To extend a new family of aminophosphine-coordinated[FeFe]-hydrogenase mimics for catalytic hydro-gen(H_(2))evolution,we carried out the ligand substitutions of diiron hexacarbonyl precursors[Fe_(2)(μ-X_(2)pdt)(CO)_(...To extend a new family of aminophosphine-coordinated[FeFe]-hydrogenase mimics for catalytic hydro-gen(H_(2))evolution,we carried out the ligand substitutions of diiron hexacarbonyl precursors[Fe_(2)(μ-X_(2)pdt)(CO)_(6)](X_(2)pdt=(SCH_(2))_(2)CX_(2),X=Me,H)with aminodiphosphines(Ph_(2)PCH_(2))_(2)NY(Y=(CH_(2))_(2)OH,(CH_(2))_(3)OH)to obtain two new diiron aminophosphine complexes[Fe_(2)(L1)(μ-Me_(2)pdt)(CO)_(5)](1)and[Fe_(2)(L2)(μ-H_(2)pdt)(CO)_(5)](2),where L1=3-[(diphe-nylphosphaneyl)methyl]oxazolidine,L2=3-[(diphenylphosphaneyl)methyl]-1,3-oxazinane.Moreover,the structures of 1 and 2 have been fully confirmed by elemental analysis,spectroscopic techniques,and single-crystal X-ray diffraction.Using cyclic voltammetry(CV),we investigated the electrochemical redox performance and proton reduc-tion activities of 1 and 2 in acetic acid(HOAc).The CV study indicates that diiron aminophosphine complexes 1 and 2 can be considered to be hydrogenase-inspired diiron molecular electrocatalysts for the reduction of protons into H 2 generation in the presence of HOAc.CCDC:2443967,1;2443969,2.展开更多
Reaction of [（μ-SCH2）2NPh]Fe2（CO）6 with Ph2PCH2PPh2 in the presence of Me3NO·2H2O gave the title complex [（μ-SCH2）2NPh]Fe2（CO）5（Ph2PCH2PPh2）（1）in 78% yield.The new complex 1 was characterized by ele...Reaction of [（μ-SCH2）2NPh]Fe2（CO）6 with Ph2PCH2PPh2 in the presence of Me3NO·2H2O gave the title complex [（μ-SCH2）2NPh]Fe2（CO）5（Ph2PCH2PPh2）（1）in 78% yield.The new complex 1 was characterized by elemental analysis,spectroscopy and X-ray crys-tallography.It crystallizes in triclinic,space group P1 with a = 10.832（2）,b = 12.003（2）,c = 15.579（3）,V = 1785.6（6）3,Z = 2,C32H26Fe2NO5PS2,Mr = 819.40,Dc = 1.524 g/cm3,μ（MoKα）= 1.064 mm-1,F（000）= 840,T = 113（2）K,the final R = 0.0543 and wR = 0.1218 for 6203 observed reflections（I 2σ（I））.The Ph2PCH2PPh2 ligand resides in an axial position of the square-pyramidal coordination sphere of the Fe atom and trans to the benzene ring in order to reduce the steric repulsion between Ph2PCH2PPh2 and the benzene ring.展开更多
As DNA cleavage agent, a new diiron（Ⅲ） complex （Fe2Lb）, in which a DNA-intercalator （pyrene） is covalently linked to a diferric moiety, has been synthesized and characterized. The DNA-binding property and DNA c...As DNA cleavage agent, a new diiron（Ⅲ） complex （Fe2Lb）, in which a DNA-intercalator （pyrene） is covalently linked to a diferric moiety, has been synthesized and characterized. The DNA-binding property and DNA cleavage activity of the complex have also been investigated.展开更多
The title complex,（μ-pdt）Fe_2（CO）_5（Ph_2PCH_3）（pdt = SCH_2CH_2CH_2S）,was obtained by the reaction of the parent complex（μ-pdt）Fe_2（CO）_6 with Ph_2PCH_3 and Me_3NO·2H_2O in good yield（90%）. The tit...The title complex,（μ-pdt）Fe_2（CO）_5（Ph_2PCH_3）（pdt = SCH_2CH_2CH_2S）,was obtained by the reaction of the parent complex（μ-pdt）Fe_2（CO）_6 with Ph_2PCH_3 and Me_3NO·2H_2O in good yield（90%）. The title complex was characterized by IR,~1H NMR,^（31）P{~1H} NMR and ^（13）C{~1H} NMR spectroscopy as well as by single-crystal X-ray diffraction analysis. The molecular structure shows that the title complex contains a butterfly diiron propanedithiolate cluster with five terminal carbonyls and a monophosphine ligand Ph_2PCH_3. The crystal packing diagram reveals that intermolecular C H···O hydrogen bonds between CH_2 and carbonyls,π-π stacking interactions and van der Waals＇ interactions stabilize the solid state to form a three-dimensional network.展开更多
