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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(κ2-dppbz)(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[~(31)P(~1H)NMR]、红外光谱(IR)、元素分析及X射线单晶结构衍射等表征.
The azo compound 4,4’-dimethyl-4,5-dihydro-3H-pyrrole (N_2C_5H_ (10)) with 5-membered ring structure was heated under reflux in FeSO_4 with Fe_3 (CO) (N_2C_5H_ (10)) (CO) 6 (1). The double bond of N = N was reduced and the ligand coordinated with FeIFeI in the form of (N_2C_5H_ (10) Form a 34e-compound with a butterfly structure.It was found that 1 reacted with monodentate phosphine ligand PR3 to form Fe2 (N_2C_5H_ (10)) - (CO) 5 (PR_3) in the presence of decarbonylation reagent Me_3NO (PR_3 = PPh_3 , 2a; PCy3,2b) monosubstituted complexes.Under illumination, CO ligands in compound 1 can also be replaced by the bidentate phosphine ligand dppe [dppe = 1,2-C_2H_4 (PPh_2) _2] and dppbz [dppbz = 1,2-C_6H_4 (PPh_2) _2], the type of the product is related to the included angle of the phosphine ligand, and the reaction of dppe with larger angle produces the bridging product Fe_2 (N_2C_5H_ (10)) (CO) 4 μ-dppe) (3a). For the reaction with the more rigid dppbz, the butterfly structure of Fe2 (NR) 2 was opened to a four-membered ring. One of the COs on Fe was substituted and dppbz was chelated to the Fe center. CO 2 (μ 2 CO) 4 (κ 2 -dppbz) (3b) with bridged CO was synthesized. The carbonyl compound with FeI-CO-FeI structure Is an important challenge to simulate the reduced Fe2 (SR) 2 (μ-CO) - (CO) _ (5-x) L_x in the active site of [FeFe] The synthesis of (PR3) x compounds can provide new ways and ideas for exploring the active center structure of [FeFe] hydrogenase.The above compounds are characterized by [~ (31) P (~ 1H) NMR, , Elemental analysis and X-ray single crystal structure diffraction characterization.