. [DOI: 10.1007/s00894-016-3123-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 09/08/2016] [Indexed: 10/20/2022]
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6
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Hasani M, Yarger JL, Angell CA. On the Use of a Protic Ionic Liquid with a Novel Cation To Study Anion Basicity. Chemistry 2016; 22:13312-9. [DOI: 10.1002/chem.201601428] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Mohammad Hasani
- School of Molecular Sciences; Arizona State University; Tempe Arizona 85287 USA
| | - Jeffery L. Yarger
- School of Molecular Sciences; Arizona State University; Tempe Arizona 85287 USA
| | - C. Austen Angell
- School of Molecular Sciences; Arizona State University; Tempe Arizona 85287 USA
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7
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Carlin CM, Gordon MS. Ab Initio Investigation of Cation Proton Affinity and Proton Transfer Energy for Energetic Ionic Liquids. J Phys Chem A 2016; 120:6059-63. [DOI: 10.1021/acs.jpca.6b02990] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Caleb M. Carlin
- Department
of Chemistry and
Ames Laboratory, Iowa State University, Ames, Iowa 50011, United States
| | - Mark S. Gordon
- Department
of Chemistry and
Ames Laboratory, Iowa State University, Ames, Iowa 50011, United States
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8
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Chevrot G, Fileti EE, Chaban VV. Enhanced stability of the model mini-protein in amino acid ionic liquids and their aqueous solutions. J Comput Chem 2015; 36:2044-51. [PMID: 26250927 DOI: 10.1002/jcc.24042] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Revised: 07/10/2015] [Accepted: 07/15/2015] [Indexed: 01/15/2023]
Abstract
Using molecular dynamics simulations, the structure of model mini-protein was thoroughly characterized in the imidazolium-based amino acid ionic liquids and their aqueous solutions. Complete substitution of water by organic cations and anions further results in hindered conformational flexibility of the mini-protein. This observation suggests that amino acid-based ionic liquids are able to defend proteins from thermally induced denaturation. We show by means of radial distributions that the mini-protein is efficiently solvated by both solvents due to a good mutual miscibility. Amino acid-based anions prevail in the first coordination sphere of positively charged sites of the mini-protein whereas water molecules prevail in the first coordination sphere of negatively charged sites of the mini-protein.
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Affiliation(s)
- Guillaume Chevrot
- Department of Physics, Chemistry and Pharmacy, MEMPHYS-Center for Biomembrane Physics, University of Southern Denmark, Campusvej 55, Odense, 5230, Denmark
| | - Eudes Eterno Fileti
- Instituto de Ciência e Tecnologia, Universidade Federal de São Paulo, 12231-280, São José dos Campos, São Paulo, Brazil
| | - Vitaly V Chaban
- Instituto de Ciência e Tecnologia, Universidade Federal de São Paulo, 12231-280, São José dos Campos, São Paulo, Brazil
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Lu L, Zhang H, Zhang S, Li F. A Family of High-Efficiency Hydrogen-Generation Catalysts Based on Ammonium Species. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201500942] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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10
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Lu L, Zhang H, Zhang S, Li F. A Family of High-Efficiency Hydrogen-Generation Catalysts Based on Ammonium Species. Angew Chem Int Ed Engl 2015; 54:9328-32. [DOI: 10.1002/anie.201500942] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 05/09/2015] [Indexed: 11/11/2022]
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11
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Wang YL, Sarman S, Li B, Laaksonen A. Multiscale modeling of the trihexyltetradecylphosphonium chloride ionic liquid. Phys Chem Chem Phys 2015; 17:22125-35. [DOI: 10.1039/c5cp02586a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hierarchical trihexyltetradecylphosphonium cationic and chloride anionic models.
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Affiliation(s)
- Yong-Lei Wang
- System and Component Design
- Department of Machine Design
- KTH Royal Institute of Technology
- SE-100 44 Stockholm
- Sweden
| | - Sten Sarman
- Department of Materials and Environmental Chemistry
- Arrhenius Laboratory
- Stockholm University
- SE-106 91 Stockholm
- Sweden
| | - Bin Li
- Theoretical Chemistry
- Chemical Center
- Lund University
- SE-221 00 Lund
- Sweden
| | - Aatto Laaksonen
- Department of Materials and Environmental Chemistry
- Arrhenius Laboratory
- Stockholm University
- SE-106 91 Stockholm
- Sweden
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