摘要
以5‑(三氟甲基)‑1,2,4‑三唑‑3‑胺为原料,两步合成了一种含氟稠环含能化合物3‑(1H‑四唑)‑7‑(三氟甲基)‑1,2,4‑三唑[5,1‑c]‑1,2,4‑三嗪‑4‑氨基(2)。采用X射线单晶体衍射仪确定了目标化合物的晶体结构,通过核磁共振、傅里叶红外光谱、差示扫描量热仪对其进行了结构测试与性能表征,通过EXPLO5预测了爆轰性能,采用BAM标准方法进行了感度测定。结果表明,合成过程高效、无毒、简单,所得目标化合物的晶体2·DMF属于三斜晶系,Pī空间群,晶胞参数a=4.9035(10) Å,b=10.219(2) Å,c=15.194(3) Å,V=720.4(3)
图文摘要
高能材料对人类的进步和繁荣作出了巨大的贡献。除了高性能和低感度外,增加热稳定性似乎是下一代高能材料发展的重要方向之
近年来,在兼具高性能和分子稳定性的新型含能骨架中,稠环因其平面结构和π‑π相互作用而多被用作构建含能材料的基本骨
研究发现,三氟甲基(—CF3)可以为有机化合物带来高热稳定性、高耐化学性、低表面能和高电负性等特
基于此,本研究采用新方法设计并合成了一种新的、含—CF3稠环分子的化合物3‑(1H‑四唑)‑7‑(三氟甲基)‑1,2,4‑三唑[5,1‑c]‑1,2,4‑三嗪‑4‑氨基(2)。研究以5‑(三氟甲基)‑1,2,4‑三唑‑3‑氨基为原料与丙二腈进行环化反应,接着再与叠氮化钠反应得到化合物2。采用核磁共振、傅里叶红外光谱、差示扫描量热和X射线单晶体衍射等手段对化合物2进行结构表征和理化性能测试,并用EXPLO5对化合物2的爆轰性能进行预测。研究为含氟多氮稠环含能化合物的制备与应用提供了参考。
试剂:5‑(三氟甲基)‑1,2,4‑三唑‑3‑氨基,N,N‑二甲基甲酰胺(DMF),丙二腈,醋酸钠,浓盐酸,氯化锌,叠氮化钠(实验室自制
仪器:Avance Ⅲ 500MHz核磁共振仪(德国Bruker公司);Nicolet IS⁃10型傅里叶变换红外光谱仪(德国赛默飞世尔公司);VarioEL Ⅲ元素分析仪(德国Elemantar公司);DSC 823e差示扫描量热仪。
3‑(1H‑四唑)‑7‑(三氟甲基)‑1,2,4‑三唑[5,1‑c]‑1,2,4‑三嗪‑4‑氨基(2)的设计合成路线如

Scheme 1 Synthetic route of compound 2
将化合物5‑(三氟甲基)‑1,2,4‑三唑‑3‑胺(0.357 g, 2.35 mmol)溶于10 mL水和0.5 mL 37%盐酸的混合溶液中。接着,加入3 mL亚硝酸钠(0.162 g, 2.35 mmol)的水溶液,并在‑2 ℃下搅拌0.5 h。然后,向该反应体系中滴加5 mL丙二腈(0.155 g, 2.35 mmol)和乙酸钠(0.964 g, 11.75 mmol)的水溶液,并继续反应1 h。最后,再升温至30 ℃搅拌2 h。反应结束后过滤沉淀,水洗、风干,得到化合物1(0.394 g, 1.72 mmol),产率为73.1%。
将化合物1(1.145 g,5.00 mmol)、NaN3(0.332 g, 5.10 mmol)和ZnCl2(0.82 g, 6.00 mmol)加入到12 mL水中,加热回流0.5 h,然后冷却至室温,用20%盐酸酸化至pH 1~2,过滤得到固体2(1.274 g,4.68 mmol),产率为93.6%,纯度97.6%
单晶结构测试:将化合物2溶于DMF中,过滤后取大约2 mL溶液置于干净的小玻璃瓶中,于室温下缓慢挥发溶剂,约一周后得到淡黄色透明晶体2·DMF。选取尺寸为0.15 mm×0.12 mm×0.10 mm的晶体,用单晶衍射仪进行结构分析。
热性能测试:在氮气气氛(流速30 mL·mi
性能计算:运用密度泛函理论中的B3LYP基
基于相关文献报

