氮杂环卡宾配位的铁磷簇合物  

Iron Phosphorus Clusters with N-Heterocyclic Carbene Ligation

作　　者：杜牧 杨程博 陈琦 邓亮 Du Mu;Yang Chengbo;Chen Qi;Deng Liang(University of Science and Technology of China,School of Chemistry and Materials Science,Hefei 230022;State Key Laboratory of Organometallic Chemistry,Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences,Shanghai 200032;School of Chemistry and Materials Science,Hangzhou Institute for Advanced Study,University of Chinese Academy of Sciences,Hangzhou 310024)

机构地区：[1]中国科学技术大学化学与材料科学学院,合肥230022 [2]中国科学院上海有机化学研究所、金属有机化学国家重点实验室,上海200032 [3]中国科学院大学杭州高等研究院、化学与材料科学学院,杭州310024

出　　处：《化学学报》2024年第9期932-939,共8页Acta Chimica Sinica

基　　金：科技部国家重点研发计划(No.2021YFA1500203);国家自然科学基金(Nos.22201290,22231010,22061160464,21821002);中科院战略先导科技专项(No.XDB0610000);上海市科学与技术委员会(No.22JC1403400)资助.

摘　　要：通过三配位零价铁配合物[(NHC)Fe(η^(2):η^(2)-dvtms)](NHC=氮杂环卡宾;dvtms=四甲基二乙烯基二硅氧烷)与白磷的反应合成了三种氮杂环卡宾配位的铁磷簇合物,对其进行了结构和光谱学表征.通过分步重结晶的方法从[(IMes)Fe(η^(2):η^(2)-dvtms)](IMes=1,3-双(2,4,6-三甲基苯基)咪唑-2-亚基)与等物质的量的P4在低温下(-30℃到室温)的反应中分离到了三种铁磷簇合物[(IMes)2Fe2(μ-η^(5):η^(5)-cyclo-P5)](1)、[(IMes)3Fe3(μ-η^(6):η^(6):η^(6)-P9)](2)和[(IMes)2Fe2(μ-η^(2):η^(2)-cyclo-P4P(IMes))(μ-η^(3):η^(3)-P3)](3).配合物1和3可分别以18%和32%的产率从该零价铁配合物与等物质的量的P4在80℃和低温下的反应中分离得到.配合物2仅能得到痕量的晶体.这些配合物的结构均通过单晶X射线衍射表征.配合物1为反三明治型的双核铁配合物.Fe…Fe距离为0.2515(1)nm,其桥联μ-η^(5):η^(5)-cyclo-P5配体乱序,结构类似的配合物[(IDep)2Fe2(μ-η^(5):η^(5)-cyclo-P5)][4,IDep=1,3-双(2,6-二乙基苯基)咪唑-2-亚基]可通过[(IDep)Fe(η^(2):η^(2)-dvtms)]与P4反应合成.其单晶X射线衍射所得的结构中桥联μ-η^(5):η^(5)-cyclo-P5配体无乱序现象,两个铁中心具有相同的配位环境.配合物1在80 K下的零场57Fe穆斯堡尔谱仅含一组四极距分裂的双峰,同质异能位移δ=0.32 mm•s^(−1),四极距裂分|ΔEQ|=0.61 mm•s^(−1).磁化率测试表明配合物1的基态自旋量子数S=1/2.这些表征数据显示该类反三明治型的双铁配合物可看作是一个Robin-DayⅢ型混合价态配合物.配合物2为首例具有P9配体的过渡金属磷簇合物.其P9配体含两个相对的三角形P3面和三个船式P6面.每个船式P6面与一个Fe(IMes)片段以η^(6)-形式配位.Fe…Fe距离平均值为0.2626(1)nm.配合物3中μ-η^(2):η^(2)-cyclo-P4P(IMes)配体和μ-η^(3):η^(3)-P_(3)配体的结构参数与[(IMes)2Co2(μ-η^(2):η^(2)-cyclo-P4P(iPr2Im))(μ-η^(3):η^(3)-P_(3))]中相应配体相近.^(1)HThree iron phosphorus clusters with N-heterocyclic carbene ligation have been synthesized from the reactions of low-coordinate iron(0)complexes[(NHC)Fe(η^(2):η^(2)-dvtms)](NHC=N-heterocyclic carbene,dvtms=divinyltetramethylisiloxane)with white phosphorus and characterized by spectroscopic methods.The iron phosphorus clusters[(IMes)2Fe2(μ-η5:η5-cyclo-P5)](1),[(IMes)3Fe3(μ-η^(6):η^(6):η^(6)-P9)](2)and[(IMes)2Fe2(μ-η^(2):η^(2)-cyclo-P4P(IMes))(μ-η^(3):η^(3)-P3)](3)were isolated from the equimolar reaction of[(IMes)Fe(η^(2):η^(2)-dvtms)](IMes=1,3-dimesitylimidazol-2-ylidene)with P4 at low temperature(-30℃to room temperature)upon recrystallization.Complexes 1 and 3 can be synthesized in 18%and 32%isolated yields,respectively,from the reactions of[(IMes)Fe(η^(2):η^(2)-dvtms)]with P4 at different reaction temperature(80℃and-30℃to room temperature,respectively).Complex 2 can only be obtained in trace amount from the low-temperature reaction.The three iron phosphorus clusters 1~3 have been characterized by single-crystal X-ray diffraction studies.Complex 1 shows an anti-sandwich type structure with the Fe…Fe distance of 0.2515(1)nm and theμ-η5:η5-P5 ligand in disorder.Analogous complex[(IDep)2Fe2(μ-η5:η5-P5)][4,IDep=1,3-di(2',6'-diethylphenyl)imidazol-2-ylidene]can be synthesized from the reaction of[(IDep)Fe(η^(2):η^(2)-dvtms)]with P4.Its molecular structure established by X-ray diffraction study does not exhibit disorder in theμ-η5:η5-P5 ligand and the two iron centers show nearly identical coordination environment.The zero-field 57Fe Mössbauer spectrum of 1 measured at 80 K shows a quadrupole doublet with the isomer shiftδ=0.32 mm•s^(−1)and quadrupole splitting|ΔEQ|=0.61 mm•s^(−1).Magnetic susceptibility measurements point out a doublet state(S=1/2)for 1.The characterization data suggests that 1 and 4 can be described as the III-type mixed valence complex based on the Robin-Day Models.Complex 2 represents the first example of metal complexes featuring a P9 ligand.The pol

关 键 词：氮杂环卡宾 铁 白磷 簇合物 多磷化物 

分 类 号：O641.4[理学—物理化学]