Lanthanide(III) solvation: N,N-dimethylformamide as a unidentate O-donor

Structure determinations for the lanthanide (Ln) complexes [(CH₃)₂NH₂][Gd(dmf)₈](ClO₄)₄, [Tb(dmf)₈](ClO₄)₃ and [Ho(dmf)₇(OH₂)](ClO₄)₃ (dmf=N,N-dimethylformamide) show all three to contain an LnO₈ coordination unit of essentially square-antiprismatic geometry. The geometry of the inner coordination sphere appears to be little perturbed by quite major differences in the lattice environment of the cations. Attractive interactions between coordinated dmf molecules may be one contributor to the stability of the primary coordination sphere.     

Lanthanide nitrate complexes of 4-N-(2′-Hydroxy-1 ′-naphthylidene)-aminoantipyrine

Lanthanide nitrates form with 4-N-(2′-hydroxy-l′- naphthylidene)aminoantipyrine (HNAAP) complexes of the type [Ln(HNAAP)₂(NO₃)₃] (where Ln = La, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Y). The IR spectra of these complexes show that HNAAP acts as a bidentate neutral ligand and nitrate group is coordinated monodentately. The electronic spectra of the Nd complex show reasonable covalency in the metal-ligand bond. The magnetic moments of these complexes are in better agreement with the Van Vleck values. All these complexes are thermally stable up to200 °C.     

Heterobinuclear Zn‐Ln (Ln = La,Nd, Eu,Gd, Tb,Er and Yb) complexes based on asymmetric Schiff‐base ligand: synthesis,characterization and photophysical properties

With a novel asymmetric Schiff‐base zinc complex ZnL (H₂L = N‐(3‐methoxysalicylidene)‐N′‐(5‐bromo‐3‐methoxysalicylidene)phenylene‐1,2‐diamine), obtained from phenylene‐1,2‐diamine, 3‐methoxysalicylaldehyde and 5‐bromo‐3‐methoxysalicylaldehyde, as the precursor, a series of heterobinuclear Zn‐Ln complexes [ZnLnL(NO₃)₃(CH₃CN)] (Ln = La, 1; Ln = Nd, 2; Ln = Eu, 3; Ln = Gd, 4; Ln = Tb, 5; Ln = Er, 6; Ln = Yb, 7) were synthesized by the further reaction with Ln(NO₃)₃·6H₂O, and characterized by Fourier transform‐infrared, fast atom bombardment mass spectroscopy and elemental analysis. Photophysical studies of these complexes show that the strong and characteristic near‐infrared luminescence of Nd³⁺, Yb³⁺and Er³⁺ with emissive lifetimes in the microsecond range has been sensitized from the excited state of the asymmetric Schiff‐base ligand due to effective intramolecular energy transfer; the other complexes do not show characteristic emission due to the energy gap between the chromophore and lanthanide ions. Copyright © 2012 John Wiley & Sons, Ltd.     

New complexes of La(III), Ce(III), Pr(III), Nd(III), Sm(III), Eu(III) and Gd(III) ions with morin

New solid complex compounds of La(III), Ce(III), Pr(III), Nd(III), Sm(III), Eu(III) and Gd(III) ions with morin were synthesized. The molecular formula of the complexes is Ln(C₁₅H₉O₇)₃ · nH₂O, where Ln is the cation of lanthanide and n = 6 for La(III), Sm(III), Gd(III) or n = 8 for Ce(III), Pr(III), Nd(III) and Eu(III). Thermogravimetric studies and the values of dehydration enthalpy indicate that water occurring in the compounds is not present in the inner coordination sphere of the complex. The structure of the complexes was determined on the basis of UV-visible, IR, MS, ¹H NMR and ¹³C NMR analyses. It was found that in binding the lanthanide ions the following groups of morin take part: 3OH and 4CO in the case of complexes of La, Pr, Nd, Sm and Eu, or 5OH and 4CO in the case of complexes of Ce and Gd. The complexes are five- and six-membered chelate compounds.     

