Leonard I. Katzin

REGULARITIES IN THE ABSORPTION SPECTRA OF HALIDES

Original absorption spectra of halides and a large body of literature absorption spectrum data are assembled. Certain characteristic features are pointed out which can be ascribed to transitions of electrons localized on the halide portion of a molecule or ion, such that their removal to an excited condition essentially leaves a neutral halogen atom as part of the excited state configuration. Recognition of this portion of the spectrum should assist understanding of halide spectra.

Factors affecting the solution of inorganic salts in organic solvents

Abstract Inorganic salts are appreciably soluble in organic media, principally of the oxygenated forms (alcohols, ketones, ethers, esters), when they are capable of forming neutral molecules in solution. This property is largely confined to the transition elements. Those of the first long series, and in the trans-radium region, accomplish this without forming undebatably covalent compounds; other subgroup elements which are solvent-soluble show a stronger tendency toward covalent bond formation, and may show solubility in chlorinated hydrocarbons and benzenoid solvents in which the first group mentioned are not usually soluble. The salts of the first three groups of the periodic table generally are not organic-soluble, because their co-ordinative power is relatively low, and their solid lattice energies are high. They tend strongly to approach the point-charge characterization on which the electrostatic approach to aqueous solution chemistry is based.

Infra-red spectra of water in tributyl phosphate containing dissolved salts, and the effects of solutes on the trialkyl phosphate spectrum

Abstract Data are presented on shifts of infra-red spectral peaks for the phosphoryl group of tributyl phosphate when various salts are co-ordinated. The effects of dissolved salts on the spectrum of water present in the phosphate are also pointed out.

Ionization Differences Between Coordination States of a Cation. Octahedral—Tetrahedral Equilibrium of Transition‐Element Chlorides in Dimethylformamide

In a high‐dielectric‐constant, low‐base‐strength medium, such as dimethyl formamide, formation of chloride complexes of the first transition elements in the tetrahedral configuration is promoted. The effect is linked with a greater dissociation (weaker anion complexing) of the octahedral configuration, as indicated by the over‐all equilibrium expression 2oct(MCl2X4)= oct(MClX5+)· tet(MCl3X)−+2X. The corresponding change in the absorption spectrum has been followed for the chlorides of Mn(II), Fe(II), Fe(III), Co(II), Ni(II), and Cu(II). The spectra with and without added LiCl are described. Some relations to current ligand‐field theories concerning the configuration change are pointed out.

Variations in Absorption Spectrum of the Nitrate Group

Lithium, magnesium, calcium, aluminum, manganous, cobaltous, nickelous, cupric, zinc, cadmium and thorium nitrates, and nitric acid, show an absorption in tertiary butyl alcohol solution which is different from that of dilute aqueous solutions of nitrates. The most marked effects are shown by the transition elements with partially completed d shells. The variety of the spectra indicate that a single change, such as the rearrangement of the normally planar nitrate ion into a pyramidal form, cannot account for nitrate spectrum changes.

Note on the Absorption Spectrum of Iodine in Oxygenated Solvents and the Dissociation of Iodine Water

Data are presented on factors in the appearance of the tri‐iodide absorption spectrum in solutions of iodine in water and in the alcohols. Some implications of the dissociation of iodine in water for the theory of the iodine‐solvent interaction are pointed out.

Infrared studies of binding and structure in monobasic organophosphorus acids and their salts

Abstract The PO vibrations of a number of monobasic acids, which are alkyl and aryl derivatives of P(V), are followed through a series of their salts. Trends are pointed out, and relations to crystal bonding, including possible resonance equivalence of the phosphoryl oxygens, are discussed. Certain acids are reported in which no PO absorption band has been detected. The relation of this phenomenon to crystal structure, phosphoryl base strength, and oxygen resonance is discussed. Some unusual characteristics of cations in the salts are also pointed out.

Infrared spectral observation on the PO group vibration of some homogeneous series of organic derivatives of P (V)

Abstract Wave numbers for i.r. frequencies of PO vibrations in complete series of neutral organic derivatives of phosphoric acid for groups n -butyl, 2-ethylhexyl, n -octyl and phenyl are presented, together with values for the diester acids, phosphonic acid half-esters and phosphinic acids. These data have been used to evaluate generalizations relating group electronegativity and PO frequency. There is no direct correlation between pK and PO frequency.

Optical Rotatory Dispersion of Some Amino Acids and Criteria of Protein Configuration

Rotatory dispersion of amino acids is well represented by a two-term Drude equation. The parameters of the equation are obtained by least-squares fitting with the aid of an electronic computer. using data for some 42 different wavelengths between 0.65 and 0.27 mu . Data are presented for the amino acids alanine, serine, valine, leucine, proline, aspartic acid, glutamic acid, asparagine, and lysine, in their several states of protonation and ionization. The median root mean square deviation between experimental and computed STA alpha !/sub lambda / is plus or minus 0.175 deg for the data in toto. The bearing of the data on problems of helix-random coil transition of proteins, relation of structure to optical rotation, and use of rotatory dispersion as a form of spectroscopy for attacking chemical problems was discussed. (auth)

A manganese-dioxide procedure for isolation and concentration of protactinium from irradiated thorium compounds☆

Abstract Traces of protactinium may be coprecipitated on manganese dioxide with good recovery from solutions 1N to 4N in nitric acid upon precipitating 1·5 g of dioxide per litre by the addition of potassium permanganate to manganous nitrate in excess. Good separation is obtained from macro concentrations of thorium nitrate. In concentrations up to 0·65M the thorium does not interfere with the precipitation, while at twice this concentration definite interference is found owing to the effect on the physical properties of the solution. With the aid of hydroxylamine to redissolve the dioxide, it is possible to concentrate the protactinium with respect to carrier by a factor of 100 per cycle. Hydrogen peroxide, sodium nitrite, and formic acid were less satisfactory reagents. Simultaneous purification from thorium and uranium may be achieved. Thorium is found to carry well in trace concentrations, but the efficiency of this process falls off with increasing thorium concentration.