Polynuclear Complexes with Propynylidene C3-Bridges: General Synthetic Route to Bis-, Tris-, and Tetrakis(ethynylcarbene) Complexes
✍ Scribed by Cornelia Hartbaum; Gerhard Roth; Helmut Fischer
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 805 KB
- Volume
- 1998
- Category
- Article
- ISSN
- 1434-1948
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✦ Synopsis
The sequential reaction of two equivalents of the dimethyl-(PEt 3 ) 2 CϵCH], is described. When three equivalents of 1a are treated, first with three equivalents of nBuLi and then amino (ethynyl)carbene complexes [(CO) 5 M=C(NMe 2 )CϵCH] [M = W (1a), Cr (1b)] with two equivalents of nBuLi and one with one equivalent of the trihalides PCl 3 or BBr 3 , the novel tris(ethynylcarbene) complexes [{(CO) 5 W=C(NMe 2 )CϵC} 3 E] equivalent of a transition metal dichloride, [Cl 2 MЈ(L n )], affords trinuclear biscarbene complexes of the type [(CO) 5 M= [E = B (11a), P (12a)] are obtained. The reaction of four equivalents of 1a, b with four equivalents of nBuLi, followed by C(NMe 2 )CϵCϪMЈ(L n )ϪCϵCC(NMe) 2 =M(CO) 5 ] [MЈ(L n ) = Ni(PEt 3 ) 2 (2a, b), Pd(PEt 3 ) 2 (3a, b), Pt(PEt 3 ) 2 (4a, b), Fe(dmpe) 2 addition of one equivalent of a group 14 tetrachloride [MЈCl 4 ], yields the novel tetrakis(ethynylcarbene) complexes (6a), Hg (8a), Ti(η 5 -C 5 H 5 ) 2 (9a, b)] [dmpe = 1,2-bis(dimethylphosphino)ethane]. Treatment of 1a with equimolar amounts [{(CO) 5 M=C(NMe 2 )CϵC} 4 MЈ] [MЈ = Si (13a, b), Ge (14a), Sn (15a, b)]. The complexes 8a, 9a, 12a, and 15a were charac-of first nBuLi and then [Cl 2 MЈ(L n )] results in the formation of the monosubstitution products [(CO) 5 W=C(NMe 2 )CϵCMЈ-terized by X-ray structural analyses. All spectroscopic and structural data suggest that the carbene fragments and the (L n )] [MЈ(L n ) = trans-Pd(PEt 3 ) 2 Cl (5a), trans-Fe(dmpe) 2 Cl (7a)]. Additionally, the synthesis of the heterobimetallic central transition metal or heteroatom in these new bis-, tris-, and tetrakis(ethynylcarbene) complexes interact only ethynylcarbene complex [(CO) 5 W=C(NMe 2 )CϵCPd-(PEt 3 ) 2 CϵCH] (10a), starting from 1a and [ClPd-weakly.