In situ metal/ligand reactions have been investigated for decades and turn out to be efficient for discovery of new organic reactions and coordination compounds with novel topology and functionalities. 4-[(2-Pyridin-2...In situ metal/ligand reactions have been investigated for decades and turn out to be efficient for discovery of new organic reactions and coordination compounds with novel topology and functionalities. 4-[(2-Pyridin-2-yl)-1-(pyridin-2-yl)vinylthio]benzoic acid(L) was in situ generated in solvethermal condition with CuO and CuBr2. A copper coordination polymer[Cu2(L)Br2]n(1) was obtained synchronously and characterized by X-ray single crystal diffraction,elemental analysis and FTIR spectrum. The Cu+ ions were bridged into a tetranuclear cluster by μ3-Br and μ2-Br ions,and the clusters were further linked into 1D ribbon-like chain. The intermolecular in situ elimination is rare but meaningful in the synthesis of organic compounds.展开更多
Zeolite catalysts,such as H-mordenite(H-MOR),are readily deactivated by coke deposition in carbonylation reactions.Pyridine modification of H-MOR can improve its stability but can lead to an undesirable loss in cataly...Zeolite catalysts,such as H-mordenite(H-MOR),are readily deactivated by coke deposition in carbonylation reactions.Pyridine modification of H-MOR can improve its stability but can lead to an undesirable loss in catalytic activity.Herein,we report the intrinsic impact of the pyridine adsorption behavior on H-MOR and the spacial hindrance of the zeolite frameworks on dimethyl ether(DME)carbonylation at a molecular level.We discovered that acid sites at O2 positions,located on common walls of eight-membered ring(8-MR)side pockets and 12-MR channels,were active in DME carbonylation,but were unfortunately poisoned during pyridine modification.Density functional theory calculations revealed that the pyridine-poisoned acid sites at the O2 positions could be easily regenerated due to the spacial hindrance of the zeolite frameworks.Accordingly,they can be facilely regenerated by proper thermal treatment,which induces 60%promotion in the catalytic activity along with a high stability.Our findings demonstrate the determining role of O2 positions in H-MOR for DME carbonylation and provide a new avenue for the rational design of other efficient zeolite-relevant catalytic systems.展开更多
C_(10)H_8N_2O_2S_2, Mr=252. 32,monoclinic,P2_(1/c),a=7.165(5).b=7.659(3),c=19.543(8)A,β=96. 76(5)°,V=1065.0(9) A,Z=4,D_c=1. 57 g/cm￣3.The structure was solved by direct methods and refined to final R(R_w)=0.051...C_(10)H_8N_2O_2S_2, Mr=252. 32,monoclinic,P2_(1/c),a=7.165(5).b=7.659(3),c=19.543(8)A,β=96. 76(5)°,V=1065.0(9) A,Z=4,D_c=1. 57 g/cm￣3.The structure was solved by direct methods and refined to final R(R_w)=0.051(0.057) for 1446 observed reflections with I≥3σ(Ⅰ).The sulfur-sulfur bond length is found to be 2. 019(2) A with a dihedral angle CSSC of 93.29°.展开更多
文摘In situ metal/ligand reactions have been investigated for decades and turn out to be efficient for discovery of new organic reactions and coordination compounds with novel topology and functionalities. 4-[(2-Pyridin-2-yl)-1-(pyridin-2-yl)vinylthio]benzoic acid(L) was in situ generated in solvethermal condition with CuO and CuBr2. A copper coordination polymer[Cu2(L)Br2]n(1) was obtained synchronously and characterized by X-ray single crystal diffraction,elemental analysis and FTIR spectrum. The Cu+ ions were bridged into a tetranuclear cluster by μ3-Br and μ2-Br ions,and the clusters were further linked into 1D ribbon-like chain. The intermolecular in situ elimination is rare but meaningful in the synthesis of organic compounds.
基金supported by the National Natural Science Foundation of China(21476159,21676182)~~
文摘Zeolite catalysts,such as H-mordenite(H-MOR),are readily deactivated by coke deposition in carbonylation reactions.Pyridine modification of H-MOR can improve its stability but can lead to an undesirable loss in catalytic activity.Herein,we report the intrinsic impact of the pyridine adsorption behavior on H-MOR and the spacial hindrance of the zeolite frameworks on dimethyl ether(DME)carbonylation at a molecular level.We discovered that acid sites at O2 positions,located on common walls of eight-membered ring(8-MR)side pockets and 12-MR channels,were active in DME carbonylation,but were unfortunately poisoned during pyridine modification.Density functional theory calculations revealed that the pyridine-poisoned acid sites at the O2 positions could be easily regenerated due to the spacial hindrance of the zeolite frameworks.Accordingly,they can be facilely regenerated by proper thermal treatment,which induces 60%promotion in the catalytic activity along with a high stability.Our findings demonstrate the determining role of O2 positions in H-MOR for DME carbonylation and provide a new avenue for the rational design of other efficient zeolite-relevant catalytic systems.
文摘C_(10)H_8N_2O_2S_2, Mr=252. 32,monoclinic,P2_(1/c),a=7.165(5).b=7.659(3),c=19.543(8)A,β=96. 76(5)°,V=1065.0(9) A,Z=4,D_c=1. 57 g/cm￣3.The structure was solved by direct methods and refined to final R(R_w)=0.051(0.057) for 1446 observed reflections with I≥3σ(Ⅰ).The sulfur-sulfur bond length is found to be 2. 019(2) A with a dihedral angle CSSC of 93.29°.
