[理学]120324-高等无机化学-d-block ppt 3.pptVIP

4.3 structure of coordination  compounds Isomerism and stereochemistry Werner, classical coordination compounds Non-werner Host-guest chem. Supramolecular chemistry Building block Intermolecular recognition Chiral Lock-and-key model 4.3.1 coordination number and  geometries of d-block metal complexes mononuclear complexes regular geometries, distorted structure steric effects bond length and angles where the energy difference between different possible structures is small,fluxional behaviour in solution may be observed VSEPR theory is not applicable to d-block metal complexes crystal field stabilization energy John-Teller effect angualr overlap model the Kepert model(repulsion low) The Kepert model The metal lies at the centre of a sphere and the ligands are free to move over the surface of the sphere. CN=2 to be linear D∞h AgCl2 CN=3 equlateral triangle with metal at the center of the plane sp hybridization D3h Pt(PPh3)3 CN=4 tetrahedral Td MnO4 ,Ni(CO)4 square planar D3h Ni(CN)4 PdCl4 CN=5 trigonal bipyramidal Fe(CO)5 D3h square pyramidal C4v TiF5 Berry pseudorotation for CN=5 tbp sp tbp CN=6 Octahedral Oh [Co(NH3)6] tetragonal distortion D4h trigonal distortion D3d trigonal prism Re(S2C2Ph2)3 D3h CN=7 pentagonal bipyramid D5h ZrF7 capped octahedron NbOF6 C3v capped trigonal prism C3v NbF7 (capped to a rectangular face) they are of comparable stability and easily interconvertible CN=8 the cube CsCl Td trigonal dodecahedron Mo(CN)8 D2d square antiprism