An easy and direct access to POP-type osmium(II) osmium(IV) complexes, including OsH4{dbf(PiPr2)2} (dbf(PiPr2)2 = 4,6-bis(diisopropylphosphine)dibenzofuran), is reported. This tetrahydride derivative an efficient catalyst for the selective formation of imines from alcohols amines with liberation H2, proving that osmium a promising alternative ruthenium catalysis.

The synthesis, characterization, and ethylene polymerization behavior of a family chromium(III) complexes formula [2,6-bis(imino)pyridyl]CrCl3 is reported. X-ray diffraction studies two the new compounds show that geometry around chromium atom octahedral, with three chlorine ligands in mer disposition. distance between metal one trans-disposed atoms significantly longer than other Cr−Cl distances. Treatment methylaluminoxane (MAO) leads to very active catalysts afford highly linear...

Aromatic diosmatricyclic nitrogen-containing compounds are prepared from Os(VI) complex OsH6(PiPr3) by double 1,3-C-H bond activation of aromatic six-membered cycles with imino substituents meta disposed.

Chloro[2,6-bis{1-(phenyl)iminoethyl}pyridine]rhodium(I) complexes (RhCl(N,N,N); 1−11) have been prepared by reaction of the dimer [Rh(μ-Cl)(η2-C2H4)2]2 with corresponding nitrogen donor ligand. These afford nanoparticles a mean diameter 1.5 ± 0.2 nm stabilized partially hydrogenated ligand, under 1 atm hydrogen, in 2-propanol as solvent, at 60 °C, and presence KtBuO. Under constant atmospheric pressure catalyze dehalogenation chlorobenzene 1,2-, 1,3-, 1,4-dichlorobenzene,...

Novel homoleptic and heteroleptic NHC carbene containing bis(tridentate) osmium(II) complexes have been designed, synthesized, characterized, their photophysical properties studied. The complex OsH6(PiPr3)2 (1) reacts with the tetrafluoroborate salts of 1,3-bis(3-methylbenzimidazolium-1-yl)benzene 1,3-bis(3-methylimidazolium-1-yl)benzene, in dimethylformamide, under reflux to afford hydride–carbonyl derivatives [OsH(CNHCCarylCbenzimidazolium)(CO)(PiPr3)2]BF4 (2)...

9,9-Dimethyl-4,5-bis(diisopropylphosphino)xanthene (xant(P(i)Pr2)2) derivatives RhCl{xant(P(i)Pr2)2} (1) and I rHCl{xant(P(i)Pr2)[(i)PrPCH(Me) CH2]} (2) react with diphenylsilane triethylsilane to give the saturated d(6)-compounds RhHCl(SiR3){xant(P(i)Pr2)2} (SiR3 = SiHPh2 (3), SiEt3 (4)) IrHCl(SiR3){xant(P(i)Pr2)2} (5), (6)). Complexes 3 5 undergo a Cl/H position exchange process via MH{xant(P(i)Pr2)2} (M Rh (8), Ir (E)) intermediates. The rhodium complex affords square planar d(8)-silyl...

RuHX(H2)L2 (L = PtBu2Me; X Cl, I) and OsH3ClL2 PiPr3) react (time of mixing) with terminal alkynes in a 1:2 stoichiometry to give MHX(CCHR)L2 RCHCH2. The reactions PhC⋮CD lead RuDX(CCHPh)L2 as the only isotopomers. This result is understood terms an insertion alkyne Ru−H bond make vinyl, followed by α-hydrogen migration, giving hydrido/vinylidene. reaction path has been studied ab initio (B3LYP) calculations location minima transition states. In agreement isotopic labeling experiments, it...

The reactions of the hexahydride OsH6(PiPr3)2 (1) with 1.0 equiv BPh4−, BF4−, and Br− salts 1-(2-pyridylmethyl)-3-methylimidazolium, in tetrahydrofuran under reflux, have been studied. In three cases, mixtures abnormal [OsH(η2-H2){κC5,N-[1-(2-pyridylmethyl)-3-methylimidazol-5-ylidene]}(PiPr3)2]A (A = BPh4 (2a), BF4 (2b), Br (2c)) normal [OsH(η2-H2){κC2,N-[1-(2-pyridylmethyl)-3-methylimidazol-2-ylidene]}(PiPr3)2]A (3a), (3b), (3c)) isomers are obtained. formation rate isomer to ratio decrease...

