| 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)3(MeCN)3 were studied and the structures of their corresponding products were synthesized.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 allyl isomerization was discussed.The main results are listed as following:(1)In this thesis,substituted tetramethylcyclopentadienyl ligands[(C5Me4H)R][R= allyl(1),Bu(2),iBu(3),benzyl(4),PhMe-2(5)]were synthesized.Reactions of these substituted tetramethylcyclopentadienyl ligands with Fe(CO)5,Ru3(CO)12and Mo(CO)3(MeCN)3 in refluxing xylene gave the corresponding dinuclear metal carbonyl complexes[(η5-C5Me4R)M(CO)(μ-CO)]2[M=Ru,R=1-propenyl(6),R=Bu(7),R=iBu(8), R=benzyl(9),R=PhMe-2(10);M=Fe,R=1-propenyl(11),R=Bu(12),R=iBu(13),R= benzyl(14),R=PhMe-2(15)];[(η5-C5Me4R)Mo(CO)3]2 R=allyl(16),R=Bu(17),R=iBu (18),R=benzyl(19),R=PhMe-2(20)].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.Complexes 6-15 had good thermal stability,which reduced as the atomic radius increase. (2)When allyl functionalized tetramethylcyclopentadienyl ligand 1 reacted with Fe(CO)5 and Ru3(CO)12,the double bound isomerization complexes [(η5-C5Me4CHCHCH3)Ru(CO)(μ-CO)]2(6)and[(η5-C5Me4CHCHCH3)Fe(CO)(μ-CO)]2(11) were obtained instead of normal allyl functionalized tetramethylcyclopentadienyl Fe-Fe bond complex and Ru-Ru bond complex.The molecular structure of the complex 11 was determined by X-ray diffraction.The possible mechanism of the allyl isomerization was discussed.It maybe proceeds aπ-allyl metal hydride mechanism. (3)Total 15 unknown complexes were characterized by 1H NMR,IR spectra and elemental analysis.The molecular structures of 8 typical complexes were determined by X-ray diffraction analysis. |
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