Synthesen und Kristallstrukturen von Cu‐ und Ag‐Komplexen mit [Ta6S17]4—‐Ionen als Liganden

Syntheses and Crystal Structures of Cu and Ag Complexes with [Ta₆S₁₇]^4— Ions as Ligands In the presence of phosphines saturated solutions of the thiotantalates (NEt₄)₄[(Ta₆S₁₇)] · 3MeCN react with copper or silver salts to give new heterobimetallic Ta—M—S clusters (M = Ag, Cu). These clusters contain the intact cluster core of the [Ta₆S₁₇]^4— anion. Compounds [Cu(PMe₃)₄]₃[(Ta₆S₁₇)Cu(PMe₃)] · 2MeCN ( 1 ), (NEt₄)[(Ta₆S₁₇)Ag₃(PMe₂ⁱPr)₆] · 5MeCN ( 2 ), [(Ta₆S₁₇)Cu₄ (PMe₂ⁱPr)₈] · MeCN ( 3 ), [(Ta₆S₁₇)Cu₅Cl(PMe₂ⁱPr)₉] · MeCN ( 4 ) and [Ta₂Cu₂S₄Cl₂(PMe₂ⁱPr)₆] · 2MeCN ( 5 ) are presented herein. The structures of these compounds were elucidated by single crystal X‐ray structural analyses.     

Direct Cu‐Catalyzed Allylic Acetoxylation of Δ5‐Steroids at 7‐Position

The efficiency and selectivity of Cu‐catalyzed allylic acetoxylation of alkene in different solvent systems is improved by the presence of different metallic salts in the reaction medium. The methodology is particularly well employed for the direct allylic acetoxylation of Δ⁵‐steroids at 7‐position, for which the resulting acetoxylated product obtained was exclusively α‐isomer. Excellent yield was achieved (up to 90%) under optimized conditions, while significantly reducing the costs and environmental hazards and increasing the yield as compared to the other previously reported methods.     

A Photoactivated Cu–CeO2 Catalyst with Cu‐[O]‐Ce Active Species Designed through MOF Crystal Engineering

Fully utilizing solar energy for catalysis requires the integration of conversion mechanisms and therefore delicate design of catalyst structures and active species. Herein, a MOF crystal engineering method was developed to controllably synthesize a copper–ceria catalyst with well‐dispersed photoactive Cu‐[O]‐Ce species. Using the preferential oxidation of CO as a model reaction, the catalyst showed remarkably efficient and stable photoactivated catalysis, which found practical application in feed gas treatment for fuel cell gas supply. The coexistence of photochemistry and thermochemistry effects contributes to the high efficiency. Our results demonstrate a catalyst design approach with atomic or molecular precision and a combinatorial photoactivation strategy for solar energy conversion.     

Synthesis of 6‐Aminoindolo[2,1‐a]isoquinoline‐5‐carbonitriles by the Cu‐Catalyzed Reaction of 2‐(2‐Bromophenyl)‐1H‐indoles with CH2(CN)2

A series of 6‐aminoindolo[2,1‐a]isoquinoline‐5‐carbonitriles 4 have been prepared by treatment of 2‐(2‐bromophenyl)‐1H‐indoles 1 , available from 1‐(2‐bromophenyl)ethanones or 1‐(2‐bromophenyl)propan‐1‐ones by using Fischer indole synthesis, with propanedinitrile in the presence of a catalytic amount of CuBr and an excess of K₂CO₃ in DMSO at 100°.     

Synthesen und Kristallstrukturen von Cu‐ und Ag‐Komplexen mit Dithiophosphinat‐ und Trithiophosphonat‐Liganden

Syntheses and Crystal Structures of Copper and Silver Complexes containing Dithiophosphinato and Trithiophosphonato Ligands The reactions of Cu^I and Ag^I salts with diphenyldithiophosphinic acid trimethylsilylester in the presence of tertiary phosphines yield the complexes [Cu(μ‐S)SPPh₂(PR₃)]₂ (R = Me 1a , ⁱPr 1b ), [Ag(μ‐S)SPPh₂(PⁿPr₃)]₂ ( 2 ), [Ag(S₂PPh₂)(PEt₃)]₂ ( 3 ), and [Cu₈(μ₈‐S)(S₂PPh₂)₆] ( 4 ). The cage complex [(PhPS₃)₂Cu₄(PMe₃)₅] ( 5 ) is obtained by the reaction of phenyltrithiophosphonic acid trimethylester. All compounds were structurally characterised by X‐ray crystallography.     

Reaktion von Kupferarylen mit Imidazol‐2‐ylidenen oder Triphenylphosphan ‐ Bildung von 1:1‐Addukten mit zweifach koordinierten Kupferatomen

Reaction of Copper Aryls with Imidazol‐2‐ylidenes or Triphenylphosphane — Formation of 1:1‐Adducts with Two‐coordinate Copper Atoms The reaction of the copper aryls CuDmp (Dmp = 2, 6‐Mes₂C₆H₃; Mes = 2, 4, 6‐Me₃C₆H₂) and CuMes with the σ‐donors triphenylphosphane and 1, 3‐Di‐iso‐propyl‐4, 5‐dimethylimidazol2‐ylidene affords the adducts DmpCu←PPh₃ ( 1 ), DmpCu←C{N(iPr)CMe}₂ ( 2 ) and MesCu←C{N(iPr)CMe}₂ ( 3 ) in yields between 65 and 84 %. The colorless compounds were characterized by ¹H and ¹³C‐NMR‐spectroscopy, single crystal structure analysis as well as by ³¹P NMR‐spectroscopy ( 1 ), elemental analysis ( 2 ), mass spectrometry ( 2 , 3 ), IR‐spectroscopy ( 2 ) and melting point ( 2 , 3 ). In the solid state structures the two‐coordinate copper atoms possess relatively short Cu—P and Cu—C(carbene) distances of 218, 91(11) ( 1 ), 190, 2(3) ( 2 ) and 191, 1(4) pm ( 3 ).     

Ultrasound‐assisted green synthesis of Cu‐based complexes of β‐cyclodextrin and their SOD‐like activity

A novel Cu–Zn β‐cyclodextrin (CuZn/β‐CD) model compound was synthesized under ultrasound irradiation to mimic the functionality of copper zinc superoxide dismutase (CuZnSOD). For comparison, Cu/β‐CD and Zn/β‐CD complexes were also synthesized via a sonochemical approach. The obtained complexes were characterized by FTIR, ICP‐OES, UV–vis and Scanning electron microscopy‐Energy dispersive X‐ray (SEM‐EDX) techniques. The SOD activity of the complexes was evaluated by a pyrogallol autoxidation method. These enzyme‐mimetic materials scavenge ambient free radicals, with the potential to provide significant antioxidant protection (scavenging ability > 70%).     

The Formation of CuCl2‐Specific Metallogels of Pyridyloxalamide Derivatives in Alcohols

Isomeric pyridyloxalamide derivatives 1 – 3 , which differed in the position of the nitrogen atom on the pyridyl ring, showed remarkably different gel‐forming aptitudes in the presence of CuCl₂ salt in alcohols. Whilst derivatives 1 and 3 formed a soluble complex and a solid precipitate, respectively, ligand 2 generated a remarkably metal‐ and anion‐specific metallogel.