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Application of 15N NMR Spectroscopy to Determine Coordination Sphere Geometry in Pd(II), Pt(II), Pt(IV), Co(III) and Rh(III) Complexes with Azines

Pazderski L.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 7

1241-1253

EN

The comparison of 15N NMR spectral data for Pd(II), Pt(II), Pt(IV), Co(III) and Rh(III) complexes with simple azines, such as pyridine (py), 2,2'-bipyridine (bpy), 1,10-phenanthroline (phen) and their alkyl or aryl derivatives (2pic, 3pic, 4pic = 2-, 3-, 4-picoline, i.e. 2-, 3-, 4-methyl-py; 2,6lut, 3,5lut = 2,6-, 3,5-lutidine, i.e. 2,6-, 3,5-dimethyl-py; 2,4,6col = 2,4,6-collidine, i.e. 2,4,6-trimethyl-py; 2ppy, 3ppy, 4ppy = 2-, 3-, 4-phenyl-py; 4-tert-butyl-py; 4,4'-dmbpy = 4,4'-dimethyl-bpy; 4,4'-dpbpy = 4,4'-di phen yl-bpy; 4,7-dmphen = 4,7-dimethyl-phen; 4,7-dpphen = 4,7-di phen yl-phen), as well as isoquinoline (isoquin) and 2,2'-biquinoline (bquin) exhibits that 15N NMR coordination shifts, defined as differences between 15N chemical shifts of the same nitrogen in the complex and ligand molecules (Delta coord 15N = delta compl 15N – delta lig 15N ), are, for a given central ion, noticeably dependent on the type of anauxiliary ligand in the trans position. Particularly, absolute magnitudes of Delta coord 15N (| Deltacoord 15N |) decrease in the order of nitrogens opposite to donor atoms N > Cl >> C, what allows to distinguish and assign various geometric isomers of the concerned complexes. The above dependencies were applied to re-determine the geometry of various isomers of some previously reported Pd(II) and Pt(II) chloride complexes with 1,2,4-triazolo-[1,5a]-pyrimidines.

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63Cu and 31P Nuclear Magnetic Resonance for Characterization of Cu(I) Complexes with P-Donor Ligands

Szymańska I.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 7

1095-1117

EN

The analysis of the 63Cu and 31PNMR resonances and the spin-spin coupling patterns for elucidation of the Cu(I) phosphines complexes geometry and ligands' coordination modes in solutions are reviewed. The influences of the steric and electronic properties of P-donor ligands and the dynamic processes in solution on the 63Cu and 31P NMR spectra of Cu(I) complexes are discussed.

3

15N NMR Coordination Shifts in Transition Metal Chloride Complexes with Azines versus Type of Central Ion

Pazderski L.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 7

1083-1093

EN

15N NMR coordination shift is the difference between the 15N chemical shift of the concerned nitrogen atom in the complex and ligand molecules (Delta coord 15N =delta compl 15N - delta lig 15N ). Themeasurements, convenient for complexes with diamagnetic transition metal ions, allow to determinemetallation siteswithin potentially ambidentateN-donor heterocycles. In case of azines, the 15N coordination shifts of pyridine-type nitrogens are usually negative, i.e. the shielding is observed. Variable low-frequency 15N coordination shifts (ca. 70-140 ppm) were noted for a number of chloride complexes of Pd(II), Pt(II), Au(III), Pd(IV), Pt(IV), Co(III), Rh(III) and Zn(II) with pyridine, 2,2'-bipyridine, 1,10-phenanthroline, 2,2'-biquinoline, purine and 1,2,4-triazolo-[1,5a]-pyrimidine(s). Some dependencies between the magnitude of the shielding effect and such features of the concerned complex as the type of central ion, its electron configuration (oxidation state) and the coordination sphere geometry were discussed.

4

Synthesis and Characterization of Ionic Cu(I) Perfluorocarboxylate Compounds with 1,4-Bis(diphenylphosphino)butane

Szymańska I., Pazderski L., Kucharek R., Szłyk E.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 11

1705-1711

EN

A series of ionic Cu(I) perfluorocarboxylate compounds with 1,4-bis(diphenyl - phosphino)bu tane (dppb) of gen eral formula [Cu(dppb)2](RCOO), where R = C2F5, C3F7, C4F9, C6F13, C8F17, was prepared and characterized with MS, IR and 1H, 13C, 19F, 31P NMR spectroscopy. The studied species contained monomeric, bis-chelated [Cu(dppb)2]+ cations and uncoordi nated RCOO- anions. The Cu(I) coordi nation of the diphosphines resulted in slight high-frequency shifts of the 31P NMR resonances of the equivalent phosphorus atoms.