Pedro L. Andreu

The different reactivity of 2-aminopyridines and 2-pyridone with [Ru3(CO)12]. X-Ray crystal structure of [Ru3(µ-H)(µ3-anpy)(CO)9](hanpy = 2-anilinopyridine)

The complex [Ru3(CO)12] reacts with 2-aminopyridines [2-aminopyridine, 2-amino-4-methylpyridine, -5-methylpyridine, and -6-methylpyridine, 2-(methylamino)pyridine, and 2-anilinopyridine] to give hydrido trinuclear clusters of the type [Ru3(µ-H)(µ3-L)(CO)9](1)–(6)(L = a 2-aminopyridinate-type ligand). Although the presence of substituents on the pyridine ring or on the aminic nitrogen has no influence on the reactivity of the ligands towards [Ru3(CO)12], it affects the fluxionality of the complexes they form. The solid-state structure of [Ru3(µ-H)(µ3-anpy)(CO)9](6)(Hanpy = 2-anilinopyridine) has been determined by X-ray diffraction methods: monoclinic, space group P21/n, Z= 4, a= 12.705(1), b= 10.621 (2), c= 18.427(2)A, and β= 107.349(7)°. The structure was solved by direct and Fourier methods and refined by full-matrix least squares to R= 0.019, R′= 0.021, for 3 621 observed reflections. The reaction of [Ru3(CO)12] with 2-(dimethylamino)pyridine (dmapy) gives [Ru3(µ-dmapy)(µ-CO)3(CO)7]. However, with 2-pyridone (HOpy) the polymer [{Ru2(µ-Opy)2(CO)4}n](8) or the dimer [Ru2(µ-Opy)2(CO)4(HOpy)2](13) are formed depending on the ratio of the reactants. The reactivity of the polymer (8) with neutral ligands to give the binuclear ruthenium(I) dimers [Ru2(µ-Opy)2(CO)4L2][L = CO, (9); MeCN, (10); PPh3, (11); P(OPh)3, (12); or HOpy, (13)] is also reported.

The chemical and electrochemical oxidation of pyridonate-bridged ruthenium(I) dimers. X-Ray structure of [Ru2(μ-pyO)2(CO)4(pyOH)2] (pyOH = 2-pyridone)

Abstract Chemical and electrochemical studies have shown that the pyridonate-bridged ruthenium(I) dimers [Ru 2 (μ-pyO) 2 (CO) 4 (L) 2 ] ( 1 ) (L = PPh 3 , 1a ; P i Pr 3 , 1b ; or pyOH, 1c ; pyOH = 2-pyridone) can be oxidized to the cationic paramagnetic species [Ru 2 (μ-pyO) 2 (CO) 4 (L) 2 ] + ( 2 ). The species 2 are very unstable at room temperature, decomposing into a mixture of 1 and the ruthenium(II) cations [Ru(pyO)(CO) 2 (L)] + ( 3 ). The latter can be obtained quantitatively by reaction of 1 with two equivalents of oxidant. The structure of complex 1c , which has an oxidant peak in its cyclic voltammogram at an unexpectedly high potential (1.11 versus 0.47 V for 1a and 0.33 V for 1b ), has been determined by X-ray crystallography, revealing the presence of two intramolecular hydrogen bonds between the oxygen. atoms of the bridging and the terminal pyO fragments.

Synthesis and reactivity of triruthenium carbonyl clusters containing bis(diphenylphosphino)methane and the face-bridging ligand 2-amido-6-methylpyridi

