A gas-phase electron-diffraction investigation of trimethylenemethaniron tricarbonyl, C(CH2)3Fe(CO)3

Surface Organometallic Chemistry on Metals: Formation of a Stable ⋮Sn(n-C4H9) Fragment as a Precursor of Surface Alloy Obtained by Stepwise Hydrogenolysis of Sn(n-C4H9)4 on a Platinum Particle Supported on Silica

“…1 C at 2.12 Å and 3 Pt at 2.72 Å (Table ). The EXAFS-derived Sn−C distance is consistent with that expected for a tin−carbon σ-bond, and the Sn−Pt distance of 2.72 Å falls within the range (2.5−2.8 Å) previously reported in the literature. ,,− Any attempt to include Sn−O or Sn−Sn interactions resulted in significantly higher R factors, suggesting that the tin atoms are isolated and bonded directly to Pt rather than to the silica surface. To further investigate the feasibility of a Sn−O surface contribution to the EXAFS, refinements were also carried out using k 1 -weighting since such a weighting favors near shells of light scatters (O and C backscattering decays rapidly with increasing k value) whereas k 3 emphasises the higher shells.…”

Triplet electronic ground state of trimethylenemethane

“…The le/' combination is no longer a symmetry orbital but is likely to be converted (during the adiabatic twisting motion) to a distorted atomic p function perpendicular to the function with coefficient 2.0 in the le/' orbital of eq 11. That is the orbitals of eq 11 are likely to correlate with the orbitals (12) Hence the electron configuration for orthogonal trimethylenemethane should be lari 2ari lbri 3ari 4ari Sari 2bri 6ari7ari 3bri lbri 4bri Sari 2bri 5b2 la» (13) In the present study we have carried out ab initio SCF calculations on the planar 3A/, ', and 4A/ states arising from electron configuration 4. To test the effects of the spatial symmetry restrictions implicit in (4), the same electronic states have been studied with orbitals constrained only to be of C2s symmetry. That is, SCF wave functions have been obtained for the 3B2 and 4B2 states, which arise from electron configuration 5.…”

“…We have not plotted the 5h>2 orbital, since it has little magnitude in the plane 0.7 B above the molecule. However, inspection of the expansion coefficients shows the 5b2 orbital to be as in (12), a 2p orbital in the plane of the four carbon atoms. Finally, the total 7 electron density for the 3A2' ground state is seen in Figure 5 of ref s and p functions on each of the four carbons and from all but the orthogonal hydrogen s functions.…”

Binuclear heptalene iron carbonyl complexes: Comparison with related azulene and pentalene complexes

“…One of the four-carbon units complexed to an iron atom is a cisoid 1,3-diene unit leading to a substructure analogous to the known butadiene iron tricarbonyl. However, the other four-carbon unit is a Y-shaped trimethylenemethane unit similar to that found in the known trimethylenemethane-iron tricarbonyl [35,36] The lowest energy structures for the more highly unsaturated binuclear heptalene diiron carbonyl derivatives are higher spin states, namely triplets for C 12 H 10 Fe 2 (CO) n (n ¼ 4, 3) and a quintet for C 12 H 10 Fe 2 (CO) 2 . For C 12 H 10 Fe 2 (CO) n (n ¼ 4, 3) the B3LYP method appears to favor cis structures whereras the BP86 method favors trans structures.…”