Błażej Gierczyk

Inorganic Esters of Ethylene Glycol as Macrocyclic Ligands

Six different inorganic esters of ethylene glycol: B(OR)3, P(OR)3, OS(OR)2, OP(OR)3, OPH(OR)2 and As(OR)3, where R = CH2CH2OCH3 were obtained. Their structures were studied by multinuclear NMR. These compounds can complex metal cations and behave like macrocyclic ligands. The influence of metal cation complexation on spectra were investigated by 1, 13C, 17O, 11B, 7Li, 87Rb and 31P NMR.

Synthesis of new dendritic antenna-like polypyridine ligands

An efficient synthesis of multidentate polypyridine ligands, 3,5-bis(2,2′-bipyridin-4-ylethynyl)benzoic acid and 3,5-bis(2,5-bis(2-pyridyl)-pyridin-4-ylethynyl)benzoic acid, with potential application in the production of ruthenium dyes for dye-sensitised solar cells was developed. Isolation of intermediate products and final compounds is simple and the yields are very high. The ligands obtained can be used in the synthesis of dendritic analogues of well known and very efficient N3 dye and “black dye”.

Anion-π interactions—interactions between benzo-crown ether metal cation complexes and counter ions

The loss of X· radical from [M + Cu + X]+ ions (copper reduction) has been studied by the so called in-source fragmentation at higher cone voltage (M = crown ether molecule, X− = counter ion, ClO4−, NO3−, Cl−). The loss of X· has been found to be affected by the presence/lack of aromatic ring poor/rich in electrons. Namely, the loss of X· occurs with lower efficiency for the [NO2-B15C5 + Cu + X]+ ions than for the [B15C5 + Cu + X]+ ions, where NO2-B15C5 = 3-nitro-benzo-15-crown-5, B15C5 = benzo-15-crown-5. A reasonable explanation is that Anion-π interactions prevent the loss of X· from the [NO2-B15C5 + Cu + X]+ ions. The presence of the electron-withdrawing NO2 group causes the aromatic ring to be poor in electrons and thus its enhances its interactions with anions. For the ion containing the aromatic ring enriched in electrons, namely [NH2-B15C5 + Cu + ClO4]+ where NH2-B15C5 = 3-amino-benzo-15-crown-5, the opposite situation has been observed. Because of Anion-π repulsion the loss of X· radical proceeds more readily for [NH2-B15C5 + Cu + X]+ than for [B15C5 + Cu + X]+. Iron reduction has also been found to be affected by Anion-π interactions. Namely, the loss of CH3O· radical from the ion [B15C5 + Fe + NO3 + CH3O]+ proceeds more readily than from [NO2−B15C5 + Fe + NO3 + CH3O]+.

STUDIES OF COMPLEXATION OF METAL CATIONS BY TRIS(3,6-DIOXAHEPTYL)AMINE IN SOLUTION

Abstract The complexation of some cations (Zn 2+ , Fe 2+ , Fe 3+ , Ni 2+ , Cu 2+ , Co 2+ , Pb 2+ , Na + , Li + , Mn 2+ , Cd 2+ , K + , Mg 2+ , Cr 3+ ) by tris(3,6-dioxaheptyl)amine in various solvents was studied by the thin layer chromatography, liquid secondary ion mass spectra, FT-IR and 13 C NMR spectroscopies as well as kinetic methods. In this article, the structure of the complexes is discussed.

Studies of Silicon Podand Solvents

Three types of silicon podands, Me2Si(OR)2, EtSi(OR)3 and PhSi(OR)3, where R is a polyoxaethylene chain with different numbers of oxygen atoms (two, three or four), were obtained and studied by 1H, 13C and 29Si NMR methods. NMR spectra of 1H, 7Li, 13C, 23Na and 29Si nuclei were also used for the study of lithium, sodium and rubidium complexes with the silicon podands. Theoretical calculations were performed using the PM3 hamiltonian. The heats of reactions between the compounds obtained and SbCl5 were determined.

