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Discontinuous Thermal Expansions and Phase Transformations in Crystals at Higher Temperatures (open access)

Discontinuous Thermal Expansions and Phase Transformations in Crystals at Higher Temperatures

The purpose of this investigation is to make more detailed studies of transformations. Fourteen compounds have been examined by high temperature X-ray diffraction for this purpose. The investigations have been carried out in such a way as to reveal: 1. the existence of transformations, 2. the influence of polarizability on thermal expansion, 3. the anisotropy of expansion, and 4. the discontinuity of thermal expansion.
Date: 1967
Creator: Hsu, Yuan Tsun
System: The UNT Digital Library
Magnetic Exchange in Oxovanadium(IV) Complexes with N-Salicylideneamino Acids (open access)

Magnetic Exchange in Oxovanadium(IV) Complexes with N-Salicylideneamino Acids

Copper(II) and oxovanadium(IV) ions resemble one another magnetically in having one unpaired electron in their complexes irrespective of their geometrical structures and bond types involved. Copper(II) complexes with antiferromagnetic exchange are well known. On the contrary, antiferromagnetic exchange in oxovanadium(IV) complexes is rather new and not well established. Very few oxovanadium(IV) complexes have been reported to have this anomalous magnetic property. In the investigation of the magnetic properties of oxovanadium(IV) complexes, we have successfully prepared two series of new oxovanadium(IV) complexes with N-salicylideneamino acids.
Date: January 1968
Creator: Hu, James Hung-Jen
System: The UNT Digital Library
The Electrochemical Properties of the Mercury/lithium Nitrate-potassium Nitrate Eutectic Interface (open access)

The Electrochemical Properties of the Mercury/lithium Nitrate-potassium Nitrate Eutectic Interface

The original purpose of this investigation was to attempt to apply the coulostatic method directly to a molten salt system. The inability to duplicate the reported capacity data for this system resulted in an investigation of the probable cause of this discrepancy between the data obtained by these different methods (14, 15).
Date: August 1968
Creator: Flinn, David R.
System: The UNT Digital Library
Metal (II) Complexes with N-Salicylideneamino Acids (open access)

Metal (II) Complexes with N-Salicylideneamino Acids

Transition metal complexes derived from Schiff bases have rendered an important contribution to the development of modern coordination chemistry. Various stable compounds have been prepared having synthetic, biological, and physicochemical interest. In particular, complexes of salicylaldimines, B-ketoamines, and closely related ligand systems have been investigated.
Date: August 1969
Creator: Carlisle, Gene Ozelle
System: The UNT Digital Library
Some Studies Pertaining to the Biosynthesis and Metabolism of Asparagine and Lysine in Lactobacillus Arabinosus: I. B-Aspartylhydroxamic Acid: Its Action as a Feedback Inhibitor and a Repressor of Asparagine Synthetase in Lactobacillus Arabinosus II. Purification and Properties of Diaminopimelate Decarboxylase from Lactobacillus Arabinosus (open access)

Some Studies Pertaining to the Biosynthesis and Metabolism of Asparagine and Lysine in Lactobacillus Arabinosus: I. B-Aspartylhydroxamic Acid: Its Action as a Feedback Inhibitor and a Repressor of Asparagine Synthetase in Lactobacillus Arabinosus II. Purification and Properties of Diaminopimelate Decarboxylase from Lactobacillus Arabinosus

That Lactobacillus arabinosus 17-5, ATCC 8014, can supply its own requirement for the amino acid, lysine, is demonstrated by the fact that the organism is capable of growth in media devoid of lysine. Since the final biosynthetic step in lysine formation in all bacteria studied to date involves the decarboxylation of meso-dlaminopimelic acid (DAP) to produce lysine, it was of interest to determine whether an enzyme catalyzing such a reaction (DAP decarboxylase) is present in L. arabinosus.
Date: August 1969
Creator: Chen, Yueh Tsun
System: The UNT Digital Library
Nuclear Magnetic Resonance Spectra of Some 1,2,4-triazoles (open access)

Nuclear Magnetic Resonance Spectra of Some 1,2,4-triazoles

In the work undertaken here, NMR has been used to ascertain the structure of some 1,2,4-triazoles. The investigation provides information concerning the structure of potentially tautomeric triazoles such as hydroxy- and aminotriazole. Connected with this aspect of triazole chemistry is the larger problem of mesohydric tautomerism. The present study also yields information for a comparison of substituent effects in triazoles, N-heteroaromatic substances and benzene.
Date: January 1967
Creator: Creagh, Linda Truitt
System: The UNT Digital Library
Kinetics and Mechanism Study of Diphenylketene Cycloadditions (open access)

Kinetics and Mechanism Study of Diphenylketene Cycloadditions

From a review of the published work in the field of cycloadditions, it is evident that further research is needed to establish the mechanism of ketene cycloadditions. This work was initiated with the intent of obtaining kinetic data which will contribute to the elucidation of the mechanism of ketene cycloadditions.
Date: August 1967
Creator: O'Neal, Hubert Ronald
System: The UNT Digital Library
Conformationally Stable Cyclohexyllithium Compounds (open access)

Conformationally Stable Cyclohexyllithium Compounds

Organolitnium compounds have been employed in synthetic worK for many years. However only during the last decade has much progress been made in establishing the mechanistic pathways for the reactions of these compounds.
Date: January 1968
Creator: Selman, Charles Melvin
System: The UNT Digital Library
Metal Complexes of 2,3-Quinoxalinedithiol (open access)

Metal Complexes of 2,3-Quinoxalinedithiol

A series of new planar complexes with the dianion of 2,3-quinoxalinedithiol ligand has been prepared. The complexes have been characterized from the study of their analyses, magnetic moment, conductance, polarograms, electron spin resonance spectra, and electronic spectra, and compared with the available data on the corresponding maleonitriledithiolene and toluene-3,4-dithiolene complexes.
Date: May 1969
Creator: Ganguli, Kalyan Kumar, 1912-
System: The UNT Digital Library