Configuration-Specific Synthesis of the Facial and Meridional Isomers of Tris(8-hydroxyquinolinate)aluminum (Alq₃)

Treatment of AlO(OH) with 3 equiv of 8-hydroxyquinolinol in refluxing deionized water provided the meridional and facial isomers of tris(8-hydroxyquinolinate)aluminum (Alq3) with good yields as solid deposits after 1 and 90 h, respectively. X-ray diffraction and solid-state 13C NMR studies revealed that mer-Alq3 is formed in the early stage of the reaction and then gradually converts to fac-Alq3, which is thermodynamically less stable, although no existence of a catalyst substance is implied

Configuration-Specific Synthesis of the Facial and Meridional Isomers of Tris(8-hydroxyquinolinate)aluminum (Alq₃)

Treatment of AlO(OH) with 3 equiv of 8-hydroxyquinolinol in refluxing deionized water provided the meridional and facial isomers of tris(8-hydroxyquinolinate)aluminum (Alq3) with good yields as solid deposits after 1 and 90 h, respectively. X-ray diffraction and solid-state 13C NMR studies revealed that mer-Alq3 is formed in the early stage of the reaction and then gradually converts to fac-Alq3, which is thermodynamically less stable, although no existence of a catalyst substance is implied

Configuration-Specific Synthesis of the Facial and Meridional Isomers of Tris(8-hydroxyquinolinate)aluminum (Alq₃)

Treatment of AlO(OH) with 3 equiv of 8-hydroxyquinolinol in refluxing deionized water provided the meridional and facial isomers of tris(8-hydroxyquinolinate)aluminum (Alq3) with good yields as solid deposits after 1 and 90 h, respectively. X-ray diffraction and solid-state 13C NMR studies revealed that mer-Alq3 is formed in the early stage of the reaction and then gradually converts to fac-Alq3, which is thermodynamically less stable, although no existence of a catalyst substance is implied

Configuration-Specific Synthesis of the Facial and Meridional Isomers of Tris(8-hydroxyquinolinate)aluminum (Alq₃)

Treatment of AlO(OH) with 3 equiv of 8-hydroxyquinolinol in refluxing deionized water provided the meridional and facial isomers of tris(8-hydroxyquinolinate)aluminum (Alq3) with good yields as solid deposits after 1 and 90 h, respectively. X-ray diffraction and solid-state 13C NMR studies revealed that mer-Alq3 is formed in the early stage of the reaction and then gradually converts to fac-Alq3, which is thermodynamically less stable, although no existence of a catalyst substance is implied

A Self-Assembled Monolayers Assisted Solid-State Conversion of Boehmite Particles to Aluminum Oxide Film

An aluminum oxide coating film is prepared for the first time by a solid-state conversion of boehmite (AlOOH·nH2O) particles, which are covalently attached on self-assembled monolayers (SAMs) of 11-mercaptoundecanoic acid (MUA) built on Au layer. The particles held on MUA SAMs are subject to sintering at elevated temperatures to fuse into monolithic film. X-ray photoelectron spectroscopy confirmed the existence of the hexacoordinate Al atoms. Fabrication steps are monitored by atomic force microscopy

Oxidation of the Sulfide Ligands to SO₄^2- in the Dinuclear Complex {RuCl[P(OMe)₃]₂}₂(μ-S₂)(μ-Cl)(μ-N₂H₄): Synthesis and Characterization of {RuCl[P(OMe)₃]₂}₂(μ-S₂)(μ-Cl)(μ-N₂H₄)⁺HSO₄^-, {RuCl₂[P(OMe)₃]₂}₂(μ-S)(μ-N₂H₄), and {RuCl[P(OMe)₃]₂}₂(μ-S₂O₅)(μ-N₂H₄)