Two new diiron ethanedithiolate complexes Fe2（S2C2H4）（CO）5（2-Ph2PC6H4NH2） （1） and Fez（S2CzH4）（CO）5（2-PhzPC6H4CHzNH2） （2） as active site models of [FeFe] hydrogenases have been prepared by the treatment...Two new diiron ethanedithiolate complexes Fe2（S2C2H4）（CO）5（2-Ph2PC6H4NH2） （1） and Fez（S2CzH4）（CO）5（2-PhzPC6H4CHzNH2） （2） as active site models of [FeFe] hydrogenases have been prepared by the treatment of （,u-SCHzCH2S-μ）Fe2（CO）6 with 2-PhzPC6H4NH2 or 2-PhzPC6H4CH2NH2 in the presence of the decarbonylating agent Me3NO＇2H20. As new complexes, both 1 and 2 were fully characterized by elemental analysis, IR and^1H （13C, 31p） NMR spectroscopies. In addition, the molecular structure of complex 1 was established by X-ray crystallography. The crystal of Fe2（S2C2H4）（CO）5（2-PhzPC6H4NH2） （1） crystallizes in orthorhombic, spacegroup Pna21 with a = 20.9461（17）, b = 13.7615（11）, c = 9.3133（7）A, V= 2684.6（4） A3, Z = 4, C25Hz0FezNOsPS2, Mr = 621.21, Dc = 1.537 g/cm^3, F（000） = 1264. The final R = 0.0197 and wR = 0.0495 for 4605 observed reflections with I 〉 2a（/） and R = 0.0206 and wR = 0.0501 for all data.展开更多
Treatment of complex [（μ-SCH2）2NCH2Ph]Fe2（CO）6 with PPh3 in the presence of decarbonylating agent Me3NO-2H2O afforded the rifle complex [（μ-SCH2）2NCH2Ph]Fe2（CO）5（PPh3） in 70% yield. The new complex was cha...Treatment of complex [（μ-SCH2）2NCH2Ph]Fe2（CO）6 with PPh3 in the presence of decarbonylating agent Me3NO-2H2O afforded the rifle complex [（μ-SCH2）2NCH2Ph]Fe2（CO）5（PPh3） in 70% yield. The new complex was characterized by elemental analysis, IR, and 1H （31p, 13C） NMR spectroscopic techniques as well as by X-ray crystallography. It crystallizes in triclinic, space group P i with a = 9.3016（19）, b = 12.698（3）, c = 13.904（3） A, V = 1519.8（7） A3, Z = 2, C32H26Fe2NOsPS2, Mr = 711.33, Dc = 1.554 g/cm3, μ（MoKa） = 1.187 mm^-1, F（000） = 728, T= 113（2） K, the final R = 0.0288 and wR = 0.0680 for 3982 observed reflections （I 〉 2σ（I））. The PPh3 ligand resides in an axial position of the square-pyramidal geometry of the neighboring Fe atom and trans to the benzene ring in order to minimize the steric repulsion between PPh3 and the benzene ring.展开更多
The reaction of [Fe2S2（CO）6] with one equiv.of o-OCH3C6H4CH2Br under the re-duction of LiBHEt3 in dry THF afforded a tetranuclear cluster [（μ4-S）{（μ-SCH2（o-OCH3）Ph）Fe2（CO）6}2]（1）.Complex 1 crystallizes i...The reaction of [Fe2S2（CO）6] with one equiv.of o-OCH3C6H4CH2Br under the re-duction of LiBHEt3 in dry THF afforded a tetranuclear cluster [（μ4-S）{（μ-SCH2（o-OCH3）Ph）Fe2（CO）6}2]（1）.Complex 1 crystallizes in monoclinic,space group P21/n with a = 16.5623（6）,b = 12.8265（5）,c = 18.2702（7） ,β = 115.95（1）o,V = 3489.9（4） 3,Z = 4,μ = 1.87 mm-1,Dc = 1.709 Mg/m3,T = 296（2） K,C28H18Fe4O14S3,Mr = 898.03,F（000） = 1800,S = 1.10,R = 0.032 and wR = 0.058.Complex 1 consists of two diiron fragments possessing a {Fe2（CO）6} core.The two diiron units are bridged by an inorganic sulfide in a μ4-S binding mode and the sulfide is in a distorted tetrahedral geometry with the four iron atoms at each corner of the distorted tetrahedral.In its solid state,two types of non-classic intermolecular hydrogen bonding interactions plus a weak π-π stacking interaction led to a 2-D network.展开更多
