title: Orbital interaction and electron density transfer in PdII([9]aneB2A)L2 complexes: theoretical approaches.
abstract: The geometric structures of Pd-complexes {Pd([9]aneB2A)L2 and Pd([9]aneBAB)L2 where A = P, S; B = N; L = PH3, P(CH3)3, Cl-}, their selective orbital interaction towards equatorial or axial (soft A…Pd) coordination of macrocyclic [9]aneB2A tridentate to PdL2, and electron density transfer from the electron-rich trans L-ligand to the low-lying unfilled a1g(5s)-orbital of PdL2 were investigated using B3P86/lanl2DZ for Pd and 6-311+G** for other atoms. The pentacoordinate endo-[Pd([9]aneB2A)(L-donor)2]2+ complex with an axial (soft A--Pd) quasi-bond was optimized for stability. The fifth (soft A--Pd) quasi-bond between the σ-donor of soft A and the partially unfilled a1g(5s)-orbital of PdL2 was formed. The pentacoordinate endo-Pd([9]aneB2A)(L-donor)2]2+ complex has been found to be more stable than the corresponding tetracoordinate endo-Pd complexes. Except for the endo-Pd pentacoordinates, the tetracoordinate Pd([9]aneBAB)L2 complex with one equatorial (soft A-Pd) bond is found to be more stable than the Pd([9]aneB2A)L2 isomer without the equatorial (A-Pd) bond. In particular, the geometric configuration of endo-[Pd([9]anePNP)(L-donor)2]2+ could not be optimized.
authors.affiliation: Department of Chemistry Education and Research Institute of Natural Science, Educational Research Institute Teachers College, Gyeongsang National University, Jinju 660-701, Korea. mc7@gnu.ac.kr.
authors.forename: Ock Keum
authors.initials: OK
authors.lastname: Kwak
authors.forename: Mahreen
authors.initials: M
authors.lastname: Arooj
authors.forename: Yong-Jin
authors.initials: YJ
authors.lastname: Yoon
authors.forename: Euh Duck
authors.initials: ED
authors.lastname: Jeong
authors.forename: Jong Keun
authors.initials: JK
authors.lastname: Park
mesh_terms: D002614:Chelating Agents / Q000737:chemistry; D003198:Computer Simulation; D056831:Coordination Complexes / Q000737:chemistry*; D008024:Ligands; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D010165:Palladium / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: D002614:Chelating Agents; D056831:Coordination Complexes; D008024:Ligands; D010165:Palladium