title: Tetrel, chalcogen, and CH⋅⋅O hydrogen bonds in complexes pairing carbonyl-containing molecules with 1, 2, and 3 molecules of CO2.
abstract: The complexes formed by H2CO, CH3CHO, and (CH3)2CO with 1, 2, and 3 molecules of CO2 are studied by ab initio calculations. Three different types of heterodimers are observed, most containing a tetrel bond to the C atom of CO2, and some supplemented by a CH⋅⋅O H-bond. One type of heterodimer is stabilized by an anti-parallel arrangement of the C=O bonds of the two molecules. The binding energies are enhanced by methyl substitution on the carbonyl, and vary between 2.4 and 3.5 kcal/mol. Natural bond orbital analysis identifies a prime source of interaction as charge transfer into the π*(CO) antibonding orbital. Heterotrimers and tetramers carry over many of the geometrical and bonding features of the binary complexes, but also introduce O⋅⋅O chalcogen bonds. These larger complexes exhibit only small amounts of cooperativity.
authors.affiliation: Instituto de Química Médica, CSIC, Juan de la Cierva, 3, E-28006 Madrid, Spain.
authors.forename: Luis M
authors.initials: LM
authors.lastname: Azofra
authors.affiliation: Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322-0300, USA.
authors.forename: Steve
authors.initials: S
authors.lastname: Scheiner
mesh_terms: D001300:Audiometry, Evoked Response; D002245:Carbon Dioxide / Q000737:chemistry*; D018011:Chalcogens / Q000737:chemistry*; D006860:Hydrogen Bonding; D013816:Thermodynamics
chemical_list: D018011:Chalcogens; D002245:Carbon Dioxide