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

Abstract

Synthesis and selected lanthanide coordination chemistry of new ((1H-pyrazol-1-yl)methyl)pyridine and -pyridine 1-oxide ligands, Polyhedron (2015), doi: http://dx. ABSTRACTSyntheses for new potentially chelating ligands, 2,6-bis((1H-pyrazol-1-yl)methyl)pyridine 1-oxide (2), (4) and 2-((1H-pyrazol-1-yl)methyl)-6-((diphenylphosphoryl)methyl)pyridine 1-oxide (5), that are based upon pyridine or pyridine N-oxide platforms functionalized with pyrazol-1-ylmethyl and diphenylphosphinoylmethyl substituents, are reported along with results from molecular modeling analyses that assess the strain energy encountered by the ligands in tridentate chelate interactions for gas phase [Eu(L) 3+ ]complexes.Coordination chemistry with selected lanthanide nitrates is described along with X-ray crystal structure determinations for the three ligands and three representative coordination complexes.

Synthesis, Structures, and Luminescent Properties of Chloride and Nitrate LnIIIComplexes Coordinated by tris(Pyrazolyl)methane

“…The Yb−N distances in 1Yb hrm proved to be slightly elongated compared to the previously reported nitrate complex [Yb(Tpma)(NO 3 ) 3 ] (2.365(3)–2.453(3) Å; Tpma=tris((1 H ‐pyrazol‐1‐yl)methyl)amine) [15] . The Eu−N bond lengths in 1Eu fall into the range typical for Eu−N distances in previously reported Eu 3+ nitrate complexes coordinated by neutral polydentate pyrazolyl containing ligands (2.494(6)–2.657(2) Å) [16–22] . The Yb−O (2.3689(5)–2.4099(5) Å) and Eu−O (2.440(2)–2.490(2) Å) bonds in 1Ln have lengths close to those in nine‐coordinate complexes (Yb−O 2.320(4)–2.492(4) Å, Eu−O 2.452(3)–2.479(3) Å) [23–29] …”

“…[15] The EuÀ N bond lengths in 1Eu fall into the range typical for EuÀ N distances in previously reported Eu 3 + nitrate complexes coordinated by neutral polydentate pyrazolyl containing ligands (2.494(6)-2.657(2) Å). [16][17][18][19][20][21][22] The YbÀ O (2.3689(5)-2.4099(5) Å) and EuÀ O (2.440(2)-2.490(2) Å) bonds in 1Ln have lengths close to those in nine-coordinate complexes (YbÀ O 2.320(4)-2.492(4) Å, EuÀ O 2.452(3)-2.479(3) Å). [23][24][25][26][27][28][29] According to the deformation electron density (DED) analysis of 1Yb hrm , the YbÀ N and YbÀ O interactions in the ytterbium coordination sphere are both peak-hole and peakpeak interactions (Figure 2, Figure S4).…”