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• 作者：Dorothy J. Gearhart ; Katharine L.C. Hunt ; James F. Harrison
• 关键词：Thermochemistry ; Electronic structure ; Quadrupole moments ; Metal acetylides
• 刊名：Journal of Molecular Structure ; THEOCHEM
• 出版年：2008
• 期刊代码：63_01661280
• 类别：ch
• 出版时间：15 June 2008
• 卷：858
• 期：1-3
• 页码：31-38
• 文件大小：235 K

摘要

The electronic structure of Nab>2b>Cb>2b> is studied using ab initio electronic structure methods and is compared to the companion molecule Lib>2b>Cb>2b>. Both the linear Db>∞hb> and planar structures are minima on the ground state potential surface with the planar Db>2hb> conformation being the lowest energy form, similar to Lib>2b>Cb>2b>. At the CCSD(t) level the planar form is more stable that the linear by 11.2 kcal/mol as compared with 7.34 kcal/mol for Lib>2b>Cb>2b>. Both molecules are significantly ionic. The vibrational frequencies, atomization energy at 0 K, Db>0b>, and the standard enthalpy of formation, b=MathURL&_method=retrieve&_udi=B6TGT-4S21TGN-1&_mathId=mml14&_user=1067359&_cdi=5263&_rdoc=6&_acct=C000050221&_version=1&_userid=10&md5=0a481d2fc9d30dbbe59a858c49c3f908">bVlW-zSkWz" alt="View the MathML source" title="View the MathML source" align="absbottom" border="0" height=21 width="33"/> are calculated and compared to those of Lib>2b>Cb>2b> as well as HCCH, FCCF and ClCCCl. We find Db>0b> and b=MathURL&_method=retrieve&_udi=B6TGT-4S21TGN-1&_mathId=mml15&_user=1067359&_cdi=5263&_rdoc=6&_acct=C000050221&_version=1&_userid=10&md5=737b64ea13e385c636a0554b3a576b7f">bVlW-zSkWz" alt="View the MathML source" title="View the MathML source" align="absbottom" border="0" height=21 width="34"/> to be 331.1 and 84.92 kcal/mol for Lib>2b>Cb>2b> and 298.3 and 93.25 kcal/mol for Nab>2b>Cb>2b>. We calibrate these by calculating the same quantities for HCCH, FCCF and ClCCCl.