The activation of dioxygen and incorporation into hydrocarbons have been achieved under mild conditions by a methane monooxygenase (MMO)-like system using a dinuclear iron complex [Fe2Dhist(OAc)2] BPh4 ·3H2O as t...The activation of dioxygen and incorporation into hydrocarbons have been achieved under mild conditions by a methane monooxygenase (MMO)-like system using a dinuclear iron complex [Fe2Dhist(OAc)2] BPh4 ·3H2O as the model complex, zinc powder as the electron donor, HOAc as the proton source and methylviologen as the electron transfer agent. The results show that styrene is oxygenated predominantly to styrene oxide (1 396 mol/100 mol of the Fe2 complex), benzaldehyde (16160) and acetophenone (986), and cyclohexane to cyclohexanol (9370) and cyclo-hexanone (2670). EPR studies indicate that the hypervalent ironoxo spiecs FeⅣFeⅣ=O, derived from FeⅢFeⅢ core via reduction, O2-binding and protonation, is the active intermediate which inserts the activated oxygen atom into C=C or C-H bond giving each product. The system closely resembles MMO and its close relative hemerythrin in the aspects of reaction phenomena, EPR characteristics and product distributions. The Mn2 analog cmplex、 Fe-Zn het-erodinuclear complex and mononuclear iron complex show no catalytic activity, indicating that dinuclear iron core is in-despansable to catalytic activity.展开更多
In this paper,a novel diiron ethane-1,2-dithiolate complex[Fe2(CO)4{κ2-(Ph2P)2(1,2-C6H4)}(μ-SCH2CH2S)]has been prepared and structurally characterized.Treatment of the parent complex[Fe2(CO)6(μ-SCH2CH2S)]with 1 equ...In this paper,a novel diiron ethane-1,2-dithiolate complex[Fe2(CO)4{κ2-(Ph2P)2(1,2-C6H4)}(μ-SCH2CH2S)]has been prepared and structurally characterized.Treatment of the parent complex[Fe2(CO)6(μ-SCH2CH2S)]with 1 equivalent of 1,2-bis(diphenylphosphino)benzene and Me3NO?2H2O as the oxidative agent gave the title complex in good yield.The title complex has been characterized by elemental analysis,IR,1H NMR,31P{1H}NMR,13C{1H}NMR spectroscopy,and X-ray crystallography.X-ray crystal structure of the title complex contains a butterfly diiron cluster with a bridging ethane-1,2-dithiolate,four terminal carbonyls,and a chelating 1,2-bis(diphenylphosphino)benzene.In addition,electrochemical studies revealed that the title complex can catalyze the reduction of protons to H2 in the presence of acetic acid.展开更多
Iron sites in both nitrogenase enzymes and chemical catalysts for N_(2) fixation are typically at constrained distances and angles.Herein,we report a one-electron reduction reaction realized by constrained diiron dini...Iron sites in both nitrogenase enzymes and chemical catalysts for N_(2) fixation are typically at constrained distances and angles.Herein,we report a one-electron reduction reaction realized by constrained diiron dinitrogen cores.Using the semicircular bis(β-diketiminate)ligand,a series of diiron dinitrogen complexes were synthesized,in which the N_(2) groups were allowed to bind with Fe-Ct_(N2)-Fe angles ranging from 154°to 158°(Ct_(N2)=centroid of N_(2)).One-electron reduction of complex 2a[LFe(μ-N_(2))Fe(Et_(2)O)]gave dimer product 3a[LFe(μ-N_(2))FeK]_(2)(μ-N_(2))or monomer 3b[LFe(μ-N_(2))Fe(DMAP)K].Based on superconducting quantum interference device measurements and density functional theory calculations,2a,3a,and 3b exhibited ground spin states of S=3,S=5,and S=5/2,respectively.In addition,complex 3 underwent N_(2)derivatization via a silylation pathway followed by an acidic cleavage to yield N_(2)H_(4)as the product.展开更多
