Influence of halogens on organometallic open pentadienyl lanthanum complexes XLa(C5H7)2 (X = H, F–I)

The electron and structural understanding of metal-coordinated pentadienyl ligands is essential for their subsequent use in different areas of chemistry, especially in the area of organometallic chemistry. Thus, in this work we have analyzed in gas-phase the influence of group 17 elements in complexes formed with the lanthanum atom and the open pentadienyl ligand, X La(C 5 H 7 ) 2 , where X = H, F, Cl, Br, and I. The results, using density functional theory (PBE0/def2-TZVP) and NBO analysis, suggest that all carbon atoms of both ligands are η 5 coordinated to the lanthanum atom, and X atoms play a very important role in affecting the electron transfer from the ligands to the central atom due to their electronegativity. In addition, the NBO analysis and the geometry of each structure suggest that the atoms that contribute the most as charge donors to the lanthanum atom are those at the center of the pentadienyl ligand. Energies were computed with the domain based local pair-natural orbital coupled-cluster (DLPNO-CCSD(T)) method. Graphic abstract