Competition between hydrogen bonds and halogen bonds in complexes of formamidine and hypohalous acids.
Quantum chemical calculations have been per-formed for the complexes of formamidine (FA) and hypohalous acid (HOX, X = F, Cl, Br, I) to study their structures, properties, and competition of hydrogen bonds with halogen bonds. Two types of complexes are formed mainly through a hydrogen bond and a halogen bond, respectively, and the cyclic structure is more stable. For the F, Cl, and Br complexes, the hydrogen-bonded one is more stable than the halogen-bonded one, while the halogen-bonded structure is favorable for the I complexes. The associated H-O and X-O bonds are elongated and exhibit a red shift, whereas the distant ones are contracted and display a blue shift. The strength of hydrogen and halogen bonds is affected by F and Li substitutents and it was found that the latter tends to smooth differences in the strength of both types of interactions. The structures, properties, and interaction nature in these complexes have been understood with natural bond orbital (NBO) and atoms in molecules (AIM) theories.
The Laboratory of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Yantai University, Yantai, 264005, People's Republic of China.
Xiulin
X
An
Hongying
H
Zhuo
Yingying
Y
Wang
Qingzhong
Q
Li
D000578:Amidines / Q000737:chemistry*; D001959:Bromates / Q000737:chemistry*; D017611:Fluorine Compounds / Q000737:chemistry; D006860:Hydrogen Bonding; D006997:Hypochlorous Acid / Q000737:chemistry*; D017613:Iodine Compounds / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D011789:Quantum Theory; D013816:Thermodynamics
D000578:Amidines; D001959:Bromates; D017611:Fluorine Compounds; D017613:Iodine Compounds; C081961:hypoiodous acid; C077922:formamidine; D006997:Hypochlorous Acid; C027664:hypobromous acid