Herein,a first example of energetic-energetic cocrystal polymorphs with a 1:1 M ratio was discovered by cocrystallizing CL-20(2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane)with 1,3-DNP(1,3-dinitropyrazole...Herein,a first example of energetic-energetic cocrystal polymorphs with a 1:1 M ratio was discovered by cocrystallizing CL-20(2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane)with 1,3-DNP(1,3-dinitropyrazole).These two energetic cocrystal polymorphs(cocrystal 1 and cocrystal 2)exhibit distinct crystal packing styles,which lead to significant variations in their physicochemical properties.Notably,cocrystal 2 has a high density of 1.963 g·cm^(-3)at 170 K,exhibiting high detonation performances(9187 m·s^(-1);38.68 GPa)comparable to HMX(1,3,5,7-tetranitro-1,3,5,7-tetrazocane)meanwhile displaying an improved safety(10 J)relative to RDX(1,3,5-trinitro-1,3,5-triazinane),making it a potential high-energy,low-sensitivity energetic material.This work opens up a new strategy to deeply tune properties of energetic materials by constructing energetic-energetic cocrystal polymorphs.These energetic cocrystal polymorphs represent a new field of energetic materials that has not yet been studied.展开更多
Cocrystallization integrates the merits of high energy and insensitivity between energetic molecules to obtain energetics with satisfying performance.However,how to obtain supramolecular synthons accurately and rapidl...Cocrystallization integrates the merits of high energy and insensitivity between energetic molecules to obtain energetics with satisfying performance.However,how to obtain supramolecular synthons accurately and rapidly for predicting the structure and property of cocrystal remains a challenging problem.In this research,an efficient systematic search approach to predict CL-20/2,4-DNI cocrystal has been proposed that 2,4-DNI revolves around CL-20 with a stoichiometric ratio of 1:1 in accordance with the specified rules(hydrogen bond length:2.2-3.0 Å;search radius:6.5 Å;the number of hydrogen bond:1-3).Eight possible supramolecular synthons were obtained by combining quantum chemistry with molecular mechanics.Crystal structure prediction indicated that there are four structures in cocrystal,namely P21/c,P212121,Pbca and Pna21,and CL-20/2,4-DNI cocrystal is likely to be P21/c and the corresponding cell parameters are Z=4,a=8.28 Å,b=12.17 Å,c=20.42 Å,α=90°,β=96.94°,γ=90°,and ρ=1.9353 g/cm^(3).To further study the intermolecular interaction of CL-20/2,4-DNI cocrystal,a series of theoretical analyses were employed including intermolecular interaction energy,electrostatic potential(ESP),Density of State(DOS),Hirshfeld surface analysis.The C-H…O hydrogen bonds are demonstrated as the predominant driving forces in the cocrystal formation.The mechanical properties and detonation properties of CL-20/2,4-DNI cocrystal implies that the cocrystal shows better ductility and excellent detonation performances(9257 m/s,39.27 GPa)and can serve as a promising energetic material.Cocrystal structure predicted was compared with the experimental one to verify the accuracy of systematic search approach.There is a less than 8.8%error between experiment and predict results,indicating the systematic search approach has extremely high reliability and accuracy.The systematic search approach can be a new strategy to search supramolecular synthons and identify structures effectively and does have the potential to promote the development of energetic cocrystal by theoretical design.展开更多
The structural evolution and optical properties of CL-20/DNB cocrystals under high pressure are systematically studied via Raman,florescence,and absorption spectroscopy and Gaussian calculations.Interestingly,the pres...The structural evolution and optical properties of CL-20/DNB cocrystals under high pressure are systematically studied via Raman,florescence,and absorption spectroscopy and Gaussian calculations.Interestingly,the pressure induced a significant change in color from colorless to yellow to red in the CL-20/DNB cocrystal sample.This phenomenon is accompanied by a redshift in the absorption edge,resulting from the enhanced hydrogen bonding interaction and theπ‒πstacking effect.Additionally,the photoluminescence(PL)emission clearly increases between 1 atm and 19.5 GPa and quenches later above 20 GPa,which is also caused by the change in the lattice stacking of the cocrystal explosive under high pressure.Moreover,no structural phase transition occurs in the CL-20/DNB cocrystal at pressures ranging from 1 atm to 20 GPa according to the high-pressure Raman spectra,indicating that the cocrystal demonstrates markedly superior structural stability compared with either CL-20 or DNB when considered individual components under high pressure.展开更多
基金support for this study by the National Natural Science Foundation of China(Grant No.22275175)。
文摘Herein,a first example of energetic-energetic cocrystal polymorphs with a 1:1 M ratio was discovered by cocrystallizing CL-20(2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane)with 1,3-DNP(1,3-dinitropyrazole).These two energetic cocrystal polymorphs(cocrystal 1 and cocrystal 2)exhibit distinct crystal packing styles,which lead to significant variations in their physicochemical properties.Notably,cocrystal 2 has a high density of 1.963 g·cm^(-3)at 170 K,exhibiting high detonation performances(9187 m·s^(-1);38.68 GPa)comparable to HMX(1,3,5,7-tetranitro-1,3,5,7-tetrazocane)meanwhile displaying an improved safety(10 J)relative to RDX(1,3,5-trinitro-1,3,5-triazinane),making it a potential high-energy,low-sensitivity energetic material.This work opens up a new strategy to deeply tune properties of energetic materials by constructing energetic-energetic cocrystal polymorphs.These energetic cocrystal polymorphs represent a new field of energetic materials that has not yet been studied.
