Combining carbaboranes with transition-metal clusters; synthesis and X-ray structure analysis of a 1,2,3,4,5-pentamethyl-2,3,4,5-tetracarba-nido-hexaborane(6) derivative

1996 ◽  
pp. 1219-1220 ◽  
Author(s):  
Max Herberhold ◽  
Uwe Bertholdt ◽  
Wolfgang Milius ◽  
Alexandra Glöckle ◽  
Bernd Wrackmeyer
Keyword(s):  
Transition Metal ◽  
Structure Analysis ◽  
Metal Clusters ◽  
Transition Metal Clusters ◽  
X Ray

Delocalized bonding in tetrahedral organo-transition metal clusters: an EHMO study of metal vertex rotations in Co2Fe(CO)9S, CpMoCo2(CO)8CR, and in Cp2Mo2(CO)4(RC≡CR)

1996 ◽  
Vol 74 (6) ◽  
pp. 1021-1031 ◽  
Author(s):  
Krisztina L. Malisza ◽  
Lijuan Li ◽  
Michael J. McGlinchey
Keyword(s):  
Transition Metal ◽  
Key Words ◽  
Molecular Orbital ◽  
Metal Clusters ◽  
Metal Cluster ◽  
Molecular Orbital Calculations ◽  
Transition Metal Clusters ◽  
X Ray ◽  
Metal Bonding ◽  
Metal Metal

Molecular orbital calculations at the extended Hückel level are used to rationalize the barriers to vertex rotation in the tetrahedral metal cluster complexes FeCo2(CO)9S, 2, and (C5H5)MoCo2(CO)8CH, 3. It is shown that, in accord with experimental observations on 2, rotation of an Fe(CO)3 fragment through 60° brings about a weakening of the metal–metal bonding interactions within the FeCo2 triangle. In the MoCo2 cluster, 3, rotation of the CpMo(CO)2 fragment about an axis joining the molybdenum to a central point within the tetrahedron gives rise to three minima in which the cyclopentadienyl ring is oriented proximal or distal relative to the capping carbynyl moiety, or in the plane of the three metals. The rotation trajectory of the CpMo(CO)2 vertices in Cp2Mo2(CO)4(HC≡CH), 4, has been elucidated by means of a Bürgi–Dunitz analysis of the X-ray crystal structures of a series of related clusters in which the CpMo(CO)2 units exhibit a range of orientations. The calculations suggest that the barriers to vertex rotations in 4 are primarily of steric rather than electronic origin. Key words: metal clusters, vertex rotations, EHMO calculations.

Competitive adsorption of phenol and toluene onto silica-supported transition metal clusters for biofuel purification

2021 ◽  
Author(s):  
Saber Gueddida ◽  
Michael Badawi ◽  
Tejraj Aminabhavi ◽  
Sébastien Lebègue
Keyword(s):  
Transition Metal ◽  
Competitive Adsorption ◽  
Metal Clusters ◽  
Hydrocarbon Fuel ◽  
Energy Performance ◽  
Transition Metal Clusters ◽  
Gas Emissions ◽  
Toxic Gas

Biomass-based renewable hydrocarbon fuel is a complex mix that contains many oxygenating substances, in particular phenolics, which leads to adverse consequences such as reduced engine energy performance and increased toxic gas emissions.

Soluble lanthanide-transition-metal clusters Ln36Co12 as effective molecular electrocatalysts for water oxidation

2021 ◽  
Vol 57 (29) ◽  
pp. 3611-3614
Author(s):  
Rong Chen ◽  
Chao-Long Chen ◽  
Ming-Hao Du ◽  
Xing Wang ◽  
Cheng Wang ◽  
...  
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Synergistic Effect ◽  
Water Oxidation ◽  
Metal Clusters ◽  
Bond Formation ◽  
Transition Metal Clusters ◽  
Oxidation Activity ◽  
Acidic Conditions ◽  
Effective Water

The stable 48-metal Ln36Co12 clusters show an effective water oxidation activity under weak acidic conditions because of the synergistic effect between lanthanide and transition metals in O–O bond formation.

Regiospezifische Insertion von [SCN]- und [SeCN]- in die S – C- bzw. Se– C-Bindung Übergangsmetall-koordinierter Thietane und SelenetaneRegiospecific Insertion of [SCN]- and [SeCN]- in the S–C- and Se–C-Bond of Transition-Metal-Coordinated Thietanes and Selenetanes

1993 ◽  
Vol 48 (11) ◽  
pp. 1613-1620 ◽  
Author(s):  
Helmut Fischer ◽  
Claudia Kalbas ◽  
Carsten Troll ◽  
Klaus H. Fluck
Keyword(s):  
Nitrogen Atom ◽  
Transition Metal ◽  
Structure Analysis ◽  
Trans Isomer ◽  
X Ray ◽  
Tungsten Complexes ◽  
Membered Heterocycle

Pentacarbonyl(thietane)tungsten complexes react with thiocyanate, [SCN]-, and SiO2/H2O by insertion of the CN group into a S—C bond of the four-membered heterocycle, 1,3-migration of the pentacarbonyltungsten fragment and protonation of the nitrogen atom to give tungsten-coordinated thiazinthione complexes. Analogously, the reactions of a thietane tungsten complex with [SeCN]- and SiO2/H2O affords a thiazinselone complex. A selenazinthione complex is obtained from a selenetane complex and [SCN]- (+ SiO2/H2O). The insertions are regiospecific and stereoselective. The structure of the trans-isomer of a pentacarbonyl-(thiazinthione) complex has been established by X-ray structure analysis.

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