Herein,we describe the synthesis and characterization of four complexes containing half-sandwich iridium metal-corner which were obtained through the interaction between known complexes Cp*MCl(o-C_(2)B_(10)H_(11)CS_(2...Herein,we describe the synthesis and characterization of four complexes containing half-sandwich iridium metal-corner which were obtained through the interaction between known complexes Cp*MCl(o-C_(2)B_(10)H_(11)CS_(2))(M=Ir/Rh,Complex 1a and 1b)and corresponding reagents.An incomplete cubane-like complex[Cp*Ir(o-C_(2)B_(10)H_(11)CHS_(2))]_(2)(Complex 2)has been prepared through the reaction between 1a and LiBH4 or NaBH4.Co-thermolysis between 1a and BH_(3)·THF in toluene produces a trimer metallacycle complex[Cp*Ir(o-C_(2)B_(10)H_(10)CS_(2))]_(3)(Complex 3),while its rhodium analogue[Cp*Rh(o-C_(2)B_(10)H_(10)CS_(2))]_(3)(Complex 4)can be prepared through BiPh_(3)-assisted dechlorination reaction of 1b.Furthermore,the oxidative addition reaction of 1a towards SnCl_(2)generates a mononuclear complex Cp*Ir(SnCl_(3))(o-C_(2)B_(10)H_(11)CS_(2))(Complex 5)with a direct Sn-Ir bond.These complexes have been characterized,including X-Ray single crystal diffraction,NMR spectroscopy and elemental analysis methods.展开更多
The syndiotactic polymerization of styrene（St） and the copolymerization of St with ethylene（E） were carried out by using a series of chiral half-sandwich rare-earth metal dialkyl complexes（Cp^x＊） as the catalys...The syndiotactic polymerization of styrene（St） and the copolymerization of St with ethylene（E） were carried out by using a series of chiral half-sandwich rare-earth metal dialkyl complexes（Cp^x＊） as the catalysts. The complexes are Ln（CH2SiMe3）2（THF）（1-4： Ln = Sc（1）, Ln = Lu（2）, Ln = Y（3）, Ln = Dy（4）） bearing chiral cyclopentadienyl ligand containing bulky cylcohexane derivatives in the presence of activator and AliBu3. For the St polymerization, a high activity up to 3.1 × 10^6 g of polymer mol Ln^-1·h^-1 and a high syndiotactic selectivity more than 99% were achieved. The resulting syndiotactic polystyrenes（sPSs） have the molecular weights（Mn） ranging from 3700 g·mol^-1 to 6400 g·mol^-1 and the molecular weight distributions（Mw/Mn） from 1.40 to 5.03. As for the copolymerization of St and E, the activity was up to 2.4 × 10^6 g of copolymer mol Sc^-1·h^-1·MPa^-1, giving random St-E copolymers containing syndiotactic polystyrene sequences with different St content in the range of 15 mol%-58 mol%. These results demonstrate that the bulky cyclopentadienyl ligands of the chiral half-sandwich rare-earth metal complexes effectively inhibit the continued insertion of St monomers into the（co）polymer chain to some extent in comparison with the known half-sandwich rare-earth metal complexes.展开更多
A series of half-sandwich group IV metal complexes with tridentate monoanionic phenoxy-imine arylsulfide [O-NS] ligand [2-Bu^t4-Me-6-（（2-（SC6H5）C6H4N = CHC6H2O）]- （La） and dianionic phenoxy-amine arylsulfide [O...A series of half-sandwich group IV metal complexes with tridentate monoanionic phenoxy-imine arylsulfide [O-NS] ligand [2-Bu^t4-Me-6-（（2-（SC6H5）C6H4N = CHC6H2O）]- （La） and dianionic phenoxy-amine arylsulfide [O-N-S] ligand [2-Bu^t4-Me-6-（（2-（SC6H5）C6H4N-CH2C6H2O）]2- （Lb） have been synthesized and characterized. Lb was obtained easily in high yield by reduction of ligand La with excess LiAlH4 in cool diethyl ether. Half-sandwich Group Ⅳ metal complexes CpTi[O-NS]Cl2 （1a）, CpZr[O-NS]Cl2 （1b）, CpTi[O-N-S]Cl （2a）, CpZr[O-N-S]Cl （2b） and CpZr[O-N-S]Cl （2c） were synthesized by the reactions of La and Lb with CpTiCl3, CpZrCl3 and Cp ZrCl3, and characterized by IR, ^1H-NMR, ^13C-NMR and elemental analysis. In addition, an X-ray structure analysis was performed on ligand Lb. The title Group IV half-sandwich bearing tridentate [O,N,S] ligands show good catalytic activities for ethylene polymerization in the presence of methylaluminoxane （MAO） as co-catalyst up to 1.58 × 10^7 g-PE.mol-Zr-1.h-1. The good catalytic activities can be maintained even at high temperatures such as 100 ℃ exhibiting the excellent thermal stability for these half-sandwich metal pre-catalysts.展开更多