基金the support of the National Natural Science Foundation of China(No.22005090)Beijing Institute of Technology Research Fund Program for Young Scholars+2 种基金the National Natural Science Foundation of China(No.11672040 and No.21801016)Open Research Fund Program of Science and Technology on Aerospace Chemical Power Laboratory(STACPL120201B02)the State Key Laboratory of Explosion Science and Technology(No.YB2016-17)。
文摘Cocrystallization integrates the merits of high energy and insensitivity between energetic molecules to obtain energetics with satisfying performance.However,how to obtain supramolecular synthons accurately and rapidly for predicting the structure and property of cocrystal remains a challenging problem.In this research,an efficient systematic search approach to predict CL-20/2,4-DNI cocrystal has been proposed that 2,4-DNI revolves around CL-20 with a stoichiometric ratio of 1:1 in accordance with the specified rules(hydrogen bond length:2.2-3.0 Å;search radius:6.5 Å;the number of hydrogen bond:1-3).Eight possible supramolecular synthons were obtained by combining quantum chemistry with molecular mechanics.Crystal structure prediction indicated that there are four structures in cocrystal,namely P21/c,P212121,Pbca and Pna21,and CL-20/2,4-DNI cocrystal is likely to be P21/c and the corresponding cell parameters are Z=4,a=8.28 Å,b=12.17 Å,c=20.42 Å,α=90°,β=96.94°,γ=90°,and ρ=1.9353 g/cm^(3).To further study the intermolecular interaction of CL-20/2,4-DNI cocrystal,a series of theoretical analyses were employed including intermolecular interaction energy,electrostatic potential(ESP),Density of State(DOS),Hirshfeld surface analysis.The C-H…O hydrogen bonds are demonstrated as the predominant driving forces in the cocrystal formation.The mechanical properties and detonation properties of CL-20/2,4-DNI cocrystal implies that the cocrystal shows better ductility and excellent detonation performances(9257 m/s,39.27 GPa)and can serve as a promising energetic material.Cocrystal structure predicted was compared with the experimental one to verify the accuracy of systematic search approach.There is a less than 8.8%error between experiment and predict results,indicating the systematic search approach has extremely high reliability and accuracy.The systematic search approach can be a new strategy to search supramolecular synthons and identify structures effectively and does have the potential to promote the development of energetic cocrystal by theoretical design.
基金supported by the Fundamental Research Funds for the Central Universities(WK2030000058)the Fund of the National Key Laboratory of Shock Wave and Detonation Physics(JCKYS2022212008)acknowledge beamline 15U1 of the Shanghai Synchrotron Radiation Facility(SSRF)and Supercomputing Center of the University of Science and Technology of China.
文摘The structural evolution and optical properties of CL-20/DNB cocrystals under high pressure are systematically studied via Raman,florescence,and absorption spectroscopy and Gaussian calculations.Interestingly,the pressure induced a significant change in color from colorless to yellow to red in the CL-20/DNB cocrystal sample.This phenomenon is accompanied by a redshift in the absorption edge,resulting from the enhanced hydrogen bonding interaction and theπ‒πstacking effect.Additionally,the photoluminescence(PL)emission clearly increases between 1 atm and 19.5 GPa and quenches later above 20 GPa,which is also caused by the change in the lattice stacking of the cocrystal explosive under high pressure.Moreover,no structural phase transition occurs in the CL-20/DNB cocrystal at pressures ranging from 1 atm to 20 GPa according to the high-pressure Raman spectra,indicating that the cocrystal demonstrates markedly superior structural stability compared with either CL-20 or DNB when considered individual components under high pressure.