Complexes of lanthanoid salts with macrocyclic ligands. Part 32. Synthesis and characterization of the complexes between lanthanoid nitrates and a tetraoxadiaza macrocycle

Lanthanoid nitrates react with 1,7,10,16-tetraoxa- 4,13-diaza-N,N′-dimethylcyclooctadecane, Me₂(2,2), to give complexes with two different metal:ligand ratios, 1:1 (Ln = La, Ce, Tb) and 4:3 (Ln = Pr, Nd, Sm, Eu, Gd, Th, Dy, Ho). The complexes were isolated from anhydrous solutions in acetonitrile and characterized by elemental analysis, X-ray diffraction, magnetic susceptibility measurements and vibrational analysis.The La and Ce 1:1 complexes are non-ionic and probably 12-coordinated, with the metal ion bound to the six donor atoms of the ligand and to three bidentate nitrate ions. The 4:3 complexes are ionic; they contain three bis(nitrato) complex cations [Ln(NO₃)₂·Me₂(2,2)]⁺ and one hexakis(nitrato) anion [Ln(NO₃)₆]³⁻. Spectroscopic data, including luminescence spectra, point to the 1:1 Tb-complex as being a 4:3 complex with an additional outer-sphere coordinated molecule of ligand.In solution, the 1:1 complexes remain essentially non-ionic, although some dissociation cannot be ruled out, whereas the 4:3 complexes behave as 2:1 (of even 3:1) electrolytes.     

Ruthenium(II/III) mediated transformation of 1,2-bis(2′-pyridylmethyleneimino)benzene (L) to 2-(2′-benzimidazolyl)pyridine (L′H) and its in situ formed complexes with Ru(II): X-ray structure of trans-[Ru(PPh3)2(L′H)2](ClO4)2

A series of ruthenium (II) complexes of formulae trans-[Ru(PPh₃)₂(L′H)₂](ClO₄)₂ (1), [Ru(bpy)(L′H)₂](ClO₄)₂ (2), [Ru(bpy)₂(L′H)](ClO₄)₂ (3), cis-[Ru(DMSO)₂(L′H)₂]Cl₂ (4), and [Ru(L′H)₃](PF₆)₂ (5) (where L′H = 2-(2′-benzimidazolyl)pyridine) have been synthesized by reaction of the appropriate ruthenium precursor with 1,2-bis(2′-pyridylmethyleneimino)benzene (L). The complexes were characterized by elemental analyses, spectroscopic and electrochemical data. All the complexes were found to be diamagnetic and hence metal is in +2 oxidation state. The molecular structure of trans-[Ru(PPh₃)₂(L′H)₂](ClO₄)₂ has been determined by the single crystal X-ray diffraction studies. The molecular structure shows that Ru(II) is at the center of inversion of an octahedron with N₄P₂ coordination sphere. The ligand acts as a bidentate N,N′donor. The electronic spectra of the complexes display intense MLCT bands in the visible region.Cyclic voltammetric studies show quasi-reversible oxidative response at 0.99-1.32 V (vs Ag/AgCl reference electrode) due to Ru(III)/Ru(II) couple.     

Mono-, bi- and trinuclear bis(diphenylarsino)methane gold complexes. Crystal and molecular structure of [{(C6F5)3Au(Ph2AsCH2AsPh2)}2Ag(OClO3)]dd]Dedicated to Professor Rafael Usón on his 60th birthday.

Addition of bis(diphenylarsino)methane (dpam) to neutral or cationic gold(l) or gold(III) complexes containing weakly coordinating ligands leads to the formation of mononuclear {R₃Au(dpam), R₂ClAu(dpam), [R₂Au(dpam)]ClO₄ (RC₆F₅)} or binuclear complexes {RAu(dpam)AuR, [Au₂(dpam)₂](ClO₄)₂}. Mixed gold(III)gold(I) compounds can be synthesized either by oxidation of the gold(I) complexes or from mononuclear gold(III) derivatives. Reaction of R₃Au(dpam)with ClAu(tht), [Au(tht)₂]ClO₄ or AgClO₄ leads to the trinuclear complexes [{R₃Au(dpam)}₂Au]X (X=[AuCl₂] or ClO₄) or [{R₃Au(dpam)}₂Ag(OClO₃)], respectively. The structure of the silver complex has been determined by X-ray crystallography.     

