Joseph E. Earley

Effect of Pressure on Dielectric Properties and Volume of 1‐Propanol and Glycerol

Dielectric constants and loss have been measured to pressures of 1000 kg/cm2 at audio‐ and radio‐frequencies from 212 to 240°K for glycerol and 124 to 210°K for 1‐propanol. Compressions to 1000 kg/cm2 have been measured to room temperature.The increases in static dielectric constant are less than predicted from density increase alone, and the differences are discussed in terms of molecular compression and liquid structure effects. Larger increases of relaxation time with pressure are found at lower temperatures. Constant volume relaxation times do not conform to a simple rate law, and cannot be explained by activation energies depending only on volume. Glycerol shows small, temperature independent, percentage volume decrease with pressure over the whole range; 1‐propanol becomes much less compressible at low temperatures.

Chemical “Substances” That Are Not “Chemical Substances”

The main scientific problems of chemical bonding were solved half a century ago, but adequate philosophical understanding of chemical combination is yet to be achieved. Chemists routinely use important terms (“element,” “atom,” “molecule,” “substance”) with more than one meaning. This can lead to misunderstandings. Eliminativists claim that what seems to be a baseball breaking a window is merely the action of “atoms, acting in concert.” They argue that statues, baseballs, and similar macroscopic things “do not exist.” When macroscopic objects like baseballs move, exceedingly large numbers (∼1025) of microscopic components coordinate their activities. Understanding how this happens requires attention to the interactions that link parts into larger units. Eliminativists say that everything that truly exists has causal relationships in addition to those of its components—“nonredundant causality.” This paper holds that if a number of entities interact in such a way that the effect of that collection on test objects is different than it would have been in the absence of the interaction, then identification of that collection as a single composite agent is warranted, for purposes to which that difference is relevant. Ordinary “chemical substances” (both elementary materials such as dihydrogen and compounds such as water) fulfill this version of the requirement of nonredundant causality. Other sorts of chemical coherences, including chemical dissipative structures (e.g., flames), also fulfill that criterion. All these types of coherences qualify as “substances” (as that term is used in philosophy) even though they are not all “chemical substances.”The main scientific problems of chemical bonding were solved half a century ago, but adequate philosophical understanding of chemical combination is yet to be achieved. Chemists routinely use important terms (“element,” “atom,” “molecule,” “substance”) with more than one meaning. This can lead to misunderstandings. Eliminativists claim that what seems to be a baseball breaking a window is merely the action of “atoms, acting in concert.” They argue that statues, baseballs, and similar macroscopic things “do not exist.” When macroscopic objects like baseballs move, exceedingly large numbers (∼1025) of microscopic components coordinate their activities. Understanding how this happens requires attention to the interactions that link parts into larger units. Eliminativists say that everything that truly exists has causal relationships in addition to those of its components—“nonredundant causality.” This paper holds that if a number of entities interact in such a way that the effect of that collection on test o...

Varieties of Properties

Abstract: The traditional distinction between primary (observation independent) and secondary (observation dependent) qualities is not based on a difference that can be sustained in the full light of contemporary scientific understanding. An alternative division of physical and chemical properties is proposed. Like the traditional division of qualities, the alternative system has two main categories. Properties of compound particulars that result from simple combination (e.g., addition) of the properties of their component parts constitute the first class: properties that depend on details of interactions between component parts (e.g. cooperative effects) make up the second type. Application of the alternative dichotomy is considered for the cases of mass (traditionally a primary property) and color (a secondary quality, in the usual division). Both these types of properties can fall in either of the two classes of the alternate division of qualities, depending on the nature of the interaction that occurs between components. Both mass and color show that intermediate cases occur. Application of the alternative categorical scheme is straightforward, but not always simple. The proposed system shows that in chemical combination (and, perforce, in the many more complex systems common in human culture) interactions profoundly influence properties of entities that enter the interaction. This is not adequately treated by philosophical theories of wholes and parts (mereology), which should be extended to apply to such important cases.

