The solubility of tris(pentane-2,4-dionato)chromium(III) (Cr(acac)(3)) in supercritical carbon dioxide (SC-CO(2)) containing organic modifiers (1,1,1,3,3,3-hexafluoro-2-propanol (HFP) and 3,5-bis(trifluoromethyl)phenol (BTMP)) of hydrogen-bond donors was investigated by UV/VIS spectrophotometry. A great solubility enhancement of Cr(acac)(3) in SC-CO(2) was accomplished by adding HFP and BTMP. T...

1. The solubilities and differential heats of solution of d-tyrosine, dl-tyrosine, diiodo-dl-tyrosine, dibromo-l-tyrosine (hydrated), dibromo-l-tyrosine (anhydrous), and dichloro-l-tyrosine (hydrated) have been determined. 2. Evidence has been advanced that dl-tyrosine is a compound. 3. From the solubility determinations at various acidities, the apparent acid and basic dissociation constants o...

Solutions of tannic (digallic) acid at concentrations of 5 or 50 parts per million reduce dissolved ferric iron to the ferrous state when the pH is less than 4. In solutions with a pH of 4 or more, a black material containing ferric iron and tannic acid is precipitated. In a solution containing 500 parts per million of tannic acid, a ferrous complex forms at a pH of more than 5. This complex is...

The kinetics of binding of cyanide to sperm whale metmyoglobin has been studied in the pH range from 4.7 to 10.6 by simple mixing and stopped flow methods with classical and relaxation techniques and the aid of a digital computer. The apparent second order rate constant is strongly dependent on the nature and concentration of the buffer. Extrapolation to zero buffer concentration at constant to...

THE latest work on the isoelectric point of lecithin is that of Price and Lewis [1933] investigating the macrocataphoresis oflecithin dispersions. As in previous work it was noted that the electrical properties of lecithin show a gradual change with the time. Thus the (presumably negative) mobility of a freshly prepared dispersion "increased, at given PHX with the age of the lecithin used, reac...

The rate constant for dissociation of ADP from actomyosin subfragment 1 (S1) has been measured in this laboratory and elsewhere for a variety of vertebrate muscle types. We have made the following observations: (i) In solution, the dissociation of ADP from actomyosin-S1 limits the rate of dissociation of actomyosin-S1-ADP by ATP and, presumably, also limits the rate of crossbridge detachment in...

The sensitivities of CH4 and CD4 differ by about 2 percent and are probably equal within the experimental uncertainty. The total ionization is apparently the same for CH4, CH3D, and CH?D2. The low value for CHD3 is not significant in view of the uncertainty in this spectrum. The difference in the total ionization of CH4 and CD4, however, is greater than the estimated error; and since the number...