B. Gierczyk

NMR study of the complexes of tris(oxaalkyl) borates with SbCl5

Abstract The complex formation between three tris(oxaalkyl) borates ( B2 , B3 , B4 ) and SbCl 5 as well as the structure of these complexes were studied by calorimetric and NMR methods. Results of the calorimetric titration indicate a dependence of Δ H of the reaction heats on the length of the oxaalkyl chains, and a formation of stable complexes. The 1 H and 13 C NMR data confirmed the formation of the respective stable complexes. The structure of the complexes is discussed.

23Na NMR and FT-IR studies of sodium complexes with the ionophore lasalocid in solution

Abstract Lasalocid forms 1:1 or 2:2 complexes with sodium ions. The process of complexation was studied in different solvents at various temperatures by 23 Na NMR. The formation constants and Δ G values were determined. The nature of the complex between lasalocid and Na + ions was also studied by FT-IR spectroscopy. In chloroform, a 2:2 complex of lasalocid and Na + ions is formed. A continuous absorption is observed in the far FT-IR spectrum of this complex. It indicates the large Na + polarizability due to fast fluctuations of the Na + ions in multiminima potentials, in the dimeric structure.

FT-IR and NMR study of tris(oxaalkyl) borates and their complexes with HAuCl4

Abstract Three tris(oxaalkyl) borates and their complexes with HAuCl 4 were studied by FT-IR, 1 H and 13 C NMR spectroscopy. Continuous absorption in the FT-IR spectra of the complexes testifies the formation of proton channels showing large proton polarizability. The shape of the proton potential is discussed on the basis of the NMR data.

Multinuclear NMR studies of tris(oxaalkyl) borates and their complexes with some metal cations

Abstract Nuclear magnetic resonance (NMR) of 1 H, 13 C, 11 B and 17 O nuclei has been used for the study of complexation of CoCl 2 , NiCl 2 and CuCl 2 salts with three tris(oxaalkyl) borates. All NMR techniques demonstrated the formation of complexes but the most informative were the 13 C and 17 O NMR measurements. The structures of the complexes formed are discussed in this article.

15N NMR and FTIR studies of 2,4-dinitroanilines and their salts

Abstract Twenty-two 2,4-dinitroanilines were synthesised and their p K a values were determined. The 2,4-dinitroanilines and their protonated forms were studied by 15 N NMR spectroscopy. The relations between the 15 N NMR chemical shifts and the p K a values of the 2,4-dinitroanilines and their salts were found to be linear. The deprotonation reaction of N -methyl-2,4-dinitroanilines and N -methyl-2,4,6-trinitroaniline by MTBD was successful only for the latter and yielded protonated MTBD molecule and the anion in which the electrons are strongly delocalised. The kinetic parameters of the 2,4-dinitroanilines in reactions with hydroxide ions in mixed solvent DMSO:water (95:5, v/v) were determinated and discussed.

Studies of reaction heats and structures of complexes formed between macro compounds and SbCl5 in CCl4

Abstract The heats of reactions between the acyclic and cyclic macro-compounds are determined. The values can be used as a measure of the donor abilities of the macro ligands. Formation of two types of complexes between the macro compounds and SbCl 5 is established. The acyclic macro-compounds form 1:1 complexes, whereas the macrocyclic compounds only 1:2 complexes.

Multinuclear magnetic resonance studies of fluoronitroanilines

Ten fluoronitroanilines have been synthesized and the 1H, 13C, 15N and, 19F NMR spectra of these compounds have been recorded and fully assigned. Density functional theory(DFT) calculations have been performed for all compounds studied. Experimental and theoretical results are compared and the structure and atom character influence on the accuracy of the calculation discussed. Copyright