Comprehensive Summary Isochromanone is the core structure of many bioactive compounds.Direct oxidation of isochromans is one of leading methods for the construction of isochromanones,while most established processes remain suffering from the use of environmentally unfriendly metal oxidants,harsh reaction conditions,and the difficulty in catalyst recycling and product separation.Herein,we report a convenient,cost-effective,and green method for the synthesis of high-value added isochromanones via isochroman oxidations with O_(2) by a novel heterogeneous vanadium cluster catalyst(Cat.1)under mild conditions.This reaction protocol demonstrates high catalytic activity with good catalyst recyclability and reusability for a wide scope of substrates.
Better understanding the determining factors of dynamic magnetic relaxation in polynuclear lanthanide based single-molecule magnets(SMMs)remains a challenge due to the complexity of such architectures involving interactions between the magnetic centers.To address this issue,two structurally related heterometal Dy^(III)_(2)Zn^(II)_(2) SMMs,[Zn_(2)Dy_(2)(L)_(4)(Ac)_(2)(DMF)(CH_(3)OH)]·CH_(3)OH·2H_(2)O(1)and[Zn_(2)Dy_(2)(L)_(4)(Ac)_(2)(DMF)_(2)]·4CH_(3)CN(2)(H_(2)L=(E)-2-((2-hydroxy-3-methoxybenzylidene)amino)-4-methyphenol,DMF=N,N-dimethylformamide),are introduced and investigated.Through modifying the auxiliary ligands on one Dy^(III) site while retaining that on the other Dy^(III),the intramolecular magnetic interactions and relaxation dynamics in these two heterometallic-Dy^(III)_(2)Zn^(II)_(2) SMMs can be tuned,demonstrating a dramatic change in the magnet relaxation behavior with energy barrier changing from a negligible value for 1 to 305 K for 2.Ab initio calculations reveal that changing the coordination geometries on the Dy^(III) sites can significantly affect the magnetic interactions as well as single-ion anisotropy.
Gao-Peng LiHong-Fang XieShi-Rui YangYun-Long FuYi-Quan ZhangYao-Yu Wang
By solvothermal reaction of Cd(II)with organic ligand N,N’-bis(3,5-dicarboxylphenyl)-thiophene-2,5-dicarboxamide(H_(4)L),a water-stable complex[Cd_(4)(H_(2)L)_(4)(H_(2)O)_(10)]·2CH_(3)OH·8H_(2)O·4DMF(1,C_(102)H_(120)Cd_(4)N_(12)O_(64)S_(4))has been successfully synthetized(DMF=N,N-dimethylformamide).1 crystallizes in the triclinic space group of P1 with a=11.815(7),b=16.209(9),c=16.742(9)Å,α=82.224(13)°,β=76.741(13)°,γ=70.313(12)°,V=2932(3)Å^(3),M_(r)=3115.93,Z=1,F(000)=1584,D_(c)=1.765 Mg/cm^(3),μ=0.901 mm^(-1),GOOF=1.101,the final R=0.0391 and wR=0.1297 for 9007 observed reflections(I>2σ(I)).1 is a tetranuclear Cd(II)bicyclic complex with strong ligand-based blue emission and can stably exist in aqueous solutions over the pH range of 2~11.1exhibits high sensitivity,selectivity and anti-interference capability for picric acid(PA)detection in aqueous solution by luminescent quenching.The value of quenching constant(K_(sv))is 3.2×10^(4)M^(-1) within the PAconcentration range of 0~40μM and the detection limit is 6.89×10^(-7) M.Lastly,we went into depth on possible mechanism of the luminescent quenching.
WANG MingWANG Xiao-MeiCHEN Ming-YuLIU ChengDING GeZHOU Xin-Hui
A new tetranuclear cuprous halide complex,(CuBr)_(4)(PN)_(2)(PN=2-(diphenylphosphaneyl)-6-methoxypyridine),was synthesized and fully characterized.In solid state,this complex exhibits efficient blue emission with a photoluminescence quantum yield of 43.3%and a decay time of 19μs at room temperature.The theoretical calculations,combined with the temperature dependence of spectroscopic properties and emission decay behaviors,indicate that the emission in the solid state originates from the ^(1,3)(MLCT+XLCT)excited states,which are in thermal equilibrium with a small energy gap of about 0.1 eV.