Synthesis of Soluble Complexan Polymers in Organic Solvents for Using as a Polymer–Chelate Precursor to YBa2Cu3O7-x Thin Films

Abstract

A soluble complexan polymer in organic solvents, derived from 1,2-diaminocyclohexane-N,N,N′,N′-tetraacetic acid (CyDTA), was synthesized and used as a polymer chelate precursor to YBa2Cu3O7-x thin films. Five complexan polymers (3) were prepared by a ring-opening polyaddition of CyDTA dianhydride (1) with several diamines (2). The polymer (3e) prepared with 1,2-diaminocyclohexane (2e) was soluble in water, dimethyl sulfoxide (DMSO), methanol, and ethanol. A clear aqueous solution (pH 8) containing 3e and 1/2 equivalent molar amount of metal nitrates of Y, Ba, and Cu (1 : 2 : 3 in molar ratio) was poured into tetrahydrofurane (THF) to precipitate a polymer–metal chelate. The chelate formations of each metal were confirmed by C=O stretching bonds. The polymer chelate precursor was soluble in methanol, DMSO, and water, and partially soluble in ethanol. The polymer–metal chelate was dissolved in methanol, of which the metal concentration was adjusted to 3 wt%. This solution was spin-coated onto SrTiO3 (100) and MgO (001) substrates for preparing YBa2Cu3O7-x thin films. According to an X-ray diffraction analysis, YBa2Cu3O7-x film with a c-axis orientation was formed on a SrTiO3 substrate; even the precursor film was sintered at 780 °C for 1 h under air. Superconducting YBa2Cu3O7-x films with a c-axis orientation were also prepared on a MgO (001) substrate.

A facile precursor route to transition metal molybdates using a polyzwitterionic matrix bearing simultaneously charged moieties and complexing groups

“…Among these methods, the precursor routes, based on the decomposition of citrate gels, 1 oxalates, 2 or polyaminocarboxylates like EDTA and its analogs, 3 were successfully used. Alternatively, structurally simple organic polymers such as poly(ethylene glycol), 4 poly(amide) and poly(imide) derivatives, 5 but also more elaborate polymer structures, resulting from the association of monomers bearing carboxylic acid or amine moieties, 6 were occasionally employed to synthesize polymer-metal complexes, which are thermally treated 7 to obtain the inorganic materials. The latter polymers constitute particularly interesting systems for this kind of application because of their tunable properties: solubility in various polar media, number of functional groups of each type, presence of additional substituents able to induce suprastructure or complexation of the cations, etc.…”

Nickel(II) and iron(III) complexes of a diamide derivative of the hexadentate complexone trans-1,2-diaminocyclohexane-tetraacetic acid

“…The diacid/diamide complexone ligand H 2 L was prepared in good yield from H 4 cdta via the dianhydride 1 [6]. The mononuclear nickel(II) and iron(III) complexes (2 and 3 respectively) of the dianionic, hexadentate ligand L 2À were prepared by precipitation from methanol or ethanol.…”

“…Synthesis of trans-1,2-bis{carboxymethyl-½2-ð2, 3-dihydro-indol-1-ylÞ-2-oxoethyl-amino}-cyclohexane ðH 2 LÞ Dianhydride 1 [6] (1.55 g, 5 mmol) was added in small portions over 10-15 min to a stirred solution of excess indoline (2.40 g, 20 mmol) in acetonitrile (50 cm 3 ). The crude product precipitated as an off-white powder during the course of the addition, and was isolated by filtration, dried in air and recrystallised from methanol/ water as fine, colourless needles of H 2 L Á 6H 2 O; yield 1.74 g (53% A solution of nickel(II) nitrate hexahydrate (0.29 g, 1 mmol) in methanol (5 cm 3 ) was added to a solution of H 2 L (0.55 g, 1 mmol) and KOH (0.11 g, 2 mmol) in methanol (10 cm 3 ).…”

Solid‐State Reactions

“…Approaches involving the use of polymer-metal complexes based on structurally simple organic polymers such as poly(ethylene glycol), poly(vinyl alcohol), poly(acrylic acid), polyamide or polyimide derivatives, have been described to synthesize many oxide-type inorganic materials [122,123]. When nitrate ions are simultaneously present, auto-ignited combustion may occur and lead to multicomponent oxides [124].…”