A kinetic and isotope study of the mechanism of decomposition of the tetraperoxochromate(V) ion in basic solution

Abstract The decomposition of K 3 CrO 8 in aqueous alkaline solution has been reinvestigated. Over the pH range from 8.0 to 11.2, the rate is first-order each in tetraperoxochromate ion and hydrogen ion concentrations. No evidence was found for any rate effect due to carbonate or phosphate buffer. Inhibition by H 2 O 2 , NH 3 and by ethylenediamine occurs; the nature of these rate retardations was studied. Isotope labelling of the peroxide oxygen atoms showed that all of the oxygen atoms in product O 2 originated as peroxide oxygens in the anions, and that small but real amount of scrambling occurs. The marked complexities which obtain in this systems are discussed in terms of the kinetic and isotope data.

Synthesis of 6-amino-6-(4-aminobenzyl)-1,4,8,11-tetra-azacyclotetradecane, a new pentadentate polyamine ligand, and crystal structure of its Co(III) complex

The facile synthesis of the hydrochloride salt of the 6-amino-6-(4-aminobenzyl)-1,4,8,11-tetra-azacyclotetradecane L 3 is reported. The Co(III) complex of this new pentadentate ligand crystallizes in the space group P 2 1 / n , with a =15.5901(3), b =8.9267(2), c =20.6011(4) A, β =100.5960(10)°. X-ray crystal structure analysis has shown the 6-amino group axially coordinated to the metal center, and the cyclam moiety taking a trans I configuration. Water coordinates at the sixth site. The axial Co–N distance is 1.935(3) A, and the cyclam core nitrogen–Co distances are in the range between 1.957(3) and 1.964(3) A, shorter than previously reported data for similar macrocyclic complexes. The crystal structure of the complex [Cu(L 2 )(NO 3 ) 2 ] (L 2 : 6-nitro-6-(4-nitrobenzyl)-1,4,8,11-tetraazacyclotetradecane), synthetic precursor to the L 3 ligand is also reported. It crystallizes in the space group P 2 1 / n , with a =19.49560(10), b =8.38520(10), c =15.8518(2) A, β =111.03°.

Reduction of Ru2(CH3COO)4+ and Co(C2O4)33− by oxalatotitanuim(III) complexes in aqueous acidic solution

Reductions of Ru2(CH3COO)4+ and CO(C2O4)33− by oxalato complexes of titanium(III) have been studied in LiCF3SO3 media of 1.0 mol dm−3 ionic strength. At 25°C and [H+]f = 0.150 mol dm−3, Ru2(CH3COO)4+ and Co(C2O4)33− are reduced by Ti(C2O4)2− with second-order rate constants of (4.17 ± 0.08) x 1O3 and (3.20 ± 0.05) x 103 dm3 mol−1 s−1, respectively. Both oxidants show no detectable reactivity towards Ti(C2O4)+. Both reactions are base-catalysed. The magnitude of the rate constant for reduction of Ru2(CH3COO)4+ establishes an outer-sphere mechanism; the magnitude of the rate constant for Co(C2O4)33− indicates a substitution-limited inner-sphere mechanism.

Kinetics of replacement of bridging ligands in a diruthenium (II, III) cation

Abstract Tetrakis-μ-propionatodiruthenium(II,III) cation reacts with oxalate, in acidic aqueous solution (0.10 M LiCF 3 SO 3 , [H + ] 0.01 M at 29.4°C) in a two-phase process. An initial rapid change results in a small decrease in absorbance. This is ascribed to replacement of one propionate ligand by oxalate. A subsequent slower reaction, of which the rate is proportional to added oxalate concentration ( k bi 1.3 M −1 s −1 ), corresponds to a relatively large increase of absorbance at 475 nm, the absorbance maximum of the product. The data indicate formation of a bis(μ-oxalato)bis(μ-propionato)diruthenium(II,III) anion with a formation constant K f > 2 x 10 4 M −1 and an extinction coefficient of 1.3 x 10 3 M −1 cm −1 at 475 nm. A third, much slower, change results in decomposition of that product. The occurrence of replacement of bridging ligands under mild conditions indicates that tris-μ-carboxylatodiruthenium(II,Ill) species (otherwise unknown) function as kinetic intermediates.

