Two[FeFe]-hydrogenase compounds with 2-cyanobenzyl groups,{Fe_(2)[(SCH_(2)CH_(3))(SR)](CO)_(6)}(1 or 1′,which are the crystalline states from petroleum ether and dichloromethane solution,respectively)and{Fe_(2)[(SCH_...Two[FeFe]-hydrogenase compounds with 2-cyanobenzyl groups,{Fe_(2)[(SCH_(2)CH_(3))(SR)](CO)_(6)}(1 or 1′,which are the crystalline states from petroleum ether and dichloromethane solution,respectively)and{Fe_(2)[(SCH_(2)CH_(3))(SR)](CO)_(5)(PPh_(3))}(2)(R=2-cyanobenzyl),were synthesized and characterized by infrared spectroscopy,UV-Vis spectroscopy,single-crystal diffraction,powder X-ray diffraction,etc.Their performances as photocatalysts for H_(2)production through water splitting were evaluated.The results showed that 316.8μmol of H_(2)was produced on compound 1 after 3 h of illumination,with a catalytic efficiency of 25.1μmol·mg^(-1)·h^(-1)and a turnover number(TON)of 36.8.The replacement of carbonyl with PPh3 could significantly improve the catalytic performance of the complex,and 705.0μmol of H_(2)was produced on 2 after 3 h of illumination,with a catalytic efficiency of 37.9μmol·mg^(-1)·h^(-1)and a TON of 81.8.CCDC:2515700,1;2515702,1′;2515701,2.展开更多
A compound containing[FeFe]‑hydrogenase,[Fe_(2)((SCH_(2))_(2)R)(CO)_(6)](1)(R=4‑{(1H‑benzo[d]imidazol‑1‑yl)methyl}‑anilino),was prepared and thoroughly characterized by infrared spectroscopy,single‑crystal X‑ray diffr...A compound containing[FeFe]‑hydrogenase,[Fe_(2)((SCH_(2))_(2)R)(CO)_(6)](1)(R=4‑{(1H‑benzo[d]imidazol‑1‑yl)methyl}‑anilino),was prepared and thoroughly characterized by infrared spectroscopy,single‑crystal X‑ray diffraction,and density functional theory calculations.Its performance as a photocatalyst for hydrogen production via water splitting was evaluated under simulated sunlight.Within 3 h,the amount of H_(2)produced was 386.5μmol,achieving a catalytic efficiency of 25.26μmol·mg^(-1)·h^(-1)and a turnover number(TON)of 0.45.CCDC:2457448.展开更多
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
以Fe(CO)_(5)和含一个巯基的配体为原料,通过多步反应合成了两个新的[FeFe]氢化酶模拟物1和2;构建了以化合物1和2为光催化剂、藻红B钠盐(EBS^(2-))为光敏剂、三乙胺(TEA)为电子给体和质子源的三组分光催化产氢体系,该体系在pH值为12且...以Fe(CO)_(5)和含一个巯基的配体为原料,通过多步反应合成了两个新的[FeFe]氢化酶模拟物1和2;构建了以化合物1和2为光催化剂、藻红B钠盐(EBS^(2-))为光敏剂、三乙胺(TEA)为电子给体和质子源的三组分光催化产氢体系,该体系在pH值为12且体积比为1∶1的CH_(3)CN/H_(2)O溶液中,经可见光(λ>420 nm)照射4 h,最大产氢量为205.0μmol,相对于化合物2的催化转化数(TON)为51.4;研究表明,配体中含有较多的质子捕获位点,有利于形成产氢活性中间体H 2-2Fe2S(η2-H 2-Fe II Fe I)物种,从而提高催化剂的产氢活性,光生电子从1*EBS^(2-)化合物1和2的第一个电子的转移均为热力学可行过程,到化合物1和2的第二个电子转移是热力学不可行过程。展开更多
A new 2Fe2 S complex[(2-C5H4N)N(μ-CH2S)2Fe2(CO)6](1) related to the active site of[FeFe]-hydrogenase was obtained by treating(HS)2Fe2(CO)6 with(pyridin-2-ylazanediyl)dimethanol.Protonation occurred at t...A new 2Fe2 S complex[(2-C5H4N)N(μ-CH2S)2Fe2(CO)6](1) related to the active site of[FeFe]-hydrogenase was obtained by treating(HS)2Fe2(CO)6 with(pyridin-2-ylazanediyl)dimethanol.Protonation occurred at the pyridine nitrogen atom when two equivalents of HBF4·OEt2acid were added to the toluene solution of 1,leading to the formation of[(2-C5H4NH)N(μ-CH2S)2Fe2(CO)6]·BF4·OEt2(1H~+),whose molecular structure was further established by singlecrystal X-ray analysis.Complex 1 crystallizes in the monoclinic system,space group P21/n with α=7.728(3),b = 11.825(4),c = 17.888(6) A,β= 92.968(5)°,while complex 1H~+ crystallizes in the triclinic system,space group P1 with a = 7.672(4),b = 10.382(5),c = 16.480(10) A,α=106.575(13),β= 93.18(3),γ=104.262(17)°.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
