The synthesis and lanthanide coordination chemistry of 2,6-bis[(dicyclohexyl)phosphino-methyl]pyridine N,P,P′-trioxide

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

“…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 resulting calculated relative strain free energies (G) per donor group were then compared with data for similar ligand types. The method has been used in the evaluation of a number of other ligand systems[43] including studies of several related NOPO and NOPOPO ligands[22][23][24][44][45][46][47][48]. The energy minimized free ligand conformers for 2, 4 and 5 are shown in Figures 5a, 6a and 7a, respectively.…”

Complexes of lanthanide chlorides with tricyclohexylphosphine oxide. The single crystal X-ray structures and solution properties of pentagonal bipyramidal complexes [Ln(H2O)5(Cy3PO)2]3+·Cy3PO·3Cl− Ln=Dy, Er

“…4 The single crystal X-ray structures and solution properties of pentagonal 5 bipyramidal complexes [Ln(H 2 O) 5 a b s t r a c t 24 The products of the reactions of tricyclohexlyphosphine oxide, Cy 3 PO = L, with lanthanide chlorides 25 (Ln = La, Dy, Er, Yb) have been investigated by solution NMR spectroscopy and single crystal X-ray crys- 26 tallography (Dy, Er). The structures of the complexes are based on a pentagonal bipyramidal arrangement 27 around the central Ln 3+ ion with two Cy 3 PO in axial positions and five water molecules in the equatorial 28 plane with molecular formulae LnL n (H 2 O) 5 ÁLÁ3ClÁH 2 OÁEtOH.…”

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].…”