A ( μ oxo)( μ CO 3)diiron(Ⅲ) complex of tri(2 pyridylmethyl)amine(TPA), [Fe 2L 2( μ O) ( μ CO 3)] (ClO 4) 2·MeOH·EtOH·H 2O], was synthesized and characterized, where L represents TPA. This complex ...A ( μ oxo)( μ CO 3)diiron(Ⅲ) complex of tri(2 pyridylmethyl)amine(TPA), [Fe 2L 2( μ O) ( μ CO 3)] (ClO 4) 2·MeOH·EtOH·H 2O], was synthesized and characterized, where L represents TPA. This complex crystallizes in the monoclinic space group P2 1/c with a =1.181 0(3) nm, b =3.728 1(8) nm, c = 1.377 0(3) nm , β =115.393(3)°, V =5.477(2) nm 3, Z =4. R 1=0.084 9 and wR 2=0.196 2. The UV Vis spectra of this compound show multiply absorption bands in 200-800 nm range, which are similar to that of N - 3 coordinated met hemerythrin. , was synthesized and characterized, where L represents TPA. This complex crystallizes in the monoclinic space group P2 1/c with a =1.181 0(3) nm, b =3.728 1(8) nm, c = 1.377 0(3) nm , β =115.393(3)°, V =5.477(2) nm 3, Z =4. R 1=0.084 9 and wR 2=0.196 2. The UV Vis spectra of this compound show multiply absorption bands in 200-800 nm range, which are similar to that of N - 3 coordinated met hemerythrin.展开更多
The synthesis and structure of [Fe(Phen)3][(μ-oxo)Fe2Cl6]稤MF are reported. The crystal data for the compound: monoclinic, P2l /c,a =15.491(1),b = 13.217(1),c = 20.748(2)牛?= 93.83(3),V = 4239(2)?,Z = 4,Dc = 1.562g/c...The synthesis and structure of [Fe(Phen)3][(μ-oxo)Fe2Cl6]稤MF are reported. The crystal data for the compound: monoclinic, P2l /c,a =15.491(1),b = 13.217(1),c = 20.748(2)牛?= 93.83(3),V = 4239(2)?,Z = 4,Dc = 1.562g/cm3,μ(MoK)=1.44 mm-1,F(000)= 2040.0, (C39H31Cl6Fe3N7O2) and Mr = 1009.96. X-ray crystallographic studies reveal that the title compound contains complexes of [Fe(Phen)3]2+ and [Fe2(μ-oxo)Cl6]2- which consists of two [FeCl3] fragments connected by an oxo bridge,with the bond distances of Fe(3)O(1) 1.744(4) and Fe(2)O(1) 1.754(4)牛琣nd a bond angle Fe(2)O(1)Fe(3) of 162.9(3). In the [Fe2(μ-oxo)Cl6]2- complex, the two iron (Ⅲ) centres exhibit tetrahedral coordination, with the distorted tetrahedra formed by three Cl atoms and an oxo bridge. The bond lengths to the donor atoms lie in the range 2.211(1)～2.226(1)?for FeCl, and the non-bonded Fe…Fe distance is 3.459?展开更多
Photocatalytic reduction of CO2 to CO is a promising approach for storing solar energy in chemicals and mitigating the greenhouse effect of CO2.Our recent studies revealed that[(μ-bdt)Fe2(CO)6](1,bdt=benzene-1,2-dith...Photocatalytic reduction of CO2 to CO is a promising approach for storing solar energy in chemicals and mitigating the greenhouse effect of CO2.Our recent studies revealed that[(μ-bdt)Fe2(CO)6](1,bdt=benzene-1,2-dithiolato),a[FeFe]-hydrogenase model with a rigid and conjugate S-to-S bridge,was catalytically active for the selective photochemical reduction of CO2 to CO,while its analogous complex[(μ-edt)Fe2(CO)6](2,edt=ethane-1,2-dithiolato)was inactive.In this study,it was found that the turnover number of 1 for CO evolution reached 710 for the 1/[Ru(bpy)3]2+/BIH(BIH=1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]-imidazole)system under optimal conditions over 4.5 h of visible-light irradiation,with a turnover frequency of 7.12 min−1 in the first hour,a high selectivity of 97%for CO,and an internal quantum yield of 2.8%.Interestingly,the catalytic selectivity of 1 can be adjusted and even completely switched in a facile manner between the photochemical reductions of CO2 to CO and of protons to H2 simply by adding different amounts of triethanolamine to the catalytic system.The electron transfer in the photocatalytic system was studied by steady-state fluorescence and transient absorption spectroscopy,and a plausible mechanism for the photocatalytic reaction was proposed.展开更多