The cycloaddition reactions of methane and ethylene mediated by Ir^(+) have been designed and studied by the techniques of mass spectrometry in conjunction with theoretical calculations.Studies have shown that Ir^(+) ...The cycloaddition reactions of methane and ethylene mediated by Ir^(+) have been designed and studied by the techniques of mass spectrometry in conjunction with theoretical calculations.Studies have shown that Ir^(+) can mediate the cycloaddition reaction of CH4and two C_(2)H_(4) to generate a half-sandwich structure IrHCp^(+)(Cp=η^(5)-C_(5)H_(5))including pentamethylcyclopentadienyl ligand by continuous dehydrogenation reaction with the forming of three C-C bonds and seven C-H bonds.The orbital analysis indicates the mechanism of the cyclization reaction to generation of pentamethylcyclopentadienyl ligand with odd number carbon atom depends on the overlap ofπorbitals in-C_(2)H_(2) and carbene,which is more difficult than the forming of cyclobutadiene ligand and benzene.This study may help to understand the reaction mechanism in the cycloaddition reactions of organic compounds,which will be useful to guide the rational design of new catalysts with tailored selectivity and increased efficiency.展开更多
Treatment of 1,3-di- t -butylcyclopentadiene with rhodium trichloride in EtOH leads to the formation of binuclear half-sandwich complex [Cp t RhCl( μ -Cl)] 2 (1) (Cp t = η 5- t Bu 2C 5H 3) which reacts with trimethy...Treatment of 1,3-di- t -butylcyclopentadiene with rhodium trichloride in EtOH leads to the formation of binuclear half-sandwich complex [Cp t RhCl( μ -Cl)] 2 (1) (Cp t = η 5- t Bu 2C 5H 3) which reacts with trimethylphosphine to give Cp t Rh(PMe 3)Cl 2(2) in high yield. 2 reacts with ammonium polysulfide, (NH 4) 2S x to give cyclooligosulfido half-sandwich complexes Cp t Rh(PMe 3)(S n )( n =4(4a),6(4b)). Desulfurization of 4b by excess PPh 3 results in cyclotetrasulfido product 4a, while 4a takes up sulfur from polysulfide to convert cyclohexasulfido product 4b. The reaction of 2 with Et 4NI gives diiodide complex 3 which is determined by single crystal X-ray crystallographic analysis.展开更多
The reaction of the 16e half-sandwich complex Cp*Co(S2C2B10H10) (1) (Cp* = pentamethylcyclopentadienyl) with excess methyl acetylene monocarboxylate, HC≡C-CO2Me, affords the 18e complexes 2-6. Compound 2 bears a B-CH...The reaction of the 16e half-sandwich complex Cp*Co(S2C2B10H10) (1) (Cp* = pentamethylcyclopentadienyl) with excess methyl acetylene monocarboxylate, HC≡C-CO2Me, affords the 18e complexes 2-6. Compound 2 bears a B-CH2 unit in which B-substitution occurs in the B(3)/B(6) position of the ortho-carborane cage. Complexes 3-6 are geometrical isomers, in which the alkyne is twofold inserted into one of the Co-S bonds in all the four possible ways. Treatment of 1 with excess 3-butyn-2-one or phenyl ethynyl ketone, HC≡C-C(O)R (R = Me, Ph), at ambient temperature leads to the 18e complexes 7-10, respectively, with two alkynes inserted into one of the Co-S bonds. All the new complexes were fully characterized by spectroscopic techniques and elemental analysis. The solid-state structures of 2, 3, 5, 7, 8, 9 and 10 were further characterized by X-ray structural analysis.展开更多
