Erbium complexes with tetra-15-crown-5-phthalocyanine: Synthesis and spectroscopic study

Erbium mono-, bis-, and tris(phthalocyaninates) with tetra-15-crown-5-phthalocyanine (H₂R₄Pc) were synthesized and studied by spectroscopic methods. The complexes were obtained by reacting H₂R₄Pc with erbium salts in high-boiling solvents. To compare the efficiency of two approaches to the synthesis of double-decker lanthanide phthalocyaninates, bis(phthalocyaninate) [Er(R₄Pc)₂] was also obtained by a template procedure from dicyanobenzo-15-crown-5. A combination of physicochemical methods (UV and IR spectroscopy, MALDI-TOF mass spectrometry, ¹H NMR) was used for identifying the compounds and proving their individuality and structure. The photoluminescence method demonstrated that solutions of erbium bis- and tris(phthalocyaninates) in CHCl₃ are nonfluorescent in the visible range of light whereas solutions of mono(phthalocyaninate) in CHCl₃ and DMSO exhibit fluorescence with maxima at 707 and 695 nm, respectively. The oxidation of erbium mono(phthalocyaninate) leads to fluorescence quenching.     

Synthesis and spectroscopic study of praseodymium(III) complexes with tetra-15-crown-5-phthalocyanine

Praseodymium(III) complexes with tetra-15-crown-5-phthalocyanine—the neutral radical [(R₄Pc^?·)Pr³⁺(R₄Pc^2?)]⁰ and one-electron reduced [(R₄Pc^2?)Pr³⁺(R₄Pc^2?)]^? forms of the sandwich double-decker complex and the triple-decker complex Pr₂(R₄Pc)₃ (R₄Pc^2? is [4,5,4′,5′,4″,5t",4″′,5″′-tetrakis(1,4,7,10,13-pentaoxatridecamethylene)phthalocyaninate ion])—have been synthesized and spectrally characterized. These compounds have been obtained by direct interaction of tetra-15-crown-5-phthalocyanine with praseodymium(III) acetate or acetylacetonate. The salt anion has an effect on the yield and structure of the reaction products. The complexes have been obtained in high yields, isolated, and characterized by different physicochemical methods: UV and visible electronic absorption spectroscopy, ¹H NMR, and MALDI-TOF mass spectrometry. The double-decker complex is stable in the solid state and in solutions. The triple-decker complex is stable only in the solid state. In a chloroform-methanol (10 vol %) solution, it slowly decomposes.     

Ruthenium(ii) complexes with tetra-15-crown-5-phthalocyanine: synthesis and spectroscopic investigation

The ruthenium complexes with tetra-15-crown-5-phthalocyanine and various axial ligands were synthesized and characterized by spectroscopy. A method for the synthesis of bisaxially coordinated ruthenium(ii) tetra-15-crown-5-phthalocyaninates with the N-donor ligands (R₄Pc)Ru(L₂) (R₄Pc^2– = [4,5,4",5",4,5,4,5-tetrakis(1,4,7,10,13-pentaoxotridecamethylene)phthalocyaninate-ion], L is trimethylamine (Me₃N), pyridine (py), isoquinoline (iqnl), triethylamine (Et₃N), pyrazine (pyz)) was developed. The preparation technique involves selective decarbonylation of (R₄Pc)Ru(CO)(MeOH) on treatment with Me₃NO in excess N-donor solvent.     

First example of X-ray characterized aluminum(iii) complex with tetra-15-crown-5-phthalocyanine

X-ray diffraction analysis was used to establish the structure of aluminum(iii) alkoxide tetra-15-crown-5-phthalocyaninate complex.     

Photoelectric and photorefractive properties of composites based on poly(vinylcarbazole) and ruthenium(II) tetra-15-crown-5-phthalocyanine with axially coordinated pyrazine molecules

The photoelectric and photorefractive characteristics of composites based on poly(vinylcarbazole) containing crown-substituted ruthenium phthalocyanine with axially coordinated pyrazine molecules, (R₄Pc)Ru(pyz)₂ (where R₄Pc^?2 is [4,5,4′,5′,4″,5″,4″′,5″′-tetrakis-(1,4,7,10,13-pentaoxatridecamethylene)phthalocyanine ion], pyz is pyrazine), have been studied. Supramolecular ensembles of these complexes are responsible for optical absorption and photoelectric and photorefractive sensitivity in the near IR region. It has been found that under the action of a 1064-nm laser, the quantum efficiency of formation of mobile charge carriers, estimated from the photocurrent, corresponds to the Onsager equation when the quantum yield of formation of thermalized electron-hole pairs φ₀ = 0.35 and the separation distance is 9.8 Å, irrespective of the (R₄Pc)Ru(pyz)₂ content. The kinetic curves of amplification of the information laser beam are bellshaped. This suggests that the photorefractive characteristics are underestimated owing to lowering to zero of the field E ₀ inside the layer as a result of buildup of space charge in the near-electrode space upon passing the dark current. The two-beam gain coefficient at an (R₄Pc)Ru(pyz)₂ content of 7 wt % is Γ = 62 cm^?1 as estimated from the maximum of the bell-shaped curve.     