Antimicrobial study on trivalent lighter rare-earth complexes of 2-pyrazinecarboxylate with hydrazinium cation

The hydrazinium lanthanide metal complexes of 2-pyrazinecarboxylic acid (HpyzCOO) of the formulae (N₂H₅)₂[Ln(pyzCOO)₅]·2H₂O, where Ln=La or Ce and (N₂H₅)₃[Ln(pyzCOO)₄(H₂O)]·2NO₃, where Ln=Pr, Nd, Sm or Dy have been synthesized by the addition of an aqueous solution of the corresponding metal nitrate hydrates to an aqueous mixture of the respective carboxylic acids and hydrazine hydrate. The in vitro antibacterial screening of the free acid and its metal complexes has been carried out against Escherichia coli, Salmonella typhi and Vibrio cholerae. Antifungal activities of all the synthesized compounds were screened for in vitro growth inhibitory activity against Aspergillus fumigatus and Aspergillus niger by using the disc diffusion method. The antimicrobial activities of the prepared metal complexes show more promising activity than the corresponding free acid, its hydrazinium salts, and the standard control antibiotics, Co-trimoxazole and Carbendazim.     

Synthesis and characterization of new lanthanide complexes with hexadentate hydrazonic ligands

In this paper, we report the synthesis and the characterization of a novel series of lanthanide (III) complexes with two potentially hexadentate ligands.The ligands contain a rigid phenanthroline moiety and two flexible hydrazonic arms with different donor atom sets (NNN′N′OO and NNN′N′N″N″, respectively for H₂L¹ (2,9-diformylphenanthroline)bis(benzoyl)hydrazone and H₂L² (2,9-diformylphenanthroline)bis(2-pyridyl)hydrazone).Both nitrate and acetate complexes of H₂L¹ with La, Eu, Gd, and Tb were prepared and fully characterized, and the X-ray crystal structure of the complex [Eu(HL¹)(CH₃ COO)₂] · 5H₂O is presented.The stability constants of the equilibria Ln³⁺ + H₂L¹ = [Ln(H₂L¹)]³⁺ and Ln³⁺ + (L¹)²⁻ = [Ln(L₁)]⁺ (Ln = La(III), Eu(III), Gd(III), and Tb(III)) are determined by UV spectrophotometric titrations in DMSO at t = 25 °C. The nitrate complexes of H₂L² with La, Eu, Gd and Tb were also synthesized, and the X-ray crystal structures of [La(H₂L²)(NO₃)₂(H₂O)](NO₃), [Eu(H₂L²)(NO₃)₂](NO₃) and [Tb(H₂ L²)(NO₃)₂](NO₃) are discussed.     

Synthesis,density functional theory calculations and luminescence of lanthanide complexes with 2,6‐bis[(3‐methoxybenzylidene)hydrazinocarbonyl] pyridine Schiff base ligand

A pyridine‐diacylhydrazone Schiff base ligand, L = 2,6‐bis[(3‐methoxy benzylidene)hydrazinocarbonyl]pyridine was prepared and characterized by single crystal X‐ray diffraction. Lanthanide complexes, Ln–L, {[LnL(NO₃)₂]NO₃.xH₂O (Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy and Er)} were prepared and characterized by elemental analysis, molar conductance, thermal analysis (TGA/DTGA), mass spectrometry (MS), Fourier transform infra‐red (FT‐IR) and nuclear magnetic resonance (NMR) spectroscopy. Ln–L complexes are isostructural with four binding sites provided by two nitro groups along with four coordination sites for L. Density functional theory (DFT) calculations on L and its cationic [LnL(NO₃)₂]⁺ complexes were carried out at the B3LYP/6–31G(d) level of theory. The FT‐IR vibrational wavenumbers were computed and compared with the experimentally values. The luminescence investigations of L and Ln–L indicated that Tb–L and Eu–L complexes showed the characteristic luminescence of Tb(III) and Eu(III) ions. Ln–L complexes show higher antioxidant activity than the parent L ligand.     

Diethyl and diisopropyl phosphite complexes of lanthanide(III) chlorides

Lanthanide chlorides form adducts of the type [Ln(L)_nCl₃] (where Ln = La, Pr, Nd, Sm, Eu, when n = 6; and Ln = Gd, Tb, Dy or Yb when n = 5; and L = (EtO)₂P(O)H or (PrⁱO)₂P(O)H upon interacting with the diethyl and diisopropyl phosphites in dry ethyl and isopropyl alcohol, respectively. Complexes were recrystallised from ethanol or isopropanol and washed with n-hexane. On the basis of elemental analysis, infrared, ¹H NMR and ³¹P NMR spectral studies, it is concluded that these phosphites coordinate to the lanthanide metal atom through the oxygen atom which has the greatest affinity for lanthanides in these adducts.     

