109 research outputs found
Variable Temperature IR Spectroelectrochemical Investigation of the Stability of the Metal-Metal Bonded Radical-Anions [(CO)C5DMnRe(CO)C3(L)Re(Br) (CO)C3] Controlled by the Lowest pi* (alpha-diimine) Orbital Energy
Unusually stable radical anionic complexes [(CO)sub5MnRe(CO)sub3BPM]-,[(CO)sub5MnRe(CO)sub3BPMRe(CO)sub3Br]- and [Ossub3(CO)sub10BPMRe(CO)sub3Br]-(BPM=2,2'-bipyrimidine) studies with cyclic voltammertry and IR spectroelectrochemistry at variable temperatu
Density Functional Study of Ground and Excited States of MnC2(CO)C10
The precise nature of the excited states of Mn2(CO)lo leading to the well-known photochemistry-both Mn-Mn
and Mn-CO bond breaking upon low-energy excitation-is still unclear. In order to identify possibly dissociative
excited states (either Mn-Mn, Mn-CO,, or Mn-CO,,), the nature of the highest occupied Mn-3d orbitals is
analyzed as well as the composition of the virtual orbitals. The following features are noted. (a) The low-energy
excitations at 337-355 nm arise from B - CJ* and dn - u* excitations, while d - d excitations occur at much
higher energy. (b) The Mn-Mn CJ bonding HOMO as well as the u* LUMO cannot simply be classified as
arising from the 3d,2 components of eg parentage in the local octahedrons around Mn, they have little 3d,2 - 3d,2
(anti)bonding character but significant contributions come from M n - 4 ~ a~n d CO-2ne,, orbitals. Mn-Mn B
antibonding is only strong in the B* orbital due to these contributions. (c) Due to the strong involvement of
Mn-4p2, th 3d,2 orbital not only occurs in the B and u* orbitals but also in a higher set of virtuals, denoted d,d*,
-1.5 eV above the u* orbital. Antibonding with axial CO’s is strong in these higher virtuals but absent or weak
in the B and CJ* orbitals. CJ antibonding with equatorial CO’s is strong in the 3d2+ orbital of eg parentage, that
is located very high in the virtual spectrum, -2 eV above the u* orbital. Mn-Mn dissociation will occur only
from the B - B* excitation; CO loss will probably occur from the high-lying d - d excited states (excitations
into d,d* and 3d2-,2). The observed photochemistry at low energy will have to be explained from curve crossings
between the low-energy excited states and the photoactive states
Surface enhanced raman scattering spectroscopy of organometallics in systems with aqueous silver colloids
Spectroscopy and Photochemistry of the Clusters OsC3(XCO)C10(L) (L= 2,2E'-Bipyridine (BPM), 2,2E'-Bipyridine (BPM), 2,3-Bis(2-pyridyl)-pyrazine (DPP), 2,3-Bis(2-pyridyl)-benzoquinoxaline (DPB)), and OsC3(CO)C10(BPM)Re(CO)C3Br
Similarities in the architecture of the active sites of Ni-hydrogenases and Fe-hydrogenases detected by means of infrared spectroscopy
Similarities in the architecture of the active sites of Ni-hydrogenases and Fe-hydrogenases detected by means of infrared spectroscopy
Synthesis, spectroscopic properties and photochemistry of [Re(R)(CO)3(4,4'-Me2-bpy)] (R=alkyl) complexes
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