Ab initio study of some peroxides. HOOH, CH3OOH and, CH3OOCH3

✍ Scribed by Dines Christen; Hans-Georg Mack; Heinz Oberhammer

• Publisher: Elsevier Science
• Year: 1988
• Tongue: French
• Weight: 673 KB
• Volume: 44
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(01)86231-1

✦ Synopsis

The geometries of HOOH, CH300H, and CH300CH utro optimized with different basis sets (3-216. S-316 et4 ana 995*') at different levels of theory (HF. HP2, fiP4, and CI). HF/3-2lC optirizations result in planar trans conformations for all three peroxides. HF/6-3lG*+ calculations predict Skew conformations for HOOH and CH300H, but a planar trans Struture for CH300CH3. For the larger basis set the calculated bond lengths, especially the O-O bonds, are too short. Op-ti~lzatlons for HOOH including electron correlation at the XP2, l4P3. liP4, Cl, and CC0 level improve the ayreemtnt for bond lengths and the OOH angle, but result in dihedral angles which are too large by 3 -8'. In the case Of CH300CH3, similar calculations at the BP2 and CI level predict planar trans structures instead of the exptrirentally observed skew conformation. On the other hand, HP4 single point calculations at HP2 optimized paranetcrs result in a correct skew structure. For all three peroxides a computationally *economic' method. i.e., single point calculations rt HP2 or HP4 level with HF/3-2lC optimized parameters, result in close agrteetnt between CdlCutatt?d and exptrioental structures.