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Dirhodium(II,II) Complexes as Electrocatalysts for CO<sub>2</sub> ReductionManamperi, Hemanthi D. January 2020 (has links)
No description available.
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Investigation of Rh<sub>2</sub>(II,II) complexes for applications in photochemotherapy and mismatch detectionAkhimie, Regina Nicole January 2017 (has links)
No description available.
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Molecular Modeling of Dirhodium ComplexesDebrah, Duke A 01 December 2014 (has links)
Dirhodium complexes such as carboxylates and carboxylamidates are very efficient metal catalysts used in the synthesis of pharmaceuticals and agrochemicals. Recent experimental work has indicated that there are significant differences in the isomeric ratios obtained among the possible products when synthesizing these complexes. The relative stabilities of the Rh2(NPhCOCH3)4 tolunitrile complexes, Rh2(NPhCOCH3)4(NCC6H4CH3)2, were determined at the HF/LANL2DZ ECP, 6-31G and DFT/B3LYP/LANL2DZ ECP, 6-31G levels of theory using NWChem 6.3. The LANL2DZ ECP (effective core potential) basis set was used for the rhodium atoms and 6-31G basis set was used for all other atoms. Specifically, the o-tolunitrile, m-tolunitrile, and p-tolunitrile complexes of the 2,2-trans and the 4,0- isomers of Rh2(NPhCOCH3)4 were compared.
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Structure Property Relationships for Dirhodium Antitumor Active Compounds: Reactions with Biomolecules and In Cellulo StudiesAguirre-Flores, Jessica Dafhne 2009 December 1900 (has links)
The molecular characteristics that affect the activity of various
dirhodium complexes are reported. The importance of the axial position in
the action of dirhodium compounds was studied. Three dirhodium complexes
with increasing number of accessible axial coordination sites were
synthesized and characterized. In cis-[Rh2(u-OAc)2(np)2]2+ (np = 1,8-
naphthyridine) both axial sites are available for coordination, whereas for
cis-[Rh2(u-OAc)2(np)(pynp)]+2 (pynp = 2-(2-pyridyl)1,8-naphthyridine) and
cis-[Rh2(u-OAc)2(pynp)2]+2 the pyridyl arm on the ligand pynp blocks one and
two axial sites, respectively. The availability of the axial positions affects the
in vitro and in cellulo activity of these complexes demonstrating that open
axial coordination sites are necessary for biological activity.
The inhibitory activity of derivatives of dirhodium-dppz complexes
(dppz = dipyrido[3,2-a:2',3'-c]phenazine) has also been investigated. The
dppz derivatives included compounds with electron-withdrawing (Cl, CN,
and NO2) as well as electro-donating (MeO and Me) substituents. These
compounds inhibit transcription of T7-RNA polymerase by reducing
accessible cysteine residues. The activity correlates with the electron withdrawing character of the substituent on the dppz ligand. Density
functional theory (DFT) calculations reveal that the lowest unoccupied
molecular orbitals (LUMOs) in the series are ligand-based pi* orbitals
localized on the phenazine ring. These complexes represent the first family
of dirhodium complexes whose inhibitory ability can be tuned by controlling
their redox properties.
The effect of the presence of diimine ligands in the dirhodium core in
both in vitro and in cellulo activity is discussed. The presence of one diimine
ligand allows for dual binding, intercalation and covalent, as observed by
melting temperature and relative viscosity measurements, as well as
electrophoretic mobility shift assay (EMSA). The mono-substituted
dirhodium complexes are effective against HeLa and COLO-316 cell lines,
with [Rh2(u-O2CCH3)2(n1-O2CCH3)(dppz)]+ being the most effective compound
of the series. Results of the comet assay indicate that all of the monosubstituted
complexes studied damage nuclear DNA, although in different
degrees. The cytotoxic effect of these complexes is not affected by the
presence of glutathione. The addition of the second diimine ligand hinders
the ability of the complexes to damage DNA. The bis-substituted complexes
are also slightly less cytotoxic than their mono-substituted congeners. Thus,
the number of equatorial positions occupied by diimine ligands play a critical
role in the mechanism of cytotoxicity of dirhodium(II,II) complexes.
Finally, the results also demonstrate that improving the
internalization of the dirhodium complexes can be achieved by co-incubation
with cell penetrating peptides. This work provides a foundation for the
preparation of new and more effective dirhodium complexes.
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Permeability of POPC bilayer by dirhodium complexesSears, Randy Bryan 10 December 2007 (has links)
No description available.
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Ab Initio and Semi-Empirical Calculations of Cyanoligated Rhodium Dimer ComplexsAsiri, Yazeed 01 May 2017 (has links)
Molecular modeling, using both ab initio and semi-empirical methods has been undertaken for a series of dirhodium complexes in order to improve the understanding of the nature of the chemical bonding in this class of homogeneous catalysts. These complexes, with carboxylamidate and carboxylate ligands, are extremely functional metal catalysts used in the synthesis of pharmaceuticals and agrochemicals. The X-ray crystallography shows anomalies in the bond angles that have potential impact on understanding the catalysis. To resolve these issues, minimum energy structures of several examples (e.g. Rh2(NHCOCH3)4, Rh2(NHCOCH3)4NC, Rh2(CO2CH3)4, Rh2(CO2CH3)4NC, Rh2(CHO2)4, and Rh2(CHO2)4NC) were calculated using Hatree-Fock and Density Functional Theory/B3LYP with the LANL2DZ ECP (Rh), and cc-pVDZ (all other atoms) basis sets.
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