Modeling organochlorine compounds and the σ-hole effect using a polarizable multipole force field.
The charge distribution of halogen atoms on organochlorine compounds can be highly anisotropic and even display a so-called σ-hole, which leads to strong halogen bonds with electron donors. In this paper, we have systematically investigated a series of chloromethanes with one to four chloro substituents using a polarizable multipole-based molecular mechanics model. The atomic multipoles accurately reproduced the ab initio electrostatic potential around chloromethanes, including CCl4, which has a prominent σ-hole on the Cl atom. The van der Waals parameters for Cl were fitted to the experimental density and heat of vaporization. The calculated hydration free energy, solvent reaction fields, and interaction energies of several homo- and heterodimer of chloromethanes are in good agreement with experimental and ab initio data. This study suggests that sophisticated electrostatic models, such as polarizable atomic multipoles, are needed for accurate description of electrostatics in organochlorine compounds and halogen bonds, although further improvement is necessary for better transferability.
Department of Biomedical Engineering, ‡Division of Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin , Texas 78712, United States.
Xiaojiao
X
Mu
Qiantao
Q
Wang
Lee-Ping
LP
Wang
Stephen D
SD
Fried
Jean-Philip
JP
Piquemal
Kevin N
KN
Dalby
Pengyu
P
Ren
D002251:Carbon Tetrachloride / Q000737:chemistry; D005740:Gases / Q000737:chemistry; D006219:Halogens / Q000737:chemistry; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry*; D008737:Methyl Chloride / Q000737:chemistry; D008958:Models, Molecular; D011789:Quantum Theory; D055672:Static Electricity; D013816:Thermodynamics
D005740:Gases; D006219:Halogens; D006843:Hydrocarbons, Chlorinated; D008737:Methyl Chloride; D002251:Carbon Tetrachloride