Modeling of the Response of Hydrogen Bond Properties on an External Electric Field: Geometry, NMR Chemical Shift, Spin-Spin Scalar Coupling

Abstract

The response of the geometric and NMR properties of molecular systems to an external electric field has been studied theoretically in a wide field range. It has been shown that this adduct under field approach can be used to model the geometric and spectral changes experienced by molecular systems in polar media if the system in question has one and only one bond, the polarizability of which significantly exceeds the polarizability of other bonds. If this requirement is met, then it becomes possible to model even extreme cases, for example, proton dissociation in hydrogen halides. This requirement is fulfilled for many complexes with one hydrogen bond. For such complexes, this approach can be used to facilitate a detailed analysis of spectral changes associated with geometric changes in the hydrogen bond. For example, in hydrogen-bonded complexes of isocyanide C≡15N-1H⋯X, 1J(15N1H) depends exclusively on the N-H distance, while δ(15N) is also slightly influenced by the nature of X.

Weak, Broken, but Working—Intramolecular Hydrogen Bond in 2,2′-bipyridine

“…This force was a fluctuating electric field present in the solution. Its effects and amplitude have been evaluated in the past for several molecular adducts [ 66 , 83 , 88 , 97 , 98 ]. However, the influence of this field on proton transfer can only be modeled if the transfer occurs along the symmetry axis of the adduct under consideration.…”

Nuclear Magnetic Resonance

“…Another efficient low-scaling MP2 computation of NMR shieldings with Choleskydecomposed densities and an attenuated Coulomb metric was proposed by Ochsenfeld et al 16 Shenderovich and Denisov provided a theoretic study of the impact of an external electric field on the geometry and NMR properties of hydrogen bond. 17 They also studied NMR properties of CN-as two-faced hydrogen bonding acceptor. 18 Sarotti et al 19 reported on further development of DP4þ method in order to design an universal and customized method used in combination with GIAO NMR results.…”

“…118 Theoretical calculations on 11 B NMR parameters in boron crystalline materials were also reported. 119 Dynamic of solid drug ibuprofen and terephthalic acid using 17 O and 2 H NMR was studied experimentally and supported by DFT calculations of nuclear shieldings. 120 Graphene has been a hot topic in both basic and applied science.…”

Influence of an Oriented External Electric Field on the Mechanism of Double Proton Transfer between Pyrazole and Guanidine: from an Asynchronous Plateau Transition State to a Synchronous or Stepwise Mechanism

“…The effect of an electric field on molecular structure and chemical reactivity has long been known. At a very fundamental level, electric fields have been used in numerical experiments to model environmental effects (solid state, solution) − or specific experimental conditions (e.g., STM) and thus better understand their influence on molecular structure as well as on other observables measured by various experimental techniques (e.g., NMR, , vibrational spectroscopy − ). Thanks to these studies, the effect of an electric field on covalent and noncovalent ,− bonds has been largely elucidated.…”

“…At a very fundamental level, electric fields have been used in numerical experiments to model environmental effects (solid state, solution) − or specific experimental conditions (e.g., STM) and thus better understand their influence on molecular structure as well as on other observables measured by various experimental techniques (e.g., NMR, , vibrational spectroscopy − ). Thanks to these studies, the effect of an electric field on covalent and noncovalent ,− bonds has been largely elucidated. Hydrogen bonded complexes ,− and proton transfer reactions ,− in particular have been widely investigated, due to their widespread occurrence in chemistry and biology.…”