title: Spin-spin coupling constants in [corrected] artificial DNA intercalated with silver cations: theoretical prediction.
abstract: The indirect nuclear spin-spin coupling constants of Ag(+) cation intercalated between imidazole rings in DNA chains are calculated by means of DFT with relativistic effects taken into account by the use of the zeroth-order regular approximation Hamiltonian (DFT-ZORA). The calculations model how the (1)J((15)N,(109)Ag) coupling constant is affected by different types of geometry deformations and by the presence of water, which is simulated by means of the polarizable continuum model and explicitly present water molecules. Calculations for systems containing two and three imidazole pairs are also carried out to model the influence of stacking interactions. The computed (1)J((15)N,(109)Ag) spin-spin coupling constant is in the range of 85-105 Hz (depending on the computational model) and is in good agreement with the experimental value (ca. 92 Hz). This coupling constant is very little affected by the presence of solvent, stacking interactions, and geometry deformations. Such behavior is explained by visualization of the coupling path by means of coupling energy density (CED). Bigger models allow the coupling constant between two adjacent silver ions to be computed, and give a value of approximately 1 Hz, which is probably too small to be of practical interest. The (2)J((15)N,(15)N) value is calculated to be about 2.5 Hz, and is therefore of measurable magnitude.
authors.affiliation: Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warszawa, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Kauch
authors.forename: Magdalena
authors.initials: M
authors.lastname: Pecul
mesh_terms: D002414:Cations, Monovalent; D003198:Computer Simulation; D004247:DNA / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D006046:Gold / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry; D007364:Intercalating Agents / Q000737:chemistry*; D008958:Models, Molecular; D011789:Quantum Theory; D012834:Silver / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
chemical_list: D002414:Cations, Monovalent; D007093:Imidazoles; D007364:Intercalating Agents; D012997:Solvents; D014867:Water; D012834:Silver; D006046:Gold; C029899:imidazole; D004247:DNA