Christopher Imogen L, Liu Xiaojiao, Lloyd Hayleigh J, Bull Craig L, Funnell Nicholas P, Portius Peter, Michalchuk Adam A L, Kennedy Stuart R, Pulham Colin R, Morrison Carole A
EaSTChem School of Chemistry, The University of Edinburgh, King's Buildings, West Mains Road, Edinburgh, EH9 3FJ, UK.
Diamond Light Source, Harwell Science and Innovation Campus, Fermi Avenue, Didcot, OX11 0DE, UK.
Phys Chem Chem Phys. 2024 Jun 12;26(23):16859-16870. doi: 10.1039/d4cp01595a.
We report the preparation of a co-crystal formed between the energetic molecule 3-nitro-1,2,4-triazol-5-one (NTO) and 4,4'-bipyridine (BIPY), that has been structurally characterised by high-pressure single crystal and neutron powder diffraction data up to 5.93 GPa. No phase transitions or proton transfer were observed up to this pressure. At higher pressures the crystal quality degraded and the X-ray diffraction patterns showed severe twinning, with the appearance of multiple crystalline domains. Computational modelling indicates that the colour changes observed on application of pressure can be attributed to compression of the unit cell that cause heightened band dispersion and band gap narrowing that coincides with a shortening of the BIPY π⋯π stacking distance. Modelling also suggests that the application of pressure induces proton migration along an N-H⋯N intermolecular hydrogen bond. Impact-sensitivity measurements show that the co-crystal is less sensitive to initiation than NTO, whereas computational modelling suggests that the impact sensitivities of NTO and the co-crystal are broadly similar.
我们报道了含能分子3-硝基-1,2,4-三唑-5-酮（NTO）与4,4'-联吡啶（BIPY）形成的共晶体的制备，该共晶体已通过高达5.93 GPa的高压单晶和中子粉末衍射数据进行了结构表征。在该压力以下未观察到相变或质子转移。在更高压力下，晶体质量下降，X射线衍射图谱显示严重孪晶，出现多个晶域。计算模拟表明，施加压力时观察到的颜色变化可归因于晶胞压缩，这导致能带色散增强和带隙变窄，同时BIPY π⋯π堆积距离缩短。模拟还表明，施加压力会诱导质子沿着N-H⋯N分子间氢键迁移。冲击敏感性测量表明，该共晶体对起爆的敏感性低于NTO，而计算模拟表明NTO和该共晶体的冲击敏感性大致相似。