Studies on the thermal behaviour and decomposition mechanism of complexes of rare earth(III) nitrates) with benzo-15-crown-5

Thermal dissociation reactions and mechanism of complexes of rare earth(iii) nitrates with the crown ether benzo-15-crown-5 were investigated by means of TG-DTG, DSC, DTA and IR technique. The results have shown that the dissociation processes of the complexes consist of several steps, one of which is a fast decomposition reaction. The fast decomposition peak temperatures (DSC) of all the complexes of the lanthanides (except Pm and Tm) decrease regularly with increasing atomic number. Moreover, values of the enthalpy change of desolvation, fast and the fourth step of decomposition and the apparent activation energies of fast and the fourth step of decomposition were obtained.

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Zusammenfassung Mittels TG-DTG-, DSC-, DTA- und IR-Techniken wurden einschließlich Mechanismus die thermischen Dissoziationsreaktionen von Komplexen der Seltenerden(III)nitrate mit dem Titelkronenether untersucht. Die Ergebnisse zeigen, daß die Dissoziationsvorgänge der Komplexe aus mehreren Schritten bestehen, von denen einer eine schnelle Zerfallsreaktion ist. Die Peaktemperaturen für die schnellen Zersetzungen (DSC) aller Lanthanidenkomplexe (ausgenommen Pm und Tm) sinken mit ansteigender Ordnungszahl der Lanthaniden ständig im Wert. Außerdem wurden Werte für die Enthalpieänderungen bei der Desolvatation, für den schnellen und den vierten Zersetzungsschritt und für die Aktivierungsenergien des schnellen und vierten Zersetzungsschrittes erhalten.

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The authors express their gratitude to Gan-Che Wang, Xi-Mei Guo and Xi-Ning Xu for their assistance.     

二环己基18-冠-6异构体D与十五个稀土硝酸盐配合物的合成及其性质的研究

合成了二环己基18-冠-6-的异构体D与十五个稀土硝酸盐的配合物,系统研究了它们的FOURIER变换红外光谱的变化规律;测定了部分配合物的核磁共振氢谱和碳谱。结果均表明,在稀土系列内离子直径与冠醚穴大小的比例是否合适是影响配合稳定性的主要因素。文中还讨论了配合物中NO3[-]与稀土离子形成接触离子对对红外光谱及核磁共振谱的影响。在NO3[-]v6(B1)中观察到镧系"斜W"规律。基于红外光谱及核磁共振谱的结果,初步讨论了配合物的结构。     

A novel efficient approach to heteronuclear triple-decker complexes of rare earth elements with phthalocyanines

A novel approach to heteroleptic heteronuclear rare earth metal(III) trisphthalocyaninates was proposed with the complexes [(15C5)₄Pc]M*[(15C5)₄Pc]M(Pc) as examples (15C5 is 15-crown-5, Pc^2? is the phthalocyaninate dianion, and M* ?? M = Yb and Y). Unsubstituted lanthanum bisphthalocyaninate, La(Pc)₂, was used for the first time as a Pc^2? donor in the synthesis of such complexes. This substantially increased the yields of the target heteronuclear complexes over the previous literature data.     

稀土冠醚类配合物的研究 XX: 三价及二价稀土硫氰酸盐与辛二酰双(4'-苯并-15-冠-5)配合物的合成和性质

在乙腈和二氯甲烷混合溶液中合成了三价稀土元素(La, Nd, Eu, Dy, Er, Yb)硫氰酸盐与辛二酰双(4'-苯并-15-冠-5)的六个新配合物。并在氩气氛中, 以四氢呋喃为溶剂, 锂-萘为还原剂, 制得了二价铕硫氰酸盐与辛二酰双(4'-苯并-15-冠-5)的固体配合物。通过元素分析、红外光谱、差热热重分析、荧光光谱、穆斯堡尔谱、电子自旋共振谱、还原性实验等研究了双冠醚与稀土离子的配位作用, 并讨论了三价和二价稀土配合物在物理化学性质上的差别。     

Synthesis of alkynylbenzo-15-crown-5 ethers

Reactions of 4"-iodobenzo-15-crown-5 ether with ethynylarenes or 4"-ethynylbenzo-15-crown-5 ether with haloarenes in the presence of catalytic amounts of Pd^IIcomplex salts, CuI, and Et₃N gave 4"-(arylethynyl)benzo-15-crown-5 ethers in 55—80% yields.     

