The mesomorphie properties of title complexes are investigated by means of DSC and polarizing microscopy. The mesophase temperature ranges of complexes are wider than that of corresponding organic ligands. The bridgin...The mesomorphie properties of title complexes are investigated by means of DSC and polarizing microscopy. The mesophase temperature ranges of complexes are wider than that of corresponding organic ligands. The bridging groups of the complexes have profoand effects on the mesomorphic behavior, When the bridging groups are opticallhy active. the compleve show chiral smectic展开更多
Quantum density functional theory （DFT） results are reported for the building block [LaL^1（NO3）] of La complex [LaL^1（NO3）]NO3·5H2O （L^1 = （CH3）2CHCH2CH（NCHC4H3O）COO^-）. The structure was optimized an...Quantum density functional theory （DFT） results are reported for the building block [LaL^1（NO3）] of La complex [LaL^1（NO3）]NO3·5H2O （L^1 = （CH3）2CHCH2CH（NCHC4H3O）COO^-）. The structure was optimized and the calculation results show that the lanthanum ion is coordinated by one nitrogen atom and three oxygen atoms of L^1 and two oxygen atoms of nitrate ion. The bond length of La-N is 0.2637 nm and the average length of La-O is 0.2526 nm, which are consistent with the literatures. In addition, the stabilities, electronic structural characteristics and IR spectra of the complex have been analyzed, which describe the coordination of lanthanum ion with other atoms in detail.展开更多
Using density functional theory calculation based on the B3LYP method,we have studied the interactions of H2 molecules with alkali-metal organic complexes C6H6-nLin（n = 1～3）,C6H5Na and C6H5K.A significant part of t...Using density functional theory calculation based on the B3LYP method,we have studied the interactions of H2 molecules with alkali-metal organic complexes C6H6-nLin（n = 1～3）,C6H5Na and C6H5K.A significant part of the electronic charge of M s orbital（Li 2s,Na 3s,K 4s） is donated to phenyl and is accommodated by H2 bonding orbital.For all the complexes considered,each bonded alkali-metal atom can adsorb up to five H2 in molecular form with the mean binding energy of 0.59,0.55 and 0.56 eV/H2 molecule for C6H6-nLin（n = 1～3）,C6H5Na and C6H5K,respectively.The kinetic stability of these hydrogen-covered organometallic complexes is discussed in terms of energy gap between HOMO and LUMO.It is remarkable that these alkali-metal organic complexes can store up to 23.80 wt% hydrogen.Therefore,the complexes studied may be used as hydrogen storage materials.展开更多
Some new complexes RE2(EDODA)3·3H2O, where RE = La, Nd, Eu, Gd, Tb, Er, Yb, Lu and Y, EDODA = ethylene-1,2-dioxydiacetate, have been synthesized and characterized by elemental analysis, molar conductance, IR...Some new complexes RE2(EDODA)3·3H2O, where RE = La, Nd, Eu, Gd, Tb, Er, Yb, Lu and Y, EDODA = ethylene-1,2-dioxydiacetate, have been synthesized and characterized by elemental analysis, molar conductance, IR spectra, UV spectra, TG-DTA, 1H NMR and 13C NMR spectra. Various analyses indicate that the complexes are of nine-coordinated binuclear structure. The carboxylates are bidentate ligands and the ether oxygen atoms also coordinate to rare earth ions. Three water molecules are crystalline water. In addition, the influence of concentration on the chemical shift has been studied through the 1H NMR spectra of the complex Lu2(EDODA)3·3H2O in different concentrations.展开更多
The metathesis reaction between pyrrolidinyl-ethylene fluorenyl lithium salts with in situ prepared cationic rare-earth metal dialkyl species[Ln(CH_(2)SiMe_(3))_(2)(THF)_(x)][BPh_(4)]afford efficiently the correspondi...The metathesis reaction between pyrrolidinyl-ethylene fluorenyl lithium salts with in situ prepared cationic rare-earth metal dialkyl species[Ln(CH_(2)SiMe_(3))_(2)(THF)_(x)][BPh_(4)]afford efficiently the corresponding constrained-geometry complexes L^(1)Ln(CH_(2)SiMe_(3))_(2)(L^(1)=FluCH_(2)CH_(2)NC_(4)H_(8),Ln=Y(1a),Lu(1b),Sc(1c))and L^(2)Ln(CH_(2)SiMe_(3))_(2)(L^(2)=(2,7-di-tert-butyl)FluCH_(2)CH_(2)NC_(4)H_(8),Ln=Y(2a),Lu(2b),Sc(2c))in good yields.All these complexes were characterized by NMR spectroscopy,and the solid-state molecular structure of yttrium complex 1a was defined with single-crystal X-ray diffraction analysis.The catalytic performance of these complexes towards 2-vinylpyridine polymerization was investigated,where these complexes alone can efficiently promote the polymerization of 2-vinylpyridine giving isotactic poly(2-vinylpyridine).Upon the activation with[Ph_(3)C][B(C_(6)F_(5))_(4)],the yttrium and lutetium complexes also afford isotactic poly(2-vinylpyridine),while the scandium complexes produce syndiotactic poly(2-vinylpyridine).展开更多