The complex OsH6(PiPr3)2 (1) is a basic precursor which promotes the direct metalation of imidazolium salts. Thus, it reacts with 1-mesityl-3-methylimidazolium tetraphenylborate and 1-mesityl-3-ethylimidazolium to give abnormal NHC derivatives [OsH5(1-mesityl-3-methylimidazol-4-ylidene)(PiPr3)2]BPh4 (2) [OsH5(1-mesityl-3-ethylimidazol-4-ylidene)(PiPr3)2]BPh4 (3), respectively. Treatment 2 3 NaH produces deprotonation metal center formation tetrahydride...

[6]-Azaosmahelicenes, the first d(4)-heterometallahelicenes, have been synthesised and fully characterised. Their optical properties (UV-Vis absorption luminescence) are reported.

A wide range of osmium-polyhydride complexes stabilized by the POP-pincer ligand xant(PiPr2)2 (9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene) have been synthesized through cis-OsCl2{κ-S-(DMSO)4} (1, DMSO = dimethyl sulfoxide). Treatment toluene solutions this adduct with diphosphine, under reflux, leads to OsCl2{xant(PiPr2)2}(κ-S-DMSO) (2). The reaction 2 H2 in presence Et3N affords OsH3Cl{xant(PiPr2)2} (3), which can be also prepared addition unsaturated d4-trihydride OsH3Cl(PiPr3)2...

The square-planar monohydride complex RhH{xant(PiPr2)2} (1; xant(PiPr2)2 = 9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene) activates C–H bonds of arenes. Heating benzene solutions 1 at 80 °C affords RhPh{xant(PiPr2)2} (2). Under the same conditions, toluene gives Rh(m-tolyl){xant(PiPr2)2} (3a) and Rh(p-tolyl){xant(PiPr2)2} (3b) in a 78:22 molar ratio, whereas m-xylene leads to Rh(C6H3-3,5-Me2){xant(PiPr2)2} (4). At room temperature, fluorobenzene 1,3-difluorobenzene generate...

A wide range of ruthenium complexes stabilized by the POP-pincer ligand xant(P(i)Pr2)2 (9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene) were prepared starting from cis-RuCl2{κ-S-(DMSO)4} (1; DMSO = dimethyl sulfoxide). Treatment toluene solutions this adduct with diphosphine under reflux leads to RuCl2{xant(P(i)Pr2)2}(κ-S-DMSO) (2), which reacts H2 in presence a Brønsted base. The reaction Et3N affords RuHCl{xant(P(i)Pr2)2}(κ-S-DMSO) (3), whereas NaH removes both chloride ligands give...

The hexahydride complex OsH6(PiPr3)2 (1) reacts with 1-mesitylimidazole, 1-methylimidazole, 1-(2-hydroxy-2-phenylethyl)imidazole, and 1-(2-hydroxypropyl)imidazole to give the N-bound imidazole compounds OsH4(RIm)(PiPr3)2 (R = Mes (2), Me (3), CH2CH(OH)Ph (4), CH2CH(OH)CH3 (5)) H2. In toluene under reflux alcohol derivatives 4 5 evolve into C-bound complexes OsH3{CNHCHCHNCH═C(R)O}(PiPr3)2 Ph (6), CH3 (7)), bearing an NH wingtip. These NHC-enolate species result from transformation of...

The stoichiometric reactions proposed in the mechanism of rhodium-mediated decyanative borylation have been performed and all relevant intermediates isolated characterized including their X-ray structures. Complex RhCl{xant(PiPr2)2} (1, xant(PiPr2)2 = 9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene) reacts with bis(pinacolato)diboron (B2pin2), benzene, to give rhodium(III) derivative RhHCl(Bpin){xant(PiPr2)2} (4) PhBpin. reaction involves oxidative addition B2pin2 1...

The pincer d(8)-monohydride complex RhH{xant(P(i)Pr2)2} (xant(P(i)Pr2)2 = 9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene) promotes the release of 1 equiv hydrogen from H3BNH3 and H3BNHMe2 with TOF50% values 3150 1725 h(-1), to afford [BH2NH2]n [BH2NMe2]2 tandem ammonia borane dehydrogenation-cyclohexene hydrogenation. DFT calculations on dehydrogenation suggest that process takes place by means cis-κ(2)-PP-species, through four stages including: (i) Shimoi-type coordination borane, (ii)...