Synthesis of a novel D-glucose-conjugated 15-crown-5 ether with a spiro ketal structure

This paper describes a synthetic approach to a novel D-glucose-conjugated 15-crown-5 ether having a spiroketal structure starting from a 1-C-vinylated glucose derivative. The approach consists of the glycosylation of the vinylated glucose derivative to give an ethyleneoxy spacer derivative using bismuth(III) triflate, the conversion of the 1-C-vinyl group of the glucoside produced into a carboxylic acid group, and the intramolecular condensation between the carboxyl group and the terminal hydroxyl group in the ethyleneoxy spacer. A D-glucose-conjugated 15-crown-5 ether having a unique spiroketal structure was thus successfully synthesized.     

Synthesis of bis-benzo-15-crown-5 and bis-benzo-18-crown-6-ethers

Bis-crown ethers with benzo-15-crown-5 and benzo-18-crown-6 moieties bridged by different length of polyethylene ethers have been successfully synthesized.     

Synthesis,structure, and character of two rare earth carboxylic acid complexes

Two rare earth carboxylic acid complexes, [Sm(MeBA)₃(2,2′-bipy)]₂·2(2,2′-bipy) (MeBA = 3-methylbenzoic acid; 2,2′-bipy = 2,2′-bipyridine) (1) and [Pr(MeBA)₃(H₂O)₂]_n?n(4,4′-bipy) (4,4′-bipy = 4,4′-bipyridine) (2), have been synthesized under hydrothermal conditions and structurally determined by single-crystal X-ray diffraction. Compound 1 is a dimer and further assembles into an infinite chain, two-dimensional net and three-dimensional supramolecular structure via weak π–π and C–H···π interactions. Some 2,2′-bipy coordinates with Sm and some exist by non-covalent C–H···π interactions. Compound 2 is a 1D infinite chain structure, with adjacent 1D chains connected into a 2D layer structure by O–H···N hydrogen bonds. The two complexes were characterized by elemental analyses, IR, photoluminescence, and TGA. In order to illustrate subtle structural characteristics of intermolecular interactions and magnetic sensitivity of the complex, 2D-IR correlation spectra (2D-IR COS) under magnetic perturbation for 1 were performed.     

Structural aspects of crown complexes with alkali and alkaline earth cations. Benzo-15-crown-5 as a discriminating macrocycle

X-ray structural results have been reviewed for the related M^z+ L _z ^– -B15C5 complexes where M^z+=Li⁺ to Cs⁺ and Mg²⁺ to Ba²⁺, L^–=2,4,6-trinitrophenolate (Picrate or Pic) and 3,5-dinitrobenzoate (Dnb), and B15C5=benzo-15-crown-5. These results combined with those for come MX_z-B15C5 (X=NCS^–, I^–, NO ₃ ^– , ClO ₄ ^– , BPh ₄ ^– ) complexes have revealed that B15C5 is a useful macrocycle with regard to the within-the-group and between-the-groups discriminations of M^z+ in the solid state.     

Synthesis and characterization of rare earth complexes with Phthalaldehyde-lysine Schiff base

Ten new rare earth complexes with Schiff base (HL) derived from phthalaldehyde with two-CHO groups and lysine, which has unsymmetrical α-and ε--NH₂ groups, were synthesized and characterized by elemental analysis, TG-DTA analysis, UV-Vis, IR, and ¹H NMR spectra. They were confirmed to be as LnL₂(NO₃)·4H₂O (Ln=La, Pr, Nd, Sm, Y) and LnL₂(NO₃)·3H₂O (Ln=Gd, Tb, Dy, Er, Yb), respectively. Furthermore, their coordination mechanism, spectral properties and probable molecular structures were also discussed. __________ Translated from Journal of Zhejiang University (Science Edition), 2005, 32 (5) (in Chinese)     

The Synthesis of Perfluorocyclohexano-15-crown-5 Ether

Perfluorocyclohexano-15-crown-5 ether, trans- (1) and cis-(2) isomers have been prepared by direct fluorination using the LaMar fluorination technique¹. They have several potential applications and are of special interest in a variety of fields².