A series of {2Fe3S} complexes bearing phosphino thioether chelating ligand were synthesized on the basis of Fe2（Me2pdt）（1,2-Cy2PC6H4SMe）（CO）4 （Me2pdt= Me2C（CH2S ）2, 1）. The disubstituted Fe（1）Fe（1） compo...A series of {2Fe3S} complexes bearing phosphino thioether chelating ligand were synthesized on the basis of Fe2（Me2pdt）（1,2-Cy2PC6H4SMe）（CO）4 （Me2pdt= Me2C（CH2S ）2, 1）. The disubstituted Fe（1）Fe（1） compound 1 exhibits a reversible one-electron redox even for [Fe（Ⅰ）Fe（Ⅱ）]＋/0 couple. Based on the oxidation of I to [1]＋, the tri-substituted [Fe（Ⅰ）Fe（Ⅱ）]＋ cationic complex [Fe2/Me2pdt）/1,2-Cy2PC6H4SMe） （PPh3）（CO）3]＋ （[2]＋） was synthesized. Reduction of [2]＋ provided the neutral tri-substituted Fe（l）Fe（1） compound 2. The substitution of the CO in I ligand by PPh3 results in an anodic shift of the Fe11Fe＋/Fe1Fe1 couple of470 mV. Most importantly, this substitution also leads to the Fe-Fe bonds in 1 and 2 with large Lewis basicity difference, i.e. △pKaMeCN ～ 10.展开更多
文摘To extend a new family of aminophosphine-coordinated[FeFe]-hydrogenase mimics for catalytic hydro-gen(H_(2))evolution,we carried out the ligand substitutions of diiron hexacarbonyl precursors[Fe_(2)(μ-X_(2)pdt)(CO)_(6)](X_(2)pdt=(SCH_(2))_(2)CX_(2),X=Me,H)with aminodiphosphines(Ph_(2)PCH_(2))_(2)NY(Y=(CH_(2))_(2)OH,(CH_(2))_(3)OH)to obtain two new diiron aminophosphine complexes[Fe_(2)(L1)(μ-Me_(2)pdt)(CO)_(5)](1)and[Fe_(2)(L2)(μ-H_(2)pdt)(CO)_(5)](2),where L1=3-[(diphe-nylphosphaneyl)methyl]oxazolidine,L2=3-[(diphenylphosphaneyl)methyl]-1,3-oxazinane.Moreover,the structures of 1 and 2 have been fully confirmed by elemental analysis,spectroscopic techniques,and single-crystal X-ray diffraction.Using cyclic voltammetry(CV),we investigated the electrochemical redox performance and proton reduc-tion activities of 1 and 2 in acetic acid(HOAc).The CV study indicates that diiron aminophosphine complexes 1 and 2 can be considered to be hydrogenase-inspired diiron molecular electrocatalysts for the reduction of protons into H 2 generation in the presence of HOAc.CCDC:2443967,1;2443969,2.
基金supported by the National Natural Science Foundation of China (20902051,21002090)the Key Laboratory of Pesticide Chemistry and Application,Ministry of Agriculture (MOA) (No.MOAPCA201005)+1 种基金the Foundation of the Education Committee of Zhejiang Province (Y201018479,Z200906833)the Natural Science Foundation of Ningbo (2010A610186)
文摘Reaction of [（μ-SCH2）2NPh]Fe2（CO）6 with Ph2PCH2PPh2 in the presence of Me3NO·2H2O gave the title complex [（μ-SCH2）2NPh]Fe2（CO）5（Ph2PCH2PPh2）（1）in 78% yield.The new complex 1 was characterized by elemental analysis,spectroscopy and X-ray crys-tallography.It crystallizes in triclinic,space group P1 with a = 10.832（2）,b = 12.003（2）,c = 15.579（3）,V = 1785.6（6）3,Z = 2,C32H26Fe2NO5PS2,Mr = 819.40,Dc = 1.524 g/cm3,μ（MoKα）= 1.064 mm-1,F（000）= 840,T = 113（2）K,the final R = 0.0543 and wR = 0.1218 for 6203 observed reflections（I 2σ（I））.The Ph2PCH2PPh2 ligand resides in an axial position of the square-pyramidal coordination sphere of the Fe atom and trans to the benzene ring in order to reduce the steric repulsion between Ph2PCH2PPh2 and the benzene ring.
文摘As DNA cleavage agent, a new diiron（Ⅲ） complex （Fe2Lb）, in which a DNA-intercalator （pyrene） is covalently linked to a diferric moiety, has been synthesized and characterized. The DNA-binding property and DNA cleavage activity of the complex have also been investigated.