Abstract The compounds [Ru 3 (μ-H)(μ 3 -ampy)(CO) 9 ] ( 1 ) and [Ru 3 (μ-H) 2 (μ 3 -ampy)(CO) 9 ]BF 4 ( 2 ) (Hampy = 2-amino-6-meth (dppm) to give [Ru 3 (μ-H)(μ 3 -ampy)(CO) 7 (dppm)] ( 3 ) and [Ru 3 (η-H) 2 (μ 3 -ampy)(CO) 7 (dppm)]BF 4 ( 4 ), respectiv ligand are cis to both the hydride and the amido-fragment of the bridging ampy ligand, whereas in complex 4 each P atom is trans to a hydri 2 affords [Ru 3 (μ-H) 2 (μ 3 -ampy)(CO) 7 (dppm)BF 4 ( 5 ), which is an isomer of complex 4 ; in fact, 5 can also be obtain tetrahydrofuran. Complex 5 undergoes deprotonation upon reaction with potassium methoxide or triethylamine, giving 3 ; however, the reaction of methoxycarbonyl derivative [Ru 3 (μ-H) 2 (μ 3 amfy)(CO 2 Me)(CO) 6 (dppm)] ( 6 ), which contains the CO 2 Me group in an equatorial

Synthesis and reactivity of diphenylphosphine derivatives of [Ru3(μ-H)(μ3-ampy)(CO)9] and [Ru3(μ-H)2(μ3-ampy)(CO)9][BF4] (Hampy = 2-amino-6-methylpyridine)

Abstract The reactions of [Ru 3 (μ-H)(μ 3 -ampy)(CO) 9 ] ( 1 ) (Hampy=2-amino-6-methylpyridine) with one or two equivalents of PPh 2 H give the complexes [Ru 3 (μ-H)(μ 3 -ampy)(CO) 8 (PPh 2 H)] ( 3 ) or [Ru 3 (μ-H)(μ 3 -ampy)(CO) 7 (PPh 2 H) 2 ] ( 4 ), in which the PPh 2 H ligands are cis to the bridging NH fragment and cis to the hydride. Complex 3 eliminates hydrogen in refluxing tetrahydrofuran to give the phosphidobridged derivative [Ru 3 (μ-ampy)(μ 3 -PPh 2 )(μ-CO) 2 (CO) 6 ] ( 5 ), which contains the PPh 2 ligand spanning one of the two RuRu edges unbridged by the amido moiety. Under similar conditions, complex 4 gives a separable mixture of two isomers of [Ru 3 (μ-H)(μ 3 -ampy)(μ-PPh 2 ) 2 (CO) 6 ] in a 5:1 ratio; the major product ( 6a ) has a plane of symmetry, whereas the minor one ( 6b ) is asymmetric. Compound 6a can also be prepared by reaction of 5 with PPh 2 H. Complexes 3 and 4 undergo protonation with HBF 4 ·OEt 2 at an amido-unbridged P-bonded RuRu edge, rendering [Ru 3 (μ-H) 2 (μ 3 -ampy)(CO) 8 (PPh 2 H)][BF 4 ] ( 7a ) and [Ru 3 (μ-H) 2 (μ 3 -ampy)(CO) 7 (PPh 2 H) 2 ][BF 4 ] ( 8 ), respectively. Upon reaction with potassium methoxide, the cation 7a regenerates the neutral complex 3 , while complex 8 gives a mixture of 4, 6a and 6b . Treatment of the dihydride [Ru 3 (μ-H) 2 (μ 3 -ampy)(CO) 9 ][BF 4 ] ( 2 ) with PPh 2 H gives [Ru 3 (μ-H) 2 (μ 3 -ampy)(CO) 8 (PPh 2 H)][BF 4 ] ( 7b ), which has the PPh 2 H ligand cis to the bridging NH moiety and cis to the hydride on the Ru atom bonded to only one hydride, being therefore an isomer of complex 7a . The cation 7b undergoes nucleophilic attack by potassium methoxide to give the neutral methoxycarbonyl derivative [Ru 3 (μ-H) 2 (μ 3 -ampy)(CO 2 Me)(CO) 7 (PPh 2 H)] ( 9 ). Proton and 31 P { 1 H} NMR and IR spectra of all the compounds are included and discussed in relation to their structures.

