Ru-Cl Bond Research Articles

Notes. High-valent ruthenium oxo complexes of NNN′N′-tetramethyl-3,6-dimethyl-3,6-diazaoctane-1,8-diamine (L1). X-Ray crystal structure determination of cis-[RuIII(L1)Cl2]ClO4

The reaction of K2[RuCl5(H2O)] with NNN′N′-tetramethyl-3,6-dimethyl-3,6-diazaoctane-1,8-diamine (L1) in ethanol yielded cis-[RuIII(L1)Cl2]+, which was isolated as the ClO4– salt. The optical spectrum of cis-[RuIII(L1)Cl2]ClO4 in acetonitrile displays one intense band at 375 nm attributed to a pπ(Cl)→dπ*(Ru) transition. cis.-[RuIII(L1)Cl2]ClO4 has been characterized by X-ray crystallography: space group P21/c, a= 11.716(5), b= 13.089(4), c= 12.981(5)Å, β= 94.28(2)°, Z= 4, and R= 0.076 for 1 913 observed Mo-Kα data. The co-ordination geometry around the metal ion is distorted octahedral with cis arrangement of the two chloride ligands. The average Ru–N and Ru–Cl bond distances are 2.17(1) and 2.345(4)Å, respectively. Treatment of cis-[RuIII(L1)Cl2]ClO4 with silver(I)p-toluenesulphonate in hot water and then H2O2 gave [RuVI(L1)(O)2]2+ isolated as the ClO4– salt. [RuVI(L1)(O)2][ClO4]2 is diamagnetic (µeff.= 0) and has an intense i.r. band at ca. 850 cm–1 attributed to νasym(RuO) stretching. The E½ value of the [RuVI(L1)(O)2]2+/[RuIV(L1)(O)(H2O)]2+ couple in 0.1 mol dm–3 CF3CO2H is 0.79. V vs. a saturated calomel electrode. The reaction of [RuIV(L1)(O)2][ClO4]2 with styrene produced benzaldehyde.

Cyclopentadienyl-ruthenium and -osmium complexes: V. Synthesis, reactivity and crystal structure determination of carbonylchloro(η-cyclopentadienyl)-(triphenylphosphine)ruthenium(II)

CpRuCl(CO)PPh 3 is formed as the result of refluxing CpRuCl(PPh 3) 2 in ethylene glycol (yield up to 15%). A dissociation process is postulated with liberation of one PPh 3 molecule and simultaneous rearrangement of the cation formed earlier: [CpRu(CO)(PPh 3) 2] + Cl − → CpRuCl(CO)PPh 3 + PPh 3. CpRuCl(CO)PPh 3 reacts reluctantly with the alkoxy anion to give CpRuH(CO)PPh 3, in contrast to CpRuCl(PPh 3) 2, which undergoes very facile transformation into CpRuH(PPh 3) 2. The structure of CpRuCl(CO)PPh 3 has been determined by the single-crystal X-ray diffraction method. The compound is triclinic, space group P 1 , a 9.378(2), b 10.584(2), c 16.590(4) Å, α 126.11(1), β 55.91(1), γ 101.49(1)°. The unit cell contains both R and S enantiomers. A shorter distance of the RuCl bond has been noted in CpRuCl(CO)PPh 3 (2.396 Å) in comparison with the RuCl distance in CpRuCl(PPh 3) 2 (2.453 Å). This causes a diminishing tendency to lose a chloride ion and as a result, nucleophilic attack of RO − on CpRuCl(CO)PPh 3.

Alkyl, hydrido-, and related compounds of ruthenium(II) with trimethylphosphine. X-Ray crystal structures of hydrido(tetrahydroborato-HH′)tris(trimethylphosphine)ruthenium(II), tri-µ-chloro-bis[tris(trimethylphosphine)ruthenium(II)] tetrafluoroborate, and bis[cis-methyltetrakis(trimethylphosphine)ruthenio]mercury(II)–tetrahydrofuran(1/1)

