Current Search: Perumareddi, Jayarama R. (x)
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- Title
- The electronic spectra and electronic energy levels of tetragonal chromium(III) complexes.
- Creator
- Schatschneider, Bohdan Hindulak., Florida Atlantic University, Perumareddi, Jayarama R.
- Abstract/Description
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We have studied the electronic spectra of tetragonal chromium (III) complexes namely trans-[Cr(NH3)4(CN)2]ClO4, trans-[Cr(en)2(CN)2]ClO4, and trans-[Cr(cyclam)(CN) 2]ClO4. These spectra have been analyzed by Gaussian analysis to locate the band maxima of the tetragonal components. The band maxima are then fitted with the tetragonal energy matrices of d3 configuration with full configuration interaction, neglecting spin-orbit interaction. The Dq, Dt, and Ds ligand field and the B and C...
Show moreWe have studied the electronic spectra of tetragonal chromium (III) complexes namely trans-[Cr(NH3)4(CN)2]ClO4, trans-[Cr(en)2(CN)2]ClO4, and trans-[Cr(cyclam)(CN) 2]ClO4. These spectra have been analyzed by Gaussian analysis to locate the band maxima of the tetragonal components. The band maxima are then fitted with the tetragonal energy matrices of d3 configuration with full configuration interaction, neglecting spin-orbit interaction. The Dq, Dt, and Ds ligand field and the B and C electron correlation parameters have been extracted from the fitting procedure. The parameters have been analyzed to understand the bonding of these complexes. We have also uncovered the low intensity absorption doublet bands and a high intensity charge transfer band of trans-[Cr(en)2(CN)2]ClO4 which occur around 15,000cm-1 and 49,000cm-1, respectively.
Show less - Date Issued
- 2001
- PURL
- http://purl.flvc.org/fcla/dt/12756
- Subject Headings
- Chromium--Spectra, Ligand field theory, Atomic spectra
- Format
- Document (PDF)
- Title
- The jj-coupling scheme by tensor operators and a thorough interpretation of the spectra of some nickel(II) complexes.
- Creator
- Alves, Gelio., Florida Atlantic University, Perumareddi, Jayarama R.
- Abstract/Description
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The ligand field theory of complexes has been completely developed and the energy matrix elements for complexes in various geometries in different coupling schemes have been worked in considerable detail. However for many coupling schemes the computing of energy matrix elements is a tedious and laborious process. In the first part of my thesis we present a solution to the Weak-Field II problem using ladder operators and tensor operators. We used the Weak-Field II as an example to stress the...
Show moreThe ligand field theory of complexes has been completely developed and the energy matrix elements for complexes in various geometries in different coupling schemes have been worked in considerable detail. However for many coupling schemes the computing of energy matrix elements is a tedious and laborious process. In the first part of my thesis we present a solution to the Weak-Field II problem using ladder operators and tensor operators. We used the Weak-Field II as an example to stress the complexity of computing energy matrix elements using ladder operators versus the simplicity of calculating matrix elements with tensor operators. Also the Weak-Field II was used as a model example hoping to be able to accomplish the same with the jj-II coupling scheme. In the last part of my thesis we present a derivation of simplifying expressions for the energy matrix elements for the d 2 complex in the jj-II coupling scheme. It is worth mentioning that the expressions derived can be applied to complexes other than octahedral and further they can be generalized for complexes with n-electrons in the valence shell. Finally, we present a thorough analysis of the electronic spectra of some Nickel(II) complexes.
Show less - Date Issued
- 2005
- PURL
- http://purl.flvc.org/fcla/dt/13256
- Subject Headings
- Ligand field theory, Quantum chemistry, Stereochemistry
- Format
- Document (PDF)
- Title
- Electronic Spectra of Quadrate Chromium (III) Complexes.
- Creator
- Lowry, Robert K. Jr., Perumareddi, Jayarama R., Florida Atlantic University
- Abstract/Description
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Ligand field theory of d^3 transition metal ions in cubic and quadrate fields is briefly summarized, along with the features of the predicted spectra. Diffuse reflectance spectra of a variety of quadrate chromium(III) complexes are measured with special emphasis on uncovering the component structures of the spin-forbidden transitions. Energy level assignments are made for components of both spin-allowed and spin-forbidden bands by fitting of the calculated and observed energy levels. Electron...
