摘要
为了获得性能优良的含能材料,以4‑氯吡唑为原料,经硝化、水解、酸化及成盐反应合成了一种新型含能离子盐4‑羟基‑3,5‑二硝基吡唑胍盐(DNPOG),采用红外光谱、核磁共振分析及元素分析对其结构进行了表征,培养得到了DNPOG单晶,晶体结构为三斜晶系,空间群为P‑1,相对分子质量Mr=233.17 g·c
图文摘要
4‑Hydroxy‑3,5‑dinitropyrazole guanidine salt (DNPOG) was synthesized and characterized by FTIR, NMR, EA analysis and X‑ray diffraction. The hirshfeld surface, 2D finger pattern and non‑covalent interaction (NCI) were employed to study the contribution of hydrogen bonds and π‑π conjugation to the molecular interaction. The thermal decomposition properties were analyzed by DSC and TG. The detonation performance were evaluated via experimental density value and calculated enthalpy of formation.
含能材料是一种重要的能源,以炸药、推进剂和烟火药等形式被广泛应用于军事及民用领域,发展具有能量性能高、稳定性好、环境友好、低易损性等优良性能的含能材料,成为含能材料领域的研究热点之
硝基吡唑类含能化合物分子结构中含有π电子稳定结
2010年以来,世界各国研究者对硝基吡唑类含能化合物4‑羟基‑3,5‑二硝基吡唑(DNPO)合成方法、工艺条件及其潜在应用价值进行了探
本研究以4‑氯吡唑为原料经硝化、水解、酸化及中和反应合成了一种新型含能离子盐4‑羟基‑3,5‑二硝基吡唑胍盐(DNPOG),采用溶剂挥发法得到了单晶,利用X‑射线单晶衍射仪对DNPOG的单晶结构进行了分析;采用Hirshfeld表面、2D指纹图及弱相互非共价键分析(NCI)分析了DNPOG晶体中的弱相互作用力;采用通过DSC‑TG测试技术,研究了的热稳定性;利用感度仪进行了摩擦和撞击感度测试;利用EXPLO5软件预估了爆轰性能。
4‑氯吡唑、氢氧化钾、乙酸乙酯,盐酸胍(安耐吉化学萨恩化学技术(上海)有限公司)、盐酸、浓硫酸、发烟硝酸(国药集团化学试剂有限公司),以上均为分析纯。实验用水为去离子水。
X‑射线单晶衍射分析采用Bruker SMART APEX Ⅱ CCD面探单晶衍射仪完成;热分析采用瑞士METTLER TOLEO公司生产的差示扫描量热(DSC)及差示扫描量热‑热重联用仪(TGA/DSC),测试条件:Al2O3坩埚,N2气氛,流速80 mL·mi
以4‑氯吡唑为原料,高温硝化制得4‑氯‑3,5‑二硝基吡唑(1),与氢氧化钾在高温条件下制得4‑羟基‑3,5‑二硝基吡唑的钾盐(2),经盐酸酸化制得4‑羟基‑3,5‑二硝基吡唑(3),与氢氧化锂溶液作用制得锂盐,然后与盐酸胍(G∙HCl)发生复分解反应得4‑羟基‑3,5‑二硝基吡唑胍盐(DNPOG)。具体合成路线如

Scheme 1 Synthesis of DNPOG
依据参考文献[
13C NMR(100 MHz,DMSO‑d6)δ:149.41,103.29。IR(KBr,ν/c
依据参考文献[
13C NMR(100 MHz,DMSO‑d6)δ:143.74,153.65
将15 mL去离子水加入到50 ml茄形瓶中,反应升温至60 ℃,加入0.174 g化合物(3),加入0.05 g氢氧化锂,反应0.5 h。称取0.19 g盐酸胍加入到反应液中,反应1 h后,降至室温,得澄清液,过滤静置,3天后析出橘红色晶体(DNPOG),收率70.2%。
13C NMR(100 MHz,DMSO‑d6)δ:170.96,158.75,100.88
选取尺寸为0.20 mm×0.13 mm×0.08 mm的DNPOG单晶,置于Bruker SMART APEX Ⅱ CCD面探单晶衍射仪上,采用经石墨单色器单色化的MoKα射线(λ=0.71073 Å)作为X射线源,以ω扫描方式在一定的θ范围收集单晶衍射数据。所有强度数据进行Lp因子及经验吸收校正。晶体结构通过直接法由SHELXS‑97解析得到,全矩阵最小二乘法精修由SHELXL‑97程序完成。非氢原子由直接法获得,氢原子通过理论加氢获得。晶体学数据详见
DNPOG的分子结构和晶胞堆积图分别如

图1 (a)DNPOG的晶体结构图;(b)DNPOG分子间氢键作用图;(c)DNPOG的晶体堆积图
Fig.1 (a) Crystal structure of DNPOG. (b) Hydrogen‑bond interaction of DNPOG. (c) Crystal packing map of DNPOG
由
采用Hirshfeld表面分析、2D指纹图及弱相互非共价键分析(NCI

图2 (a)DNPOG的Hirshfeld表面分析;(b)单原子接触百分比;(c)DNPOG的2D指纹图;(d)DNPOG的NCI分析
Fig.2 (a) Hirshfeld surfaces calculation of DNPOG; (b) Individual atomic contact percentage of DNPOG; (c) Two‑dimension fingerprint plots of DNPOG; (d) Noncovalent interaction analysis