Mercury—ruthenium mixed-metal carbonyl clusters containing 2-amido-6-methylpyridine (ampy) as a μ3,η2-ligand. Crystal structures of [Ru6(μ4-Hg)(μ3-ampy)2(CO)18]·2C4H8O and [Ru3(μ-HgBr)(μ3-ampy)(CO)9]

The cluster [Ru3(μ-H)(μ3-ampy)(CO)9] (1) (Hampy = 2-amino-6-methylpyridine) reacts with HgPh2 to give [Ru6(μ4-Hg)(μ3-ampy)2(CO)18] (2). An X-ray diffraction study of the solvate 2·2THF has shown it to contain two “Ru3(μ3-ampy)(CO)9” moieties bridged by a mercury atom which is bonded to the two NH-bridged ruthenium atoms of each trinuclear moiety. Complex 2 reacts with mercury(II) halides to give [Ru3(μ-HgX)(μ3-ampy)(CO9](X = Cl(3), Br(4), I(5)). The cystal structure of cluster 4 shows it to contain a HgBr fragment spanning the same RuRu edge as the amido group of the ampy ligand. Some reactions of the clusters 2 and 3 are also described.

Ru3(CO)9(PPh3)3: a convenient starting material for the synthesis of binuclear ruthenium(I) complexes. Crystal structure of Ru2(μ-L2)(CO)4(PPh3)2 (H2L2 = 1,8-diaminonaphthalene)

Abstract The thermal reaction of Ru 3 (CO) 9 (PPh 3 ) 3 with precursors (HL) of binucleating anionic ligands affords the ruthenium(I) dimers Ru 2 (μ-L) 2 (CO) 4 (PPh 3 ) 2 ( 3 ), t-butylmercaptane ( 4 ); H 2 L 2 = 1,8-diaminonaphthalenene ( 5 )]. The crystal structure of complex 5 shows that each nitrogen of the 1,8-diiminonaphthalene ligand bridges the two ruthenium atoms, leading to a vary distorted, octahedral arrangement of the ligands and a very short RuRu distance, 2.5788(3) A.

Synthesis and reactivity of mono-, tri-, and poly-nuclear ruthenium carbonyl complexes containing the pyridine-2-thiolate ligand (pyS). Stepwise preparation of [Ru(pyS)2(CO)2] by reaction of [Ru3(CO)12] with pyridine-2-thiol

The thermal reaction of [Ru3(CO)12] with pyridine-2-thiol (pySH) gives the trinuclear complex [Ru3(µ-H)(µ3-pyS)(CO)9](1), which is subsequently converted into the polymer [{Ru(µ3-pyS)(CO)2}n](2). Further reaction of polymer (2) with pyridine-2-thiol gives the monomeric compound [Ru(pyS)2(CO)2](3). Complexes (1) and (2) contain triply bridging pyS ligands while in complex (3) both pyS ligands are chelating. These results indicate that the reactivity of [Ru3(CO)12] with pyridine-2-thiol is different to that found for [Os3(CO)12] and for [Ru3(CO)12] with 2-aminopyridine and 2-hydroxypyridine. The reactions of complexes (1)–(3) with several P-donor ligands are also described. Infrared and 1H and 31P-{1H} n.m.r. spectral data for all the compounds are presented and discussed in relation to their structures.

Protonation and deprotonation reactions of triruthenium nona- and octa-carbonyl clusters containing a µ3-2-amido-6-methylpyridine (µ3-ampy) ligand. X-Ray structures of [Ru3(µ-H)2(µ3-ampy)(CO)9][BF4] and of one of the two isolated isomers of [Ru3(µ-H)2(µ3-ampy)(CO)8(PPh3)][BF4]