Show moreLigand field theory of d^3 transition metal ions in cubic and quadrate fields is briefly summarized, along with the features of the predicted spectra. Diffuse reflectance spectra of a variety of quadrate chromium(III) complexes are measured with special emphasis on uncovering the component structures of the spin-forbidden transitions. Energy level assignments are made for components of both spin-allowed and spin-forbidden bands by fitting of the calculated and observed energy levels. Electron correlation and ligand field parameters are derived by the fitting procedure, and the usefulness of the repulsion parameters Band C in bonding considerations is discussed. Results reveal the need for certain refinements of the present state of ligand field theory. The need for improved experimental techniques to provide more precise and abundant spectral data is evident. When more data is available it will be possible to continue the extensions of the theory of ligand fields to s ystems of lower symmetries.
Show less - Date Issued
- 1969
- PURL
- http://purl.flvc.org/fau/fd/FA00000791
- Subject Headings
- Chromium--Spectra, Ligand field theory
- Format
- Document (PDF)
- Title
- Electronic structures of some copper(II)-imidazole complexes.
- Creator
- Williams, Chamindra S., Florida Atlantic University, Perumareddi, Jayarama R.
- Abstract/Description
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Electronic-structure studies of Tetrakis(imidazole)sulphatocopper(II) - Cu(C3H4N2)4SO4 and Tetrakis(imidazole)diperchloratocopper(II) - Cu(C3H4N 2)4(ClO4)2 have been carried out by analysis of electronic spectra, magnetic properties and ESR spectra. Solution spectra of both systems in the visible and UV range as well as unpolarised single-crystal spectrum of Cu(Im)4SO4 in the visible have been recorded. Both ligand-field (LF) and charge-transfer (L --> M) bands have been identified and...
Show moreElectronic-structure studies of Tetrakis(imidazole)sulphatocopper(II) - Cu(C3H4N2)4SO4 and Tetrakis(imidazole)diperchloratocopper(II) - Cu(C3H4N 2)4(ClO4)2 have been carried out by analysis of electronic spectra, magnetic properties and ESR spectra. Solution spectra of both systems in the visible and UV range as well as unpolarised single-crystal spectrum of Cu(Im)4SO4 in the visible have been recorded. Both ligand-field (LF) and charge-transfer (L --> M) bands have been identified and assigned, with the exception of the lowest energy LF band. The Angular Overlap Model has been used to calculate the LF band-maxima and compare with the observed band-maxima The ground-state energy-term for both Cu(Im)4SO4 and Cu(Im)4(ClO4)2 has been established with the use of ESR data to be 2B1g. Magnetic moment for the complexes have been obtained from precise magnetic susceptibility measurements with temperature variation and satisfactorily compared with the calculated values.
Show less - Date Issued
- 2000
- PURL
- http://purl.flvc.org/fcla/dt/15775
- Subject Headings
- Copper compounds, Ligand field theory
- Format
- Document (PDF)
- Title
- Electronic energy levels of some tetragonal copper ion and chromium ion complexes.
- Creator
- Davari, Mortaza., Florida Atlantic University, Perumareddi, Jayarama R.
- Abstract/Description
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The electronic spectrum of Cu(II)(L-His)2 has been measured in the visible-near IR and UV regions. By assigning ligand field bands and by fitting the band maxima with calculated energies using angular overlap model, the structure of the complex has been deduced to be five-coordinate C4v1 The observed bands in the UV spectrum have been assigned as due to ligand-to-metal charge transfer transitions. Electronic spectra of Cu(II)(diphenylcarbazide)2 and Cr(II)(diphenylcarbazone)(H2O)4 complexes...
Show moreThe electronic spectrum of Cu(II)(L-His)2 has been measured in the visible-near IR and UV regions. By assigning ligand field bands and by fitting the band maxima with calculated energies using angular overlap model, the structure of the complex has been deduced to be five-coordinate C4v1 The observed bands in the UV spectrum have been assigned as due to ligand-to-metal charge transfer transitions. Electronic spectra of Cu(II)(diphenylcarbazide)2 and Cr(II)(diphenylcarbazone)(H2O)4 complexes have also been measured. By interpretation of the ligand field bands in these spectra, tentative structures of these complexes in solution have been proposed.
