Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, UK.
Department of Chemistry, Imperial College London, Imperial College Road, London, SW7 2AZ, UK.
Angew Chem Int Ed Engl. 2017 Jul 3;56(28):8144-8148. doi: 10.1002/anie.201703585. Epub 2017 Jun 12.
Elemental phosphorus displays an impressive number of allotropes with highly diverse chemical and physical properties. White phosphorus has now been filled into single-wall carbon nanotubes (SWCNTs) from the liquid and thereby stabilized against the highly exothermic reaction with atmospheric oxygen. The encapsulated tetraphosphorus molecules were visualized with transmission electron microscopy, but found to convert readily into chain structures inside the SWCNT "nanoreactors". The energies of the possible chain structures were determined computationally, highlighting a delicate balance between the extent of polymerization and the SWCNT diameter. Experimentally, a single-stranded zig-zag chain of phosphorus atoms was observed, which is the lowest energy structure at small confinement diameters. These one-dimensional chains provide a glimpse into the very first steps of the transformation from white to red phosphorus.
元素磷具有令人印象深刻的同素异形体，具有高度多样化的化学和物理性质。现在已经将白磷从液态填充到单壁碳纳米管（SWCNT）中，从而阻止了与大气氧气发生高度放热的反应。用透射电子显微镜观察到了封装的四磷分子，但发现它们在 SWCNT“纳米反应器”内很容易转化为链结构。通过计算确定了可能的链结构的能量，突出了聚合度和 SWCNT 直径之间的微妙平衡。在实验中，观察到了单链锯齿形磷原子链，这是在小限制直径下能量最低的结构。这些一维链为从白磷到红磷的转化的最初步骤提供了一个 glimpse。