The paramagnetic dinuclear Ru2+Ru3+ complex, {RuCl[P(OMe)3]2}2(μ-S2)(μ-Cl)(μ-N2H4) (1), reduces dioxygen by one-electron at room temperature in CH3CN to form 1+O2-, in which O2- is coordinated to the μ-S2 ligand. The dioxygen reduction is preceded by protonation to yield HO2+ by the bridging hydrazine ligand. Complex 1 is electrochemically more negative than HO2+, and a redox reaction generates 1+ and HO2 (→ O2- + H+). Spectroscopic studies (NMR and UV−vis) show that 1 and 1+O2- are under equilibrium, and the succeeding disproportionation reaction of 1+O2- produces two intermediates, 1+ and the dithionite complex, 1+(O2-)2, as an intermediate. The dithionite intermediate undergoes Cl- dissociation and further oxidation to yield the dinuclear Ru complex {Ru2+Cl[P(OMe)3]2}2(μ-S2O5)(μ-N2H4) (3). The liberated Cl- attacks the dithionite complex, and induces SO42- dissociation to prepare the dinuclear complex {Ru3+Cl2[P(OMe)3]2}2(μ-S)(μ-N2H4) (5). On the other hand, intermediate 1+ forms an ion pair with HSO4-, which stems from the liberated SO42-, to yield [{Ru3+Cl[P(OMe)3]2}2(μ-S2)(μ-Cl)(μ-N2H4)]+HSO4- (4 = 1+HSO4-). A trace of {Ru3+Cl[P(OMe)3]2}2(μ-S2)(μ-Cl)2 (2) is also detected in the supernatant. The UV−vis spectroscopic study revealed that complexes 2−5 are the exclusive products and the oxidation reaction can be balanced as follows:  14 × 1 + 4.5 O2 = 2 + 5 × 3 + 4 × 4 + 4 × 5. The 18O2/16O2 mixed-labeled oxygen studies proved that the external oxygen was the source of oxygen for the formation of the S2O5 and HSO4- groups in 3 and 4, respectively. The structures of 3, 4, and 5 are characterized by X-ray crystallographic structure determinations. The dinuclear framework of complex 4 remains identical with that of 1 except for the significantly shorter Ru−S distance. The hydrazine hydrogens of complex 3 show intramolecular hydrogen bonding, which is reflected on a significantly low field shift of the hydrazine 1H NMR resonance. Complex 3 possesses the μ-S2O52- ligand, in which the two μ-SO2-O,S‘ bridges are linked at the sulfur atoms through the μ-oxo bonds. Comparison of the site symmetries around the Ru atoms of 1, 3, and 5 strongly supports the occurrence of coordination rearrangements

A Self-Assembled Monolayers Assisted Solid-State Conversion of Boehmite Particles to Aluminum Oxide Film

An aluminum oxide coating film is prepared for the first time by a solid-state conversion of boehmite (AlOOH·nH2O) particles, which are covalently attached on self-assembled monolayers (SAMs) of 11-mercaptoundecanoic acid (MUA) built on Au layer. The particles held on MUA SAMs are subject to sintering at elevated temperatures to fuse into monolithic film. X-ray photoelectron spectroscopy confirmed the existence of the hexacoordinate Al atoms. Fabrication steps are monitored by atomic force microscopy

A Self-Assembled Monolayers Assisted Solid-State Conversion of Boehmite Particles to Aluminum Oxide Film

An aluminum oxide coating film is prepared for the first time by a solid-state conversion of boehmite (AlOOH·nH2O) particles, which are covalently attached on self-assembled monolayers (SAMs) of 11-mercaptoundecanoic acid (MUA) built on Au layer. The particles held on MUA SAMs are subject to sintering at elevated temperatures to fuse into monolithic film. X-ray photoelectron spectroscopy confirmed the existence of the hexacoordinate Al atoms. Fabrication steps are monitored by atomic force microscopy

Synthesis and Characterization of the Tetranuclear Ru^II Complex [RuCl(μ-Cl)- (P(OMe)₃)₂(μ,η¹,η²-S₂)Ru(P(OMe)₃)(μ-P(OMe)₃- <i>P</i>,<i>O</i>)]₂ Containing a <i>trans</i>-Ru^IISSRu^II Core

Synthesis and Characterization of the Tetranuclear RuII Complex [RuCl(μ-Cl)- (P(OMe)3)2(μ,η1,η2-S2)Ru(P(OMe)3)(μ-P(OMe)3- P,O)]2 Containing a trans-RuIISSRuII Cor

A Self-Assembled Monolayers Assisted Solid-State Conversion of Boehmite Particles to Aluminum Oxide Film

An aluminum oxide coating film is prepared for the first time by a solid-state conversion of boehmite (AlOOH·nH2O) particles, which are covalently attached on self-assembled monolayers (SAMs) of 11-mercaptoundecanoic acid (MUA) built on Au layer. The particles held on MUA SAMs are subject to sintering at elevated temperatures to fuse into monolithic film. X-ray photoelectron spectroscopy confirmed the existence of the hexacoordinate Al atoms. Fabrication steps are monitored by atomic force microscopy