Mimics of [FeFe]-hydrogenases having two [(μ-adt)Fe_(2)(CO)_(6)] moieties linked through 1,2,3-triazole ringswith polyethylene glycol (PEG) chains [(-OCH_(2)CH_(2)O-)4 (7) and (-OCH_(2)CH_(2)O-)5 (8)] are able to coo...Mimics of [FeFe]-hydrogenases having two [(μ-adt)Fe_(2)(CO)_(6)] moieties linked through 1,2,3-triazole ringswith polyethylene glycol (PEG) chains [(-OCH_(2)CH_(2)O-)4 (7) and (-OCH_(2)CH_(2)O-)5 (8)] are able to coordinateto alkali ions (Na^(+), K^(+)) via the O-PEG atoms and the triazole-N3 positions. Electrocatalytic studies intrifluoroacetic acid (TFA) demonstrate that their catalytic performance is affected by the presence of Na+and K+ salts. The addition of NaPF6 decreases the electrocatalytic activity of 7 and 8 (about 50% reductionof the TOF values). As, in TFA, 7 and 8 could be protonated in both the triazole and adt-amino groups, thereduction in TOF values suggests that NaPF6 inhibits the contribution of the triazolium species to theelectrocatalytic process, likely due to the involvement of the triazole-N3 positions in Na^(+) binding.However, the addition of KPF_(6) either does not change (7) or increases the TOF values (8). ^(1)H NMR titrationexperiments demonstrate that, despite the presence of K^(+) ions in the media, triazolium salts are formed.Therefore, the TOF values should reflect the contribution of species protonated in both the triazole andadt-amino groups to the HER process.展开更多
In order to enrich the chemistry of the Fe/Te cluster compounds related to the active site of the[FeFe]-hydrogenase,the reactions of compound Fe_(2)(μ-TeAr)_(2)(CO)_(6)with tertiary phosphines were described.Three ty...In order to enrich the chemistry of the Fe/Te cluster compounds related to the active site of the[FeFe]-hydrogenase,the reactions of compound Fe_(2)(μ-TeAr)_(2)(CO)_(6)with tertiary phosphines were described.Three types of novel phosphine substituted Fe/Te model compounds were successfully prepared.That is,the treatment of Fe_(2)(μ-TeAr)_(2)(CO)_(6)(Ar=C_(6)H_(5)A,C_(6)H_(4)-F-4 B)with 2 equivalents of PPh_(3)under UV conditions produced dinuclear compounds Fe_(2)(μ-TeC_(6)H_(5))_(2)(CO)_(4)(PPh_(3))_(2)(1)and Fe_(2)(μ-TeC_(6)H_(4)-F-4)_(2)(CO)_(4)(PPh_(3))_(2)(2)in moderate yields together with unusual tetranuclear compounds Fe4(μ-TeC_(6)H_(5))_(6)(CO)_(6)(PPh_(3))_(2)(3)and Fe4(μ-TeC_(6)H_(4)-4-F)_(6)(CO)_(6)(PPh_(3))_(2)(4).The syn-and anti-isomers of 1 and 2 were isolated in the solid state using the TLC method.Furthermore,the reaction of Fe_(2)(μ-TeAr)_(2)(CO)_(6)and 4 equivalents of PMe_(3)gave new types of mononuclear PMe_(3)-disubstituted compounds Fe(TeC_(6)H_(5))_(2)(CO)_(2)(PMe_(3))_(2)(5)and Fe(TeC_(6)H_(4)-4-F)_(2)(CO)_(2)(PMe_(3))_(2)(6)which could mimic Fed of the[FeFe]-hydrogenase.All the new compounds were fully characterized by elemental analysis,IR,NMR spectroscopy,UV-Visible absorption and particularly some of them by X-ray crystallography.The electrochemical properties of 1,2,5 and 6 were also investigated,demonstrating that these compounds can be considered as electrochemical catalysts for the hydrogen evolution reaction.According to the electrochemical behavior of 5 and 6,a CEECC mechanism was proposed for the catalytic process.展开更多
