Study On The Reactions Of Substituted Tetramethylcyclopentadienes And Benzofulvenes With Metal Carbonyl Complexes

Increasing attention has been paid to dinuclear metal complexes, due to the significant cooperative effect of both metal centers on their reactivity and catalytic applications. Intensive study of these complexes will help to provide new catalyts with potential application prospects and expand organometallic chemical theory. In this dissertation, reactions of substituted tetramethylcyclopentadienyl ligands with Fe(CO)5、Ru3(CO)12and Mo(CO)6were studied and the structures of their corresponding products were synthesized. The reactions of fulvene ligand with Ru3(CO)12was studied too. It showed that the steric effects of the substituents had influence on the molecular structures, especially on the M-M bond distances. The possible mechanism of the result of Mo-O-Mo was discussed. The main results are listed as following:(1) In this thesis, substituted tetramethylcyclopentadienyl ligands [(CsMe4H)R][R=C2H5(1), C(CH2)(2), PhNMe2-4(3)] and the fulvene ligand [C9H6C(CH2)4](11)were synthesized. Reactions of these ligands with Fe(CO)5、Ru3(CO)12and Mo(CO)6in refluxing xylene gave the corresponding dinuclear metal complexes [(η-C5Me4R)M(CO)(μ-CO)]2[M=Fe, R=C2H5(4), R=C(CH2)(5), R=PhNMe2-4(6); M=Ru, R=C(CH2)(7)];[(η5-C5Me4R)Mo(CO)3]2[R=C2H5(8), R=C(CH2)(9)];[(η5-C5Me4)PhNMe2-4]2Mo2O2(μ-O)(10)�'�[(η5-C9H6)C(C4H7)Ru(CO)2]2(12)(2) It showed that the steric effect of substituent had important effect on the M-M bond distances of the complexes. The M-M bond distance increases with the increasing of the steric effect of the substituent. All complexes had good thermal stability, which reduced as the atomic radius increase.(3) When the ligand3reacted with Mo(CO)6, the oxo bridged Mo complexes [(η5-C5Me4)PhNMe2-4]2Mo2O2(μ-O)(10) was obtained instead of normal Mo-Mo bond complex. The molecular structure of the complex10was determined by X-ray diffraction. The result showed that each Mo atom was connected two terminal oxo. The possible mechanism of the result of Mo-O-Mo was discussed. (4) We did not obtain the normal complex from reaction of the ligand4with Ru3(CO)12too. In this reaction, the fulvene undergo double bond isomerization.Total8unknown complexes were characterized by1H NMR, IR spectra and elemental analysis. The molecular structures of the new complexes were determined by X-ray diffraction analysis.