The construction of interlocked topologies by metal-cation-template methods has been extensively explored.However,construction of these species using template-free chemical self-assembly methods is hard to rationally ...The construction of interlocked topologies by metal-cation-template methods has been extensively explored.However,construction of these species using template-free chemical self-assembly methods is hard to rationally achieve due to the inherent unpredictability of self-assembly processes.In this work,a strategy to construct interlocked[2]catenanes by coordination-driven template-free self-assembly is demonstrated,whereby combining rigid bidentate ligands with large conjugated-πarea units and building blocks with appropriate lengths facilitated construction of interlocked[2]catenane compounds.Two rigid bidentate ligands,L1 and L2,were chosen to self-assemble with three dinuclear building blocks B1,B2 and B3.Ultimately,the successful construction of three[2]catenanes demonstrated the validity of the strategy.Although[2]catenanes are the simplest of all interlocked topologies,this motif is the basis for constructing more intricate topologies.This successful strategy may therefore lead to construction of other,more intricate topologies in the future.展开更多
Half-sandwich zirconium complex 3 containing tridentate carborane [S,S,O] ligand 2 [(HOC6H2R2-4,6)(CH2)SC(B10H10) C(Ph)2P=S, R=tBu] was synthesized by the reaction of CpZrCl3(Cp=η5-C5H5) with sodium salt of ligand 2....Half-sandwich zirconium complex 3 containing tridentate carborane [S,S,O] ligand 2 [(HOC6H2R2-4,6)(CH2)SC(B10H10) C(Ph)2P=S, R=tBu] was synthesized by the reaction of CpZrCl3(Cp=η5-C5H5) with sodium salt of ligand 2. Zirconium complex 3 was characterized by elemental and NMR analyses. DFT calculations were also performed on complex 3 to analyze the stereochemistry. The results from DFT calculations indicate that structure S1, in which no sulfur atom bonds to the zirconium atom, exists at the lowest energy level. In the presence of methylaluminoxane(MAO), complex 3 exhibited good catalytic activities for ethylene polymerization and long life-time up to 10 h. Moreover, the complex 3/MAO system displayed excellent catalytic activities toword ethylene copolymerization with 1-hexene or polar olefins.展开更多
We report herein a practical approach for regio-selective B—H/C—H bond activation at azo-substituted carboranes. The reaction proceeded through Iridium(III)-induced selective B—H/C—H bond activations based on an a...We report herein a practical approach for regio-selective B—H/C—H bond activation at azo-substituted carboranes. The reaction proceeded through Iridium(III)-induced selective B—H/C—H bond activations based on an azo directing group. Through this strategy, a series of mononuclear, trinuclear and tetranuclear cyclometalated iridium complexes containing Cp*Ir—B or Cp*Ir—C bonds were successfully isolated in a high yield. In this work, efficient routes are developed through one-pot reactions to prepare polynuclear organometallic complexes.展开更多
Treatment of CptRh(PMe3)Cl2(1) (Cpt=5η-tBu2C5H3) with [Et4N]2Se6 in DMF solution leads to the for-mation of cyclo-tetraselenido half-sandwich rhodium com-plexes CptRh(PMe3)(Se4) (2). The elimination of 2 with ex-cess...Treatment of CptRh(PMe3)Cl2(1) (Cpt=5η-tBu2C5H3) with [Et4N]2Se6 in DMF solution leads to the for-mation of cyclo-tetraselenido half-sandwich rhodium com-plexes CptRh(PMe3)(Se4) (2). The elimination of 2 with ex-cess of nBu3P results in cyclo-diselenido rhodium complex CptRh(PMe3)(Se2) (3). 1 reacts with [nBu4N]2Te5 in DMF solution to yield cyclo-ditellurido rhodium complex CptRh (PMe3)(Te2) (4) in which carbon atom from CH2C12 can be inserted into Te-Te bond to form CptRh(PMe3)(TeCH2Te) (5). The new complexes 2-5 have been characterized by their IR, EI-MS, and 1H, 13C, 31P, 103Rh NMR spectra as well as ele-mental analysis.展开更多