Show less - Date Issued
- 1996
- PURL
- http://purl.flvc.org/fcla/dt/15318
- Subject Headings
- Copper compounds, Chromium compounds, Electron spectroscopy
- Format
- Document (PDF)
- Title
- POLARIZED CRYSTAL SPECTRA OF QUADRATE CHROMIUM(III) COMPLEXES.
- Creator
- KLEIN, ROBERT LEWIS, JR., Florida Atlantic University, Perumareddi, Jayarama R., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
- Abstract/Description
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The polarized crystal spectra of a series of tetragonal trans- diacidobis (ethylenediamine) chromium (III) complexes, trans-[Cr(en)2XY], where X= Y = Br-, H2O, F-, Cl- and X= H2O, Y = OH-, F-, have been measured at liquid nitrogen temperature, achieving better resolution of the split components of the cubic spin-allowed bands, and also definite energy level assignments. The observed band positions have been fitted with the predicted transition energies by the use of the appropriate energy...
Show moreThe polarized crystal spectra of a series of tetragonal trans- diacidobis (ethylenediamine) chromium (III) complexes, trans-[Cr(en)2XY], where X= Y = Br-, H2O, F-, Cl- and X= H2O, Y = OH-, F-, have been measured at liquid nitrogen temperature, achieving better resolution of the split components of the cubic spin-allowed bands, and also definite energy level assignments. The observed band positions have been fitted with the predicted transition energies by the use of the appropriate energy equations for d^3 configuration immersed in tetragonal fields with full configuration interaction. The ligand field parameters, which include the cubic and axial, and the electron correlation parameter B have been evaluated by such a fitting. The derived parameters have been analyzed and their significance discussed. Using thick crystals, we have uncovered a rich doublet structure in some of the complexes and tentative values of the electron correlation parameter C have been obtained for all the complexes.
Show less - Date Issued
- 1971
- PURL
- http://purl.flvc.org/fcla/dt/13454
- Subject Headings
- Chromium
- Format
- Document (PDF)
- Title
- REACTIONS OF LINEAR ALKYLDIMETHYLAMINE OXIDES WITH IODINE IN WATER, DICHLOROMETHANE AND HEPTANE.
- Creator
- HUDSON, ALICE PETERSON, Florida Atlantic University, Perumareddi, Jayarama R., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
- Abstract/Description
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The complexes of iodine with linear alkyl (C1, C8, C10 , C12 , C14 and C16) dimethylamine oxides have been studied in the solvents heptane, dichloromethane, and water. In the solvents heptane and dichloromethane and in aqueous surfactant micelles, alkyldimethylamine oxides react with iodine to form donor-acceptor complexes. Trimethylamine oxide is not soluble in heptane and does not form micelles in water so no complexes were fanned in these systems. In heptane and in dichloromethane the...
Show moreThe complexes of iodine with linear alkyl (C1, C8, C10 , C12 , C14 and C16) dimethylamine oxides have been studied in the solvents heptane, dichloromethane, and water. In the solvents heptane and dichloromethane and in aqueous surfactant micelles, alkyldimethylamine oxides react with iodine to form donor-acceptor complexes. Trimethylamine oxide is not soluble in heptane and does not form micelles in water so no complexes were fanned in these systems. In heptane and in dichloromethane the molecular complex ionizes to an "inner" complex in the presence of unassociated amine oxide. The effect of the surface activity is to reduce the concentration of free amine oxide and suppress this ionization. In the case of trimethylamine oxide in dichloromethane forming the dihydrate suppresses inner complex formation. In aqueous micelles the inner complex hydrolyzes to the protonated amine oxide, iodide ion, and hypoiodous acid which appears to oxidize water to molecular oxygen in the presence of the amine oxide micelles. Excess iodine complexes with iodide ion yielding triiodide ion which forms an undissociated ion pair with the micellar protonated amine oxide.
Show less - Date Issued
- 1977
- PURL
- http://purl.flvc.org/fcla/dt/13886
- Subject Headings
- Alkylation
- Format
- Document (PDF)