Lanthanide nitrate complexes of some macrocyclic polyethers

King, R. B.; Heckley, P. R.

doi:10.1021/ja00817a017

Cited by 112 publications

(23 citation statements)

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“…In keeping with published data [8,12,13], the 1 H NMR spectrum of dibenzo-18-crown-6 (CDCl 3 , Table 1) contains a multiplet from the aromatic protons and two triplets from the methylene protons. The spectrum of dibenzo-18-crown-6 · KOH · MeOH in DMSO-d 6 is characterized by downfield positions of signals relative to those of dibenzo-18-crown-6.…”

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confidence: 78%

Structure of the Potassium Hydroxide-Dibenzo-18-crown-6 Complex

et al. 2005

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Dibenzo-18-crown-6 reacts with potassium hydroxide in methanol to give the C 20 H 24 O 6 · KOH · MeOH complex which was characterized by the 1 H NMR, UV, and IR spectra. Depending on the conditions, the reaction of the same compounds in toluene gave products with the compositions 4 C 20 H 24 O 6 · KOH · 3 H 2 O (3 h, reflux) and 11C 20 H 24 O 6 · KOH (1 h, 80°C, 1 h).While studying the application of strong bases in the chemistry of acetylene [1] and developing concepts of superbases as systems in which the interaction between metal cation and anion is weakened due to coordination with a weakly basic ligand [2], we have encountered with the necessity of elucidating the structure of crown ether complexes with alkali metal hydroxides.The synthesis of complexes formed by macrocyclic polyethers (crown ethers) with alkali metal salts [3-6], their properties, and application in organic chemistry are extensively discussed in the literature (see, e.g., [7,8]). However, only a few data have been reported on the structure of complexes derived from crown ethers and alkali metal hydroxides: several short communications on this topic are available.The dibenzo-18-crown-6-KOH complex was reported for the first time by Pedersen [3] who revealed reduction in the electric conductivity of a solution of potassium hydroxide in methanol in the presence of dibenzo-18-crown-6, synthesized complexes of KOH with dicyclohexyl-18-crown-6 and di(tert-butylbenzo)-18-crown-6 in toluene, and determined their solubility in benzene, toluene, DMF, and DMSO. No other parameters of the complexes were given.Sam and Simmons [9] later showed that a toluene solution of the complex formed by dicyclohexyl-18-crown-6 and KOH, which was prepared in the presence of methanol [3], contains only 11% of hydroxide ions and that the fraction of methoxide ions (CH 3 O -) is 89%. This conclusion was drawn on the basis of the 1 H NMR and potentiometric titration data which were not given in [9]. It was presumed that the presence of activated methoxide ions is confirmed by the formation of o-chloroanisole from o-dichlorobenzene on heating to 90°C with the KOH-dicyclohexyl-18-crown-6 complex prepared in the presence of methanol [9]. Pedersen [10] also reported on the complex derived from sodium hydroxide and a sulfur-containing analog of dicyclohexyl-18-crown-6; its formation was proved by the data on sodium ion extraction. Lutz et al. [11] studied the IR spectra of solutions of dicyclohexyl-18-crown-6-KOH in methanol, chloroform, toluene, and heptane. The formation of the dibenzo-18-crown-6-KOH complex was also noted in [11], but no its parameters were given.In the present work we made an attempt to isolate the dibenzo-18-crown-6-KOH complex and determine its structure. The complex was prepared by heating the components in methanol (with and without addition of toluene) or toluene, followed by filtration, removal of the solvent, and evacuation of the residue. The resulting amorphous powders were analyzed by IR, UV, and 1 H NMR spectroscopy, and their elemental composi...

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confidence: 78%

Structure of the Potassium Hydroxide-Dibenzo-18-crown-6 Complex

et al. 2005

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“…The coordination chemistry of lanthanides is important. And during the last decades, an increase in the number of publications devoted to the rare earth coordination compounds has been observed [1][2][3][4][5][6], due to their biological, biochemical, medical and many other applications such as an excellent diagnostic and prognostic probe in clinical diagnostics [7], an anticancer material [2,8], lanthanide complexes based X-ray contrast imaging and lanthanide chelates based contrast enhancing agents for Magnetic Resonance Imaging (MRI) [9] are being excessively used in radiological analysis in our body systems [8], also as shift reagents for NMR spectrometry [9][10][11], as well as, their potential applications in fundamental and applied science such as organic synthesis, bioorganic chemistry and homogeneous catalysis [9,[12][13][14][15][16]. Crown ethers are cyclic chemical compounds that consist of a ring containing several ether groups.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Characterization and Antibacterial Activity of New Complexes of Some Lanthanide Ions with Benzo 18-Crown-6 and 221-Cryptand

