biostudies-literatureDhimba GNational Research Foundation14918-14923https://www.ebi.ac.uk/biostudies/studies/S-EPMC9516665biostudies-literatureUnknown61(38)Chiral cis-MoO2(acac)2 racemizes via four pathways that agree with and extend upon Muetterties' topological analysis for dynamic MX2(chel)2 complexes. Textbook Ray-Dutt and Bailar twists are the least favored with barriers of 27.5 and 28.7 kcal/mol, respectively. Rotating both acac ligands of the Bailar structure by 90° gives the lower Conte-Hippler twist (20.0 kcal/mol), which represents a valley-ridge inflection that invokes the trans isomer. The most favorable is a new twist that was found by 90° rotation of only one acac ligand of the Bailar structure. The gas-phase barrier of 17.4 kcal/mol for this Dhimba-Muller-Lammertsma twist further decreases upon inclusion of the effects of solvents to 16.3 kcal/mol (benzene), 16.2 kcal/mol (toluInorganic chemistryRacemization Pathway for MoO2(acac)2 Favored over Ray-Dutt, Bailar, and Conte-Hippler Twists.PMC9516665120842Lammertsma KMuller ADhimba GfalseRacemization Pathway for MoO2(acac)2 Favored over Ray-Dutt, Bailar, and Conte-Hippler Twists.Chiral cis-MoO2(acac)2 racemizes via four pathways that agree with and extend upon Muetterties' topological analysis for dynamic MX2(chel)2 complexes. Textbook Ray-Dutt and Bailar twists are the least favored with barriers of 27.5 and 28.7 kcal/mol, respectively. Rotating both acac ligands of the Bailar structure by 90° gives the lower Conte-Hippler twist (20.0 kcal/mol), which represents a valley-ridge inflection that invokes the trans isomer. The most favorable is a new twist that was found by 90° rotation of only one acac ligand of the Bailar structure. The gas-phase barrier of 17.4 kcal/mol for this Dhimba-Muller-Lammertsma twist further decreases upon inclusion of the effects of solvents to 16.3 kcal/mol (benzene), 16.2 kcal/mol (tolu2022-01-01T00:00:00Z2022 Sep2025-04-19T05:18:10.515Z2025-04-19T05:18:10.515ZS-EPMC95166653598018910.1021/acs.inorgchem.2c00824