Chemistry Commons^™

The Oxidative Decarboxylation Of Polyaminocarboxylic Acids - Ii. A Comparative Kinetic Study Of The Oxidation Of Nta, Edta, Cdta And Dtpa With Cerium(Iv) In Sulfuric Acid Media, Samir B. Hanna, Rita Hessley, William H. Webb, William R. Carroll

Chemistry Faculty Research & Creative Works

The rates of oxidation of four chelating agents, NTA, EDTA, CDTA, and DTPA with Ce(IV), in sulfuric acid media, were determined spectrophotometrically by a stopped-flow technique. The reductive ability is in the order CDTA > EDTA > DTPA > NTA. The influence of varying the acidity of the medium was studied, and in each case a maximum in the rate constant vs. [H+] plot was observed. A possible interpretation of the reactivities and the influence of acidity is advanced. © 1971 Springer-Verlag.

Magnetic Behavior Of Rare-Earth Iron-Rich Intermetallic Compounds, Dominique Givord, Remy Lemaire, William Joseph James, Jean Michel Moreau, Jayant S. Shah

Chemistry Faculty Research & Creative Works

The thermal variation of lattice parameters of rare earth-transition metal intermetallic compounds rich in Fe, Co, or Ni in the temperature range of 25-900oK is studied. For the Fe compounds, negative thermal expansion is observed below their magnetic ordering temperatures regardless of the nature of substitutional ordering. For Co and Ni compounds, the thermal expansion behavior is normal. It is then concluded that for the Fe compounds, the magnetic properties are mainly determined by the Fe-Fe interatomic distances and the number of Fe nearest neighbors, whereas for Co and Ni compounds the magnetic properties are determined by the conduction electron …

The Effects Of Divalent Metal Ions On The Micellar Properties Of Sodium Dodecyl Sulfate, Michael U. Oko, Raymond L. Venable

Chemistry Faculty Research & Creative Works

Critical micelle concentrations and micellar molecular weights have been determined for sodium dodecyl sulfate in the presence of nitrates of copper, lead, zinc, and magnesium and critical micelle concentrations have been determined with sodium nitrate and silver nitrate as the added electrolytes. The thickness of the ionic atmosphere at the critical micelle concentration has been found to be 34.1 Å with no electrolyte present and 33.6 Å with 9.66 x 10-6 M sodium or silver nitrate and was found to increase upon addition of the 2:1 electrolytes. This is explained in terms of molecular and ionic interactions. Micellar molecular weights …

Glory Scattering In Molecular Collisions: Formal Expressions For The Total Cross Section, Louis Biolsi

Chemistry Faculty Research & Creative Works

An Extended Distorted-Wave Treatment is Used to Obtain Formal Expressions for the Total Cross Section When Two Rigid Diatomic Molecules with Orbital and Nuclear-Spin Angular Momenta Collide. Explicit Expressions Are Obtained through Second Order, Including the Lowest-Order Inelastic Effects.

The Oxidative Decarboxylation Of Polyaminocarboxylic Acids - I. A Study Of The Reaction Of Ethylenedinitrilotetraacetic Acid (Edta) With Cerium (Iv) In Acid Solution, Samir B. Hanna, S. Al-Hashimi, William H. Webb, William R. Carroll

Chemistry Faculty Research & Creative Works

The reaction between Ce(IV) and EDTA was followed titrimetrically and spectrophotometrically and was found to occur in stages. Four equivalents of Ce(IV) are reduced per mole of EDTA almost instantaneously at room temperature. With increasing temperature and reaction time an ultimate of about 14 equivalents of Ce (IV) is consumed per mole of EDTA. Carbon dioxide, formaldehyde, and other yet unidentified compounds are the products of oxidation of EDTA. The kinetics of the reaction in aqueous sulfuric acid was studied over the temperature range 11.7°-40°C by a spectrophotometric technique. The effects of the acidity of the medium and of added …

Modification Of The Devonshire Formula For The Thermal Accommodation Coefficient Of Helium On Tungsten, D. Vincent Roach, Robert E. Harris

Chemistry Faculty Research & Creative Works

The thermal accommodation coefficients (a.c.) of 3He and of 4He on clean tungsten were calculated using the Devonshire formula for temperatures between 70 and 600°K using "realistic" Morse potential parameters. The calculated a.c. values for 3He and 4He and the calculated ratios of the 4He to 3He values are compared with experimental data. The agreement is satisfactory if allowance is made for the error in the transition probability calculation used in the Devonshire formula.

Das Problem Der Mononitrierung Von Durol, S. B. Hanna, E. Hunziker, T. Saito, H. Zollinger

Chemistry Faculty Research & Creative Works

In contrast to many previous investigations, reaction conditions were found under which the nitration of durene (nitrating ratio of 1:1) gives predominantly, and in high yield, mononitrodurene rather than the usually formed dinitrodurene (plus unreacted durene). The method consists in nitrating by nitronium phosphorohexafluoride in nitromethane as solvent in presence of two equivalents of water. With mixed acid (HNO₃ + H₂SO₄) in nitromethane and in acetonitrile durene forms also monoand no dinitrodurene; but under most conditions by‐products are formed. Some of the by‐products were identified. Some preliminary mechanistic results are reported: An addition complex of …

The Role Of The Doctor Of Engineering Degree In Graduate Education, Wouter Bosch, Robert E. Carlile

Chemistry Faculty Research & Creative Works

No abstract provided.

Magnetic Structure Investigations At The Nuclear Center, R. Ballestracci, E. F. Bertaut, J. Coing-Boyat, A. Delapalme, William Joseph James, R. Lemaire, R. Pauthenet, G. Roult

Chemistry Faculty Research & Creative Works

The magnetic structure of the compounds UOS, ß-CoSO₄, YCO₅, and HoCO₅ is briefly described.

UOS is antiferromagnetic. The Néel temperature is T_n=55°K. The magnetic cell is doubled in the c direction with a ++ - - sequence of U moments along c. The apparent spin is S∼1. The negative interaction corresponds to U-O-U links.

In ß-CoSO₄ (high-temperature modification, space group Pbnm), Co atoms are in 000, 00½, ½½½, ½½0. Here three different antiferromagnetic spin modes, mutually perpendicular, A_x(+ - - +), G_y(+-+-), and C_z(++ - - …