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Báo cáo hóa học: " Boron Fullerenes: A First-Principles Study Nevill Gonzalez Szwacki"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Boron Fullerenes: A First-Principles Study Nevill Gonzalez Szwacki | Nanoscale Res Lett 2008 3 49-54 DOI 10.1007 S11671-007-9113-1 NANO EXPRESS Boron Fullerenes A First-Principles Study Nevill Gonzalez Szwacki Received 11 November 2007 Accepted 4 December 2007 Published online 15 December 2007 to the authors 2007 Abstract A family of unusually stable boron cages was identified and examined using first-principles local-density functional method. The structure of the fullerenes is similar to that of the B12 icosahedron and consists of six crossing double-rings. The energetically most stable fullerene is made up of 180 boron atoms. A connection between the fullerene family and its precursors boron sheets is made. We show that the most stable boron sheets are not necessarily precursors of very stable boron cages. Our finding is a step forward in the understanding of the structure of the recently produced boron nanotubes. Keywords Boron clusters Boron fullerenes and nanotubes Boron sheets Quantum-mechanical modeling Introduction The chemistry of boron resembles that of carbon in its ability to catenate and form molecular networks. Unlike carbon bulk boron cannot be found in nature and all known boron allotropes where obtained in the laboratory. All of them are based on different arrangements of B12 icosahedrons. It is very natural to believe that not only carbon but also boron posesses molecular allotropes fullerenes and nanotubes . Experimental and theoretical research on the chemistry of boron nanomaterials is developing rapidly. The existence of quasi-planar 1 and tubular 2 boron clusters was predicted by theory and confirmed more N. Gonzalez Szwacki El Physics Department Texas Tech University Lubbock TX 79409-1051 USA e-mail nevill.gonzalez@ttu.edu recently by experiment 3 4 . Up to now however very little is known about the properties of these novel boron nanostructures. In this work we will describe the properties of a family of boron nearly round cages which are built from crossing boron double-rings DRs . The smallest members of