Observation and characterization of the smallest borospherene, B28(-) and B28.

Free-standing boron nanocages or borospherenes have been observed recently for B40(-) and B40. There is evidence that a family of borospherenes may exist. However, the smallest borospherene is still not known. Here, we report experimental and computational evidence of a seashell-like borospherene cage for B28(-) and B28. Photoelectron spectrum of B28(-) indicated contributions from different isomers. Theoretical calculations showed that the seashell-like B28(-) borospherene is competing for the global minimum with a planar isomer and it is shown to be present in the cluster beam, contributing to the observed photoelectron spectrum. The seashell structure is found to be the global minimum for neutral B28 and the B28(-) cage represents the smallest borospherene observed to date. It is composed of two triangular close-packed B15 sheets, interconnected via the three corners by sharing two boron atoms. The B28 borospherene was found to obey the 2(n + 1)(2) electron-counting rule for spherical aromaticity.

[1]  Yifan Jin,et al.  Coupled cluster geometries and energies of C20 carbon cluster isomers – A new benchmark study , 2015 .

[2]  V. Barone,et al.  Toward reliable density functional methods without adjustable parameters: The PBE0 model , 1999 .

[3]  Jun Li,et al.  Experimental and theoretical evidence of an axially chiral borospherene. , 2015, ACS nano.

[4]  Jijun Zhao,et al.  B80 and B101-103 clusters: remarkable stability of the core-shell structures established by validated density functionals. , 2012, The Journal of chemical physics.

[5]  Truong Ba Tai,et al.  Comment on "B38: an all-boron fullerene analogue" by J. Lv, Y. Wang, L. Zhu and Y. Ma, Nanoscale, 2014, 6, 11692. , 2015, Nanoscale.

[6]  Leiming Wang,et al.  Sn12(2-): stannaspherene. , 2006, Journal of the American Chemical Society.

[7]  H. W. Kroto,et al.  The stability of the fullerenes Cn, with n = 24, 28, 32, 36, 50, 60 and 70 , 1987, Nature.

[8]  Leiming Wang,et al.  Pb12 2-: plumbaspherene. , 2006, The journal of physical chemistry. A.

[9]  Lai‐Sheng Wang,et al.  B22- and B23-: all-boron analogues of anthracene and phenanthrene. , 2012, Journal of the American Chemical Society.

[10]  B. Yakobson,et al.  Erratum: B 80 Fullerene: An Ab Initio Prediction of Geometry, Stability, and Electronic Structure [Phys. Rev. Lett. 98 , 166804 (2007)] , 2008 .

[11]  R. Bartlett,et al.  A full coupled‐cluster singles and doubles model: The inclusion of disconnected triples , 1982 .

[12]  B28: the smallest all-boron cage from an ab initio global search. , 2015, Nanoscale.

[13]  Ya-Fan Zhao,et al.  Planar hexagonal B36 as a potential basis for extended single-atom layer boron sheets , 2014, Nature Communications.

[14]  Anastassia N. Alexandrova,et al.  All-Boron Aromatic Clusters as Potential New Inorganic Ligands and Building Blocks in Chemistry , 2006 .

[15]  M. Kappes,et al.  Boron cluster cations: transition from planar to cylindrical structures. , 2007, Angewandte Chemie.

[16]  Jun Li,et al.  The B35 cluster with a double-hexagonal vacancy: a new and more flexible structural motif for borophene. , 2014, Journal of the American Chemical Society.

[17]  R. Ahlrichs,et al.  Treatment of electronic excitations within the adiabatic approximation of time dependent density functional theory , 1996 .

[18]  Hua‐Jin Zhai,et al.  Cage-Like B41 (+) and B42 (2+) : New Chiral Members of the Borospherene Family. , 2015, Angewandte Chemie.

[19]  Wei Huang,et al.  Probing the 2D to 3D structural transition in gold cluster anions using argon tagging. , 2009, Physical review letters.

[20]  Jinlong Yang,et al.  Icosahedral B12-containing core-shell structures of B80. , 2010, Chemical communications.

[21]  Xiao Cheng Zeng,et al.  Evidence of hollow golden cages. , 2006, Proceedings of the National Academy of Sciences of the United States of America.

[22]  Jun Li,et al.  Observation of an all-boron fullerene. , 2014, Nature chemistry.

[23]  Alexander I Boldyrev,et al.  A concentric planar doubly π-aromatic B₁₉⁻ cluster. , 2010, Nature chemistry.

[24]  Lai‐Sheng Wang,et al.  TEMPERATURE EFFFECTS IN ANION PHOTOELECTRON SPECTROSCOPY OF METAL CLUSTERS , 2000 .

[25]  Sohrab Ismail-Beigi,et al.  Novel precursors for boron nanotubes: the competition of two-center and three-center bonding in boron sheets. , 2007, Physical review letters.

[26]  Paul von Ragué Schleyer,et al.  Nucleus-Independent Chemical Shifts:  A Simple and Efficient Aromaticity Probe. , 1996, Journal of the American Chemical Society.

[27]  Lai‐Sheng Wang,et al.  Understanding boron through size-selected clusters: structure, chemical bonding, and fluxionality. , 2014, Accounts of chemical research.

[28]  H. Scheraga,et al.  Global optimization of clusters, crystals, and biomolecules. , 1999, Science.

[29]  Lai‐Sheng Wang,et al.  B27(-): Appearance of the smallest planar boron cluster containing a hexagonal vacancy. , 2015, The Journal of chemical physics.

[30]  Jun Li,et al.  [B₃₀]⁻: a quasiplanar chiral boron cluster. , 2014, Angewandte Chemie.

[31]  S. Goedecker.  Minima hopping: an efficient search method for the global minimum of the potential energy surface of complex molecular systems. , 2004, The Journal of chemical physics.

[32]  Alexander I Boldyrev,et al.  Developing paradigms of chemical bonding: adaptive natural density partitioning. , 2008, Physical chemistry chemical physics : PCCP.

[33]  Lai‐Sheng Wang,et al.  Photoelectron spectroscopy of size‐selected transition metal clusters: Fe−n, n=3–24 , 1995 .

[34]  Truong Ba Tai,et al.  Electronic structure and photoelectron spectra of Bn with n = 26-29: an overview of structural characteristics and growth mechanism of boron clusters. , 2015, Physical chemistry chemical physics : PCCP.

[35]  Yanming Ma,et al.  B38: an all-boron fullerene analogue. , 2014, Nanoscale.

[36]  M. Head‐Gordon,et al.  A fifth-order perturbation comparison of electron correlation theories , 1989 .

[37]  E. Jemmis,et al.  Stuffing improves the stability of fullerenelike boron clusters. , 2008, Physical review letters.

[38]  Stefan Goedecker,et al.  Energy landscape of fullerene materials: a comparison of boron to boron nitride and carbon. , 2010, Physical review letters.

[39]  J. Pople,et al.  Self‐consistent molecular orbital methods. XX. A basis set for correlated wave functions , 1980 .

[40]  Andreas Hirsch,et al.  Spherical Aromaticity in Ih Symmetrical Fullerenes: The 2(N+1)2 Rule. , 2000, Angewandte Chemie.

[41]  Lawrence T. Scott,et al.  Gas-phase production and photoelectron spectroscopy of the smallest fullerene, C20 , 2000, Nature.

[42]  Jijun Zhao,et al.  B(80) and other medium-sized boron clusters: core-shell structures, not hollow cages. , 2010, The journal of physical chemistry. A.

[43]  S. C. O'brien,et al.  C60: Buckminsterfullerene , 1985, Nature.