Acetato and acetylacetonato ruthenium(II) complexes containing SbPri3, PPri3 and PCy3 as ligands ‡

Abstract

The triply bridged binuclear ruthenium complex [{Ru(η 1 -O 2 CMe)(SbPr i 3 ) 2 } 2 (µ-O 2 CMe) 2 (µ-OH 2 )] 2 was prepared from [Ru(η 3 -C 3 H 5 ) 2 (SbPr i 3 ) 2 ] 1 and MeCO 2 H in the presence of water. Its molecular structure was determined by X-ray crystallography. The bis(acetylacetonato) complex [Ru(acac) 2 (SbPr i 3 ) 2 ] 3, obtained either from 1 or from [Ru(acac) 3 ], is a suitable starting material for the preparation of monosubstituted derivatives [Ru(acac) 2 (SbPr i 3 )L] (L = PCy 3 4, PPr i 3 5, C 2 H 4 7 or C᎐ ᎐ CHPh 8) as well as of [Ru(acac) 2 (PPr i 3 ) 2 ] 6. Ligand-displacement reactions of 6 with PhC᎐ ᎐ ᎐ CR (R = H or SiMe 3 ) and HC᎐ ᎐ ᎐ CCPh 2 (O 2 CMe) led to the vinylidene-and allenylidene-ruthenium complexes [Ru(acac) 2 (PPr i 3 )L] [L = C᎐ ᎐ CHPh 9, C᎐ ᎐ C(SiMe 3 )Ph 10 or C᎐ ᎐ C᎐ ᎐ CPh 2 11], respectively. Treatment of 2 with PCy 3 and PPr i 3 gave the compounds [Ru(O 2 CMe) 2 (PR 3 ) 2 ] (R = Cy or PPr i 3 ), of which the first smoothly reacted with HC᎐In the course of our investigations aimed at preparing squareplanar rhodium complexes of the general composition trans-[RhCl(᎐ ᎐ CRRЈ)L 2 ], we recently found that the replacement of trialkylphosphines by trialkylstibines leads to a significant difference in the reactivity of the respective starting materials. While the phosphine complex trans-[RhCl(C 2 H 4 )(PPr i 3 ) 2 ] reacts with Ph 2 CN 2 by simple ligand exchange to give trans-This striking difference, with its favorable consequences, 3 initiated our attempts to develop also synthetic pathways to other stibine transition-metal complexes in which the metal centre should have either a 16-or an 18-electron configuration. With iridium, this goal had recently been achieved. 4 As far as ruthenium was concerned, we found not only a preparative route to hydrido and dihydrogen complexes such as [RuH(Cl)(H 2 )(SbPr i 3 ) 3 ] and [RuH 2 (H 2 )(SbPr i 3 ) 3 ], 5 but also discovered that in contrast to PPr i 3 the corresponding triisopropylstibine reacted with [{Ru(η 5 -C 5 Me 5 )(µ 3 -Cl)} 4 ] to give [Ru(η 5 -C 5 Me 5 )Cl(SbPr i3 )] as well as the unsymmetrical binuclear species [(η 5 -C 5 Me 5 )-(Pr i 3 Sb)Ru(µ-Cl) 2 Ru(η 5 -C 5 Me 5 )]. 6 This result together with the isolation and structural characterisation of the 17-electron complex [Ru(η 5 -C 5 Me 5 )Cl 2 -(SbPr i3 )] prompted us further to extend the triisopropylstibineruthenium chemistry with the special impetus to include also acetate and acetylacetonate as coligands. In this paper we describe the synthesis of corresponding ruthenium() compounds with Ru(SbPr i 3 ) 2 as a building block and show how easily they undergo ligand-exchange processes to afford triisopropyl-and tricyclohexyl-phosphine ruthenium complexes. Results and DiscussionAn unexpected binuclear Ru 2 ( -OH 2 ) complex After we had shown that the π-allyl compound [Ru(η 5 -C 5 H 5 )-(η 3 -C 3 H 5 )(PPh 3 )] reacts with carboxylic acids RCO 2 H by elimination of propene to yield [Ru(η 5 -C 5 H 5 )(η 2 -O 2 CR)(PPh 3

Synthesis and structures of two ruthenium dibenzoylmethane triphenylphosphine mixed ligand complexes

“…To date, many ruthenium mixed-ligand complexes of b-diketones and phosphines have been synthesized and characterized [1][2][3][4]. These complexes possess a diversity of coordination modes including different isomeric types and oligomeric compounds [5,6].…”

Synthesis, characterization, and catalytic applications of Ru(III) complexes containing N-[di(alkyl/aryl)carbamothioyl]benzamide derivatives and triphenylphosphine/triphenylarsine

“…Many ruthenium mixed ligand complexes of β-diketones or thio-β-diketones and phosphines or arsines have been synthesized and characterized [1,2]. Some of these complexes exhibit good catalytic properties [3] and remarkable biological activities [4].…”

“…The complexes act as efficient catalysts for the oxidation of alcohols in presence of N-methylmorpholine-N-oxide as oxidant at room temperature.Many ruthenium mixed ligand complexes of β-diketones or thio-β-diketones and phosphines or arsines have been synthesized and characterized [1,2]. Some of these complexes exhibit good catalytic properties [3] and remarkable biological activities [4].…”

The fragment bis(acetylacetonato)ruthenium: a meeting-point of coordination and organometallic chemistry

“…The mono-ene complexes cannot be obtained by use of zinc in ethanol, because they decompose rapidly in contact with ethanol in the presence of air. Similar procedures have been used to prepare cis-[Ru(acac) 2 L 2 ] [2L = 2Sb i Pr 3 , 2P i Pr 3 , (S)-BINAP] [30,31]; a few other examples of this class, including those having 2L = 2CO [32], 2PPh 3 [33][34][35], 1,5-COD [36], NBD [36] and phen [37], had been made previously by different methods.…”

“…Under the same conditions, triphenylstibine reacts with either 2 or 3 to give complexes of the type cis-[Ru(acac) 2 (g 2 -alkene)(SbPh 3 )], which reacts further with Ph 3 Sb to give cis-[Ru(acac) 2 (SbPh 3 ) 2 ]; in neither step can a trans-isomer be detected. Werner et al [30] have reported the preparation of the related complex Of the P-donor ligands listed in Scheme 1, triisopropylphosphine and tricyclohexylphosphine are unique in reacting in a 1:1 mol ratio with 3 in benzene to give isolable mono-substitution products cis-[Ru(acac) 2 (g 2 -C 2 H 4 )(L)] [L = P i Pr 3 (4), PCy 3 (5)], which then react further with L to give initially trans-and then cis-[Ru (acac) 2 L 2 ] [40]. The ethene in complexes 4 and 5 is remarkably labile, being partly replaced even by THF, though there is no evidence from the Ru-C distances in the X-ray structures of the complexes that the Ru-C 2 H 4 interaction is particularly weak.…”