Stepwise reactions of two N-CH2CN or two N-CH2C(NH)OMe groups attached to macrocyclic copper(II) complexes: Preparation of homo- and hetero-di-N-functionalized macrocyclic complexes

The hetero-functionalized macrocyclic complex [CuL²](ClO₄)₂ bearing one N-CH₂C(NH)OMe and one N-CH₂CN groups as well as [CuL³](ClO₄)₂ bearing two N-CH₂C(NH)OMe groups have been prepared selectively by the reaction of [CuL¹](ClO₄)₂ (L² = 2,13-bis(cyanomethyl)-5,16-dimethyl-2,6,13,17-tetraazatricyclo[16.4.0.^1.180^7.12]docosane) with methanol. The N-CH₂C(NH)OCH₃ group in [CuL²](ClO₄)₂ is quite inert against acid hydrolysis. On the other hand, the functional pendant arms in [CuL³](ClO₄)₂ readily undergo acid hydrolysis. Both [CuL⁴](ClO₄)₂ bearing one N-CH₂COOCH₃ and one N-CH₂C(NH)OCH₃ groups and [CuL⁵](ClO₄)₂ bearing two N-CH₂OOCH₃ groups have been prepared by the stepwise hydrolysis of [CuL³](ClO₄)₂. The reactivity of the functional pendant arms in [CuL¹](ClO₄)₂ or [CuL³](ClO₄)₂ is quite different from that in [NiL¹](ClO₄)₂ or [NiL³](ClO₄)₂. The crystal structure of [CuL²](ClO₄)₂ shows that the complex has a slightly distorted square-pyramidal coordination polyhedron with an apical Cu-N (N-CH₂C(NH)OCH₃ group) bond. The N-CH₂C(NH)OCH₃ and/or N-CH₂COOCH₃ groups in [CuL³](ClO₄)₂, [CuL⁴](ClO₄)₂, and [CuL⁵](ClO₄)₂ are involved in coordination, and the complexes have distorted trans-octahedral coordination polyhedron. The axial Cu-N (N-CH₂C(NH)OCH₃ group) distance (2.396(7) Å) of [CuL⁴](ClO₄)₂ is considerably longer than the Cu-N (N-CH₂C(NH)OCH₃ group) distance (2.169(3) Å) of [CuL²](ClO₄)₂.     

Synthesis and characterization of a topologically constrained tetraaza macropolycycle and its copper(II) complex

A new macropolycycle, 2,13-dimethyl-1,5,12,16-tetraazapentacyclo[14.6.2.2^5.12.0^6.11.0^17.22]hexacosane (L³), has been prepared by the reaction of 3,14-dimethyl-2,6,13,17-tetraazatricyclo[16.4.0.0^7.12]docosane (L¹) with 1-bromo-2-chloroethane. The macropolycycle readily reacts with anhydrous copper(II) ion to yield [CuL³]²⁺ in dry methanol but does not with nickel(II) ion, showing a high copper(II) ion selectivity. Crystal structure of [CuL³](ClO₄)₂ shows that the complex has a distorted square-planar coordination polyhedron with a trans-IV type N-conformation. The Cu-N distances [1.989(3) and 2.015(3) Å] of [CuL³](ClO₄)₂ are distinctly shorter than those of [CuL¹](ClO₄)₂ and other related macrocyclic copper(II) complexes. The d-d transition band for [CuL³](ClO₄)₂ is observed at 447 nm, which is ca. 40 nm shorter than that for [CuL¹](ClO₄)₂.     

Structure and spectroelectrochemical property of a ruthenium complex containing phenanthroline-quinone, and assembly of the complexes on a gold electrode

Ruthenium complexes containing pdon (pdon = 1,10-phenanthroline-5,6-dione) were synthesized. Their spectroscopic and electrochemical properties were examined. The molecular structure with [Ru(pdon)(bpy)₂](ClO₄)₂ ([1](ClO₄)₂) (bpy = 2,2′-bipyridyl) was determined by single crystal X-ray diffraction. The optically transparent thin-layer electrochemical measurements confirm that the quinone form of [1](ClO₄)₂ is reduced to the semi-quinone state in acetonitrile (E°′ = −8 mV). Comparing the model complex, [1](ClO₄)₂, and metal-free pdon, the positive charge on two carbon atoms of the o-quinone group is bigger than that of metal-free pdon. The assemblies of the complexes were finally examined using ligand substitution.     

