Synthesis and Coordination Properties of 1-(Diphenylphosphine oxide)-1-(2‘-pyridyl N-oxide)-3-(diphenylphosphine oxide)propane

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

“…The compound displays a low intensity parent ion [M + H + ], intense [M + Na + ] and [2M + Na + ] ions and a strong infrared absorption, Ȟ = 1188 cm -1 , that is assigned to the phosphoryl stretch. The31 P NMR spectrum for 4 shows a single resonance, į = 30.8, whose value is similar to the shifts displayed by examples of compounds from the classes E-I that carry diphenylphosphine oxide substituent groups[11][12][13][14][15][16][17][18][19][20][21][22][23][24]. The 1 H and 13 C NMR spectra are also consistent with the expected 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 1 H NMR spectrum displays a singlet at į = 5.40 that is comparable to shifts displayed by 1 and 2, į = 5.46 and 5.47, respectively, and these are assigned to the methylene group separating the pyridine and pyrazole rings. The 1 H NMR spectrum also contains a doublet, į = 4.22 (J HP = 13.8 Hz), that is assigned to the methylene group spanning the pyridine ring and the diphenylphosphine oxide substituent, and these data compare favorably with data for examples of compounds of types E-I[11][12][13][14][15][16][17][18][19][20][21][22][23][24]. The 13 C NMR spectrum contains resonances diagnostic of the two inequivalent methylene group environments: į = 31.2 (J CP = 65.9 Hz) and 51.2.…”

Reaction of secondary phosphine oxides with acylacetylenes

“…They are widely used as ligands for metal complex catalysts [1][2][3], special solvents for stabilization of nanosystems in the synthesis of semiconductors [4], extractants for noble, rare-earth, and transuranium elements [5][6][7], fire-retardants [8], and photochromic [9] and luminescent materials [10]. Phosphine oxides are successfully used as building blocks, e.g., in the Wittig-Horner reaction [11][12][13][14], specifically, for the synthesis of substituted vitamin D 3 analogs [14].…”