Al-Abdaly¹,

Al-Almery²,

Albayaty³

2013

IOSR-JAC

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Complexes of some lanthanide picrates (Ln 3+ = Pr 3+ , Nd 3+ and Dy 3+) with benzo-18-crown-6 and 221-cryptand were synthesized and characterized by elemental analysis, FTIR, and UV-Visible. Spectrophotometric methods, thermal analysis (TGA & DTG), melting point, magnetic susceptibility and molar conductance. Also an in-vitro study on gram positive (Staphylococcus aureus) and gram negative bacteria (Escherichia coli, Salmonella and pseudomonas aeruginosa) was performed and the results were compared to those of the broad spectrum antibiotic Chloramphinicol. The benzo-18-crown-6 complexes have the general formula of [Ln.L.(Pic) 2 ]Pic.nH 2 O , where; (Ln 3+ = Pr 3+ , Nd 3+ , and Dy 3+) , (L = Benzo-18-crown-6) , (Pic = Picrate anion) , (n = 1-2). In these complexes two picrate anions are coordinated to the metal ion through the phenolic oxygen and oxygen of the ortho nitro group, thus, the metal ions in these complexes have a coordination number of (10). The complexes of 221-cryptand have the general formula of [Ln.L.(Pic)]Pic 2 .nH 2 O where; (Ln 3+ = Pr 3+ , Nd 3+ , and Dy 3+), (L = 221-cryptand), (Pic = Picrate anion), (n = 1,2 or 7). In these complexes one picrate anion is coordinated to the metal ion, also through the phenolic oxygen and the oxygen from the ortho nitro group, thus the metal ions in the cryptand complexes have a coordination number of (9).

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“…Lanthanoid nitrates [Ln(NO 3 ) 3 ] form solid complexes with several poly(ethylene glycol)s and glymes 2. The lanthanoid complexes of crown ethers have also been reported 7–10. However, data on the interaction of dexran with lanthanide ions and on the preparation and applications of these complexes are very limited and are mostly reported as patent formulations.…”

Section: Introductionmentioning

confidence: 99%

Dextran–rare earth ion interactions. II. Solid‐state characteristics

Zümreoǧlu‐Karan

Mazi

Güner

2001

J of Applied Polymer Sci

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ABSTRACT:The solid-state characteristics of dextran complexes precipitated from aqueous solutions with three different light-lanthanoid cations (La 3ϩ , Ce 3ϩ , and Nd 3ϩ ) were investigated by spectroscopic and thermal methods. Spectroscopic characterization was realized by the comparative interpretation of the FTIR spectra, and the complexes were found to involve both ligating water and dextran through its O(2) and O(3) atoms. Remarkable spectral changes were noted, particularly with La 3ϩ , which parallels the previous solution studies. The order of La 3ϩ Ͼ Ce 3ϩ Ͼ Nd 3ϩ was determined to display the tendency of the Ln 3ϩ ion in favor of dextran throughout the competition between water and dextran. The thermal stabilities of the complexes were examined by thermogravimetry (TG), differential TG, and DSC methods. The decomposition steps and temperatures were assigned with respect to the lanthanoid ions used. The TG and DSC results indicated that the complexes are less stable thermally than dextran itself with increasing thermal stabilities in the order of La 3ϩ Ͻ Ce 3ϩ Ͻ Nd 3ϩ in their anhydrous states.

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Lanthanide nitrate complexes of some macrocyclic polyethers

Abstract: The macrocyclic polyether benzo-15-crown-5 reacts with the hydrated lanthanide(III) nitrates in acetone solution to form complexes of the type Ln(N03)3-Ci4H2oOs (Ln = La, Ce, Pr, Nd, and Sm) with the lighter (i.e., larger) lanthanides and of the type Ln(N03)3 • 4 2 05• 3H20 -(

Cited by 112 publications

References 0 publications

Structure of the Potassium Hydroxide-Dibenzo-18-crown-6 Complex

Structure of the Potassium Hydroxide-Dibenzo-18-crown-6 Complex

Synthesis, Characterization and Antibacterial Activity of New Complexes of Some Lanthanide Ions with Benzo 18-Crown-6 and 221-Cryptand

Dextran–rare earth ion interactions. II. Solid‐state characteristics

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