The nature of monocyclic C10. A theoretical investigation using coupled-cluster methods

✍ Scribed by John D. Watts; Rodney J. Bartlett

• Book ID: 103033614
• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 585 KB
• Volume: 190
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(92)86095-y

✦ Synopsis

Three planar monocyclic geometries of Cl0 ( DSh cumulenic ( 1 ), D ,Oh cumulenic ( 2)) and Dji, acetylenic (3) ) have been investigated using coupled-cluster methods. Geometries have been optimized with the coupled-cluster singles-and-doubles (CCSD) method, effects of triple excitations on the relative energies have been estimated using the CCSD+T(CCSD) and CCSD(T) methods, and some distortions of (2) to lower symmetry have been investigated. With all basis sets considered, (1) is the lowest energy structure, although (2) and ( ) are respectively 2.8 and 5.8 kcal mol-' higher in energy with a polarized valence doublezeta basis set, and ( ) is less than 1 kcal mol-' higher in energy than (1) with a 4s3pld basis set. (2) however, is found to have an imaginary frequency for the B,, mode, which leads to (1). It is suggested that monocyclic Cl0 is highly fluxional, (2) being the low energy transition state for automerization of (1).