Halogen Bonding Interactions for Aromatic and Nonaromatic Explosive Detection
Halogen Bonding Interactions for Aromatic and Nonaromatic Explosive Detection
复制标题
DOI：
10.1021/acssensors.8b01246
复制
发表时间：
2019-02-01
期刊：
影响因子：
8.9
通讯作者：
Parish, Carol A.
中科院分区：
文献类型：
--
作者：
Jaini, Arjun K. A.;Hughes, Lillian B.;Parish, Carol A.
改进的传感策略，需要方便，准确，快速检测芳香族和非芳香族炸药。利用密度泛函理论计算了含卤素传感器模型分子与硝基炸药之间的相对结合作用能。相互作用能范围为-18至-14 kJ/mol，观察到高度定向的卤素键合相互作用，键距范围为3.0至3.4埃。在所有几何优化的结构中，卤素上的正电性电势的σ空穴与炸药的硝基部分上的孤对电子对准。计算结果预测，最强的相互作用将发生与碘为基础的传感器，所有研究的卤素，碘是最大的，最极化的卤素与最小的电负性。基于这些有希望的概念验证结果，使用具有和不具有连接到苯环的四氟吸电子基团的1，4-二卤代苯（X = Cl、Br和I）设计了合成可访问的传感器。这些传感分子被嵌入到单壁碳纳米管上，这些碳纳米管被机械研磨到叉指阵列电极上，并且这些被用来测量对氮气中的爆炸性模型化合物环己酮和二甲基二硝基苯的响应。选择剂和对照分子的电流-时间曲线，包括浓度相关的信号增强，以及响应和恢复时间，表明选择剂对这些模型化合物的响应性，碘取代的传感器观察到的最大响应。
Improved sensing strategies are needed for facile, accurate, and rapid detection of aromatic and nonaromatic explosives. Density functional theory was used to evaluate the relative binding interaction energies between halogen-containing sensor model molecules and nitro containing explosives. Interaction energies ranged from -18 to -14 kJ/mol and highly directional halogen bonding interactions were observed with bond distances ranging between 3.0 and 3.4 angstrom. In all geometry optimized structures, the sigma-hole of electropositive potential on the halogen aligned with a lone pair of electrons on the nitro-moiety of the explosive. The computational results predict that the strongest interactions will occur with iodine-based sensors as, of all the halogens studied, iodine is the largest, most polarizable halogen with the smallest electronegativity. Based on these promising proof-of-concept results, synthetically accessible sensors were designed using 1,4-dihalobenzene (X = Cl, Br, and I) with and without tetra-fluoro electron withdrawing groups attached to the benzene ring. These sensing molecules were embedded onto single walled carbon nanotubes that were mechanically abraded onto interdigitated array electrodes, and these were used to measure the responses to explosive model compounds cyclohexanone and dimethyl-dinitro-benzene in nitrogen gas. Amperometric current-time curves for selectors and control molecules, including concentration correlated signal enhancement, as well as response and recovery times, indicate selector responsiveness to these model compounds, with the largest response observed for iodo-substituted sensors.