The Portrayal of Indonesian Image in 2007 Kompas Selected Short Stories: Social Problems, Criticisms and Hopes

Article aimed at exploring social problems reflected in 15 selected short stories printed in Kompas during 2007 both explicitly and implicitly. Specifically, this research is focused on the mapping of dominant social problems raised by the short stories, the social criticisms strongly voiced by the authors and the hopes of a better situation implicitly reflected in these interesting short stories. This study applies the Defamiliarization Effect promoted by Bertolt Brecht and Negative Dialectics or Negative Knowledge by Theodor Adorno, specifically in analyzing the literary works as a criticism tool. The result of the research shows that phenomena of social problems current lately in Indonesian context like identity, poverty, corruption, religious tensions, moral degradation, politics dirtiness, minority group problems, social security, natural disasters and the like are clearly seen and teased in these writings

Substituent Effects at the β‑Positions of the Nonfused Pyrroles in a Quadruply Fused Porphyrin on the Structure and Optical and Electrochemical Properties

We have synthesized <b>2</b>, a derivative of zinc­(II) quadruply fused porphyrinato (Zn^IIQFP) that is tetrabrominated at the β-positions of the two nonfused pyrroles, by treatment of Zn^IIQFP with <i>N</i>-bromosuccinimide. X-ray diffraction analysis of a single crystal obtained from a THF solution of <b>2</b> by vapor diffusion of ethanol (EtOH) revealed that <b>2</b> formed an unprecedented dimeric structure, (<b>2</b>)₂-L (L = EtOH), in which one of the brominated QFP ligands acts as a bridging ligand in an unprecedented μ-η³:η¹ coordination mode. In the dimeric structure, the two QFP ligands showed a unique η³ coordination mode for both Zn^II centers. In (<b>2</b>)₂-EtOH, one of the pyrrolic nitrogen atoms of the two nonfused pyrroles dissociates from the Zn^II center, and the dissociated pyrrolic nitrogen atom coordinates to the Zn^II center of the other molecule in the dimer. The Zn^II center having the μ-η³:η¹-QFP ligand is coordinated by an EtOH molecule, and the other Zn^II center is coordinated by the η³-QFP ligand and one nitrogen atom of the bridging QFP ligand. The dimeric structure is stable and maintained even in a solution of noncoordinating solvents such as dichloromethane. The bromo groups of <b>2</b> can be substituted with phenyl groups under Suzuki coupling conditions to afford the tetraphenyl derivative, <b>3</b>. Furthermore, the effects of the substituents at the β-positions on the optical and electrochemical properties and Lewis acidity of the Zn^II centers have been investigated. The redox potentials were positively shifted by introduction of electron-withdrawing groups at the β-positions, and the shift widths exhibited a linear correlation to the Hammett parameters of the substituents

Heteronuclear Ru^IIAg^I Complexes Having a Pyrroloquinolinequinone Derivative as a Bridging Ligand

Herein, we report the synthesis of a novel heterohexanuclear complex (<b>1</b>) of a heteroaromatic cofactor, pyrroloquinolinequinone (PQQ). The crystal structure of <b>1</b> was determined to reveal that two PQQ-bridged Ru^IIAg^I units were linked by two [Ag^I(OTf)₂]⁻ units (OTf = CF₃SO₃^–). A solvent-bound Ru^IIAg^I heterodinuclear complex (<b>2</b>) was formed from <b>1</b> in a coordinating solvent such as acetone to show an intense metal-to-ligand charge-transfer band at 709 nm

Visible-Light-Driven Photocatalytic CO₂ Reduction by a Ni(II) Complex Bearing a Bioinspired Tetradentate Ligand for Selective CO Production

A Ni­(II) complex bearing an S₂N₂-type tetradentate ligand inspired by the active site of carbon monoxide dehydrogenase was found to selectively catalyze CO₂ reduction to produce CO in a photocatalytic system using [Ru­(bpy)₃]²⁺ (bpy = 2,2′-bipyridine) as a photosensitizer and 1,3-dimethyl-2-phenyl-2,3-dihydro-1<i>H</i>-benzo­[<i>d</i>]­imidazole (BIH) as an electron donor. The Ni­(II) complex shows a high turnover number over 700 with high CO selectivity of >99% and quantum yield of 1.42% in the photocatalytic system

Acid–Base Properties of a Freebase Form of a Quadruply Ring-Fused PorphyrinStepwise Protonation Induced by Rigid Ring-Fused Structure

We report herein unique stepwise protonation at inner imino-nitrogen atoms of a freebase derivative of a quadruply fused porphyrin (H₂QFP), which has been newly synthesized. H₂QFP has been revealed to have the two inner NH protons on the two nonfused pyrroles by X-ray diffraction analysis and ¹H NMR spectroscopy. The first protonation at one of the two imino-nitrogen atoms of the fused pyrroles smoothly proceeds with trifluoroacetic acid (TFA) in CH₂Cl₂ and the equilibrium constant (<i>K</i>₁) of the protonation has been determined to be (1.3 ± 0.1) × 10⁵ M^–1. In contrast, the second protonation at the other imino-nitrogen atom is hard to occur unless a large excess amount of TFA is used, as reflected on a much smaller equilibrium constant, <i>K</i>₂ = 7.3 ± 0.3 M^–1. The stepwise protonation is ascribed to the structural rigidity caused by the ring fusion and the resultant steric repulsion among inner NH atoms of the diprotonated form. Electrochemical studies have revealed that protonation at the pyrrole nitrogen atoms caused positive shifts of the reduction potentials of the QFP derivatives. In addition, the ESR spectrum of the electrochemically one-electron-reduced monoprotonated QFP derivative showed well-resolved hyperfine splitting to represent its unsymmetrical electronic structure due to the monoprotonation

