| Energetic Metal-Organic Frameworks?MOFs?are consist of nitrogen-rich ligands and Metal ions,which have various structure according to different coordination modes of the ligands.Because EMOFs has higher density,higher heat of detonation,more insensitivity and the most products when it is initiated are N2,is friendly to the environment,it has drew more and more attention and develops very quickly in recent years.The traditional method to synthesis the EMOFs just change the ligand to obtain different EMOFs with various properties,while by means of modifying the ligand with different energetic group and change the anion located in the EMOFs,obtaining more EMOFs with excellent properties has not drew the attention of the researcher in energetic field.The content of this paper as follow:Firstly,through modifying amino,nitro and nitramino in the ligand of 5,5'-bis-1,2,4-triazole,and coordinating with the Cu2+/Zn2+,we study the influence in the properties and structures of the EMOFs caused by the various energetic group,finally,we get 6 different complexes.The X-ray diffraction test show that when the modifying group become bigger,the density of the complexes become higher,from the original density 1.873g/cm3 reach to the 2.117 g/cm3,which can tune the density of the complexes very well.Secondly,using the dinitranmide anion to exchange the anion located in the holes of the MOF?Cu?,we get the exchange products N?NO2?2-?MOF?Cu?,which can encapsulate the N?NO2?2-anion very well.The decomposition temperature of N?NO2?2-?MOF?Cu?reach to 221?,the highest decomposition temperature based on dinitranmide compound.Additionally,when change the molar ratio of ADN and MOF?Cu?,we can obtain EMOFs with different amount of dinitranmide anions in the EMOFs'hole,the energetic properties can be tuned in this convenient way.Compared to traditional methods,this new method is simple,eco-friendly as well as affording a new perspective for tuning the performance of energetic materials.Thirdly,we employ C?NO2?3-anion to exchange with MOF?Cu?,MOF?Zn?and MOF?CuBF4?which all of them have three-dimensional structure.Finally,we get two two-dimensional EMOFs MOF?Zn+atrz?{Zn?atrz?2[C?NO2?3]2?H2O?2·?atrz?·2H2O}and MOF?Cu+atrz?{Cu?atrz?2[C?NO2?3]2?H2O?2·?atrz?·2H2O},the C?NO2?3-anion locate in the holes of the new MOFs,and the anion exchange progress is an interesting phenomenon:crystal-crystal transformation,which also provide a new method for synthesizing energetic materials.Finally,we employ polynitroazole anion TNP,DNT and NTT,along with 4,4'-azo-1,2,4-triazole to coordinate with transition metal ion,obtaining 7 kind EMOFs with similarity in structurewhichcontaindifferentanionsinthe EMOFs[MOF?TNP?,MOF?DNT?,MOF?NTT?,MOF?CoDNT?,MOF?ZnDNT?,MOF?Fe DNT?and MOF?CoNTT?].The TG-DSC tests show that the decomposition temperature of MOF?TNP?,MOF?DNT?and MOF?CoNTT?are 250?,257?and 258?,respectively,which are the highest decomposition temperature based on these three anion compounds.Next step,we introduce the N-O bond into the three mentioned anions?TNPO,DNTO and NTTO anions?,using same method,we get another three EMOFs[MOF?TNPO??MOF?DNTO?and MOF?NTTO?]containing the TNPO,DNTO and NTTO anions in the MOFs'holes,also,these three MOFs are likely in structure as well as with the mentioned 7kind EMOFs.The decomposition temperature of three new EMOFs are 212?,212?and242?,respectively,which are the highest decomposition temperature based on these three new anions compounds.Energetic properties tests show that when the N-O bond is introduced into the azole,the properties of MOFs is improve markedly,for example,the detonation heat of MOF?NTTO?and MOF?TNPO?reach to 6816 kJ/kg and 7375kJ/kg,respectively,belonging to higher level energetic materials in heat of detonation.In a word,we introduce the polynitroazole into the MOFs for the first time,this strategy not only stabilize the liable energetic group,but also afford a brand new perspective for synthesizing excellent energetic materials. |
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