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The kinetics of homogeneous dehydrogenation of formic acid in the presence of supramolecular rhodium(III) complex with P-functionalized calix [4]resorcine were studied in dioxane, tetrahydrofuran, dimethylformamide, and binary formamide-dioxane mixtures (volume ratio 10 : 90, 20 : 80, 30 : 70) over a wide temperature range (40-90°C). The examined Rh(III) complex catalyzed the dehydrogenation process, and its catalytic activity was higher than that observed previously for rhodium complexes with non-macrocyclic phosphorus-containing ligands. The dehydrogenation rate constants were proportional to neither catalyst concentration nor dielectric constant of the medium, which is likely to be related to supramolecular nature of the Rh(III) complex. No micelle formation was observed in the examined systems.In recent time new eco-friendly technologies capable of competing with natural catalytic systems have been developed. Potentially interesting are threedimensional receptors based on calixresorcinarene scaffold, whose functionalization could give rise to catalytically active structures. For example, it is known [1, 2] that aminomethylated calix[4]resorcines catalyze hydrolysis of phosphorus acid esters.Donor groups fixed at the upper or lower rim of a calix[4]resorcine can be involved in both inner-and outer-sphere coordination to metal ions. Such metal complex systems also exhibit catalytic activity in some processes [3]. These systems are obtained with the use of platinum metal compounds, in particular rhodium compounds, and their selectivity is com-parable with that of natural catalysts [4]. Rhodium(I) and rhodium(III) complexes with organo-phosphorus ligands are known [5-7] to catalyze homogeneous dehydrogenation of formic acid under atmospheric pressure at a temperature about 50°C. We previously synthesized complex I, octachloridotetra-23-dodecaene)}tetrarhodium(III) [8] from P(III)-functionalized calix[4]resorcine and triaqua trichloro rhodium complex. In the further treatment, compound I will be referred to as a structural unit with the composition L·4 [Rh +3 (O 2 -)(Cl -) 2 ], where L is P(III)-functionalized calix[4]resorcine. The present article reports on the results of our study on the kinetics of homogeneous dehydrogenation of formic acid in the presence of complex I and its catalytic activity as compared to rhodium complexes studied previously [5,6]. Study on catalytic activity in this reaction is important from the viewpoint of understanding mechanisms of catalytic hydrogen liberation processes [5,[9][10][11][12].Catalytic activity of highly organized systems based on calix[4]resorcines often depends on the type and properties of aggregates formed therein [1,2]. Therefore, we also examined self-aggregation (self-association) of compound I in binary solvent consisting of formamide and dioxane in the range of concentrations c I from 1 × 10 -4 to 5 × 10 -4 M in the presence and in the absence of formic acid. It is known [13,14] that formamide is a strongly solvating solvent toward formic acid. By analogy with...

Calixarenes O 0450 Synthesis of Calix[4]resorcinarenes with Phosphorylaryl Substituents at the Lower Rim of the Molecule. -(GAVRILOVA*, E. L.; NAUMOVA, A. A.; BURILOV, A. R.; PUDOVIK, M. A.; KRASIL'NIKOVA, E. A.; KONOVALOV, A. I.; Russ.