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The synthesis of the ruthenium σ-acetylides (η5-C5H5)L2Ru–C C–bipy (4a, L = PPh3; 4b, L2 = dppf; bipy = 2,2′-bipyridine-5-yl; dppf = 1,1′-bis(diphenylphosphino)ferrocene) is possible by the reaction of [(η5-C5H5)L2RuCl] (1) with 5-ethynyl-2,2′-bipyridine (2a) in the presence of NH4PF6 followed by deprotonation with DBU. Heterobimetallic Fc–C C–NCN–Pt–C C–R (10a, R = bipy; 10b, R = C5H4N-4; Fc = (η5-C5H5)(η5-C5H4)Fe; NCN = [1,4-C6H2(CH2NMe2)2-2,6]−) is accessible by the metathesis of Fc–C C–NCN–PtCl (9) with lithium acetylides LiC C–R (2a, R = bipy; 2b, R = C5H4N-4).The complexation behavior of 4a and 4b was investigated.Treatment of these molecules with [MnBr(CO)5] (13) and {[Ti](μ–σ,π-C CSiMe3)2}MX (15a, MX = Cu(N CMe)PF6; 15b, MX = Cu(N CMe)BF4; 16, MX = AgOClO3; [Ti] = (η5-C5H4SiMe3)2Ti), respectively, gave the heteromultimetallic transition metal complexes (η5- C5H5)L2Ru–C C–bipy[Mn(CO)3Br] (14a: L = PPh3; 14b: L2 = dppf) and [(η5-C5H5)L2Ru–C C–bipy{[Ti](μ–σ,π-C CSiMe3)2}M]X (17a: L = PPh3, M = Cu, X = BF4; 17b: L2 = dppf, M = Cu, X = PF6; 18a: L = PPh3, M = Ag, X = ClO4; 18b: L2 = dppf, M = Ag, X = ClO4) in which the appropriate transition metals are bridged by carbon-rich connectivities. The solid-state structures of 4b, 10b, 12 and 17b are reported. The main structural feature of 10b is the square-planar-surrounded platinum(II) ion and its linear arrangement. In complex 12 the N-atom of the pendant pyridine unit coordinates to a [mer,trans-(NN′N)RuCl2] (NN′N = 2,6-bis-[(dimethylamino)methyl]pyridine) complex fragment, resulting in a distorted octahedral environment at the Ru(II) centre. In 4b a 1,1′-bis(diphenylphosphino)ferrocene building block is coordinated to a cyclopentadienylruthenium-σ-acetylide fragment. Heterotetrametallic 17b contains a (η5-C5H5)(dppf)Ru–C C–bipy unit, the bipyridine entity of which is chelate-bonded to [{[Ti](μ–σ,π-C CSiMe3)2}Cu]+. Within this arrangement copper(I) is tetra-coordinated and hence, possesses a pseudo-tetrahedral coordination sphere. The electrochemical behavior of 4, 10b, 12, 17 and 18 is discussed. As typical for these molecules, reversible oxidation processes are found for the iron(II) and ruthenium(II) ions. The attachment of copper(I) or silver(I) building blocks at the bipyridine moiety as given in complexes 17 and 18 complicates the oxidation of ruthenium and consequently the reduction of the group-11 metals is made more difficult, indicating an interaction over the organic bridging units. The above described complexes add to the so far only less investigated class of compounds of heteromultimetallic carbon-rich transition metal compounds.

This review describes the synthesis, reaction chemistry, structures and bonding of heterotri- to heterohexametallic complexes with early and late transition metal centres by applying the molecular Tinkertoy approach. The use of π-conjugated carbon-rich multifunctional organic units such as alkynyl-functionalized bipyridine, 1,4-di- and 1,3,5-trisubstituted benzene or phosphane moieties connecting the different metal atoms, is highlighted.

Resume L'epoxydation du RMN3, alcene mixte fluore–hydrogene de formule C8F17CH2CH=CH-iBu, conduit a l'epoxyde correspondant, avec des rendements allant jusqu'a 90%, selon la nature du ligand azote. Dans le cadre de cette etude, nous avons etudie l'influence de la bipyridine, substituee ou non, greffee avec des chaines fluorocarbonees ou hydrocarbonees ainsi que le positionnement de ces motifs sur les cycles pyridiniques. Pour citer cet article : A. Banu et al., C. R. Chimie 8 (2005).

Two methods of epoxidation were investigated on a hybrid fluorocarbon-hydrocarbon olefin: RuCl3/bipyridine/NaIO4 and oxone/acetone. The best yield was obtained using the first method which was extended to the synthesis of new aromatic fluorinated epoxides with very good yields.