Studies on the Failure of the First Born Approximation in Electron Diffraction. V. Molybdenum- and Tungsten Hexacarbonyl.

Valence ionization spectra of group six metal hexacarbonyls studied by the symmetry-adapted cluster-configuration interaction method

“…The M-C lengths in the present study were longer than the MP2 ͑second-order Møller-Plesset perturbation theory͒ values 40 and were similar to the DFT values 28,41,42 and experimental results. [43][44][45][46] The C-O lengths in the present study were longer than the other theoretical and experimental values. We will discuss the effects of bond lengths on the ionization energies.…”

“…27 We also performed the SAC-CI calculation of Cr͑CO͒ 6 with the neutron diffraction geometry; 45 the results are also shown in Table V. Using this geometry, the 2E g state were split into two states in 17.94 and 18.09 eV with intensity 0.19 and 0.18.…”

Highly distorted octahedral molybdenum(II) complexes: Synthesis, crystal structure, and properties of [Mo(S2C6H4)(CO)2(PMe Ph3−)2] (n= 0–3)

“…The Mo-P distance was found to decrease moving from compound 1 (2.492 Å), bearing a weakly electron-donating PPh 3 ligand, to compound 4 (2.4567 Å), which bears the strongly electrondonating PMe 3 ligand (Table 2). Turning to the bond lengths, the Mo-C distances in compounds 1-4 were significantly shorter than in Mo(CO) 6 (2.063 Å) [29]. This result implies that p back-donation from Mo to CO is strengthened by the presence of coordinating electron-rich phosphine ligands on the Mo center.…”

Density Functional Calculations of95Mo NMR Chemical Shifts: Applications to Model Catalysts for Imine Metathesis

“…Secondly, the model reaction for imine metathesis is investigated in terms of key intermediates and transition structures, and includes an assessment of substituent effects on the rate-determining barrier and on d( Geometries and chemical shifts: Optimized geometries for the test set 1 ± 11, which comprises both inorganic and organometallic species, are displayed in Figure 1 [30±32] The compounds are served in the solid state for 1, 5, 6, and 11 are included for comparison, [30] as are structural data for [Mo 2 (OCH 2 CMe 3 ) 6 ] [31] for which 10 serves as model, as well as the gas-phase electron-diffraction (GED) results for 7, [32] the only known gas-phase structure in this set. [33] As noted before for these or for similar compounds, [6] bond lengths between the transition metal and the main-group elements tend to be overestimated by up to several pm at the DFT level employedÐ even more so for the inorganic dianions than for the organometallic species.…”