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Invited for this month’s cover is the group of Dr. Paola Manini from the University of Naples Federico II. The cover picture shows the concept underlying the design of a melanin-inspired electroluminescent material for OLED devices. This article is part of a well-structured research project aimed at imitating Nature’s most enigmatic and fascinating functional pigments for the design and synthesis of innovative biomaterials for organic electronics applications. Read the full text of the article at 10.1002/cplu.201402444.

“ …to translate the unique physical–chemical properties of man's own natural pigments into the emerging fields of organic (bio)electronics and nanomedicine… ” Read more about the story behind the cover in the Cover Profile and about the research itself on page 919.

Three isoskeletal tetranuclear coordination clusters with general formula [M^II₂Dy^III₂L₄(EtOH)₆](ClO₄)₂⋅2 EtOH, (M=Co, 1; M=Ni, 2) and [Ni^II₂Dy^III₂L₄Cl₂(CH₃CN)₂]⋅2 CH₃CN (3), have been synthesized and characterized. These air-stable compounds, and in particular 3, display efficient homogeneous catalytic behavior in the room-temperature synthesis of trans-4,5-diaminocyclopent-2-enones from 2-furaldehyde and primary or secondary amines under a non-inert atmosphere.

Custom-designed catalysts: Three air-stable compounds formulated as [M^II₂Dy^III₂L₄(EtOH)₆](ClO₄)₂ 2 EtOH, [M=Co (1) and Ni (2)] and [Ni^II₂Dy^III₂L₄Cl₂(CH₃CN)₂] 2 CH₃CN (3), have been characterized. Compound 3, in particular, displays for the first time efficient homogeneous catalytic behavior in the room-temperature synthesis of trans-4,5-diaminocyclopent-2-enones from 2-furaldehyde and primary or secondary amines under a non-inert atmosphere.

A novel iron-containing Schiff base and ionic liquid based bifunctional periodic mesoporous organosilica (Fe@SBIL-BPMO) was prepared, characterized, and its catalytic application was developed. The SBIL-BPMO was first prepared by the grafting of 3-aminopropyltrimethoxysilane on an ionic-liquid-based PMO followed by treatment with 2-hydroxybenzaldehyde in toluene at reflux. This material was then reacted with Fe(NO₃)₃⋅9 H₂O to afford the Fe@BPMO-SBIL nanocatalyst. The catalyst was characterized by thermogravimetric analysis, nitrogen sorption experiments, diffuse reflectance FTIR spectroscopy, low-angle powder XRD, and TEM. The Fe@SBIL-BPMO catalyst was successfully applied in the one-pot synthesis of 3,4-dihydropyrimidinone/thione derivatives under solvent-free reactions. The stability, reactivity, and reusability of the catalyst under the reaction conditions have also been investigated.

Hard graft: A novel iron-containing Schiff base and ionic liquid based bifunctional periodic mesoporous organosilica (Fe@SBIL-BPMO) was prepared and characterized, and its catalytic application was investigated in the one-pot three-component Biginelli reaction (see picture). The catalyst illustrated excellent reactivity, recoverability, and reusability under the applied conditions.

Corrosion is a global problem for any metallic structure or material. Herein we show how metals can easily be protected against acid corrosion using hydrophobic polyoxometalate-based ionic liquids (POM-ILs). Copper metal disks were coated with room-temperature POM-ILs composed of transition-metal functionalized Keggin anions [SiW₁₁O₃₉TM(H₂O)]ⁿ⁻ (TM=Cu^II, Fe^III) and quaternary alkylammonium cations (C_nH_2 n+1)₄N⁺ (n=7–8). The corrosion resistance against acetic acid vapors and simulated “acid rain” was significantly improved compared with commercial ionic liquids or solid polyoxometalate coatings. Mechanical damage to the POM-IL coating is self-repaired in less than one minute with full retention of the acid protection properties. The coating can easily be removed and recovered by rinsing with organic solvents.

This corrosion: Hydrophobic polyoxometalate-based ionic liquids (POM-ILs) are used as temporary acid-resistant coatings for copper metal. Complete protection against acid vapors and liquid acids is observed and the POM-IL coating can withstand mechanical damage by a self-repairing mechanism. The compounds are easily removed and recovered for subsequent usage.