Prediction of the Geometries of Simple Transition Metal Polyhydride Complexes by Symmetry Analysis

Abstract

The principle of correspondence between the symmetry decompositions of the valence atomic orbitals (AOs) of the central metal and those of the hydride ligands is used to predict and rationalize the geometries of simple transition metal polyhydride complexes. In this orbitally ranked symmetry analysis method (ORSAM) the minimum energy structures have metal AOs whose irreducible representations match those of the hydrides. In agreement with previous work, the hydrides prefer to bond to the metal (n + 1)s and nd orbitals, but ORSAM also includes (n + 1)p orbitals in a natural way and avoids having to postulate hypervalency for transition metal complexes with electron counts greater than 12. Comparison with ab initio structures of 114 simple transition metal polyhydrides shows that ORSAM correctly predicts and rationalizes the geometries of both classical and nonclassical complexes.

Structures of d4 MH3X: a Computational Study of the Influence of the Metal and the Ligands

“…The Hartree−Fock and MP2 calculations by Hall et al show several isomers with relative energives that depend on the computational method used. 10 The essential structural features of the three isomers of RuH 4 are shown in Figure 3. The Ru−H bond is 1.55 Å in td.…”

“…10 In these studies, only hydride complexes were calculated but other ligands were not explicitly considered. Likewise the influence of the metal was not explored.…”

Study of the MAu6 (M: Cr, Mo, W) Molecular Species: A Transition from Halogenlike to Hydrogenlike Chemical Behavior for Gold.

“…The existence of uranium tetraauride, UAu 4 , and the tetrahedral group 4 molecules, MAu 4 , where M ¼ Ti, Zr, Hf and Th has been recently predicted. 1 In these species gold has a formal oxidation state of (À1) and acts as a ligand to the metallic center.…”

“…1 In these species gold has a formal oxidation state of (À1) and acts as a ligand to the metallic center. The MAu 4 species were compared to the corresponding MX 4 species, where X ¼ halide and it turned out, that sizewise Au gives M-Au bond lengths between M-Br and M-I ones, while energywise the M-Au bonds are weaker than the M-Br and M-I bonds. The molecular structure remains tetrahedral.…”

“…These Group-5 pentahydrides 2-4 and Group-6 hexahydrides [3][4][5][6][7][8][9][10][11] have attracted copious attention. While the earliest treatments of WH 6 simply assumed the system to be octahedral 5,6 like the WX 6 hexahalides, it was later discovered that the system strongly distorts to a C 3v structure.…”