Metallocene complex Cp tt 2ZrCl 2 (Cp tt =η 5 1,3 t Bu 2 C 5 H 3 ) (1) has been prepared from the reaction of LiCp tt with ZrCl 4 in good yield. Reactio...Metallocene complex Cp tt 2ZrCl 2 (Cp tt =η 5 1,3 t Bu 2 C 5 H 3 ) (1) has been prepared from the reaction of LiCp tt with ZrCl 4 in good yield. Reactions of 1 with dilithium dichalcogenolate o carboranes afforded new type of half sandwich compounds with dichalcogenolate o carboranyl ligands, [Li(THF) 4 ][Cp tt Zr(E 2 C 2 B 10 H 10 ) 2 ] (E=S, 2a; E=Se, 2b) in which only one cyclopentadienyl ring ligand existed. Complexes 1 and 2a were structurally characterized by X ray analyses. In complex 2a, the Zr(IV) ion is η 5 bound to one 1,3 di tert cyclopentadienyl ring and σ bound to four μ 2 sulfur atoms of two dithio carboranes. The zirconium atom and four sulfur atoms form a distorted pyramid. The coordination sphere around the zirconium atom resembles in a piano stool structure with four legs of sulfur atoms and the fulcrum at the zirconium atom.展开更多
Although supramolecular transformations have been emerged as a potent strategy for transitioning between various topologies,post-modification induced topological transformations have never been explored in the context...Although supramolecular transformations have been emerged as a potent strategy for transitioning between various topologies,post-modification induced topological transformations have never been explored in the context of[2]catenane topologies.In this study,we present a novel supramolecular transformation between a Hopf link and a macrocycle,induced by the Diels–Alder click reaction.By strategically selecting the half-sandwich ruthenium binuclear fragment B as a rigid capping agent,we successfully integrated tetrazine moieties into the metalla[2]catenane structure.We demonstrated that the introduction of 2,5-norbornadiene(NBD)as an external stimulus allows for the transformation of the novel metalla[2]catenane,featuring reactive tetrazine sites,into the corresponding monomeric ring through postmodification for the first time.The synthetic results are corroborated by single-crystal X-ray diffraction analysis,ESI-TOF/MS,elemental analysis,and detailed solution-state NMR techniques.展开更多
Half sandwich titanocenes, e.g . (ind)TiRCl 2 (R—Cl, OMe, OEt; ind—indenyl group) and β diketonate titanium complexes, e.g . (dbm) 3TiL (L—Cl, OPh, OPhMe; dbm—dibenzoylmethane group) were investigated for syndiot...Half sandwich titanocenes, e.g . (ind)TiRCl 2 (R—Cl, OMe, OEt; ind—indenyl group) and β diketonate titanium complexes, e.g . (dbm) 3TiL (L—Cl, OPh, OPhMe; dbm—dibenzoylmethane group) were investigated for syndiotactic polymerization of styrene. The optimum molar ratios of Al to Ti of β diketonate titanium complexes were different from those of mono indenyl titanium complexes. The polymerization activity of (ind)TiRCl 2 was higher than that of (dbm) 3TiL at their own optimum n (Al)/ n (Ti). Compared with (ind)TiRCl 2, the thermostability of (dbm) 3TiL was higher. The polymerization activity of (dbm) 3Ti(OPh) was 6 5×10 5 g/(mol·h) at 363 K, while that of (ind)Ti(OMe)Cl 2 was only 4 9×10 5 g/(mol·h) at the same temperature. After 2 h of polymerization, the reaction activity of the nontitanocene was remained at 6×10 5 g/(mol·h), while that of the half sandwich titanocene was only 0 71×10 5 g/(mol·h). It is indicated that the life time of (dbm) 3TiL was much longer than that of (ind)TiRCl 2. The melting temperatures ( T m) and the syndiotacticity of polystyrene by β diketonate titanium complexes were higher than those of the polymer by mono indenyl titanium complexes as well.展开更多
