Iron-Thiolate Cyanocarbonyl Complexes：Biomimetic Model Compounds of [NiFe]Hydrogenases

• Main Authors: Jung-Hong Lee, 李俊宏
• Other Authors: Wen-Feng Liaw
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/92759615868465704408

碩士 === 國立彰化師範大學 === 科學教育研究所 === 89 === Abstract Oxidative addition of diorganyl disulfides to the coordinatively unaturated, low-valent metal-carbonyl fragment [HFe(CO)4]－ produced fac-[(CO)3Fe(SR)3]－[R=S-C7H4SN (1)、S-C4H2O-o-CH3(2)], was employed as a “metallo chelating” ligand to synthesize [(CO)3Fe(S-C4H2O-o-CH3)3Ni(S-C4H2O-o-CH3)3Fe(CO)3] (3). The hexacoordinate Fe(Ⅱ) complex [PPN][(CO)(CN)Fe(S-C4H3S)2 (C8H6N4)](5)was prepared by the reaction of di-(thienyl)-disulfide, 2,2’-Bipyrimidine and [Fe(CO)4(CN)]－in CH3CN,The dinuclear Fe(Ⅱ)—thiolate cyanocarbonyl compound [PPN]2[(CO)2(CN)Fe(S,S-C6H3-m-CH3)]2(4),the promissing structural and functional model compound of the dinuclear iron active sites of [Fe] only hydrogenases isolated from D. desulfuricans and C. pasteurianum,was prepared by reaction toluene 3,4-dithiol,di-(thienyl)-disulfide and[Fe(CO)4(CN)] － in CH3CN. The dicyano-dicarbonyl iron(Ⅱ)-thiolate complex trans,cis-[(CN)2 (CO)2Fe(S, S-C-R]－[R=OEt(6)、N(Et)2(7)] was prepared from reaction of [Na][S-C(S)-R] and [(CN)2(CO)2Fe(Br)]－obtained from oxidative addition of cyanogen bromide to [Fe(CO)4(CN)]－。Photolysis of THF solution of complex(6)、(7)led to formation of the coordinate-unsaturated iron dicyanocarbonyl thiolate compound [(CN)2(CO)Fe(S, S-C-R]－[R=OEt、N(Et)2],the potential iron-site structural and functional model compound of iron-active site of [NiFe] hydrogenases isolated from D.gigas The complex[(CN)2(CO)Fe(S,S-C-R]－[R=OEt、N(Et)2] and NiA/NiC states [NiFe] hydrogenases from D.gigas exhibit the similar one band pattern in the νCO region and two band pattern in the νCN region individually,but different positions,which may be accounted for by the distinct electronic effects between[S-C(S)-R]－and thiocysteine lignads, The IR data shows that the CO vibrational frequency to the electron density changes around iron center is abount 2.6 times more sensitive than is νCN－, The complexes (6)、(7) were reobtained when the THF solution of [(CN)2(CO)Fe(S,S-C-R][R=OEt、N(Et)2] were exposed to CO atmosphere at room temperature individually.