采用热重及差示扫量热仪(TG‑DSC)研究了DNPOG的热稳定性(N2气氛,试样量0.2 mg,升温速率10 ℃·mi

图3 DNPOG的TG‑DSC曲线
Fig.3 TG‑DSC curves of DNPOG
为了研究4‑羟基‑3,5‑二硝基吡唑胍盐(DNPOG)的爆轰性能,基于Born‑Harber能量循环机理,利用Gaussian 09程序,计算了DNPOG的生成焓,得到其生成焓为-160.2 kJ·mo
(1)以4‑氯吡唑为原料,经硝化、水解、酸化及成盐反应合成了4‑羟基‑3,5‑二硝基吡唑胍盐(DNPOG)。首次培养得到了DNPOG的单晶,其晶体结构属于三斜晶系,P‑1空间群,在293 K下的晶体密度为1.750 g·c
(2)DSC‑TG结果表明,4‑羟基‑3,5‑二硝基吡唑胍盐(DNPOG)有一个明显的放热分解峰,起始分解温度为192.6 ℃,表明具有良好的热稳定性,分解过程中总的质量损失为81.2%,表明分解完全。
(3)4‑羟基‑3,5‑二硝基吡唑胍盐(DNPOG)生成焓为-160.2 kJ·mo
参考文献
吴军鹏, 曹端林, 王建龙. 3,4,5‑三硝基吡唑及其衍生物的研究进展.[J]. 含能材料, 2016, 24(11): 1121-1130. [百度学术]
WU Jun‑peng, CAO Duan‑lin, LI Yong‑xiang. et al. Research progress of 3,4,5‑trinitropyrazole and its derivatives[J]. Chinese Journal of Energetic Materials(Hanneng Cailiao), 2016, 24(11): 1121-1130. [百度学术]
Li H, Zhang L, Petrutik N, et al. Molecular and crystal features of thermostable energetic materials: Guidelines for architecture of “bridged” compounds[J]. ACS Central Science, 2020, 6(1): 54-75. [百度学术]
Zhang Z‑B, Xu C‑X, Yin X, et al. Hydrazine 5,5'‑bitetrazole‑1,11'‑diolate: A promising high density energetic salt with good propertiest[J]. Dalton Transactions, 2016, 45(47): 19045-19052. [百度学术]
薛钰冰, 程广斌, 杨红伟. 5,5'‑二氨基‑4,4'‑二硝胺基‑3,3'‑联‑1,2,4‑三唑三氨基胍盐(TAGAT)的晶体结构及爆轰性能.[J]. 含能材料, 2020, 28(7): 638-643. [百度学术]
XUE Yu‑bing, CHENG Guang‑bin, YANG Hong‑wei. et al. Crystal structure and detonation performance of 5, 5'‑diamino⁃4,4'⁃dinitroamino⁃3, 3'‑bi⁃1,2,4⁃triazole triaminoguanidinium salt(TAGAT)[J]. Chinese Journal of Energetic Materials(Hanneng Cailiao), 2020, 28(7): 638-643. [百度学术]
Zhang Y, Guo Y, Joo Y‑H, et al. 3,4,5‑Trinitropyrazole‑based energetic salts[J]. Chemistry‑A European Journal, 2010, 16(35): 10778-10784. [百度学术]
潘永飞, 汪营磊, 赵宝东. 硝基吡唑及其衍生物的合成、性能及应用研究进展[J]. 含能材料, 2018, 26(9): 796-812. [百度学术]
PAN Yong‑fei, WANG Ying‑lei, LIU Ya‑jing, et al. Research progress in synthesis, properties and applications of nitropyrazoles and their derivatives [J]. Chinese Journal of Energetic Materials(Hanneng Cailiao), 2018, 26(9): 796-812. [百度学术]
Kumar D, Imler G H, Parrish D A, et al. 3,4,5‑Trinitro‑1‑(nitromethyl)‑1H‑pyrazole (TNNMP): A perchlorate free high energy density oxidizer with high thermal stability[J]. Journal of Materials Chemistry A, 2017, 5(21): 10437-10441. [百度学术]
Yin P, Parrish D A, Shreeve J N M. Energetic multifunctionalized nitraminopyrazoles and their ionic derivatives: Ternary hydrogen‑bond induced high energy density materials[J]. Journal of the American Chemical Society, 2015, 137(14): 4778-4786. [百度学术]