The reaction of \[Cp\+\%t\%RhCl\-2\]\-2(1) (Cp\+\%t\%=η\+5\|\{\}\+\%t\%Bu\-2C\-5\|H\-3) with 1,2\|dilithium dichalcogenolate carborane Li\-2E\-2C\-2B\-\{10\}H\-\{10\}(E=S, Se) afforded the 16\|electron rhodium(Ⅲ) ha...The reaction of \[Cp\+\%t\%RhCl\-2\]\-2(1) (Cp\+\%t\%=η\+5\|\{\}\+\%t\%Bu\-2C\-5\|H\-3) with 1,2\|dilithium dichalcogenolate carborane Li\-2E\-2C\-2B\-\{10\}H\-\{10\}(E=S, Se) afforded the 16\|electron rhodium(Ⅲ) half\|sandwich complexes \{Cp\+\%t\%Rh(E\-2C\-2B\-\{10\}H\-\{10\})\}\3a), Se(3b)\]. 18\|Electron trimethyl phosphine rhodium(Ⅲ) half\|sandwich complexes Cp\+\%t\%Rh(PMe\-3)(E\-2C\-2B\-\{10\}H\-\{10\})\. 18\|Electron trimethyl phosphine rhodium(Ⅲ) half\|sandwich complexes Cp\+\%t\%Rh(PMe\-3)(E\-2C\-2B\-\{10\}H\-\{10\})\4a), Se(4b), Te(4c)\] can be synthesized both by addition of PMe\-3 into 16\|electron complexes can be synthesized both by addition of PMe\-3 into 16\|electron complexes 3a, 3b and by the reaction Cp\+\%t\%Rh(PMe\-3)Cl\-2(2) with Li\-2E\-2C\-2B\-\{10\}H\-\{10\}(\{E=S\}, Se, Te). The molecular geometry of 4b was determined by X\|ray diffraction structural analysis.展开更多
邻位碳硼烷分别与正丁基锂、硫粉和Me4Cp Co(CO)I2反应合成得到半夹芯16电子碳硼烷化合物Me4Cp Co S2C2B10H10(1)。1与二茂铁炔酮在二氯甲烷中反应得到产物{(Me4Cp Co S2C2B10H10)[Fc C(O)CHCCHCC(O)Fc]}(2)(Fc=二茂铁基)。2是一个1∶2...邻位碳硼烷分别与正丁基锂、硫粉和Me4Cp Co(CO)I2反应合成得到半夹芯16电子碳硼烷化合物Me4Cp Co S2C2B10H10(1)。1与二茂铁炔酮在二氯甲烷中反应得到产物{(Me4Cp Co S2C2B10H10)[Fc C(O)CHCCHCC(O)Fc]}(2)(Fc=二茂铁基)。2是一个1∶2的加成产物,2个二茂铁炔酮分子以头-尾的方式加成到分子1中的1个Co-S键上。1和2分别用红外、核磁、元素分析、质谱和单晶X-射线衍射等表征方法进行了结构表征。展开更多
基金The National Science Foundation of China(22031003,21720102004)the Shanghai Science Technology Committee(19DZ2270100)。
文摘Herein,we describe the synthesis and characterization of four complexes containing half-sandwich iridium metal-corner which were obtained through the interaction between known complexes Cp*MCl(o-C_(2)B_(10)H_(11)CS_(2))(M=Ir/Rh,Complex 1a and 1b)and corresponding reagents.An incomplete cubane-like complex[Cp*Ir(o-C_(2)B_(10)H_(11)CHS_(2))]_(2)(Complex 2)has been prepared through the reaction between 1a and LiBH4 or NaBH4.Co-thermolysis between 1a and BH_(3)·THF in toluene produces a trimer metallacycle complex[Cp*Ir(o-C_(2)B_(10)H_(10)CS_(2))]_(3)(Complex 3),while its rhodium analogue[Cp*Rh(o-C_(2)B_(10)H_(10)CS_(2))]_(3)(Complex 4)can be prepared through BiPh_(3)-assisted dechlorination reaction of 1b.Furthermore,the oxidative addition reaction of 1a towards SnCl_(2)generates a mononuclear complex Cp*Ir(SnCl_(3))(o-C_(2)B_(10)H_(11)CS_(2))(Complex 5)with a direct Sn-Ir bond.These complexes have been characterized,including X-Ray single crystal diffraction,NMR spectroscopy and elemental analysis methods.
基金financially supported by the National Natural Science Foundation of China (Nos. 20974014, 21274012, 21322401 and 21774014)the 111 project (No. B07012)
文摘The syndiotactic polymerization of styrene（St） and the copolymerization of St with ethylene（E） were carried out by using a series of chiral half-sandwich rare-earth metal dialkyl complexes（Cp^x＊） as the catalysts. The complexes are Ln（CH2SiMe3）2（THF）（1-4： Ln = Sc（1）, Ln = Lu（2）, Ln = Y（3）, Ln = Dy（4）） bearing chiral cyclopentadienyl ligand containing bulky cylcohexane derivatives in the presence of activator and AliBu3. For the St polymerization, a high activity up to 3.1 × 10^6 g of polymer mol Ln^-1·h^-1 and a high syndiotactic selectivity more than 99% were achieved. The resulting syndiotactic polystyrenes（sPSs） have the molecular weights（Mn） ranging from 3700 g·mol^-1 to 6400 g·mol^-1 and the molecular weight distributions（Mw/Mn） from 1.40 to 5.03. As for the copolymerization of St and E, the activity was up to 2.4 × 10^6 g of copolymer mol Sc^-1·h^-1·MPa^-1, giving random St-E copolymers containing syndiotactic polystyrene sequences with different St content in the range of 15 mol%-58 mol%. These results demonstrate that the bulky cyclopentadienyl ligands of the chiral half-sandwich rare-earth metal complexes effectively inhibit the continued insertion of St monomers into the（co）polymer chain to some extent in comparison with the known half-sandwich rare-earth metal complexes.
