Charge-transfer and intraligand electronic spectra of bipyridyl complexes of iron, ruthenium, and osmium. I. Bivalent complexes

1971 ◽  
Vol 24 (2) ◽  
pp. 257 ◽  
Author(s):  
GM Bryant ◽  
JE Fergusson ◽  
HKJ Powell
Keyword(s):  
Charge Transfer ◽  
Metal Ions ◽  
Electronic Spectra ◽  
Ruthenium Complexes ◽  
Bidentate Ligands ◽  
Metal Oxidation ◽  
Transfer Pattern ◽  
Osmium Complexes ◽  
Monodentate Ligands ◽  
Main Factor

A series of spin-paired bivalent bipyridyl complexes of iron, ruthenium, and osmium, of the type [M(bipy)3]2+, [M(bipy)2X2]n+, [M(bipy)2XY]n+, [M(bipy)X4]n+, [M(bipy)(X2)2]n+, and [M(bipy)X2Y2]n+ (X and Y include a range of monodentate ligands and X2 a range of bidentate ligands) have been prepared. Their electronic spectra within the range 41000-7000 cm-1 have been recorded. All the complexes show two intraligand transitions which are present in free bipyridyl. The iron and ruthenium complexes have two metal oxidation charge-transfer bands, while the osmium complexes have a more complex charge-transfer pattern. Trends in the positions of the bands have been related to the bonding of the ligands X and Y to the metal ions. It is suggested that the energy of the metal t2 type orbitals relative to the ligand π and π* orbitals is the main factor in determining the intense electronic spectra of these complexes.

Charge-transfer and intraligand electronic spectra of bipyridyl complexes of iron, ruthenium, and osmium. II. Tervalent complexes

1971 ◽  
Vol 24 (2) ◽  
pp. 275 ◽  
Author(s):  
GM Bryant ◽  
JE Fergusson
Keyword(s):  
Charge Transfer ◽  
Metal Ions ◽  
Electronic Spectra ◽  
Metal Reduction ◽  
Spectral Bands ◽  
Charge Transfer Transitions ◽  
Halide Ligand ◽  
Halide Ligands

The electronic spectra of a series of six-coordinate octahedral tris-, bis-, and mono-bipyridyl complexes of tervalent iron, ruthenium, and osmium have been recorded and spectral bands assigned to intraligand and charge-transfer transitions. The tris-bipyridyl complexes and bis- and mono-bipyridyl complexes containing other ligands such as pyridine and cyanide show a metal reduction transition π(bipy) → t2(metal). Bipyridyl complexes of osmium containing halide ligands show a similar transition, but for the corresponding complexes of iron and ruthenium the metal reduction transition is now X(halogen) → t2(metal), the electron originating on the halide ligand. Bipyridyl-acetylacetonate complexes have more complicated spectra. Trends in the spectral bands, for all the complexes, indicate that of the three metal ions ruthenium probably forms the strongest M→L π-interaction.

Asymmetrische Katalysen, 25 [1]. C5H5Mn(CO)2-Komplexe von optisch aktiven Chelatphosphanen als einzähnige Liganden in der enantioselektiven Katalyse / Asymmetric Catalyses, 25 [1]. C5H5Mn(CO)2 Complexes of Optically Active Chelate Phosphanes as Monodentate Ligands in Enantioselective Catalysis

1985 ◽  
Vol 40 (10) ◽  
pp. 1243-1249 ◽  
Author(s):  
Henri Brunner ◽  
Alfons Knott
Keyword(s):  
Cinnamic Acid ◽  
Enantioselective Hydrogenation ◽  
Optically Active ◽  
Enantioselective Catalysis ◽  
Dinuclear Complexes ◽  
Bidentate Ligands ◽  
Monodentate Ligand ◽  
Mononuclear Complexes ◽  
Monodentate Ligands

The chelate phosphanes Diphos, Diop, and Norphos were reacted with C5H5Mn(CO)2THF and CH3C5H4Mn(CO)2THF to give mononuclear complexes, containing the phosphanes as unidentate or as bidentate ligands, and dinuclear complexes, containing bridging phosphane ligands. In C5H5Mn(CO)2Diop one of the two P(C6H5)2 groups of Diop is coordinated to the C5H5Mn(CO)2 fragment; the uncoordinated P(C6H5)2 group makes it a monodentate ligand. C5H5Mn(CO)2Diop together with [Rh(cod)Cl]2 was used as an in situ catalyst in the enantioselective hydrogenation of (Z)-a-[N -acetam ino]cinnamic acid (78.4% ee) and in the enantioselective hydrosilylation of acetophenone with diphenylsilane (6.7% ee).

scholarly journals Synthesis characterization of Cr(III), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes of 2,12-dimethyl-3-13-di-n-propyl-l,4,ll,14-tetraazacycloeicosa-1,13,l1,13-tetraene

2002 ◽  
Vol 67 (12) ◽  
pp. 825-832 ◽  
Author(s):  
Raghu Prasad ◽  
Mala Mathur
Keyword(s):  
Metal Ions ◽  
Metal Complexes ◽  
Electronic Spectra ◽  
Magnetic Measurements ◽  
Elemental Analyses

Metal complexes of a 20-membered tetraazamacrocycle 2,12-dimethyl-3,13-di-n-propyl 1,4,11,14-tetraazacycloeicosa-1,3,11,13-tetraene(L) of the type [MLX2]X(M=Cr(III), Fe(III); X=NO3)[CoLNO3]NO3, [NiL(NO3)2], [CuL]Cl2 and [ZnLCl2]have been prepared by 2+2 cyclocondensation of 2,3-hexanedione with 1,6-diaminohexane in the presence of metal ions as templates. These complexes were characterized by elemental analyses, conductances, IR and electronic spectra and magnetic measurements.

scholarly journals A new lanthanum(III) complex containing acetylacetone and 1H-imidazole

2017 ◽  
Vol 73 (11) ◽  
pp. 1739-1742 ◽  
Author(s):  
Atsuya Koizumi ◽  
Takuya Hasegawa ◽  
Atsushi Itadani ◽  
Kenji Toda ◽  
Taoyun Zhu ◽  
...  
Keyword(s):  
Bidentate Ligand ◽  
Bidentate Ligands ◽  
Monodentate Ligand ◽  
Intermolecular Hydrogen Bonds ◽  
Molecular Plane ◽  
One Dimensional ◽  
Nitrate N ◽  
Dimensional Network ◽  
Monodentate Ligands ◽  
Nitrate Anions

In the title complex, diaqua(1H-imidazole-κN3)(nitrato-κ2O,O′)bis(4-oxopent-2-en-2-olato-κ2O,O′)lanthanum(III), [La(C5H7O2)2(NO3)(C3H4N2)(H2O)2], the La atom is coordinated by eight O atoms of two acetylacetonate (acac) anions acting as bidentate ligands, two water molecule as monodentate ligands, one nitrate anions as a bidentate ligand and one N atom of an imidazolate (ImH) molecule as a monodentate ligand. Thus, the coordination number of the La atom is nine in a monocapped square antiprismatic polyhedron. There are three types of intermolecular hydrogen bonds between ligands, the first involving nitrate–water O...H—O interactions running along the [001] direction, the second involving acac–water O...H—O interactions along the [010] direction and the third involving an Im–nitrate N—H...O interaction along the [100] direction (five interactions of this type). Thus, an overall one-dimensional network structure is generated. The molecular plane of an ImH molecule is almost parallel to that of a nitrate ligand, making an angle of only 6.04 (12)°. Interestingly, the ImH plane is nearly perpendicular to the planes of two neighbouring acac ligands.

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