Ligands play a key role in controlling activity of organometallic complexes so that development of new ligands to overcome the challenge is the main topic of modern chemistry.The first example of 1,1-hydride migratory...Ligands play a key role in controlling activity of organometallic complexes so that development of new ligands to overcome the challenge is the main topic of modern chemistry.The first example of 1,1-hydride migratory insertion and intramolecular redox reaction has been realized in this work by applying a new ligand in rare-earth metal chemistry.The novel rare-earth metal complexes L^(Mes)RECH2TMS(THF)(RE=Y(1a),Dy(1b),Er(1c),Yb(1d),L^(Mes)=1-(3-(2,6-iPr_(2)C_(6)H_(3)N=CH)C8H4N)-CH_(2)CH_(2)-3-(2-CH2–4,6-Me_(2)C_(6)H_(2))-(N(CH)_(2)NC),THF=tetrahydrofuran)bearing a ligand with imino,indolyl,NHC(N-heterocyclic carbene)multiple functionalities were synthesized and characterized.Treatment of complexes 1 with silanes(PhSiH3or PhSiH2Me or PhSiD3)selectively produced the unprecedented 1,1-hydride(or deuterated H)migratory insertion of the indolyl moiety of the novel unsymmetrical dinuclear rare-earth metal complexes 2.The complex 2a reacts with Ph_(2)C=O to give the selective C=O double bond insertion to the RE–Co-methylene-Mesbond product 3a which further reacts with another Ph_(2)C=O(or DMAP,4-N,N-dimethylaminopyridine)affording the novelμ-η^(2):η^(3)-dianionic 3-iminoindolyl dinuclear rare-earth metal complex 4a.The latter is formed through an unusual intramolecular redox reaction(through electron migration from the 2-carbanion of the indolyl ring to the imino motif)resulting in the re-aromatization of the indolyl ring.展开更多
The reaction of half-sandwich complex (Cptt Rh)2Cl2(m-Cl)2 (1) (Cptt = h5-tBu2C5H3) with 1 equiv. of AgSO3CF3 in CH2Cl2 affords tri-m-chloro dirhodium (2) cation compound, with 2 equiv. of AgSO3CF3 providing di- m-chl...The reaction of half-sandwich complex (Cptt Rh)2Cl2(m-Cl)2 (1) (Cptt = h5-tBu2C5H3) with 1 equiv. of AgSO3CF3 in CH2Cl2 affords tri-m-chloro dirhodium (2) cation compound, with 2 equiv. of AgSO3CF3 providing di- m-chloro complex 3. The reaction of 3 with pyrazine gives a novel tetra-nuclear 14-member organometallic macrocyclic complex 4. FT-IR, 1H-NMR, and EA were used to character-ize these complexes. The structures of complexes 2 and 4 are confirmed by X-ray analysis. In complex 2, the two Cptt ring and tri-chloro atoms faces are approximately parallel to each other. In complex 4, the complex cation has a rectangular cavity with the dimension of 0.3748 nm?.7027 nm, and the two-pyrazine rings are parallel to each other with a distance of 0.3510 nm.展开更多
文摘The mesomorphie properties of title complexes are investigated by means of DSC and polarizing microscopy. The mesophase temperature ranges of complexes are wider than that of corresponding organic ligands. The bridging groups of the complexes have profoand effects on the mesomorphic behavior, When the bridging groups are opticallhy active. the compleve show chiral smectic
基金This work was supported by the National Natural Science Foundation of China (20203011)
文摘Quantum density functional theory （DFT） results are reported for the building block [LaL^1（NO3）] of La complex [LaL^1（NO3）]NO3·5H2O （L^1 = （CH3）2CHCH2CH（NCHC4H3O）COO^-）. The structure was optimized and the calculation results show that the lanthanum ion is coordinated by one nitrogen atom and three oxygen atoms of L^1 and two oxygen atoms of nitrate ion. The bond length of La-N is 0.2637 nm and the average length of La-O is 0.2526 nm, which are consistent with the literatures. In addition, the stabilities, electronic structural characteristics and IR spectra of the complex have been analyzed, which describe the coordination of lanthanum ion with other atoms in detail.
基金Supported by the National Natural Science Foundation of China (No.10976019)
文摘Using density functional theory calculation based on the B3LYP method,we have studied the interactions of H2 molecules with alkali-metal organic complexes C6H6-nLin（n = 1～3）,C6H5Na and C6H5K.A significant part of the electronic charge of M s orbital（Li 2s,Na 3s,K 4s） is donated to phenyl and is accommodated by H2 bonding orbital.For all the complexes considered,each bonded alkali-metal atom can adsorb up to five H2 in molecular form with the mean binding energy of 0.59,0.55 and 0.56 eV/H2 molecule for C6H6-nLin（n = 1～3）,C6H5Na and C6H5K,respectively.The kinetic stability of these hydrogen-covered organometallic complexes is discussed in terms of energy gap between HOMO and LUMO.It is remarkable that these alkali-metal organic complexes can store up to 23.80 wt% hydrogen.Therefore,the complexes studied may be used as hydrogen storage materials.
