(395au) About The Interaction Between Cpls and CO2: A DFT and ONIOM-EE Study

ABOUT THE
INTERACTION BETWEEN CPLs AND CO2: A DFT and ONIOM-EE STUDY

Paul de Jesus Meza-Morales, Radamés Irizarry-Castillo, and María C. Curet-Arana

Department of Chemical Engineering, University of Puerto Rico, Mayagüez, PR

Coordination
polymer-ligands (CPLs) are porous-crystalline materials consisting of metal
ions linked to organic bridging ligands as shown in figure 1. Because of the
flexibility in their synthesis, a range of novel structures has been rationally
designed with high surface area, large pores and distinct gas adsorption
properties. The objective of this project is to study CO₂ - CPLs (CPL-2,
CPL-4, & CPL-7) interactions using quantum mechanical (QM) and ONIOM-EE calculations,
the last one is an integrated quantum mechanical molecular mechanical method
linked via electronic embedding. We have used two representative models for the
CPLs pores to reproduce binding sites in order to quantify energies of adsorption
and characterize the nature of the interaction. For
the QM calculations, we have compared
two exchange/correlation functionals B3LYP
and wB97XD, which has a specific treatment for non-covalent interactions. We have used a
mix of
6-311+G and LANL2DZ for the basis sets. The latter basis set was
used solely on the transition metal atom. For the ONIOM-EE calculations, we have used UFF to
describe the low level part of the system. In addition, charges from
electrostatic potential using a grid based method (CHelpG), natural bond
orbitals population analysis and electric field gradient calculations were
performed to describe the partial atomic charge distribution and electric field
properties of the framework.