Studies of lithium and sodium complexation by silicon podand solvents

Abstract The complex formation of lithium and sodium ions with silicon podand solvents: phenyl-tris(1,4-dioxapentyl) silane (PhSi23) and ethyl-tris(1,4-dioxapentyl) silane (EtSi23) has been studied by FTIR, 1 H-, 13 C-, 7 Li- and 23 Na NMR. The far FTIR spectra show that the Li + cations fluctuate very fast whereas Na + cations are still localised between the oxygen atoms of the oxaalkyl chains. The 7 Li NMR spectra prove that one Li + cation can be coordinated not only by one but also two silicon podand molecules. The concentration dependence of the molar conductivity of LiClO 4 in the podand solvents indicates charge transfer between ion clusters.

Influence of fluorine substituents on the NMR properties of phenylboronic acids.

The paper presents results of a systematic NMR studies on fluorinated phenylboronic acids. All possible derivatives were studied. The experimental 1H, 13C, 19F, 11B, and 17O spectral data were compared with the results of theoretical calculations. The relation between the calculated natural bond orbital parameters and spectral data (chemical shifts and coupling constants) is discussed. The first examples of 10B/11B isotopic effect on the 19F spectra and 4JFO scalar coupling in organic compounds are reported. Copyright

Unusual ion UO4 − formed upon collision induced dissociation of [UO2(NO3)3]−, [UO2(ClO4)3]−, [UO2(CH3COO)3]− ions

The following ions [UO2(NO3)3]−, [UO2(ClO4)3]−, [UO2(CH3COO)3]− were generated from respective salts (UO2(NO3)2, UO2(ClO4)3, UO2(CH3COO)2) by laser desorption/ionization (LDI). Collision induced dissociation of the ions has led, among others, to the formation of UO4− ion (m/z 302). The undertaken quantum mechanical calculations showed this ion is most likely to possess square planar geometry as suggested by MP2 results or strongly deformed geometry in between tetrahedral and square planar as indicated by DFT results. Interestingly, geometrical parameters and analysis of electron density suggest it is an UVI compound, in which oxygen atoms bear unpaired electron and negative charge.

Podand Solvents for Organic Reactions

Three tris(oxaalkyl)phenylsilanes and two tris(oxaalkyl)phosphates were used as podand solvents in kinetic studies of proton transfer reactions between C-acids: dimethyl (4-nitrophenyl)malonate or phenyl-4-nitrophenylcyanomethane and the strong base: 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD). The acceptor numbers were measured for all new podand solvents. The kinetic parameters for studied reactions were obtained, discussed and compared with those of acetonitrile and OP(OEt) 3 as non-podand solvents. This study demonstrated that the second order rate constants strongly decreased and the energy barrier increased for the proton transfer reaction in podand solvents. Spectroscopic observations showed that ionic products were strongly stabilised and therefore their lifetime was relatively long. The podand solvents formed the ionic channels in which ionic products are strongly solvated.

FTIR and multinuclear magnetic resonance studies of tris(oxaalkyl) borates and their complexes with Li+ and Na+ cations

FTIR and NMR of 1H, 13C, 11B, 7Li and 23Na nuclei were used for the study of the complexation of Li+ and Na+ cations by three tris(oxaalkyl) borates. The NMR techniques proved the formation of complexes and the fluctuation of Li+ and Na+ cations in the respective channels formed by three oxaalkyl chains. In the FTIR spectra of Li+ complexes with three tris(oxaalkyl) borates, continuous absorption in the far-infrared region indicates the fast fluctuations of Li+ ion between O atoms of the channels. The dependence of the continua shape on the length of the channels, i.e., the number of minima in the multiminima potentials, demonstrates that the fluctuation of Li+ ion occurs along the channel. Owing to the larger mass and diameter of the Na+ cation in the Na+–tris(oxaalkyl) borate complexes, only systems with longer channels show a large Na+ polarizability due to the fast fluctuation of Na+ cations in a multiminima potential.