Scheme 2 Synthetic mechanism of compound 2
化合物2·DMF的晶体结构数据见
parameter | 2·DMF |
---|---|
empirical formula | C9H10F3N11O |
formula weight | 345.28 |
temperature / K | 296(2) |
crystal system | triclinic |
space group | Pī |
a / Å | 4.903(10) |
b / Å | 10.219(2) |
c / Å | 15.194(3) |
α / (°) | 107.163(6) |
β / (°) | 92.486(7) |
γ / (°) | 96.438(7) |
volume / | 720.4(3) |
Z | 2 |
ρ(calc) / g·c | 1.592 |
μ / m | 0.142 |
F(000) | 352 |
crystal size / m | 0.150×0.120×0.100 |
radiation | MoKα (λ=0.71073) |
theta range for data collection / (°) | 2.104 to 27.568 |
index ranges | -6≤h≤6, -13≤k≤13, -19≤l≤19 |
reflections collected | 11178 |
independent reflections | 3307 [Rint=0.0382] |
data/restraints/parameters | 3307/36/247 |
goodness‑of‑fit on | 1.027 |
final R indexes [I>=2σ(I)] | R1=0.0517, wR2=0.1425 |
final R indexes [all data] | R1=0.0549, wR2=0.1307 |
largest diff. peak / hole / e· | 0.168 / -0.192 |
bond | bond lengths / Å | dihedral | bond angles / (°) |
---|---|---|---|
C(3)—C(4) | 1.422(3) | N(3)—C(3)—N(6)—H(6A) | 0.112(164) |
N(2)—N(3) | 1.361(2) | C(6)—C(1)—N(2)—N(3) | 2.384(180) |
N(4)—N(5) | 1.323(2) | N(5)—C(4)—C(5)—N(7) | 0.827(184) |
N(7)—N(8) | 1.334(2) | N(1)—C(2)—N(3)—C(3) | 1.923(188) |
N(8)—N(9) | 1.289(3) | ||
N(9)—N(10) | 1.359(3) |
D—H…A | d(D—H) / Å | d(H…A) / Å | d(D—A) / Å | ∠(DHA) / (°) |
---|---|---|---|---|
N(6)—H(6A)…O(1) | 0.86 | 1.92 | 2.761(2) | 166.2 |
N(6)—H(6B)…N(9) | 0.86 | 2.40 | 3.111(3) | 141.0 |
N(6)—H(6B)…N(10) | 0.86 | 2.21 | 2.831(3) | 128.5 |
N(7)—H(7)…N(4) | 0.86 | 2.04 | 2.892(2) | 173.0 |
C(9)—H(9)…N(8) | 0.93 | 2.49 | 3.386(3) | 163.0 |

a. crystal structure

b. crystal packing

c. non‑covalent interaction analysis
图1 化合物2·DMF的晶体结构图、晶体堆积方式和非共价相互作用分析
Fig.1 Crystal structure, crystal packing and non‑covalent interaction analysis of 2·DMF
从
化合物2·DMF的氢键数据列于
此外,采用Crystal Explorer软件模拟得到化合物2·DMF的Hirshfeld表面和2D指纹图,并根据不同元素计算得到其Hirshfeld表面的氢键贡献占比,如

a. finger print plots

b. individual atomic contacts percentage contribution
图2 化合物2·DMF的二维指纹图、Hirshfeld表面和原子间相互作用比例
Fig.2 Fingerprint plots, Hirshfeld surface and individual atomic contacts percentage contribution of 2·DMF
热稳定性是含能材料的重要物理因素。研究测试了化合物2的DSC曲线和TG曲线,结果如

图3 化合物2的DSC和TG曲线
Fig.3 DSC and TG curves of compound 2
为进一步分析化合物2的爆轰性能,通过Gaussian软件在b3lyp/6‑3
compound | ρ / g·c | ΔHf / kJ·mo | Tp / ℃ | D / m· | p / GPa | IS / J | FS / N |
---|---|---|---|---|---|---|---|
2 | 1.86 | 16.9 | 280.8 | 6933 | 17.1 | >40 | >360 |
TF | 1.88 | -184.7 | 281.0 | 7492 | 26.4 | >40 | >360 |
TT | 1.82 | 403.5 | 272.0 | 8580 | 31.2 | >40 | >360 |
NTT | 1.87 | 721.6 | 181.0 | 9010 | 32.8 | 35 | 300 |
HN | 1.75 | 78.2 | 318.0 | 7612 | 24.3 | 5 | 240 |
RD | 1.91 | 70.3 | 204.0 | 9144 | 39.2 | 5 | 102 |
Note: ρ is density calculated by Multiwfn. ΔHf is calculated heat of formation. Tp is thermal decomposition temperature determined by DSC exothermal peak at 10 ℃·mi

Scheme 3 Isodesmic reactions for calculating heat of formation for compound 2
由

Scheme 4 Structure of TFX, TTX, NTTA and 2
此外,通过BAM跌落锤试验和BAM摩擦试验,分别对化合物2的撞击灵敏度(IS)和摩擦感度(FS)进行分析。实验结果(
研究以5‑(三氟甲基)‑1,2,4‑三唑‑3‑胺为原料,两步合成了一种新的含三氟甲基、高稳定、不敏感的稠环三唑三嗪类含能材料2,并对该化合物的晶体结构、热分解性能、机械感度与理论爆轰性能进行表征与计算。得到如下结论:
(1)化合物2·DMF属于三斜晶系,Pī空间群,在晶胞中有2个分子,a=4.9035(10) Å,b=10.219(2) Å,c=15.194(3) Å,V=720.4(3)
(2)由于—CF3的存在,化合物2表现出高的密度(1.86 g c
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