Yang F, Zhang P, Zhou X, et al. Combination of polynitropyrazole and 5‑amino‑1,2,4‑oxadiazole derivatives: An approach to high performance energetic materials[J]. Crystal Growth & Design, 2020, 20(6): 3737-3746. [百度学术]
Dalinger I L, Vatsadze I A, Shkineva T K, et al. The specific reactivity of 3,4,5‑trinitro‑1H‑pyrazole[J]. Mendeleev Communications, 2010, 20(5): 253-254. [百度学术]
Wu B, Wang Y, Li K, et al. Novel energetic coordination compounds based on 3,5‑dinitro‑4‑oxylpyrazolate ligand with excellent thermostability and low sensitivity[J]. Inorganica Chimica Acta, 2021, 515(2021): 120042. [百度学术]
Herve G, Roussel C, Graindorge H. Selective preparation of 3,4,5‑trinitro‑1H‑pyrazole: A stable all‑carbon‑nitrated arene[J]. Angewandte Chemie International Edition, 2010, 49(18): 3177-3181. [百度学术]
Zhang J, Zhang J, Imler G H, et al. Sodium and potassium 3,5‑dinitro‑4‑hydropyrazolate: Three‑dimensional metal‑organic frameworks as promising super‑heat‑resistant explosives[J]. ACS Applied Energy Materials, 2019, 2(10): 7628-7634. [百度学术]
Dalinger I L, Vatsadze I A, Shkineva T K, et al. Efficient procedure for high‑yield synthesis of 4‑substituted 3,5‑dinitropyrazoles using 4‑chloro‑3,5‑dinitropyrazole[J]. Synthesis‑Stuttgart, 2012, 44(13): 2058-2064. [百度学术]
Wu B, Du H, Hu P, et al. Novel high‑energy ionic molecules deriving from new monovalent and divalent 4‑oxyl‑3,5‑dinitropyrazolate moieties[J]. Journal of Energetic Materials, 2020, 39(1): 10-22. [百度学术]
Li C, Zhang M, Chen Q, et al. 1‑(3,5‑Dinitro‑1H‑pyrazol‑4‑yl)‑3‑nitro‑1H‑1,2,4‑triazol‑5‑amine (HCPT) and its energetic salts: Highly thermally stable energetic materials with high‑performance[J]. Dalton Transactions, 2016, 45(44): 17956-17965. [百度学术]
Zhang S, Cheng G, Yang H. Studies on the synthesis and properties of nitramino compounds based on tetrazine backbones[J]. Dalton Transactions, 2020, 49(17): 5590-5596. [百度学术]
Zhang M,Gao H,Li C,et al.Towards improved explosives with a high performance: N‑(3,5‑dinitro‑1H‑pyrazol‑4‑yl)‑1H‑tetrazol‑5‑amine and its salts[J]. Journal of Materials Chemistry A, 2017, 5(4): 1769-1777. [百度学术]
Spackman M A, Mckinnon J J. Fingerprinting intermolecular interactions in molecular crystals[J]. Cryst Eng Comm, 2002, 4(66): 378-392. [百度学术]
Spackman M A, Jayatilaka D. Hirshfeld surface analysis[J]. Cryst Eng Comm, 2009, 11(11): 19-32. [百度学术]
Johnson E R, Keinan S, Mori‑Sanchez P, et al. Revealing noncovalent interactions[J]. Journal of the American Chemical Society, 2010, 132(18): 6498-6506. [百度学术]