Efficient Sensitized Luminescence of Binuclear Ln(III) Complexes Based on a Chelating Bis-Carbacylamidophosphate

Binuclear rare earth complexes Ln₂L₃phen₂ (Ln^III = Nd^III, Sm^III, Eu^III, Tb^III, Dy^III, Yb^III and Y^III) with bis-CAPh type ligand - tetramethyl N,N'-(2,2,3,3,4,4-hexafluoro-1,5-dioxopentane-1,5-diyl)bis(phosphoramidate) (H₂L) and 1,10-phenanthroline (phen) were synthesized and characterized by elemental analysis, IR, NMR, absorption and luminescence spectroscopy. Luminescence measurements were performed for all the complexes in solid state and for the Eu^III, Tb^III and Y^III complexes - in solution in DMSO as well. The effective energy transfer from organic ligands to Ln^III ions strongly sensitizes the Ln^III ions emission and under excitation by UV light, the complexes exhibited bright characteristic emission of lanthanide metal centers. It was found that the energy level of the ligands lowest triplet state in the complexes matches better to resonance level of Eu^III rather than Tb^III ion. Depending on temperature the emission decay times of solid europium and terbium complexes were in the range of 1.5-2.0 ms. In solid state at room temperature the Eu^III complex possess intense luminescence with very high intrinsic quantum yield 91% and decay time equal 1.88 ms.

Carbacylamidophosphates: Structure and Properties of Bis(N,N′,-morpholido)-[(N″-morpholido)-carboxamido] phosphate

The bis(N,N′-morpholido)-[(N″-morpholido)-carboxamido] phosphate: O(CH2CH2 )NC(O )-N(H)P(O)[N(CH2CH2 )O]2 [HL], has been prepared and characterized by means of IR, 31P and 1H NMR spectroscopy and X-ray diffraction (triclinic, a = 9.282(2), b = 9.308(2), c = 21.341(4) Å, α = 80.79(3)°, β = 80.92(3)° γ = 66.92(3)°, V = 1665.1(6) Å3, space group P1̄̄, Z = 4 and R = 0.0423, wR2 = 0.1303 for 6774 unique reflections used). The unit cell consists of two independent molecules connected by hydrogen bonds N-H...O=P into non-symmetric dimers. The compound behaves as a HL molecule with a protonation constant corresponding to the -C(O)N(H)P(O)- group of pK = 8.65 as determined by potentiometric studies.

Synthesis, IR and X-Ray Studies of Tetra(N,N′-tetraethyl-N″-benzoyl- phosphorictriamide)-tetra(μ-3-methoxo)-tetra(methanol)tetra-NickeI(II)

A new nickel(II) complex with N,N′-tetraethyl-N″-benzoylphosphortriamide (HL = C6H5C(O)N(H)P(O)(NEt2)2) of composition Ni4L4(OCH3)4·(HOCH3)4 (1) has been synthe­ sized. The crystal and molecular structure of 1 has been determined from the X-Ray diffraction data (tetragonal, space group P4̄21c with a = 17.000(2) Å, c = 15.338(3) Å, Z = 2; R = 0.0399 for 1412 unique reflections). The structure is made up of cubane-like tetramers. In the corners of a cube there are 4 atoms of nickel and 4 atoms of oxygen of methoxy groups. The nickel atoms are characterized by a slightly distorted octahedral environment, which consists of three oxygen atoms of methoxy groups, carbonylic and phosphorylic oxygen atoms of the ligand L-, and an oxygen atom of a methanol molecule. The ligands L- coordinate to the metal ion forming a chelate via the oxygen atoms of carbonylic and phosphorylic groups.

catena-Poly[neodymium(III)-bis-[μ-N-(dimorpholinophosphor-yl)benzene-sulfonamidato]-sodium(I)-bis-[μ-N-(dimorpholinophosphor-yl)benzene-sulfonamidato]]

The cubic crystal structure of the title compound, [NaNd(C₁₄H₂₁N₃O₅PS)₄]_n, is composed of one-dimensional polymeric chains propagating in [100], built up from [Nd(C₁₄H₂₁N₃O₅PS)₄]⁻ anions and sodium cations functioning as linkers. In the complex anion, the Nd³⁺ ion has an eightfold coordination environment formed by the sulfonyl and phosphoryl O atoms of four bidentate chelating N-(dimorpholinophosphor­yl)benzene­sulfonamidate ligands: the resulting NdO₈ polyhedron can be described as inter­mediate between dodeca­hedral and square anti­prismatic. The sodium ion adopts an NaO₄ tetra­hedral geometry arising from four monodentate benzene­sulfonamidate ligands. The resulting crystal structure is unusual because it contains substantial voids (800 ų per unit cell), within which there is no evidence of included solvent.