The complex [Ru3(µ-H)(µ3-ampy)(CO)9](1)(Hampy = 2-amino-6-methylpyridine) reacts with HBF4·OEt2 to give the dihydride [Ru3(µ-H)2(µ3-ampy)(CO)9][BF4](2), the structure of which has been determined by X-ray diffraction [monoclinic, space group C2/c, a= 23.468(6), b= 15.524(6), c= 15.283(3), β= 122.83(2)°, Z= 8]. Compound (2) reacts with NEt3 regenerating (1) and with potassium methoxide giving a mixture of (1) and two isomers [(3) and (4)] of the methoxycarbonyl complex [Ru3(µ-H)2(µ3-ampy)(CO2Me)(CO)8]. Complexes (1) and (2) react with PPh3 to give [Ru3(µ-H)(µ3-ampy)(CO)8(PPh3)](5) and [Ru3(µ-H)2(µ3-ampy)(CO)8(PPh3)][BF4](6), respectively. In both cases substitution has taken place selectively at an equatorial position cis to the NH fragment and cis to one hydride and, in the case of complex (2), on the Ru atom bonded to only one hydride ligand. Complex (5) undergoes protonation with HBF4·OEt2 to give [Ru3(µ-H)2(µ3-ampy)(CO)8(PPh3)][BF4](7). The X-ray structure of (7)·OEt2[triclinic, space group P, a= 10.657(5), b= 12.318(3), c= 16.622(3)A, α= 99.14(2), β= 104.18(1), γ= 92.76(1)°, Z= 2] shows that the PPh3 ligand is now on the Ru atom bonded to the two hydrides and trans to the hydride which spans the edge bridged by the amido group. Compounds (6) and (7) are isomers; the former can be converted into the latter upon heating in refluxing tetrahydrofuran. Treatment of complex (7) with NEt3 or potassium methoxide results in deprotonation giving (5). However, although the reaction of (6) with NEt3 also gives (5), the reaction of (6) with potassium methoxide leads to the methoxycarbonyl complex [Ru3(µ-H)2(µ3-ampy)(CO2Me)(CO)7(PPh3)](8). Arguments are presented which suggest that in the reactions leading to (3), (4), and (8), the attack of the methoxide ion takes place at equatorial CO ligands bonded to the ruthenium atoms which are attached to two hydrides. Proton and 31P-{1H} n.m.r. and i.r. spectra of all the compounds are also included and discussed in relation to their structures.

Selective carbonyl substitution reactions on [Ru3(μ-H)(μ3-ampy)(CO)9] and on its protonated derivative. Crystal structure of [Ru3(μ-H)2(μ3-ampy)(CO)9][BF4] (Hampy = 2-amino-6-methylpyridine)

Abstract The reactions of [Ru3(μ-H)(μ3-ampy)(CO)9] (1) (Hampy = 2-amino-6-methylpyridine) with PPh3 or dppm lead to replacement of one or two of the equatorial CO ligands that are cis to the bridging NH fragment and cis to the hydride. In contrast, the reactions of the protonated derivative [Ru3(μ-H)2(μ3-ampy)(CO)9][BF4] (2) with PPh3 or dppm involve replacement of equatorial CO ligands only on the ruthenium atoms bonded to one hydride ligand.

Mercury-bridged transition-metal clusters. Synthesis of pentanuclear Ru3HgM (M Mo, W, or Co) clusters and X-ray structure of [(Ru3(μ3,η2-ampy)(CO)9)-(μ3-Hg)Co(CO)4] (Hampy 2-amino-6-methylpyridine)

Abstract Redistribution reactions of the compound [Ru 3 (μ-HgCl)(μ 3 ,η 3 -ampy)(CO) 9 ] ( 1 ) (Hampy = 2-amino-6-methylpyridine) with the metal-metal bonded transition-metal dimers [M 2 Cp 2 (CO) 6 ] (M  MO or W) and [CO 2 (CO) 8 ] give a separable mixture of the mixed-metal clusters [{RU 3 (μ 3 ,η 2 -ampy)(CO) 9 }(μ 3 -Hg)ML n ] (ML n  MOCp(CO) 3 ( 2 ), WCp(CO) 3 ( 3 ), Co(CO) 4 ( 4 )) and the corresponding chloro complexes [MClL n ]. The compounds 2–4 contain an Hg-ML n fragment spanning the same Ru-Ru edge as the amido moiety of the ampy ligand, as has been determined by 13 C NMR spectroscopy and, in the case of complex 4 , by an X-ray diffraction study. Crystal data for 4 : triclinic, space group P −1 , a = 9.598(3), b = 11.817(3), c = 12.835(6) A, α = 76.40(3), β = 75.34(4), γ = 83.34(3)°, V = 1366(1) A 3 , Z = 2; R = 0.0359, R W = 0.0362 for 3508 observed reflections and 372 variables.