Synthesis, structural characterization, and some properties of 2-acylmethyl-6-ester group-difunctionalized pyridine-containing iron complexes related to the active site of [Fe]-hydrogenase.
As biomimetic models for [Fe]-hydrogenase, the 2-acylmethyl-6-ester group-difunctionalized pyridine-containing iron(II) complexes 1-4 have been successfully prepared via the following three separate steps. In the first step, the acylation or esterification of difunctionalized pyridine 2-(p-MeC6H4SO3CH2)-6-HOCH2C5H3N with acetyl chloride or benzoic acid gives the corresponding pyridine derivatives 2-(p-MeC6H4SO3CH2)-6-RCO2CH2C5H3N (A, R = Me; B, R = Ph). The second step involves reaction of A or B with Na2Fe(CO)4 followed by treatment of the intermediate Fe(0) complexes [Na(2-CH2-6-RCO2CH2C5H3N)Fe(CO)4] (M1, R = Me; M2, R = Ph) with iodine to afford 2-acylmethyl-6-acetoxymethyl or 6-benzoyloxymethyl-difunctionalized pyridine-containing Fe(II) iodide complexes [2-C(O)CH2-6-RCO2CH2C5H3N]Fe(CO)2I (1, R = Me; 3, R = Ph). Finally, when 1 or 3 is treated with sodium 2-mercaptopyridinate, the corresponding difunctionalized pyridine-containing Fe(ii) mercaptopyridinate complexes [2-C(O)CH2-6-RCO2C5H3N]Fe(CO)2(2-SC5H4N) (2, R = Me; 4, R = Ph) are produced. While the structures of model complexes 1-4 are confirmed by X-ray crystallography, the electrochemical properties of 2 and 4 are compared with those of the two previously reported models. In addition, complexes 2 and 4 have been found to be catalysts for H2 production in the presence of TFA under CV conditions.
Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin 300071, China. lcsong@nankai.edu.cn.
Li-Cheng
LC
Song
Fu-Qiang
FQ
Hu
Miao-Miao
MM
Wang
Zhao-Jun
ZJ
Xie
Kai-Kai
KK
Xu
Hai-Bin
HB
Song
D000215:Acylation; D040761:Biomimetic Materials / Q000138:chemical synthesis / Q000737:chemistry*; D002384:Catalysis; D020134:Catalytic Domain; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006864:Hydrogenase / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D007506:Iron-Sulfur Proteins / Q000737:chemistry*; D008745:Methylation; D008958:Models, Molecular; D011725:Pyridines / Q000138:chemical synthesis / Q000737:chemistry*
D056831:Coordination Complexes; D007506:Iron-Sulfur Proteins; D011725:Pyridines; D007501:Iron; C118830:iron hydrogenase; D006864:Hydrogenase; C023666:pyridine