基金Supported by the Natural Science Foundation of Zhejiang Province(No.LY16B020009)K.C.Wong Education Foundation
文摘The title complex,（μ-pdt）Fe_2（CO）_5（Ph_2PCH_3）（pdt = SCH_2CH_2CH_2S）,was obtained by the reaction of the parent complex（μ-pdt）Fe_2（CO）_6 with Ph_2PCH_3 and Me_3NO·2H_2O in good yield（90%）. The title complex was characterized by IR,~1H NMR,^（31）P{~1H} NMR and ^（13）C{~1H} NMR spectroscopy as well as by single-crystal X-ray diffraction analysis. The molecular structure shows that the title complex contains a butterfly diiron propanedithiolate cluster with five terminal carbonyls and a monophosphine ligand Ph_2PCH_3. The crystal packing diagram reveals that intermolecular C H···O hydrogen bonds between CH_2 and carbonyls,π-π stacking interactions and van der Waals＇ interactions stabilize the solid state to form a three-dimensional network.
基金supported by Science & Technology Department of Sichuan Province (2011JY0052,2012JY0115, 2010GZ0130)Sichuan University of Science & Engineering (2011RC06, 2012PY04, 2012PY14)
文摘Two new diiron ethanedithiolate complexes Fe2（S2C2H4）（CO）5（2-Ph2PC6H4NH2） （1） and Fez（S2CzH4）（CO）5（2-PhzPC6H4CHzNH2） （2） as active site models of [FeFe] hydrogenases have been prepared by the treatment of （,u-SCHzCH2S-μ）Fe2（CO）6 with 2-PhzPC6H4NH2 or 2-PhzPC6H4CH2NH2 in the presence of the decarbonylating agent Me3NO＇2H20. As new complexes, both 1 and 2 were fully characterized by elemental analysis, IR and^1H （13C, 31p） NMR spectroscopies. In addition, the molecular structure of complex 1 was established by X-ray crystallography. The crystal of Fe2（S2C2H4）（CO）5（2-PhzPC6H4NH2） （1） crystallizes in orthorhombic, spacegroup Pna21 with a = 20.9461（17）, b = 13.7615（11）, c = 9.3133（7）A, V= 2684.6（4） A3, Z = 4, C25Hz0FezNOsPS2, Mr = 621.21, Dc = 1.537 g/cm^3, F（000） = 1264. The final R = 0.0197 and wR = 0.0495 for 4605 observed reflections with I 〉 2a（/） and R = 0.0206 and wR = 0.0501 for all data.
基金Supported by the start-up foundation of Ningbo University of Technologythe National Natural Science Foundation of China (20902051,21002090)+1 种基金Foundation of the Education Committee of Zhejiang Province (Z200906833)the Natural Science Foundation of Ningbo city (2010A610186)
文摘Treatment of complex [（μ-SCH2）2NCH2Ph]Fe2（CO）6 with PPh3 in the presence of decarbonylating agent Me3NO-2H2O afforded the rifle complex [（μ-SCH2）2NCH2Ph]Fe2（CO）5（PPh3） in 70% yield. The new complex was characterized by elemental analysis, IR, and 1H （31p, 13C） NMR spectroscopic techniques as well as by X-ray crystallography. It crystallizes in triclinic, space group P i with a = 9.3016（19）, b = 12.698（3）, c = 13.904（3） A, V = 1519.8（7） A3, Z = 2, C32H26Fe2NOsPS2, Mr = 711.33, Dc = 1.554 g/cm3, μ（MoKa） = 1.187 mm^-1, F（000） = 728, T= 113（2） K, the final R = 0.0288 and wR = 0.0680 for 3982 observed reflections （I 〉 2σ（I））. The PPh3 ligand resides in an axial position of the square-pyramidal geometry of the neighboring Fe atom and trans to the benzene ring in order to minimize the steric repulsion between PPh3 and the benzene ring.
基金supported by the Education Department of Jiangxi Province (GJJ11033)
文摘The reaction of [Fe2S2（CO）6] with one equiv.of o-OCH3C6H4CH2Br under the re-duction of LiBHEt3 in dry THF afforded a tetranuclear cluster [（μ4-S）{（μ-SCH2（o-OCH3）Ph）Fe2（CO）6}2]（1）.Complex 1 crystallizes in monoclinic,space group P21/n with a = 16.5623（6）,b = 12.8265（5）,c = 18.2702（7） ,β = 115.95（1）o,V = 3489.9（4） 3,Z = 4,μ = 1.87 mm-1,Dc = 1.709 Mg/m3,T = 296（2） K,C28H18Fe4O14S3,Mr = 898.03,F（000） = 1800,S = 1.10,R = 0.032 and wR = 0.058.Complex 1 consists of two diiron fragments possessing a {Fe2（CO）6} core.The two diiron units are bridged by an inorganic sulfide in a μ4-S binding mode and the sulfide is in a distorted tetrahedral geometry with the four iron atoms at each corner of the distorted tetrahedral.In its solid state,two types of non-classic intermolecular hydrogen bonding interactions plus a weak π-π stacking interaction led to a 2-D network.
