Synthesis of Trithia-Borinane Complexes Stabilized in Diruthenium Core: [(Cp*Ru)₂(η¹-S)(η¹-CS){(CH₂)₂S₃BR}] (R = H or SMe)

The thermolysis of arachno-1 [(Cp*Ru)2(B3H8)(CS2H)] in the presence of tellurium powder yielded a series of ruthenium trithia-borinane complexes: [(Cp*Ru)2(η1-S)(η1-CS){(CH2)2S3BH}] 2, [(Cp*Ru)2(η1-S)(η1-CS){(CH2)2S3B(SMe)}] 3, and [(Cp*Ru)2(η1-S)(η1-CS){(CH2)2S3BH}] 4. Compounds 2⁻4 were considered as ruthenium trithia-borinane complexes, where the central six-membered ring {C2BS3} adopted a boat conformation. Compounds 2⁻4 were similar to our recently reported ruthenium diborinane complex [(Cp*Ru){(η2-SCHS)CH2S2(BH2)2}]. Unlike diborinane, where the central six-membered ring {CB2S3} adopted a chair conformation, compounds 2⁻4 adopted a boat conformation. In an attempt to convert arachno-1 into a closo or nido cluster, we pyrolyzed it in toluene. Interestingly, the reaction led to the isolation of a capped butterfly cluster, [(Cp*Ru)2(B3H5)(CS2H2)] 5. All the compounds were characterized by 1H, 11B{1H}, and 13C{1H} NMR spectroscopy and mass spectrometry. The molecular structures of complexes 2, 3, and 5 were also determined by single-crystal X-ray diffraction analysis

Synthesis, Structure, and Bonding of Bimetallic Bridging Borylene and Boryl Complexes

International audienceA new synthetic route for the synthesis of diruthenium boryl complexes has been established. Thermolysis of an arachno-ruthenaborane, [(Cp*Ru)(2)B3H8(CS2H)] (1; Cp* = eta(5)-C5Me5), with phenylacetylene led to the formation of the bridging boryl borylene complex [(Cp*Ru)(2) (mu-HBS2CH2-kappa B-2:kappa S-2){mu-B(C6H4)C(CH3)-kappa B-2:kappa C-2)] (2). In parallel to the formation of 2, the reaction also yielded [(Cp*Ru)(mu-H)BH-{HC=C(H)Ph}{SC(H)S}] (3a) and [(Cp*Ru)(mu-H)BH-(PhC=CH2){SC(H)S}] (3b). To understand the reaction pathways for the formation of 2, we have thermolyzed 1 in toluene, which afforded the ruthenium bridging bis(boryl) complex [(Cp*Ru)(2)(mu-HBS2CH2-kappa B-2:kappa S-2){mu,eta(2):eta(2)-SBH}] (4) along with the nido-ruthenathiaborane [(Cp*Ru)(2)(Me)(S2B2H3)] (5). nido-5 is structurally and electronically similar to nido-[(Cp+Ru)(2)(S2C2Ph2)] (Cp+ = eta(5)-C5Me4Et), which can be generated from the room-temperature reaction of [(Cp+Ru)(2)(mu, eta(1):eta(1)-S-2)(mu, eta(2):eta(1)-S-2)] with diphenylacetylene. Thus, nido-5 can be defined as a true mimic of the organometallic cluster nido-[(Cp+Ru)(2)(S2C2Ph2)]. The complex [(Cp*Ru)(2)(mu-eta(1):eta(1)-S-2)(mu, eta(2):eta(1)-S-2)] (6), the Cp* analogue of [(Cp+Ru)(2)(mu-eta(1):eta(1)-S-2)(mu, eta(2):eta(1)-S-2)], can be isolated from the reaction of Li[BH2S3] with [Cp*RuCl2](2) along with the diruthenium boryl complex [(Cp*Ru)(2)(mu-eta(1):eta(1)-S-2)(mu-(SBH)-B-2-kappa B-1:kappa S-2:kappa S-2')] (7), in which the boryl unit (S2BH) possesses no bulky heterocyclic ligand. Theoretical studies were performed to shed light on the bonding of these borylene and boryl complexes. The theoretical calculations reveal that the stability of these complexes is due to the strong interaction between the borylene and boryl units and the ruthenium centers

Stabilization of dichalcogenide ligands in the coordination sphere of a ruthenium system

