Synthesis and molecular structures of complexes of bismuth(III) nitrate with tridentate ligands : 2,6-BIS(-CH2 P((O)R2) substituted pyridine-N-oxides

Synthesis and selected lanthanide coordination chemistry of new ((1H-pyrazol-1-yl)methyl)pyridine and -pyridine 1-oxide ligands

“…The 31 P NMR spectrum shows a single resonance at į = 30.8, slightly downfield from the resonance position for 4. This downfield shift is typical for other N-oxide derivatives G and I compared to their pyridine precursors, F and H [11,12,18,23,24]. The 1 H and 13 C NMR spectra are closely comparable with the data for 4, and they are consistent with the proposed structure.…”

“…A view of the molecular structure is shown in Figure 10, and selected bond lengths are listed in Table 4. As found with 2, the initially isolated 1:1 complex transforms upon crystallization to a 2:1 complex with the composition, [Pr (5) [11][12][13][14][15][16][17][18][19][20][21][22][23][24]. The placement of pyridine and 1-methylpyrazole at the weaker end of the series derives from the relatively softer character of N atom donors.…”

“…For example, the tris-heterocyclic ligand, 2,2':6',2''-terpyridine (terpy), and its numerous derivatives represent one of the most widely investigated classes of chelating ligands used in coordination chemistry [1][2][3][4][5]. Another widely studied class of tris-heterocyclic ligands is the 2,6-In recent contributions we have described several new multidentate phosphine oxide ligands based upon pyridine and pyridine N-oxide platforms including ligands of types E-I, as shown in Figure 1, and their coordination chemistry with f-element ions has proven to be interesting [11][12][13][14][15][16][17][18][19][20][21][22][23][24]. In particular, the Noxide ligands, E and G (designated as NOPO) and I (designated as NOPOPO) appear to bind more effectively with lanthanide [Ln(III)] cations than their pyridine analogs F and H, and the more flexible ligands of types G and I coordinate more strongly than ligands of type E despite the larger chelate ring ray diffraction methods.…”

“…The metrical parameters compare favorably with related data for 2 and for examples of free ligands from types E-I[12,21,23,24]. The water molecule is hydrogen bonded to the phosphine oxide O-atom, O2-H2B···O1 with O2-H2B, was prepared by combination of 4 in CH 2 Cl 2 with a small excess of mCBPA at room temperature.…”

Synthesis of propionamide pyridine and pyridine n‐oxide ligands

“…We have also reported that 2-(methylphosphine oxide) and 2,6-bis-(methylphosphine oxide) substituted pyridines 5, 6 and pyridine N-oxides 7, 8 can be prepared. The latter two ligand types act as especially strong chelating ligands toward lanthanide and actinide ions despite the fact that the chelate rings contain seven atoms [7][8][9][10][11][12][13][14][15][16][17][18]. Indeed, representatives of the ligand 8 have proven to be very effective liquid-liquid extractants for trivalent lanthanide and actinide ions [19][20][21].…”