文摘The activation of dioxygen and incorporation into hydrocarbons have been achieved under mild conditions by a methane monooxygenase (MMO)-like system using a dinuclear iron complex [Fe2Dhist(OAc)2] BPh4 ·3H2O as the model complex, zinc powder as the electron donor, HOAc as the proton source and methylviologen as the electron transfer agent. The results show that styrene is oxygenated predominantly to styrene oxide (1 396 mol/100 mol of the Fe2 complex), benzaldehyde (16160) and acetophenone (986), and cyclohexane to cyclohexanol (9370) and cyclo-hexanone (2670). EPR studies indicate that the hypervalent ironoxo spiecs FeⅣFeⅣ=O, derived from FeⅢFeⅢ core via reduction, O2-binding and protonation, is the active intermediate which inserts the activated oxygen atom into C=C or C-H bond giving each product. The system closely resembles MMO and its close relative hemerythrin in the aspects of reaction phenomena, EPR characteristics and product distributions. The Mn2 analog cmplex、 Fe-Zn het-erodinuclear complex and mononuclear iron complex show no catalytic activity, indicating that dinuclear iron core is in-despansable to catalytic activity.
基金supported by the Natural Science Foundation of Zhejiang Province(LY19B020002)National Natural Science Foundation of China(21501124)+2 种基金Science&Technology Department of Sichuan Province(2018JY0235)Education Department of Sichuan Province(18ZA0337)Sichuan University of Science&Engineering(S201910622022)。
文摘In this paper,a novel diiron ethane-1,2-dithiolate complex[Fe2(CO)4{κ2-(Ph2P)2(1,2-C6H4)}(μ-SCH2CH2S)]has been prepared and structurally characterized.Treatment of the parent complex[Fe2(CO)6(μ-SCH2CH2S)]with 1 equivalent of 1,2-bis(diphenylphosphino)benzene and Me3NO?2H2O as the oxidative agent gave the title complex in good yield.The title complex has been characterized by elemental analysis,IR,1H NMR,31P{1H}NMR,13C{1H}NMR spectroscopy,and X-ray crystallography.X-ray crystal structure of the title complex contains a butterfly diiron cluster with a bridging ethane-1,2-dithiolate,four terminal carbonyls,and a chelating 1,2-bis(diphenylphosphino)benzene.In addition,electrochemical studies revealed that the title complex can catalyze the reduction of protons to H2 in the presence of acetic acid.
基金supported by National Natural Science Foundation of China(grant nos.21988101,22201013,92161204)China Postdoctoral Science Foundation(grant no.2020M670016)Beijing Natural Science Foundation(grant no.2222008).
文摘Iron sites in both nitrogenase enzymes and chemical catalysts for N_(2) fixation are typically at constrained distances and angles.Herein,we report a one-electron reduction reaction realized by constrained diiron dinitrogen cores.Using the semicircular bis(β-diketiminate)ligand,a series of diiron dinitrogen complexes were synthesized,in which the N_(2) groups were allowed to bind with Fe-Ct_(N2)-Fe angles ranging from 154°to 158°(Ct_(N2)=centroid of N_(2)).One-electron reduction of complex 2a[LFe(μ-N_(2))Fe(Et_(2)O)]gave dimer product 3a[LFe(μ-N_(2))FeK]_(2)(μ-N_(2))or monomer 3b[LFe(μ-N_(2))Fe(DMAP)K].Based on superconducting quantum interference device measurements and density functional theory calculations,2a,3a,and 3b exhibited ground spin states of S=3,S=5,and S=5/2,respectively.In addition,complex 3 underwent N_(2)derivatization via a silylation pathway followed by an acidic cleavage to yield N_(2)H_(4)as the product.
