Synthesis And Characterization Of Ruthenium And Osmium Complexes Containing Phosphine Ligands

Recelltly, more and more interests have been shown by the synthesist to thestudy on rePlacement of a CH grouP in benzene by an isolobaI twition metalfragment tOgether with its associated ligands to give motallabenzen evenmetallabenZyne comPlexes. Although many metallabenzene comPlexes are known,there are only two examples of which were synthesized through cyclizationinvolving 2 equiv of acetylenes and a transition metal comPlex. 1 equiv ofHCHCCH(OH)C=CH reacted with osmium complex to give a novel osmabenzenecomPlex through cycliZaion was first described in this thesis. The main results aresummarized as following:The osmabenzene comPlex [ O s (CHC (P Ph3 ) C H C (P Ph3 ) CH) Cl2(PPh3) 2] (OH)was synthesized by direct cyclization invo1ving HC=CCH(OH)C-CH and acoordinatively unstaed l6e osmium comPlex, fOllowed reacting wth PPh3. Thenew osmabenzene comPlex was characterized by NMR and IR sPectroscopy, and itssmicture was confirmed by X-ray diffraCtion anaIysis. The stfUcture shows that ithas an octahedral coordination geometry and also has the character of aromatcsystem: all the C--C bond lengths within the ring are tyPical of benzene derivatives,and the angles of the carbon atoms with the ring are consistent with a six-memberring. The bond lengths of Os--C (Q ) fal between the reported for similar structuresIII &xmaof osmabenzenes and osmabenZylle. It shows that the six-member metallic ring hasa completely delocalized strUCure.Reaction of RuHCl(CO)(PPh3)3 with suitable ligands produced a series ofinteresting bimetallic complexes bridged With C4fu, C6H4O2 and C5H5 1igands havebeen reported. In this thesis, the hydride comPlex RuHCl(CO)(PPh3)3 was attemPtedto react with 4--phenylpyridine to give RuHCl (C O ) (P Ph3 )2(4--PhPy), Whi ch fo l lo wedon treatment with HC=CCH(OH)CesCH gave the single insertion productRuCl (C O) (CH=CH--CH (OH) CesCH) (4--PhPy)(PPhs)z instead of the expecteddimetallatic ruthenium complex. No further insertion reaction was observed ontreatInent of the hydride comPlex RuHCl(CO)(PPh3)3 with the end-alkyne ofRuC l (C O) (CH=CH-- C H(OH) C=CH) (4--PhPy) (PPh3)z. Steri c e ffects are the l ikelyreason fOr the low reactivity of the C=C forctional grouP inRuCl (C O)(C H=C H-- CH(OH) CHCH) (4--PhPy)(PPh3 )z toward inserti on reactionswith it. Single crystal of RuC l2(C O)(4--PhPy)(PPh3)2 was obtained from the so lutionof RuC l (C O)(C H=CH--CH(OH)CesCH) (4--PhPy (PPh3 )2. The structur o fRu C l z (C O ) (4-- PhP y) (P Ph3 )z shows that there is a synUnetry planar thrOu gh the me talcenter and perpendicular with the octahedron axis, and the sites of Cl and COligands is someWhat different from either of the start material or the conunon one.Additionally no insertion reactions was observed when the hydride comP1exRuHCl(CO)(PPh3)s treated with (PhC-C)2PPh. However, the (PhC-C)2PPh ligandcan substitute thc PPh3 ligand Which resides in the basal coordination site to give thenew complex RuH C l (C O)(PPh3 h(P (Ph) (C = CPhb ), Who s e strUctUre was c oallrmedby single crystal X-ray ddection.It has been shown that among molecules with a Cn SyInmetry axis, moleculeswith a C3 syITnnetry axis are the on1y ones with no dipole moment but drite 6, somolecules with C3 symmetry bos are POtenially usefol as maerials for non-linerIVMI,k$ffi$Fkt$&&xoptical peLO) aPplications. So far all the organometallic compounds with C3syInmetry axis have been synthesized based on l, 3, 5-triethynylbenzene. Inprinciple, 1, 3, 5-triethenylbenzene can also be used as the basic construction only ifthe three substitllted ethenyls have suitable orientations so that the molecule possessa C3 symmetry axis. We are interested in the synihesis of organomatallic comPoundspossess C3 symmetry axis with metal-vinyl linkage. The main results aresummarized as following:The conjugated trimetallic comPlex l, 3, 5 - [RuC l (C O) (PPh3)2PyCH=C H-] 3 C6H3with vinyl-uait linkage is ma...