Microsolvation and solvent effects on NMR magnetic shieldings of solvated I anion

Y. CHAMORRO; A. F. MALDONADO; A. I. AUCAR; E. FLOREZ; G. A. AUCAR; A. RESTREPO

St. Simons Island

Simposio; The 59th Sanibel Symposium; 2019

Solvent effects are important in most of the biomolecular phenomena as well as the vast majority of chemical processes taking place in solution. The environment may strongly modify the properties of the system as compared to the isolated situation. In this research we explore the microsolvation of the I anion with up to six water molecules. We analized energies, population of the different motifs as well as response properties like NMR magnetic shielding, and relativistic effects on all of them as it was performed in previous work. The search of the geometries of different structural motifs of the anion interacting with a number N of solvent molecules was performed through the potential energy surface(PES) with the ASCEC method. Random exploration were carried out using the hybrid functional B3LYP in conjunction with pseudopotentials to generate candidate structures. For the relativistic and correlation effects, two types of optimizations were carried out: scalar relativistic and four-component at MP2 level. Relativistic optimizations were carried out by using the DHF Hamiltonian. The calculations of NMR magnetic shieldings were carried out with relativistic polarization propagator approach (Rel-PPA). We found important solvent effects on intrinsic and response  properties in the systems under study. The nuclear magnetic shielding of heavy-ion reduces their values up to 6% due to solvent effects.