基金financially supported by the Shanghai Science and Technology Committee(08DZ2270500,08DJ1400103)Shanghai Leading Academic Discipline Project(B108)the National Basic Research Program of China(2009CB825300,2010DFA41160)
文摘A series of half-sandwich group IV metal complexes with tridentate monoanionic phenoxy-imine arylsulfide [O-NS] ligand [2-Bu^t4-Me-6-（（2-（SC6H5）C6H4N = CHC6H2O）]- （La） and dianionic phenoxy-amine arylsulfide [O-N-S] ligand [2-Bu^t4-Me-6-（（2-（SC6H5）C6H4N-CH2C6H2O）]2- （Lb） have been synthesized and characterized. Lb was obtained easily in high yield by reduction of ligand La with excess LiAlH4 in cool diethyl ether. Half-sandwich Group Ⅳ metal complexes CpTi[O-NS]Cl2 （1a）, CpZr[O-NS]Cl2 （1b）, CpTi[O-N-S]Cl （2a）, CpZr[O-N-S]Cl （2b） and CpZr[O-N-S]Cl （2c） were synthesized by the reactions of La and Lb with CpTiCl3, CpZrCl3 and Cp ZrCl3, and characterized by IR, ^1H-NMR, ^13C-NMR and elemental analysis. In addition, an X-ray structure analysis was performed on ligand Lb. The title Group IV half-sandwich bearing tridentate [O,N,S] ligands show good catalytic activities for ethylene polymerization in the presence of methylaluminoxane （MAO） as co-catalyst up to 1.58 × 10^7 g-PE.mol-Zr-1.h-1. The good catalytic activities can be maintained even at high temperatures such as 100 ℃ exhibiting the excellent thermal stability for these half-sandwich metal pre-catalysts.
基金supported by Beijing Natural Science Foundation(No.2214064)the National Natural Science Foundation of China(Nos.21603037,21688102,92161115,21973016,91545122)the Fundamental Research Funds for the Central Universities(Nos.JB2015RCY03,JB2019MS052)supported by the fund of North China Electric Power University。
文摘The cycloaddition reactions of methane and ethylene mediated by Ir^(+) have been designed and studied by the techniques of mass spectrometry in conjunction with theoretical calculations.Studies have shown that Ir^(+) can mediate the cycloaddition reaction of CH4and two C_(2)H_(4) to generate a half-sandwich structure IrHCp^(+)(Cp=η^(5)-C_(5)H_(5))including pentamethylcyclopentadienyl ligand by continuous dehydrogenation reaction with the forming of three C-C bonds and seven C-H bonds.The orbital analysis indicates the mechanism of the cyclization reaction to generation of pentamethylcyclopentadienyl ligand with odd number carbon atom depends on the overlap ofπorbitals in-C_(2)H_(2) and carbene,which is more difficult than the forming of cyclobutadiene ligand and benzene.This study may help to understand the reaction mechanism in the cycloaddition reactions of organic compounds,which will be useful to guide the rational design of new catalysts with tailored selectivity and increased efficiency.
基金Financial support by the National Natural Science Foundation of China and by the Special Funds for Major State Basic Research Projects(G1999064800)is gratefully acknowledged.
文摘Treatment of 1,3-di- t -butylcyclopentadiene with rhodium trichloride in EtOH leads to the formation of binuclear half-sandwich complex [Cp t RhCl( μ -Cl)] 2 (1) (Cp t = η 5- t Bu 2C 5H 3) which reacts with trimethylphosphine to give Cp t Rh(PMe 3)Cl 2(2) in high yield. 2 reacts with ammonium polysulfide, (NH 4) 2S x to give cyclooligosulfido half-sandwich complexes Cp t Rh(PMe 3)(S n )( n =4(4a),6(4b)). Desulfurization of 4b by excess PPh 3 results in cyclotetrasulfido product 4a, while 4a takes up sulfur from polysulfide to convert cyclohexasulfido product 4b. The reaction of 2 with Et 4NI gives diiodide complex 3 which is determined by single crystal X-ray crystallographic analysis.
基金the National Natural Science Foundation of China (20925104,90713023,20771055,20721002)the Major State Basic Research Development Program of China (2006CB806104)the National Basic Research Program of China (2007CB925101,2010CB923303)
文摘The reaction of the 16e half-sandwich complex Cp*Co(S2C2B10H10) (1) (Cp* = pentamethylcyclopentadienyl) with excess methyl acetylene monocarboxylate, HC≡C-CO2Me, affords the 18e complexes 2-6. Compound 2 bears a B-CH2 unit in which B-substitution occurs in the B(3)/B(6) position of the ortho-carborane cage. Complexes 3-6 are geometrical isomers, in which the alkyne is twofold inserted into one of the Co-S bonds in all the four possible ways. Treatment of 1 with excess 3-butyn-2-one or phenyl ethynyl ketone, HC≡C-C(O)R (R = Me, Ph), at ambient temperature leads to the 18e complexes 7-10, respectively, with two alkynes inserted into one of the Co-S bonds. All the new complexes were fully characterized by spectroscopic techniques and elemental analysis. The solid-state structures of 2, 3, 5, 7, 8, 9 and 10 were further characterized by X-ray structural analysis.
基金This work was supported by the National Natural Science Foundation of China(Nos.22031003 and 21720102004)the Shanghai Science Technology Committee(No.19DZ2270100).