In this study,we present a convenient method to obtain two types of novel tetra-substituted Fe/Se salts through a dehalogenation reaction,aiming to advance research on mimicking the FeⅡFeⅡ oxidation state of[FeFe]-H...In this study,we present a convenient method to obtain two types of novel tetra-substituted Fe/Se salts through a dehalogenation reaction,aiming to advance research on mimicking the FeⅡFeⅡ oxidation state of[FeFe]-H_(2) ases.Initially,by treating[Fe_(2)(μ-SeBn)_(2)(CO)_(4)(dppv)](Bn=CH_(2)C_(6)H_(5),dppv=cis-1,2-bis(diphenylphosphino)ethylene)with one equivalent of dppv under UV and reflux conditions,the neutral FeIFeI and FeⅡFeⅡ precursors[Fe_(2)(μ-SeBn)_(2)(CO)_(2)(dppv)_(2)](1)and[Fe_(2)(μ-SeBn)_(2)(μ-Se)(CO)_(2)(dppv)_(2)](2)were successfully isolated in good yields.Subsequently,1 underwent dehalogenation reactions with halocarbons(such as CCl_(4) and CBr4)or I_(2),leading to the formation of tetra-substituted salts[Fe_(2)(μ-SeBn)_(2)(μ-X)(CO)_(2)(dppv)_(2)]+(X=Cl,Br,and I)([3]Cl,[4]Br and[5]I_(3)).GC-MS analysis of the reaction with carbon tetrachloride detected the formation of the homo-coupled product CCl_(3)-CCl_(3)(m/z=235),indicating the presence of a CCl_(3)·species.Notably,2 also exhibited intriguing reactivity with R-X and I_(2).Unlike 1,the reaction of 2 with RX or I_(2) involved cleavage of the C-Se bond,leading to the isolation of[Fe_(2)(μ-SeBn)(μ-Se_(2))(CO)_(2)(dppv)_(2)]+X-(X=Cl,Br,I_(3))([6]Cl,[6]Br and[6]I_(3))in good yields.The reaction involved debenzylation of 2 and was confirmed by GC-MS detection of C6H5CH_(2)CCl_(3)(m/z=208)in the reaction with CCl_(4),suggesting a radical pathway.展开更多
文摘Two[FeFe]-hydrogenase compounds with 2-cyanobenzyl groups,{Fe_(2)[(SCH_(2)CH_(3))(SR)](CO)_(6)}(1 or 1′,which are the crystalline states from petroleum ether and dichloromethane solution,respectively)and{Fe_(2)[(SCH_(2)CH_(3))(SR)](CO)_(5)(PPh_(3))}(2)(R=2-cyanobenzyl),were synthesized and characterized by infrared spectroscopy,UV-Vis spectroscopy,single-crystal diffraction,powder X-ray diffraction,etc.Their performances as photocatalysts for H_(2)production through water splitting were evaluated.The results showed that 316.8μmol of H_(2)was produced on compound 1 after 3 h of illumination,with a catalytic efficiency of 25.1μmol·mg^(-1)·h^(-1)and a turnover number(TON)of 36.8.The replacement of carbonyl with PPh3 could significantly improve the catalytic performance of the complex,and 705.0μmol of H_(2)was produced on 2 after 3 h of illumination,with a catalytic efficiency of 37.9μmol·mg^(-1)·h^(-1)and a TON of 81.8.CCDC:2515700,1;2515702,1′;2515701,2.
文摘A compound containing[FeFe]‑hydrogenase,[Fe_(2)((SCH_(2))_(2)R)(CO)_(6)](1)(R=4‑{(1H‑benzo[d]imidazol‑1‑yl)methyl}‑anilino),was prepared and thoroughly characterized by infrared spectroscopy,single‑crystal X‑ray diffraction,and density functional theory calculations.Its performance as a photocatalyst for hydrogen production via water splitting was evaluated under simulated sunlight.Within 3 h,the amount of H_(2)produced was 386.5μmol,achieving a catalytic efficiency of 25.26μmol·mg^(-1)·h^(-1)and a turnover number(TON)of 0.45.CCDC:2457448.