SYNTHESIS OF THE CO(6-AMINO-6-(4-AMINOBENZYL)-1,4,8,11-TETRA-AZACYCLOTETRADECANE)-PO4, A POTENTIAL PHOSPHATE-BINDING SITE FOR MOLECULAR RECOGNITION

Abstract The preparation of Co(NH 3 ) 5 (PO 4 ) and Co(L 0 )(PO 4 ) [L 0 : 6-amino-6-(4-aminobenzyl)-1,4,8,11-tetra-azacyclotetradecane] is reported. 31 P NMR resonances for the two complexes are pH dependent, and are shifted downfield compared to that of unbound phosphate at the same pH. Co(NH 3 ) 5 (PO 4 ): pH 12.0, δ P 8.17 ppm; pH 7.2, δ P 7.50 ppm; Co(L 0 )(PO 4 ): pH 7.2, δ P 7.20 ppm. Co(L 0 )(PO 4 ) is a remarkable robust complex. Over a period of five weeks at 25°C, pH 7.2, less than 1% hydrolysis (aquation) occurred, so that k 1 E −15 s −1 .

Characterisation of the kinetic intermediate of the inner-sphere electron-transfer reaction involving hexa-aquotitanium(III) cation and di-µ-acetato-diaquodi-µ-oxalato-diruthenium(II,III) anion

A long-lived intermediate (formation constant 8 × 102dm3 mol–1) is involved in the reduction (25 °C, 1M LiO3SCF3) of di-µ-acetato-diaquodi-µ-oxalato-diruthenium(II,III) anion by hexa-aquotitanium(II) cation; the rate constant for intramolecular electron transfer within the conjugate base of the trinuclear intermediate is 30 s–1(enthalpy of activation, 58 kJ mol–1).

Kinetics of the reduction of Ru2(CH3COO)4+ and of Ru(NH3)5pyridine3+ by N-(2-hydroxyethyl)-ethylenediaminetriacetatoaquotitanium(III)

Abstract The kinetics of the reaction of Ti(HEDTA)(H 2 O) with Ru 2 (CH 3 COO) 4 + and with Ru(NH 3 ) 5 py 3+ (py = pyridine) have been studied in LiCl media of 1.0 M ionic strength. Both reactions follow second-order kinetics with the rate constant dependent on acidity according to the rate law: k 2 = kK /([H + ] + K ), where K is close to 0.1 M [the acid-dissociation constant of Ti(HEDTA)(H 2 O)], and k is 1.6 x 10 4 M −1 s −1 for Ru 2 (CH 3 COO) 4 + at 25°C and k is 2.0 x 10 5 M −1 s −1 for Ru(NH 3 ) 5 py 3+ at 4.5°C. The rate constant for reaction of Ti(HEDTA)(OH) − and Ru 2 (CH 3 COO) 4 + is about one order of magnitude higher than the rate constant for reduction of Ru 2 (CH 3 COO) 4 + by Ti(OH) 2+ , as would be expected on the basis of the shift in Ti III redox potential that is caused by ligation of HEDTA and the known influence of change in driving force on rates of outer-sphere Ru III -Ti III redox reactions. The rate of reduction of Ru(NH 3 ) 5 py 3+ by Ti(HEDTA)(OH) − at 4.5°C is more than two orders of magnitude higher than the reduction rate of the same oxidant by Ti(OH) 2+ at 25°C. This non-bridging ligand effect is at least 100 times larger than can be understood on the basis of change of redox potential, and is best ascribed to a large increase in the stability constant of the precursor complex.