Synthesis, structures and magnetic properties of nickel(II), manganic(II) and zinc(II) complexes containing pyridyl-substituted nitronyl nitroxide and tris(2-benzimidazolymethyl)amine

Three new magnetic compounds were synthesized by using 2-(2′-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (NIT2Py) and tris(2-benzimidazolymethyl)amine (NTB) as ligands. The structures and magnetic properties of the complexes with formula [Ni(NIT2Py)(NTB)](ClO₄)₂(CH₃OH) 1, [Mn(NIT2Py)(NTB)](ClO₄)₂2 and {[Zn(NIT2Py)₂(CH₃OH)₂](ClO₄)₂}{[Zn(NTB)(H₂O)](ClO₄)₂} 3 were characterized. Compounds 1 and 2 both have [M(NIT2Py)(NTB)] structural units, where the metal ion is in an octahedral environment bound to one NIT2Py through one pyridyl nitrogen atom and one nitroxide oxygen atom. However, compound 3, the chelating zinc ion has two crystallographically independent molecules in the asymmetric unit: one is six coordinated octahedral structure [Zn(NIT2Py)₂(CH₃OH)₂](ClO₄)₂, and the other one is five coordinated pyramidal structure [Zn(NTB)(H₂O)](ClO₄)₂. The magnetic behaviors of these compounds indicate that both the nickel ion and the manganese ion are antiferromagnetically coupled with the NIT2Py ligand with a coupling constant of −19.44 and −0.37 cm⁻¹, respectively, whereas two NIT2Py ligands in compound 3 are ferromagnetically coupled with a coupling constant of 19.1 cm⁻¹.     

Interaction of free functional group with platinum(II) center in cyclometalated complexes: A structural and photophysical property investigation

A series of flexible multidentate ligands containing N,P-donor, 2-[N-(diphenylphosphino)methyl]amino-pyridine (L¹), 2-[N-bi-(diphenylphosphino) methyl]amino-pyridine (L²), 2-[N-(diphenylphosphino)methyl]amino-7-methyl-1,8-naphthyridine (L³) and 4-[(N-diphenylphosphino)methyl]amino-pyridine) (L⁴) have been synthesized. The mono- and dinuclear cyclometalated platinum(II) complexes [Pt(C^N^N)L¹]ClO₄ (HC^N^N = 6-phenyl-2,2′-bipyridine), [Pt₂(C^N^N)₂L¹](ClO₄)₂, [Pt₂(C^N^N)₂L²](ClO₄)₂, [Pt(C^N^N)L³]ClO₄ and [Pt₂(C^N^N)₂L⁴](ClO₄)₂ were prepared and their structures determined by X-ray crystal analysis. These complexes exhibit long-lived bright orange emissions ranging from 560 to 610 nm in the solid state at room temperature. In solution, dinuclear complexes have emissions with higher quantum yields than mononuclear complexes. This can be attributed to intramolecular interaction of free functional group with Pt(II) at axial position, resulting in the quenching of phosphorescence for platinum(II) complexes in the ³MLCT excited state.     

Synthesis, characterization and structural diversity of lanthanide chlorides supported by the β-diketiminate ligand [{(2,6-Me2C6H3)NC(Me)}2CH]

Reactions of the β-diketiminate lithium salt L²Li [L²={(2,6-Me₂C₆H₃)NC(Me)}₂CH] with anhydrous LnCl₃ (Ln=Yb, Sm, Nd) in 1:1 molar ratio in THF afforded the new β-diketiminate lanthanide complexes L²LnCl(THF)(μ-Cl)₂Li(THF)₂ (Ln=Yb (1), Sm (2), Nd (3)). Recrystallization of complexes 1-3 from toluene gave the neutral complexes L²LnCl₂(THF)₂ (Ln=Yb (4), Sm (5), Nd (6)). Recrystallization of complexes 4 and 5 in hot toluene for two times gave the dinuclear complexes L²ClLn(μ-Cl)₃LnL²(THF) (Ln=Yb (7), Sm (8)). Treatment of the mother liquor of complex 2 in hot toluene for three times gave the novel trinuclear complex L²SmCl(μ-Cl)₃SmL²(μ-Cl)Li(L²H)(THF) (9). Each of these complexes was well characterized, while complexes 3, 7 and 9 have been characterized by X-ray diffraction structure determination.     

