Stabilnost kompleksa nekih lantanida s derivatima kumarina. I. Cerijev(III)-4-metil-7-hidroksikumarin

A complex of cerium(III) with 4-methyl-7-hydroxycoumarin was synthesized by mixing water solutions of cerium(III) nitrate and 4-methyl-7-hydroxycoumarin sodium salt in a metal-to-ligand molar ratio of 1:2. The complex was characterized and identified by elemental analysis, conductometry, IR, 1H and 13C NMR-spectroscopy, mass spectral data, DTA and TGA. Thermal analysis of the complex indicated the formation of a compound of the composition Ce(R)2.(OH).5H2O, R standing for the ligand. The reaction of cerium(III) with 4-methyl-7-hydroxycoumarin was studied in detail by spectrophotometric method. The stepwise formation of two complexes, vis., CeR2+ and CeR2+, was established in the pH region studied. The equilibrium constants for 1:1 and 1:2 complexes were determined to be 10.72 and 9.22, respectively.Kompleks cerijevog(III) iona s 4-metil-7-hidroksikumarinom priređen je mješanjem vodene otopine cerijevog(III) nitrata i 4-metil-7-hidroksikumarin natrija u moalrnom omjeru 1:2. Kompleks je karakteriziran i identificiran elementarnom analizom, konduktometrijski, IR, 1H i 13C NMR-spektroskopijom, DTA, TGA i spektrometrijom masa. Termičkom analizom utvrđen je sastav kompleksa kao Ce(R)2.(OH).5H2O. Reakcija cerijevog(III) iona s 4-metil-7-hidroksikumarinom praćena je spektrofotometrijski. U proučavanom pH području utvrđeno je stupnjevito nastajanje dva kompleksa, CeR2+ i CeR2+. Konstante ravnoteže za 1:1 i 1:2 komplekse bile su 10,72, odnosno 9,22

Stabilnost kompleksa nekih lantanida s derivatima kumarina. I. Cerijev(III)-4-metil-7-hidroksikumarin

A complex of cerium(III) with 4-methyl-7-hydroxycoumarin was synthesized by mixing water solutions of cerium(III) nitrate and 4-methyl-7-hydroxycoumarin sodium salt in a metal-to-ligand molar ratio of 1:2. The complex was characterized and identified by elemental analysis, conductometry, IR, 1H and 13C NMR-spectroscopy, mass spectral data, DTA and TGA. Thermal analysis of the complex indicated the formation of a compound of the composition Ce(R)2.(OH).5H2O, R standing for the ligand. The reaction of cerium(III) with 4-methyl-7-hydroxycoumarin was studied in detail by spectrophotometric method. The stepwise formation of two complexes, vis., CeR2+ and CeR2+, was established in the pH region studied. The equilibrium constants for 1:1 and 1:2 complexes were determined to be 10.72 and 9.22, respectively.Kompleks cerijevog(III) iona s 4-metil-7-hidroksikumarinom priređen je mješanjem vodene otopine cerijevog(III) nitrata i 4-metil-7-hidroksikumarin natrija u moalrnom omjeru 1:2. Kompleks je karakteriziran i identificiran elementarnom analizom, konduktometrijski, IR, 1H i 13C NMR-spektroskopijom, DTA, TGA i spektrometrijom masa. Termičkom analizom utvrđen je sastav kompleksa kao Ce(R)2.(OH).5H2O. Reakcija cerijevog(III) iona s 4-metil-7-hidroksikumarinom praćena je spektrofotometrijski. U proučavanom pH području utvrđeno je stupnjevito nastajanje dva kompleksa, CeR2+ i CeR2+. Konstante ravnoteže za 1:1 i 1:2 komplekse bile su 10,72, odnosno 9,22

Synthesis, Toxicological, Anticoagulant Activity and Quantumchemical Study of Bis-coumarins and Other Coumarin Derivatives

Fifteen 4-hydroxycoumarin derivatives were synthesized. Seven of them are described for the first time. By means of X-ray crystal structure analysis of 4-hydroxy-3-[(2-#1086x#1086-2#1053-chromen-3-yl)-(2-#1077thoxycarbonylphenyl) methyl]-chromen-2-#1086ne (3) and 3-[2,6-dichlorophenyl) (#1077thoxy) methyl]-4- hydroxy- 2#1053-chromen-2-#1086ne (6) were confirmed the structure of these compounds previously by us. A comparative pharmacological study of the anticoagulant effect with respect to warfarin showed that the synthesized compounds have different anticoagulant activities. The QSTR model derived on the set of seventeen 4-hydroxycoumarin derivatives indicates that low i.p. toxicity could be achieved for a compound with large surface, unbranched molecule, with electronegative neighbour substituents and missing phydroxylgroup in the aldehyde fragment of the molecule