文摘The construction of interlocked topologies by metal-cation-template methods has been extensively explored.However,construction of these species using template-free chemical self-assembly methods is hard to rationally achieve due to the inherent unpredictability of self-assembly processes.In this work,a strategy to construct interlocked[2]catenanes by coordination-driven template-free self-assembly is demonstrated,whereby combining rigid bidentate ligands with large conjugated-πarea units and building blocks with appropriate lengths facilitated construction of interlocked[2]catenane compounds.Two rigid bidentate ligands,L1 and L2,were chosen to self-assemble with three dinuclear building blocks B1,B2 and B3.Ultimately,the successful construction of three[2]catenanes demonstrated the validity of the strategy.Although[2]catenanes are the simplest of all interlocked topologies,this motif is the basis for constructing more intricate topologies.This successful strategy may therefore lead to construction of other,more intricate topologies in the future.
基金supported by the National Natural Science Foundation of China (91122017, 21374019)the Shanghai Science and Technology Committee (13JC1400600, 13DZ2275200)the Program for Changjiang Scholars and Innovative Research Team in University (IRT1117)
文摘Half-sandwich zirconium complex 3 containing tridentate carborane [S,S,O] ligand 2 [(HOC6H2R2-4,6)(CH2)SC(B10H10) C(Ph)2P=S, R=tBu] was synthesized by the reaction of CpZrCl3(Cp=η5-C5H5) with sodium salt of ligand 2. Zirconium complex 3 was characterized by elemental and NMR analyses. DFT calculations were also performed on complex 3 to analyze the stereochemistry. The results from DFT calculations indicate that structure S1, in which no sulfur atom bonds to the zirconium atom, exists at the lowest energy level. In the presence of methylaluminoxane(MAO), complex 3 exhibited good catalytic activities for ethylene polymerization and long life-time up to 10 h. Moreover, the complex 3/MAO system displayed excellent catalytic activities toword ethylene copolymerization with 1-hexene or polar olefins.
基金This work was supported by the National Natural Science Foun-dation of China(Nos.21531002,21720102004,22031003)the Shanghai Science Technology Committee(No.13JC1400600).
文摘We report herein a practical approach for regio-selective B—H/C—H bond activation at azo-substituted carboranes. The reaction proceeded through Iridium(III)-induced selective B—H/C—H bond activations based on an azo directing group. Through this strategy, a series of mononuclear, trinuclear and tetranuclear cyclometalated iridium complexes containing Cp*Ir—B or Cp*Ir—C bonds were successfully isolated in a high yield. In this work, efficient routes are developed through one-pot reactions to prepare polynuclear organometallic complexes.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 29925101) also by the Special Founds for the State Major Basic Research Projects (Grant No. G1999064800).
文摘Treatment of CptRh(PMe3)Cl2(1) (Cpt=5η-tBu2C5H3) with [Et4N]2Se6 in DMF solution leads to the for-mation of cyclo-tetraselenido half-sandwich rhodium com-plexes CptRh(PMe3)(Se4) (2). The elimination of 2 with ex-cess of nBu3P results in cyclo-diselenido rhodium complex CptRh(PMe3)(Se2) (3). 1 reacts with [nBu4N]2Te5 in DMF solution to yield cyclo-ditellurido rhodium complex CptRh (PMe3)(Te2) (4) in which carbon atom from CH2C12 can be inserted into Te-Te bond to form CptRh(PMe3)(TeCH2Te) (5). The new complexes 2-5 have been characterized by their IR, EI-MS, and 1H, 13C, 31P, 103Rh NMR spectra as well as ele-mental analysis.
基金theNationalNaturalScienceFoundationofChina (No .2 992 5 10 1)theMajorStateBasicResearchDevelopmentProgram (No .G19990 64 80 0 )
文摘Metallocene complex Cp tt 2ZrCl 2 (Cp tt =η 5 1,3 t Bu 2 C 5 H 3 ) (1) has been prepared from the reaction of LiCp tt with ZrCl 4 in good yield. Reactions of 1 with dilithium dichalcogenolate o carboranes afforded new type of half sandwich compounds with dichalcogenolate o carboranyl ligands, [Li(THF) 4 ][Cp tt Zr(E 2 C 2 B 10 H 10 ) 2 ] (E=S, 2a; E=Se, 2b) in which only one cyclopentadienyl ring ligand existed. Complexes 1 and 2a were structurally characterized by X ray analyses. In complex 2a, the Zr(IV) ion is η 5 bound to one 1,3 di tert cyclopentadienyl ring and σ bound to four μ 2 sulfur atoms of two dithio carboranes. The zirconium atom and four sulfur atoms form a distorted pyramid. The coordination sphere around the zirconium atom resembles in a piano stool structure with four legs of sulfur atoms and the fulcrum at the zirconium atom.