A number of trimethylphosphine complexes of ruthenium(II) with alkyl, hydrido-, halogeno-, acetato-, and tetrahydroborato-ligands and in addition the halide-bridged complex [(Me3P)3Ru(µ-Cl)3Ru(PMe3)3]BF4 and the mercury-bridged species [cis-RuMe(PMe3)4]2Hg have been synthesized. The X-ray crystal structures of RuH(BH4)(PMe3)3 and of the tri-µ-chloro- and mercury-bridged complexes have been determined. In the borohydride the metal atom has an octahedral co-ordination, with a bidentate BH4– ligand. The two Ru–H(borohydride) bonds [1.81 (4) and 1.85(4)A] are trans to the hydride [Ru–H 1.49(4)A] and one phosphine [Ru–P 2.259(3)A]; the latter is shorter than those to the other phosphines [2.304(3) and 2.305(3)A] which are trans to each other. The chloro-bridged complex has the usual confacial bioctahedral X3MY3MX3 structure with Ru–P and Ru–Cl bond lengths in the ranges 2.248(4)–2.256(4) and 2.463(4)–2.488(4)A respectively. In the mercury-bridged species as the tetrahydrofuran solvate, the Ru–Hg distances are 2.798(4) and 2.800(4)A and the Ru–Hg–Ru angle is 170.7(2)° Ru–C distances are 2.21 (1) and 2.23(1)A whilst Ru–P distances range from 2.308(4) to 2.344(4)A with those trans to the Ru–Me bonds shorter than the rest. The mercury atom makes close contacts with a number of hydrogens from methyl groups.

Structure of trans-chloronitrosyltetrakis(pyridine)ruthenium(II) bis(hexafluorophosphate) hemihydrate

The structure of trans-chloronitrosyltetrakis(pyridine)ruthenium(II) bis(hexafluorophosphate) hemihydrate, [RuClpy 4NO] (PF 6) 2·1/2H 2O, was determined by X-ray structure analysis. The compound crystallizes in monoclinic form, space group P2 1/c, with a = 16.0201(12), b = 1.5306(15), c = 27.0912(20) Å, β = 91.78(1)°, Z = 8. Least-squares refinement of the structure yielded a final R factor of 0.051 for 4229 independent reflections with |F o|⩾ 3σ(|F o|) collected byu a counter method. There are two crystallographically independent formula units in the asymmetric unit. Both have essentially the same structure. The complex cation has a trans octahedral geometry with a nitrosyl and a chloride in the axial position and four pyridines in the equatorial position. The four pyridines form a propeller-like arrangement with an average pitch of about 46°. The RuNO group is approximately linear: the RuNO angle is 174.8(1.9)°, the RuN bond length is 1.760(9) and that of N is 1.132(13) Å. The RuCl bond length is 2.314(1) Å; this is shortened by the trans-shortening effect of the nitrosyl. The average separation distance of Ru(pyridine) is 2.111(6) Å. NMR spectra, along with their temperature dependence, suggests that rapid cogwheel rotation of pyridine rings about RuN(py) axis is occuring in solution.

Optically active transition metal complexes: LVI. [formula omitted] [Ph 2PNHCH(Me) (Ph)], where x = Cl, SnCl 3

The synthesis and resolution of (+) 578- and (-) 578-(η-C 6H 6)RuCl(Me) [Ph 2PNHCH(Me) (Ph)] is described. Insertion of anhydrous SnCl 2 into the Ru-Cl bond yielded (+) 578- and (-) 578-(η-C 6H 6)RuSnCl 3(Me)-[Ph 2PNHCH(Me) (Ph)], the stereoselectivity of which is dependent on the reaction conditions. All the new complexes were found to be configurationally stable in a wide variety of solvents up to 60°C./

The crystal and molecular structure of tetra-μ-chloro-tetra-μ-ethyloxycarbene-di- μ 3-hydroxo dodecacarbonyl-di-chloro-hexaruthenium(II)

The crystal and molecular structure of tetra-μ-chloro-tetra-μ-ethyloxycarbene-di-μ 3hydroxo-dodecacarbonyl-di-chloro-hexaruthenium(II)-benzene, [Ru 3Cl 3(COC 2H 5) 2(OH)CO) 6] 2·C 6H 6, have been determined. The complex crystallizes as monoclinic crystals in space group P 2 1/c with unit cell dimensions a = 10.71(2) Å, b = 10.41(2) Å, c = 21.92(3) Å, β = 113° 15′ (10′) and Z= 2. A three-dimensional X-ray analysis, based on 3101 observed reflections, converged to a R of 0.076. The crystal structure of the complex consists of centrosymmetric hexanuclear molecules. The three ruthenium atoms of the asymmetric unit are octahedrally coordinated. The octahedra share a common vertex occupied by a hydroxo group which bridges three ruthenium atoms Significant differences in the Ru-Cl bond lengths are accounted by the “trans influence” of the carbene nature of the C 2H 5CO groups.