Basiuk Vladimir A, Bolivar-Pineda Lina M, Meza-Laguna Victor, Rybak-Akimova Elena V, Basiuk Elena V
Instituto de Ciencias Nucleares , Universidad Nacional Autónoma de México , Circuito Exterior C.U. , 04510 Cd. México , Mexico.
Department of Chemistry , Tufts University , 62 Talbot Avenue , Medford , Massachusetts 02155 , United States.
J Phys Chem Lett. 2018 Aug 2;9(15):4420-4427. doi: 10.1021/acs.jpclett.8b02141. Epub 2018 Jul 24.
Unsubstituted phthalocyanines (including free-base HPc and many of its metal complexes) are among the most stable organic compounds. They can sublime without decomposition under reduced pressure and temperatures of up to 550 °C. This property was previously employed to design a novel approach to noncovalent functionalization of pristine single-walled carbon nanotubes (SWNTs) with 3d metal(II) phthalocyanine complexes. However, when we attempted to use the same sublimation protocol to prepare a SWNTs-HPc hybrid, an unexpected side effect of partial HPc pyrolysis was detected, phthalonitrile being a main decomposition product, under the conditions when HPc is supposed to be totally stable. By using density functional theory calculations, we offer an explanation for the thermal behavior of HPc based on its covalent attachment to the pentagonal-ring topological defects, which are very common in all graphene-derived carbon nanomaterials and capable of reacting with amines via nucleophilic addition process.
未取代的酞菁（包括游离碱HPc及其许多金属配合物）是最稳定的有机化合物之一。它们在减压和高达550°C的温度下可升华而不分解。此特性先前被用于设计一种用3d金属（II）酞菁配合物对原始单壁碳纳米管（SWNTs）进行非共价功能化的新方法。然而，当我们试图使用相同的升华方案制备SWNTs-HPc杂化物时，在HPc应完全稳定的条件下，检测到了部分HPc热解的意外副作用，邻苯二甲腈是主要分解产物。通过使用密度泛函理论计算，我们基于HPc与五边形环拓扑缺陷的共价连接对其热行为提供了解释，这种拓扑缺陷在所有源自石墨烯的碳纳米材料中都很常见，并且能够通过亲核加成过程与胺发生反应。