基金the Shanxi Province Science Foundation for Youth(No.202203021212408)the Shanxi Normal University Quality Curriculum(No.2019YZKC-13)the 1331 Project of Shanxi Province。
文摘Although supramolecular transformations have been emerged as a potent strategy for transitioning between various topologies,post-modification induced topological transformations have never been explored in the context of[2]catenane topologies.In this study,we present a novel supramolecular transformation between a Hopf link and a macrocycle,induced by the Diels–Alder click reaction.By strategically selecting the half-sandwich ruthenium binuclear fragment B as a rigid capping agent,we successfully integrated tetrazine moieties into the metalla[2]catenane structure.We demonstrated that the introduction of 2,5-norbornadiene(NBD)as an external stimulus allows for the transformation of the novel metalla[2]catenane,featuring reactive tetrazine sites,into the corresponding monomeric ring through postmodification for the first time.The synthetic results are corroborated by single-crystal X-ray diffraction analysis,ESI-TOF/MS,elemental analysis,and detailed solution-state NMR techniques.
文摘Half sandwich titanocenes, e.g . (ind)TiRCl 2 (R—Cl, OMe, OEt; ind—indenyl group) and β diketonate titanium complexes, e.g . (dbm) 3TiL (L—Cl, OPh, OPhMe; dbm—dibenzoylmethane group) were investigated for syndiotactic polymerization of styrene. The optimum molar ratios of Al to Ti of β diketonate titanium complexes were different from those of mono indenyl titanium complexes. The polymerization activity of (ind)TiRCl 2 was higher than that of (dbm) 3TiL at their own optimum n (Al)/ n (Ti). Compared with (ind)TiRCl 2, the thermostability of (dbm) 3TiL was higher. The polymerization activity of (dbm) 3Ti(OPh) was 6 5×10 5 g/(mol·h) at 363 K, while that of (ind)Ti(OMe)Cl 2 was only 4 9×10 5 g/(mol·h) at the same temperature. After 2 h of polymerization, the reaction activity of the nontitanocene was remained at 6×10 5 g/(mol·h), while that of the half sandwich titanocene was only 0 71×10 5 g/(mol·h). It is indicated that the life time of (dbm) 3TiL was much longer than that of (ind)TiRCl 2. The melting temperatures ( T m) and the syndiotacticity of polystyrene by β diketonate titanium complexes were higher than those of the polymer by mono indenyl titanium complexes as well.
文摘The reaction of \[Cp\+\%t\%RhCl\-2\]\-2(1) (Cp\+\%t\%=η\+5\|\{\}\+\%t\%Bu\-2C\-5\|H\-3) with 1,2\|dilithium dichalcogenolate carborane Li\-2E\-2C\-2B\-\{10\}H\-\{10\}(E=S, Se) afforded the 16\|electron rhodium(Ⅲ) half\|sandwich complexes \{Cp\+\%t\%Rh(E\-2C\-2B\-\{10\}H\-\{10\})\}\3a), Se(3b)\]. 18\|Electron trimethyl phosphine rhodium(Ⅲ) half\|sandwich complexes Cp\+\%t\%Rh(PMe\-3)(E\-2C\-2B\-\{10\}H\-\{10\})\. 18\|Electron trimethyl phosphine rhodium(Ⅲ) half\|sandwich complexes Cp\+\%t\%Rh(PMe\-3)(E\-2C\-2B\-\{10\}H\-\{10\})\4a), Se(4b), Te(4c)\] can be synthesized both by addition of PMe\-3 into 16\|electron complexes can be synthesized both by addition of PMe\-3 into 16\|electron complexes 3a, 3b and by the reaction Cp\+\%t\%Rh(PMe\-3)Cl\-2(2) with Li\-2E\-2C\-2B\-\{10\}H\-\{10\}(\{E=S\}, Se, Te). The molecular geometry of 4b was determined by X\|ray diffraction structural analysis.
文摘邻位碳硼烷分别与正丁基锂、硫粉和Me4Cp Co(CO)I2反应合成得到半夹芯16电子碳硼烷化合物Me4Cp Co S2C2B10H10(1)。1与二茂铁炔酮在二氯甲烷中反应得到产物{(Me4Cp Co S2C2B10H10)[Fc C(O)CHCCHCC(O)Fc]}(2)(Fc=二茂铁基)。2是一个1∶2的加成产物,2个二茂铁炔酮分子以头-尾的方式加成到分子1中的1个Co-S键上。1和2分别用红外、核磁、元素分析、质谱和单晶X-射线衍射等表征方法进行了结构表征。