Alkali and alkaline-earth metal complexes of different nuclearities with azamacrocyclic pendant-arms ligands

A new series of alkali and alkaline-earth complexes of Na(I), Ca(II), Sr(II) and Ba(II) with two pyridyl pendant-arms azamacrocyclic ligands, L¹ and L², were synthesized by reaction of the ligand and the appropriate perchlorate salt in refluxing acetonitrile. The reactions gave analytically pure products that were characterized by elemental analysis, FAB mass spectrometry, IR, conductivity measurements and ¹H NMR spectroscopy. The crystal structure of [NaL¹](ClO₄), [BaL¹](ClO₄)₂ · 2CH₃CN and [Ca₂L²(μ-ClO₄)(H₂O)₂](ClO₄)₂ · Cl · (H₂O)_0.5 could be also determined. The crystal structure of the Na(I) and Ba(II) complexes with L¹ show endomacrocyclic mononuclear species, where the metal ions are in N8 and N10 coordination environment, respectively. The geometry around the metal ions can be described as cube and bicapped cube geometry for Na(I) and Ba(II), respectively. Instead, the crystal structure of the Ca(II) compound with L² shows an exomacrocyclic dinuclear complex where both metal ions are in a similar N5O2 environment joined through a bidentate perchlorate anion. The coordination geometry for both Ca(II) ions can be described as distorted pentagonal bipyramid.     

Ligand-field excited states of hexacyanochromate and hexacyanocobaltate as sensitisers for near-infrared luminescence from Nd(iii) and Yb(iii) in cyanide-bridged d-f assemblies.

Crystallisation of [Co(CN)(6)](3-) or [Cr(CN)(6)](3-) with Ln(iii) salts (Ln = Nd, Gd, Yb) from aqueous dmf afforded the cyanide-bridged d/f systems [Ln(dmf)(4)(H(2)O)(3)(micro-CN)Co(CN)(5)] (-, discrete dinuclear species) and {[Cr(CN)(4)(micro-CN)(2)Ln(H(2)O)(2)(dmf)(4)]}(infinity) (-, infinite cyanide-bridged chains with alternating Cr and Ln centres). With Ln = Gd the characteristic long-lived phosphorescence from d-d excited states of the [M(CN)(6)](3-) units was apparent in the red region of the spectrum, with lifetimes of the order of 1 micros, since the heavy atom effect of the Gd(iii) promotes inter-system crossing at the [M(CN)(6)](3-) units to generate the phosphorescent spin-forbidden excited states. With Ln = Yb or Nd however, the d-block luminescence was completely quenched due to fast (>10(8) s(-1)) energy-transfer to the Ln(iii) centre, resulting in the characteristic sensitised emission from Yb(iii) and Nd(iii) in the near-IR region. For both - and -, calculations based on spectroscopic overlap between emission of the donor (Co) and absorption of the acceptor (Ln) suggest that the Dexter energy-transfer mechanism is responsible for the complete quenching that we observe.     

Solution studies of lanthanide (III) complexes based on 1,1,1,5,5,5-hexafluoro-2,4-pentanedione and 1,10-phenanthroline Part-I: Synthesis, H NMR, 4f-4f absorption and photoluminescence

Solution studies on the complexes of the type [Ln(hfaa)₃(phen)₂] (Ln = La, Pr and Nd) and [Ln(hfaa)₃phen] (Ln = Nd, Ho, Er and Yb; hfaa stands for the anion of 1,1,1,5,5,5-hexafluoro-2,4-pentanedione and phen stands for 1,10-phenanthroline) are presented. These complexes are synthesized in high yields by an in situ method in which hfaa, ammonium hydroxide, lanthanide chlorides and phen were allowed to react in 3:3:1:1 molar ratio in ethanol. In the case of neodymium both eight- and ten-coordinate complexes are isolated. The paramagnetic shifts of the methine protons of β-diketone have their sign opposed to those of paramagnetic shifts of phen protons and the shifts are dominated by dipolar interactions. The inter- and intramolecular shift ratios have been calculated and discussed. The 4f-4f absorption spectra of the complexes of Pr, Nd, Ho and Er are analyzed. The eight- and ten-coordinate neodymium complexes display distinctively different band shapes of the ⁴G_5/2,²G_7/2 ← ⁴I_9/2 hypersensitive transition. The efficient energy transfer from ligand to Pr(III) is reflected by strong red luminescence of this complex at room temperature.