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.
文摘以Fe(CO)_(5)和含一个巯基的配体为原料,通过多步反应合成了两个新的[FeFe]氢化酶模拟物1和2;构建了以化合物1和2为光催化剂、藻红B钠盐(EBS^(2-))为光敏剂、三乙胺(TEA)为电子给体和质子源的三组分光催化产氢体系,该体系在pH值为12且体积比为1∶1的CH_(3)CN/H_(2)O溶液中,经可见光(λ>420 nm)照射4 h,最大产氢量为205.0μmol,相对于化合物2的催化转化数(TON)为51.4;研究表明,配体中含有较多的质子捕获位点,有利于形成产氢活性中间体H 2-2Fe2S(η2-H 2-Fe II Fe I)物种,从而提高催化剂的产氢活性,光生电子从1*EBS^(2-)化合物1和2的第一个电子的转移均为热力学可行过程,到化合物1和2的第二个电子转移是热力学不可行过程。
基金supported by the National Basic Research Program of China(973 Program2012CB821702)+1 种基金the National Natural Science Foundation of China(21233009 and 21173221)the State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences
文摘A new 2Fe2 S complex[(2-C5H4N)N(μ-CH2S)2Fe2(CO)6](1) related to the active site of[FeFe]-hydrogenase was obtained by treating(HS)2Fe2(CO)6 with(pyridin-2-ylazanediyl)dimethanol.Protonation occurred at the pyridine nitrogen atom when two equivalents of HBF4·OEt2acid were added to the toluene solution of 1,leading to the formation of[(2-C5H4NH)N(μ-CH2S)2Fe2(CO)6]·BF4·OEt2(1H~+),whose molecular structure was further established by singlecrystal X-ray analysis.Complex 1 crystallizes in the monoclinic system,space group P21/n with α=7.728(3),b = 11.825(4),c = 17.888(6) A,β= 92.968(5)°,while complex 1H~+ crystallizes in the triclinic system,space group P1 with a = 7.672(4),b = 10.382(5),c = 16.480(10) A,α=106.575(13),β= 93.18(3),γ=104.262(17)°.
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.
基金Support for this work from the Ministerio de Ciencia,Innovación y Universidades(Grants PID2022-139177OB-I00 and RED2022-134287-T)is acknowledgedrecipient of an FPU fellowship(FPU16/02062).
文摘Mimics of [FeFe]-hydrogenases having two [(μ-adt)Fe_(2)(CO)_(6)] moieties linked through 1,2,3-triazole ringswith polyethylene glycol (PEG) chains [(-OCH_(2)CH_(2)O-)4 (7) and (-OCH_(2)CH_(2)O-)5 (8)] are able to coordinateto alkali ions (Na^(+), K^(+)) via the O-PEG atoms and the triazole-N3 positions. Electrocatalytic studies intrifluoroacetic acid (TFA) demonstrate that their catalytic performance is affected by the presence of Na+and K+ salts. The addition of NaPF6 decreases the electrocatalytic activity of 7 and 8 (about 50% reductionof the TOF values). As, in TFA, 7 and 8 could be protonated in both the triazole and adt-amino groups, thereduction in TOF values suggests that NaPF6 inhibits the contribution of the triazolium species to theelectrocatalytic process, likely due to the involvement of the triazole-N3 positions in Na^(+) binding.However, the addition of KPF_(6) either does not change (7) or increases the TOF values (8). ^(1)H NMR titrationexperiments demonstrate that, despite the presence of K^(+) ions in the media, triazolium salts are formed.Therefore, the TOF values should reflect the contribution of species protonated in both the triazole andadt-amino groups to the HER process.
基金support for this work was provided by the Natural Science Foundation of Shandong Province(ZR2017PB014)the National Natural Science Foundation of China(21501124)+1 种基金the Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province(CSPC201904)the Sichuan Provincial Human Resource and Social Security Department,Sichuan University of Science&Engineering(2019RC41,201710622016,y2019030).