文摘Some new complexes RE2(EDODA)3·3H2O, where RE = La, Nd, Eu, Gd, Tb, Er, Yb, Lu and Y, EDODA = ethylene-1,2-dioxydiacetate, have been synthesized and characterized by elemental analysis, molar conductance, IR spectra, UV spectra, TG-DTA, 1H NMR and 13C NMR spectra. Various analyses indicate that the complexes are of nine-coordinated binuclear structure. The carboxylates are bidentate ligands and the ether oxygen atoms also coordinate to rare earth ions. Three water molecules are crystalline water. In addition, the influence of concentration on the chemical shift has been studied through the 1H NMR spectra of the complex Lu2(EDODA)3·3H2O in different concentrations.
基金Project supported by National Natural Science Foundation of China(21805143)Natural Science Foundation of Zhejiang Province(LY21B040002)+1 种基金Natural Science Foundation of Ningbo(202003N4110)the K.C.Wong Magna Fund from Ningbo University。
文摘The metathesis reaction between pyrrolidinyl-ethylene fluorenyl lithium salts with in situ prepared cationic rare-earth metal dialkyl species[Ln(CH_(2)SiMe_(3))_(2)(THF)_(x)][BPh_(4)]afford efficiently the corresponding constrained-geometry complexes L^(1)Ln(CH_(2)SiMe_(3))_(2)(L^(1)=FluCH_(2)CH_(2)NC_(4)H_(8),Ln=Y(1a),Lu(1b),Sc(1c))and L^(2)Ln(CH_(2)SiMe_(3))_(2)(L^(2)=(2,7-di-tert-butyl)FluCH_(2)CH_(2)NC_(4)H_(8),Ln=Y(2a),Lu(2b),Sc(2c))in good yields.All these complexes were characterized by NMR spectroscopy,and the solid-state molecular structure of yttrium complex 1a was defined with single-crystal X-ray diffraction analysis.The catalytic performance of these complexes towards 2-vinylpyridine polymerization was investigated,where these complexes alone can efficiently promote the polymerization of 2-vinylpyridine giving isotactic poly(2-vinylpyridine).Upon the activation with[Ph_(3)C][B(C_(6)F_(5))_(4)],the yttrium and lutetium complexes also afford isotactic poly(2-vinylpyridine),while the scandium complexes produce syndiotactic poly(2-vinylpyridine).
基金supported by the National Natural Science Foundation of China(22031001,21871004,21861162009,22171004)the grants from the Education Department of Anhui Province(GXXT-2021-052)。
文摘Ligands play a key role in controlling activity of organometallic complexes so that development of new ligands to overcome the challenge is the main topic of modern chemistry.The first example of 1,1-hydride migratory insertion and intramolecular redox reaction has been realized in this work by applying a new ligand in rare-earth metal chemistry.The novel rare-earth metal complexes L^(Mes)RECH2TMS(THF)(RE=Y(1a),Dy(1b),Er(1c),Yb(1d),L^(Mes)=1-(3-(2,6-iPr_(2)C_(6)H_(3)N=CH)C8H4N)-CH_(2)CH_(2)-3-(2-CH2–4,6-Me_(2)C_(6)H_(2))-(N(CH)_(2)NC),THF=tetrahydrofuran)bearing a ligand with imino,indolyl,NHC(N-heterocyclic carbene)multiple functionalities were synthesized and characterized.Treatment of complexes 1 with silanes(PhSiH3or PhSiH2Me or PhSiD3)selectively produced the unprecedented 1,1-hydride(or deuterated H)migratory insertion of the indolyl moiety of the novel unsymmetrical dinuclear rare-earth metal complexes 2.The complex 2a reacts with Ph_(2)C=O to give the selective C=O double bond insertion to the RE–Co-methylene-Mesbond product 3a which further reacts with another Ph_(2)C=O(or DMAP,4-N,N-dimethylaminopyridine)affording the novelμ-η^(2):η^(3)-dianionic 3-iminoindolyl dinuclear rare-earth metal complex 4a.The latter is formed through an unusual intramolecular redox reaction(through electron migration from the 2-carbanion of the indolyl ring to the imino motif)resulting in the re-aromatization of the indolyl ring.
文摘The reaction of half-sandwich complex (Cptt Rh)2Cl2(m-Cl)2 (1) (Cptt = h5-tBu2C5H3) with 1 equiv. of AgSO3CF3 in CH2Cl2 affords tri-m-chloro dirhodium (2) cation compound, with 2 equiv. of AgSO3CF3 providing di- m-chloro complex 3. The reaction of 3 with pyrazine gives a novel tetra-nuclear 14-member organometallic macrocyclic complex 4. FT-IR, 1H-NMR, and EA were used to character-ize these complexes. The structures of complexes 2 and 4 are confirmed by X-ray analysis. In complex 2, the two Cptt ring and tri-chloro atoms faces are approximately parallel to each other. In complex 4, the complex cation has a rectangular cavity with the dimension of 0.3748 nm?.7027 nm, and the two-pyrazine rings are parallel to each other with a distance of 0.3510 nm.