Heteronuclear Ru^IIAg^I Complexes Having a Pyrroloquinolinequinone Derivative as a Bridging Ligand

Herein, we report the synthesis of a novel heterohexanuclear complex (<b>1</b>) of a heteroaromatic cofactor, pyrroloquinolinequinone (PQQ). The crystal structure of <b>1</b> was determined to reveal that two PQQ-bridged Ru^IIAg^I units were linked by two [Ag^I(OTf)₂]⁻ units (OTf = CF₃SO₃^–). A solvent-bound Ru^IIAg^I heterodinuclear complex (<b>2</b>) was formed from <b>1</b> in a coordinating solvent such as acetone to show an intense metal-to-ligand charge-transfer band at 709 nm

Visible-Light-Driven Photocatalytic CO₂ Reduction by a Ni(II) Complex Bearing a Bioinspired Tetradentate Ligand for Selective CO Production

A Ni­(II) complex bearing an S₂N₂-type tetradentate ligand inspired by the active site of carbon monoxide dehydrogenase was found to selectively catalyze CO₂ reduction to produce CO in a photocatalytic system using [Ru­(bpy)₃]²⁺ (bpy = 2,2′-bipyridine) as a photosensitizer and 1,3-dimethyl-2-phenyl-2,3-dihydro-1<i>H</i>-benzo­[<i>d</i>]­imidazole (BIH) as an electron donor. The Ni­(II) complex shows a high turnover number over 700 with high CO selectivity of >99% and quantum yield of 1.42% in the photocatalytic system

Mechanistic Insights into C–H Oxidations by Ruthenium(III)-Pterin Complexes: Impact of Basicity of the Pterin Ligand and Electron Acceptability of the Metal Center on the Transition States

A ruthenium­(II) complex, [Ru­(dmdmp)­Cl­(MeBPA)] (<b>2</b>) (Hdmdmp = <i>N</i>,<i>N</i>-dimethyl-6,7-dimethylpterin, MeBPA = <i>N</i>-methyl-<i>N</i>,<i>N</i>-bis­(pyridylmethyl)­amine), having a pterin derivative as a proton-accepting ligand, was synthesized and characterized. Complex <b>2</b> shows higher basicity than that of a previously reported Ru^II-pterin complex, [Ru­(dmdmp) (TPA)]⁺ (<b>1</b>) (TPA = tris­(2-pyridylmethyl)­amine). On the other hand, 1e^–-oxidized species of <b>1</b> (<b>1</b>_OX) exhibits higher electron-acceptability than that of 1e^–-oxidized <b>2</b> (<b>2</b>_OX). Bond dissociation enthalpies (BDE) of the two Ru^II complexes having Hdmdmp as a ligand in proton-coupled electron transfer (PCET) to generate <b>1</b>_OX and <b>2</b>_OX were calculated to be 85 kcal mol^–1 for <b>1</b>_OX and 78 kcal mol^–1 for <b>2</b>_OX. The BDE values are large enough to perform H atom transfer from C–H bonds of organic molecules to the 1e^–-oxidized complexes through PCET. The second-order rate constants (<i>k</i>) of PCET oxidation reactions were determined for <b>1</b>_OX and <b>2</b>_OX. The logarithms of normalized <i>k</i> values were proportional to the BDE values of C–H bonds of the substrates with slopes of −0.27 for <b>1</b>_OX and −0.44 for <b>2</b>_OX. The difference between <b>1</b>_OX and <b>2</b>_OX in the slopes suggests that the transition states in PCET oxidations of substrates by the two complexes bear different polarization, as reflection of difference in the electron acceptability and basicity of <b>1</b>_OX and <b>2</b>_OX. The more basic <b>2</b>_OX attracts a proton from a C–H bond via a more polarized transition state than that of <b>1</b>_OX; on the contrary, the more electron-deficient <b>1</b>_OX forms less polarized transition states in PCET oxidation reactions of C–H bonds

Redox-Noninnocent Behavior of Tris(2-pyridylmethyl)amine Bound to a Lewis Acidic Rh(III) Ion Induced by C–H Deprotonation

Rh­(III) complexes having tris­(2-pyridylmethyl)­amine (TPA) and its derivative as tetradentate ligands showed reversible deprotonation at a methylene moiety of the TPA ligands upon addition of a strong base as confirmed by spectroscopic measurements and X-ray crystallography. Deprotonation selectively occurred at the axial methylene moiety rather than equatorial counterparts because of the thermodynamic stability of corresponding deprotonated complexes. One-electron oxidation of the deprotonated Rh­(III)–TPA complex afforded a unique TPA radical bound to the Rh­(III) center by a ligand-centered oxidation. This is the first example to demonstrate emergence of the redox-noninnocent character of the TPA ligand

Tetranuclear Ruthenium(II) Complex with a Dinucleating Ligand Forming Multi-Mixed-Valence States

A square-shaped tetranuclear ruthenium­(II) complex, [Ru^II₄Cl₅(bpmpm)₂]³⁺ [<b>1</b>; bpmpm = 4,6-bis­[[<i>N</i>,<i>N</i>-bis­(2′-pyridylmethyl)­amino]­methyl]­pyrimidine], exhibited four reversible and stepwise one-electron-oxidation processes: chemical oxidation of <b>1</b> formed three different mixed-valence states, in one of which the charge is partially delocalized on the two Ru centers, to be evidenced by observation of an intervalence charge-transfer absorption band, categorized into the Robin–Day class II