中文摘要：

具有五元环结构的偶氮化合物4,4-二甲基-4,5-二氢-3H-吡咯（N_2C_5H_（10））,与Fe_3（CO）_（12）在甲苯中加热回流反应,生成双铁六羰基配合物Fe2（N_2C_5H_（10））（CO）6（1）.反应中N=N双键被还原,配体以（N_2C_5H_（10））2-的形式与FeIFeI配位,形成具有蝶形结构的34e-化合物.研究了在脱羰基试剂Me_3NO存在条件下,1和单齿膦配体PR3反应生成Fe2（N_2C_5H_（10））-（CO）5（PR3）（PR_3=PPh_3,2a;PCy3,2b）单取代配合物.光照条件下,化合物1中的CO配体还可以被双齿膦配体dppe[dppe=1,2-C_2H_4（PPh_2）_2]和dppbz[dppbz=1,2-C_6H_4（PPh_2）_2]取代,生成产物的类型和膦配体的夹角相关.与夹角较大的dppe反应,生成桥连产物Fe_2（N_2C_5H_（10））（CO）4（μ-dppe）（3a）;而与刚性较大的dppbz反应时,Fe2（NR）2的蝶形结构打开呈四元环;其中一个Fe上的CO被取代,dppbz与该Fe中心螯合,生成具有桥连CO的化合物Fe2（N_2C_5H_（10））（μ-CO）（CO）4（κ^2dppbz）（3b）.合成具有FeI-CO-FeI结构的羰基化合物,一直是模拟[FeFe]氢化酶活性中心还原态结构Fe_2（SR）_2（μ-CO）-（CO）_（5-x）L_x的重要挑战.该类Fe2（NR）2（CO）6-x（PR3）x化合物的合成,能为探索模拟[FeFe]氢化酶活性中心结构提供新的途径和思路.以上化合物均通过核磁[^31P（^1H）NMR]、红外光谱（IR）、元素分析及X射线单晶结构衍射等表征.

英文摘要：

Heating the toluene solution of 4,4-dimethyl-4,5-dihydro-3H-pyrazole（N_2C_5H_（10）） and Fe3（CO）12 at reflux for 1 h produces diiron hexacarbonyls Fe2（N_2C_5H_（10））（CO）6（1, νCO（CH_2Cl_2）： 2069, 2022, 1986 cm^-1）. Compound 1 exhibits 34 e-configuration, in which（N_2C_5H_（10））^2- coordinates to diiron（Fe^IFe^I） centers featuring a butterfly structure. To a solution of 1 in toluene was added one equiv. of decarbonyl agent Me3 NO in Me CN, and the mixture was stirred at room temperature for 20 min. Then, one equiv. of monophosphine was added. After 3 h, the solvent was removed and the residue was extracted into 5 m L CH2Cl2. The product Fe2（N_2C_5H_（10））（CO）5（PR3）（PR3=PPh3, 2a; PCy3, 2b） was obtained as brown crystals by allowing a pentane layer to diffuse into the CH2Cl2 solution at-20 ℃. ^31 P NMR spectra exhibit a singlet at δ 67 for 2a and δ 70 for 2b in CH2Cl2, respectively. In IR spectra, the νCO bands for 2a were displayed at 2032, 1968, 1952, 1907 cm^-1, which are compared to 2024, 1959, 1937, 1893 cm^-1 for 2b. Photolysis the toluene solution of 1 in the presence of chelating diphosphine ligands such as dppe [dppe=1,2-C2H4（PPh2）2] and dppbz [dppbz=1,2-C6H4（PPh2）2] affords diiron diphosphine carbonyl compounds. For dppe, the product was Fe2（N_2C_5H_（10））（CO）4（μ-dppe）（3a, 31 P NMR（CD2Cl2）： δ 95, FT-IR（CH2Cl2, νCO）： 1984, 1940, 1925 and 1900 cm^-1）, in which dppe is bridging the two iron centers. For more rigid diphosphine ligand dppbz, X-ray crystallographic analysis reveals the structure of Fe2（N_2C_5H_（10））（μ-CO）（CO）4（dppbz） [3b, ^31 P NMR（CD2Cl2）： δ 93]. In 3b,（N_2C_5H_（10））^2- coordinates to diiron centers in a planar mode, and dppbz chelates at one Fe site by the replacement of one CO ligand. Compound 3b features a Fe-CO-Fe rotated structure with a bridging CO ligand between the two Fe centers. The νCO bands for 3b were displayed at 1990, 1947, 1919, 1895 cm