文摘A ( μ oxo)( μ CO 3)diiron(Ⅲ) complex of tri(2 pyridylmethyl)amine(TPA), [Fe 2L 2( μ O) ( μ CO 3)] (ClO 4) 2·MeOH·EtOH·H 2O], was synthesized and characterized, where L represents TPA. This complex crystallizes in the monoclinic space group P2 1/c with a =1.181 0(3) nm, b =3.728 1(8) nm, c = 1.377 0(3) nm , β =115.393(3)°, V =5.477(2) nm 3, Z =4. R 1=0.084 9 and wR 2=0.196 2. The UV Vis spectra of this compound show multiply absorption bands in 200-800 nm range, which are similar to that of N - 3 coordinated met hemerythrin. , was synthesized and characterized, where L represents TPA. This complex crystallizes in the monoclinic space group P2 1/c with a =1.181 0(3) nm, b =3.728 1(8) nm, c = 1.377 0(3) nm , β =115.393(3)°, V =5.477(2) nm 3, Z =4. R 1=0.084 9 and wR 2=0.196 2. The UV Vis spectra of this compound show multiply absorption bands in 200-800 nm range, which are similar to that of N - 3 coordinated met hemerythrin.
基金Supported by the foundation of Education Committee of Fujian Province (JB01045)
文摘The synthesis and structure of [Fe(Phen)3][(μ-oxo)Fe2Cl6]稤MF are reported. The crystal data for the compound: monoclinic, P2l /c,a =15.491(1),b = 13.217(1),c = 20.748(2)牛?= 93.83(3),V = 4239(2)?,Z = 4,Dc = 1.562g/cm3,μ(MoK)=1.44 mm-1,F(000)= 2040.0, (C39H31Cl6Fe3N7O2) and Mr = 1009.96. X-ray crystallographic studies reveal that the title compound contains complexes of [Fe(Phen)3]2+ and [Fe2(μ-oxo)Cl6]2- which consists of two [FeCl3] fragments connected by an oxo bridge,with the bond distances of Fe(3)O(1) 1.744(4) and Fe(2)O(1) 1.754(4)牛琣nd a bond angle Fe(2)O(1)Fe(3) of 162.9(3). In the [Fe2(μ-oxo)Cl6]2- complex, the two iron (Ⅲ) centres exhibit tetrahedral coordination, with the distorted tetrahedra formed by three Cl atoms and an oxo bridge. The bond lengths to the donor atoms lie in the range 2.211(1)～2.226(1)?for FeCl, and the non-bonded Fe…Fe distance is 3.459?
文摘Photocatalytic reduction of CO2 to CO is a promising approach for storing solar energy in chemicals and mitigating the greenhouse effect of CO2.Our recent studies revealed that[(μ-bdt)Fe2(CO)6](1,bdt=benzene-1,2-dithiolato),a[FeFe]-hydrogenase model with a rigid and conjugate S-to-S bridge,was catalytically active for the selective photochemical reduction of CO2 to CO,while its analogous complex[(μ-edt)Fe2(CO)6](2,edt=ethane-1,2-dithiolato)was inactive.In this study,it was found that the turnover number of 1 for CO evolution reached 710 for the 1/[Ru(bpy)3]2+/BIH(BIH=1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]-imidazole)system under optimal conditions over 4.5 h of visible-light irradiation,with a turnover frequency of 7.12 min−1 in the first hour,a high selectivity of 97%for CO,and an internal quantum yield of 2.8%.Interestingly,the catalytic selectivity of 1 can be adjusted and even completely switched in a facile manner between the photochemical reductions of CO2 to CO and of protons to H2 simply by adding different amounts of triethanolamine to the catalytic system.The electron transfer in the photocatalytic system was studied by steady-state fluorescence and transient absorption spectroscopy,and a plausible mechanism for the photocatalytic reaction was proposed.
基金financial support from the "1000 Youth Talents Plan" the Natural Science Foundation of China (Nos. 21402107, 91427303)IIT Kanpur for funding
文摘A series of {2Fe3S} complexes bearing phosphino thioether chelating ligand were synthesized on the basis of Fe2（Me2pdt）（1,2-Cy2PC6H4SMe）（CO）4 （Me2pdt= Me2C（CH2S ）2, 1）. The disubstituted Fe（1）Fe（1） compound 1 exhibits a reversible one-electron redox even for [Fe（Ⅰ）Fe（Ⅱ）]＋/0 couple. Based on the oxidation of I to [1]＋, the tri-substituted [Fe（Ⅰ）Fe（Ⅱ）]＋ cationic complex [Fe2/Me2pdt）/1,2-Cy2PC6H4SMe） （PPh3）（CO）3]＋ （[2]＋） was synthesized. Reduction of [2]＋ provided the neutral tri-substituted Fe（l）Fe（1） compound 2. The substitution of the CO in I ligand by PPh3 results in an anodic shift of the Fe11Fe＋/Fe1Fe1 couple of470 mV. Most importantly, this substitution also leads to the Fe-Fe bonds in 1 and 2 with large Lewis basicity difference, i.e. △pKaMeCN ～ 10.
