Studies about chlorophyll I. The physico-chemical behaviour of chlorophyll

Chlorophyll is in the living plant photoactive to a high degree, but i\u27s at the same time extremely fast to light. In assimilating the carbon dioxide the pigment absorbs the light energy necessary for conducting a complicated chemical process, in transfering it to the reacting system (CO2,H2O) without undergoing a permanent chemical transformation. The oxygen itself which is set free by the assimilation, probably in a very reactive state, causes no oxidation of the chlorophyll in the leaf

The Kinetics of Oxidation of Aldehydes to Acidsand Acid Anhydrides. II

Continuing our studies on the catalytic decomposition of peracids into acids and on the interaction of peracids with aldehydes into acids and acid anhydrides, we examined the influence of other mixed catalysts, i. e. manganese and copper butyrates and iron and copper butyrates on reaction rates. They were found to be in good accordance with thermodynamic data. The anhydride formation in the presence of a mixture of manganese and copper catalyst was investigated and found to be slightly inferior to the yield obtained with a pure manganese catalyst

The Kinetics of Oxidation of Aldehydes to Acids and Acid Anhydrides

In an attempt to obtain a closer insi1ght into the mechanism of the catalytic autoxidation of aldehydes to acids and their anhydrides a study was undertaken in which the individual phases of the process were separately investigated, namely: a) the noncatalytic and catalytic decomposition of peracids, b) the noncatalytic and catalytic interaction of peracids with aldehydes, and c) the noncatalytic and catalytic hydrolysis of acid anhydrides

Studija o kloroflu III. Kromatografska istraživanja klorofila

Ovaj rad predstavlja nastavak radova na istraživanju klorofila. U ovim je radovima pokazano, da neki aromatski spojevi dušika mogu stvarati po svojoj prilici sa klorofilom labave molekularne spojeve, koji posjeduju veliku fotostabilnost. Kromatografska ispitivanja pokazala su da klorofil u prisutnosti p-nitrozodimetilanilina pokazuje izrazitu stalnost prema svijetlu i u adsorbiranom stanju. U odsutnosti ove tvari dolazi naprotiv do vrlo brzog izbljeđivanja na stupcu saharoze

Studije o klorofilu. Il Gašenje fluorescencije klorofila

Nastavljajuci radove o fizikalno kemijskim osebinama klorofila istra zio sam utjecaj nekih stranih tvari na gasenje fluorescencije alkoholne otopine ove biljne boje. To su aromatski nitrozo- i nitrospojevi na pr. p-nitrozodimetilanilin, nitrozobenzol, N-nitrozo-p-nitrozofenilpiperazin, nitrnbenzol, a-nitronaftalin i dr. U prijasnjem radu pokazao sam, da te tvari mogu u velikoj mjeri ili cak i potpuno stabilizirati alkoholnu otopinu klorofila prema termickoj i fotokemijskoj oksidaciji

The Precipitation of Alumina Hydrate from Aluminate Solutions in the Presence of Some Higher Alcohols and Starch

The effect of low concentrations of isopropyl alcohol, n -butyl alcohol, isovaleryl alcohol, glycol, glycerol , glucose and starch on the rate of precipitation of alumina hydrate from metastable aluminate solution s was studied. The changes of electric conductivity during the precipitation were also measured. Only glycol accelerated the precipitation of alumina hydrate at concentrations covered by the experiments; the other substances retarded the precipitation. Glycerol in a concentration of about 0.2 M/ 1., glucose in a concentration of 6.7 g./ 1., and starch in a concentration of 6.7 g./l, prevented the precipitation

On the Changes of Viscosity Preceding the Precipitationof Aluminium Hydrate from Aluminate Solutions

In order to ascertain whether and in what way the structure of clear aluminate solutions is modified prior to the precipitation of aluminium hydrate, the viscosity and specific gravity of these solutions were measured from the moment of their preparation to the moment of incipient precipitation