{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Gomez S"],"funding":["University of Antioquia"],"pagination":["1937"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC8949453"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["27(6)"],"pubmed_abstract":["High level DLPNO-CCSD(T) electronic structure calculations with extended basis sets over B3LYP-D3 optimized geometries indicate that the three methyl groups in caffeine overcome steric hindrance to adopt uncommon conformations, each one placing a C-H bond on the same plane of the aromatic system, leading to the C-H bonds eclipsing one carbonyl group, one heavily delocalized C-N bond constituent of the fused double ring aromatic system, and one C-H bond from the imidazole ring. Deletion of indiscriminate and selective non-Lewis orbitals unequivocally show that hyperconjugation in the form of a bidirectional -CH3 ⇆ aromatic system charge transfer is responsible for these puzzling conformations. The structural preferences in caffeine are exclusively determined by orbital interactions"],"journal":["Molecules (Basel, Switzerland)"],"pubmed_title":["Analysis of Conformational Preferences in Caffeine."],"pmcid":["PMC8949453"],"funding_grant_id":["Estrategia para la sostenibilidad. Internal project 2019-25332"],"pubmed_authors":["Rojas-Valencia N","Gomez S","Restrepo A"],"additional_accession":[]},"is_claimable":false,"name":"Analysis of Conformational Preferences in Caffeine.","description":"High level DLPNO-CCSD(T) electronic structure calculations with extended basis sets over B3LYP-D3 optimized geometries indicate that the three methyl groups in caffeine overcome steric hindrance to adopt uncommon conformations, each one placing a C-H bond on the same plane of the aromatic system, leading to the C-H bonds eclipsing one carbonyl group, one heavily delocalized C-N bond constituent of the fused double ring aromatic system, and one C-H bond from the imidazole ring. Deletion of indiscriminate and selective non-Lewis orbitals unequivocally show that hyperconjugation in the form of a bidirectional -CH3 ⇆ aromatic system charge transfer is responsible for these puzzling conformations. The structural preferences in caffeine are exclusively determined by orbital interactions","dates":{"release":"2022-01-01T00:00:00Z","publication":"2022 Mar","modification":"2025-04-22T01:41:13.072Z","creation":"2025-04-05T20:06:41.628Z"},"accession":"S-EPMC8949453","cross_references":{"pubmed":["35335301"],"doi":["10.3390/molecules27061937"]}}