International audienceThe synthesis, structure and electronic properties of tetraruthenium dichalcogenide complexes displaying the exclusive coordination mode of dichalcogenide ligands have been discussed. The reactions of Li[BH2E3] (E = S or Se) with [ClRu(mu-Cl)(p-cymene)](2) (p-cymene = eta(6)-{p-C6H4(Pr-i)Me}) at room temperature yielded tetrametallic dichalcogenide complexes [{Ru2Cl2(p-cymene)(2)}(2)(mu(4),eta(2)-E-2)], 1-2 (E = S (1) and Se (2)). The solid-state X-ray structure of 1 shows that two {(p-cymene)RuCl}(2) moieties are bridged by a S-S bond. In addition to 2, the reaction of Li[BH2Se3] with [ClRu(mu-Cl)(p-cymene)](2) also yielded a mononuclear tris-homocubane analogue [Ru(p-cymene){Se-7(BH)(3)}] (3) which is an analogue of 1,3,3-tris-homocubane and possesses D-3 symmetry. In order to isolate the Cp* analogue of 1, the reaction of [Cp*Ru(mu-Cl)Cl](2) with Li[BH2S3] was carried out, which led to the formation of bis/tris-homocubane derivatives [(Cp*Ru)(2){mu-S-n(BH)(2)}] (n = 7 (4) and 6 (5)) along with the formation of ruthenium disulfide complexes [(RuCp*)(2)(mu,eta(2):eta(2)-S-2)(mu,eta(1):eta(1)-S-2)] and [(RuCp*)(2)(mu-SBHS-kappa B-1:kappa S-2:kappa S-2)(mu,eta(1):eta(1)-S-2)]. Complexes 1-5 have been characterized by multi-nuclear NMR, IR, UV-vis spectroscopy, and mass spectrometry and their molecular formulations (except 2) have been determined by single crystal X-ray crystallography. Furthermore, DFT calculations were performed that rationalize the stabilization of the dichalcogenide units (E-2(2-)) by the tetrametallic systems in 1-2

Bridging Bis(boryl) and Borylene Species Stabilized in the Coordination Sphere of Ruthenium Metals

International audienceSynthetic routes for the synthesis of doubly bridging bis(boryl) and triply bridging borylene species of ruthenium have been established. The room-temperature reaction of [Cp*RuCl2]2 with LiBH4·THF followed by the addition of [S2CPPh3] led to the formation of a diruthenium bridging bis(boryl) complex, [(Cp*Ru)2(μ-HBS(C═S)S-κ2B:κ2S)(μ-HBSCH2S-κ2B:κ2S)] (1) consisting of two unsymmetrical boryl ligands. In parallel to 1, this reaction also yielded a Cp*-based ruthenium dithioformate half-sandwich complex, [Cp*Ru(PPh3){η3-SC(H)S}] (2) depicting four-legged piano stool geometry. Interestingly, when the reaction of [Cp*RuCl2]2 was carried out with NaBH4, it led to the formation of a triruthenium cluster [(Cp*Ru)3(μ-H)5(μ3-BH)2] (3) having a triply bridging borylene moiety. Cluster 3 comprises two triply bridging {BH} units axially bound to both sides of the triangular Ru3 plane giving rise to a trigonal bipyramidal Ru3B2 core. Theoretical calculations were implemented on these bridging bis(boryl) and borylene species to understand their bonding scenarios

Hydroboration of Alkynes eta(4)-Alkene-Borane versus eta(4)-E-Boratabutadiene

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Bimetallic Perthiocarbonate Complexes of Cobalt: Synthesis, Structure and Bonding

The syntheses and structural elucidation of bimetallic thiolate complexes of early and late transition metals are described. Thermolysis of the bimetallic hydridoborate species [{Cp*CoPh}{µ-TePh}{µ-TeBH3-ĸ2Te,H}{Cp*Co}] (Cp* = ɳ5-C5Me5) (1) in the presence of CS2 afforded the bimetallic perthiocarbonate complex [(Cp*Co)2(μ-CS4-κ1S:κ2S′)(μ-S2-κ2S″:κ1S‴)] (2) and the dithiolene complex [(Cp*Co)(μ-C3S5-κ1S,S′] (3). Complex 2 contains a four-membered metallaheterocycle (Co2S2) comprising a perthiocarbonate [CS4]2− unit and a disulfide [S2]2− unit, attached opposite to each other. Complex 2 was characterized by employing different multinuclear NMR, infrared spectroscopy, mass spectrometry, and single-crystal X-ray diffraction studies. Preliminary studies show that [Cp*VCl2]3 (4) with an intermediate generated from CS2 and [LiBH4·THF] yielded thiolate species, albeit different from the cobalt system. Furthermore, a computational analysis was performed to provide insight into the bonding of this bimetallic perthiocarbonate complex

Combined B–H and Si–H Bond Activations at Ruthenium

The coordination of 2-mercaptobenzothiazolyl (mbz) and 2-mercaptopyridyl (mp) to a [Ru]–H precursor led to the isolation of two hydrido(dihydroborate) complexes [RuH(PCy3)2{κ3-H,H,S-(H)2BH(L)}] (L = mbz (1a), mp (1b)). Oxidative addition of secondary and tertiary silanes to 1a and 1b afforded the dihydrido ruthenium(IV) [RuH2(SiPh2R)(PCy3){κ3-H,H,S-(H)2BH(L)}] (R = H, L = mbz (2a), mp (2b); R = Me, L = mbz (2c)) featuring a coordinated borohydride moiety and a silyl ligand in weak interaction with the two hydride ligands of the ruthenium center. 1D and 2D NMR investigations at different temperatures as well as D2 reactivity, enabled to characterize exchange between every Si–H, Ru–H, and B–H hydride sites