文摘In order to enrich the chemistry of the Fe/Te cluster compounds related to the active site of the[FeFe]-hydrogenase,the reactions of compound Fe_(2)(μ-TeAr)_(2)(CO)_(6)with tertiary phosphines were described.Three types of novel phosphine substituted Fe/Te model compounds were successfully prepared.That is,the treatment of Fe_(2)(μ-TeAr)_(2)(CO)_(6)(Ar=C_(6)H_(5)A,C_(6)H_(4)-F-4 B)with 2 equivalents of PPh_(3)under UV conditions produced dinuclear compounds Fe_(2)(μ-TeC_(6)H_(5))_(2)(CO)_(4)(PPh_(3))_(2)(1)and Fe_(2)(μ-TeC_(6)H_(4)-F-4)_(2)(CO)_(4)(PPh_(3))_(2)(2)in moderate yields together with unusual tetranuclear compounds Fe4(μ-TeC_(6)H_(5))_(6)(CO)_(6)(PPh_(3))_(2)(3)and Fe4(μ-TeC_(6)H_(4)-4-F)_(6)(CO)_(6)(PPh_(3))_(2)(4).The syn-and anti-isomers of 1 and 2 were isolated in the solid state using the TLC method.Furthermore,the reaction of Fe_(2)(μ-TeAr)_(2)(CO)_(6)and 4 equivalents of PMe_(3)gave new types of mononuclear PMe_(3)-disubstituted compounds Fe(TeC_(6)H_(5))_(2)(CO)_(2)(PMe_(3))_(2)(5)and Fe(TeC_(6)H_(4)-4-F)_(2)(CO)_(2)(PMe_(3))_(2)(6)which could mimic Fed of the[FeFe]-hydrogenase.All the new compounds were fully characterized by elemental analysis,IR,NMR spectroscopy,UV-Visible absorption and particularly some of them by X-ray crystallography.The electrochemical properties of 1,2,5 and 6 were also investigated,demonstrating that these compounds can be considered as electrochemical catalysts for the hydrogen evolution reaction.According to the electrochemical behavior of 5 and 6,a CEECC mechanism was proposed for the catalytic process.
基金the Natural Science Foundation of Shandong Province(No.ZR2020MB019)Introduction and Cultivation Project for Young Innovative Talents in Shandong Provincial Colleges and Universities for financial support.
文摘In this study,we present a convenient method to obtain two types of novel tetra-substituted Fe/Se salts through a dehalogenation reaction,aiming to advance research on mimicking the FeⅡFeⅡ oxidation state of[FeFe]-H_(2) ases.Initially,by treating[Fe_(2)(μ-SeBn)_(2)(CO)_(4)(dppv)](Bn=CH_(2)C_(6)H_(5),dppv=cis-1,2-bis(diphenylphosphino)ethylene)with one equivalent of dppv under UV and reflux conditions,the neutral FeIFeI and FeⅡFeⅡ precursors[Fe_(2)(μ-SeBn)_(2)(CO)_(2)(dppv)_(2)](1)and[Fe_(2)(μ-SeBn)_(2)(μ-Se)(CO)_(2)(dppv)_(2)](2)were successfully isolated in good yields.Subsequently,1 underwent dehalogenation reactions with halocarbons(such as CCl_(4) and CBr4)or I_(2),leading to the formation of tetra-substituted salts[Fe_(2)(μ-SeBn)_(2)(μ-X)(CO)_(2)(dppv)_(2)]+(X=Cl,Br,and I)([3]Cl,[4]Br and[5]I_(3)).GC-MS analysis of the reaction with carbon tetrachloride detected the formation of the homo-coupled product CCl_(3)-CCl_(3)(m/z=235),indicating the presence of a CCl_(3)·species.Notably,2 also exhibited intriguing reactivity with R-X and I_(2).Unlike 1,the reaction of 2 with RX or I_(2) involved cleavage of the C-Se bond,leading to the isolation of[Fe_(2)(μ-SeBn)(μ-Se_(2))(CO)_(2)(dppv)_(2)]+X-(X=Cl,Br,I_(3))([6]Cl,[6]Br and[6]I_(3))in good yields.The reaction involved debenzylation of 2 and was confirmed by GC-MS detection of C6H5CH_(2)CCl_(3)(m/z=208)in the reaction with CCl_(4),suggesting a radical pathway.