STUDIES IN THE CHLOROPHYLL SERIES. VIII. THE STRUCTURE OF CHLOROPHYLL B

Abstract

iodide and picrate, tri-p-tolylselenonium chloride and iodide, di-m-tolyl selenide, di-m-tolyl selenium dichloride, tri-m-tolylselenonium iodide and tri-?M-tolylselenonium chloride-mercuric chloride.3. Triphenylselenonium hydroxide has been prepared in dilute solution. The solution when concentrated decomposes into benzene (?) and diphenyl selenium oxide.4. The formation of triphenylselenonium chloride by fusing di-p-tolyl selenide with mercury diphenyl and the thermal decomposition of diphenylp-tolylselenonium iodide into phenyl iodide and phenyl p-tolyl selenide indicate the p-tolyl group to be more negative than the phenyl.

Isotopic fractionation factor of the hydrogen-bonded complex AcO–⋯(HOAc)nand kinetic and equilibrium solvent isotope effects on reactions of acetate ion in acetic acid

“…In these latter cases, complex formation occurs with large equilibrium constants whereas in the present case the equilibrium constant is quite low (KAcoH 34.8 dm3 mol-') and a shift in the position of the equilibrium with acetate concentration can be observed. If complex formation is represented by equation (7), the ratio of equilibrium constants in AcOH and 97% AcOD is given by (8) in which cpR, cp, and cp, are the fractionation factors of 2,4,6-trinitrophenol, the acetate solvate, and the 2,4,6-trinitrophenol-acetate complex respectively. On the assumption that qR has a value of unity, the experimental values KAcoH/KAcoD 0.83 f 0.1 and cp 0.58 & 0.05 lead to cp, 0.70 & 0.15.…”

Titration of Ketimines in Glacial Acetic Acid

“…Acetic acid was chosen for its leveling effect upon weak organic bases and excellent solvent properties (9). 1 Present address, Chemical Division, Celanese Corp. of America, Clarkwood, Tex.…”

Recent Progress in Determining the Chemical Structure of Chlorophyll.

“…Willstátter (98) established this by analysis, and various suggestions as to the position of this oxygen atom were advanced. Conant (6), by pyrolysis, phase test reaction, and saponification, obtained from methyl pheophorbide b a series of compounds entirely parallel to those in the a series (XI). These rhodins, corresponding to the chlorins in the a series, still retained the extra oxygen atom, and formed semicarbazones, indicating the presence of a carbonyl group.…”