The tetrahydride complex OsH4{xant(PiPr2)2} (1, xant(PiPr2)2 = 9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene) activates an ortho-C–H bond of benzophenone and acetophenone to give the osmaisobenzofuran derivatives OsH{κ2-C,O-[C6H4C(R)O]}{xant(PiPr2)2} (R Ph (2), CH3 (3)). reaction 1 with perdeuterated leads 2 partially protiated. deuterium distribution in latter suggests that carbonyl group ketone traps addition product, which is most disfavored from a kinetic point view. ruthenium...

The 14-valence-electron monohydride OsH(SnPh2Cl)(PiPr3)2 (a), generated from (1), activates a C(sp2)−H bond of 2-vinylpyridine, (E)-N-(phenylmethylene)-2-pyridinamine, and α,β-unsaturated ketones. activation 2-vinylpyridine affords the elongated dihydrogen (dH-H = 1.41 Å) derivative (2) in equilibrium (ΔH° −2.5 ± 0.2 kcal mol-1 ΔS° −14.8 1.0 cal K-1) with tautomer (3), where stannane is bonded to transition metal by an Os−H−Sn three-center (JH-Sn 183 Hz)....

The dihydride-dihydrogen complex [OsH2(η5-C5H5)(η2-H2)(PiPr3)]BF4 (2) has been prepared by addition of HBF4·OEt2 to OsH3(η5-C5H5)(PiPr3) (1), and its reactions with benzylideneacetone, methyl vinyl ketone, acetophenone, benzylideneacetophenone have studied. reaction benzylideneacetone leads initially [OsH2(η5-C5H5){κ1-OC(CH3)CHCHPh}-(PiPr3)]BF4 (3), which in dichloromethane is converted the hydroxyallyl derivative [OsH(η5-C5H5){η3-CH2C(OH)CHCH2Ph}(PiPr3)]BF4 (4). Complex 4 releases...

Reaction of [OsH(η2-H2){η2-C,C-κ1-N-(CH2CH-o-C5H4N)}(PiPr3)2]BF4 with benzophenone affords [OsH2{κ2-C,O−C6H4C(O)Ph}{κ-C-(HNC5H3Et)}(PiPr3)2]BF4 as a result the orthometalation ketone, hydrogenation vinyl substituent pyridine, and its subsequent tautomerization. In acetonitrile, ketone is released complex [OsH{κ-C-(HNC5H3Et)}(NCCH3)(PiPr3)2]BF4 formed.

Complex [OsH(η2-H2)(η2-CH2═CH-o-C5H4N)(PiPr3)2]BF4 (1) reacts with methyl vinyl ketone in the absence of solvent to give [OsH{CHCHC(O)CH3}2(PiPr3)2]BF4 (2), which can be described as two osmafurans joined by a common [OsH(PiPr3)2]+ fragment. The hydride ligand 2 is fairly acidic. Thus, its treatment sodium methoxide produces deprotonation metal center Os{CHCHC(O)CH3}2(PiPr3)2 (3). reaction not reversible; protonation 3 HBF4·OEt2 leads [Os{CHCHC(O)CH3}{═CHCH2C(═O)CH3}(PiPr3)2]BF4 (4),...

Complex OsH2Cl2(PiPr3)2 promotes the C−H activation of 2-vinylpyridine and subsequently couples activated substrate with a second two acetylene molecules. In absence 2-vinylpyridine, is coupled an unit to afford 2-butadienylpyridine derivative.

Treatment of the dimer [Rh(μ-Cl)(C8H14)2]2 (1a) with 9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene [xant(P(i)Pr2)2] leads to d(8) square-planar complex RhCl{xant(P(i)Pr2)2} (2), whereas reaction iridium counterpart [Ir(μ-Cl)(C8H14)2]2 (1b) gives d(6) octahedral compound IrHCl{xant(P(i)Pr2)[(i)PrPCH(Me)CH2]} (3) as a result intramolecular C-H bond activation one isopropyl substituents phosphine. Stirring 2 and 3 in 0.5 N KOH solutions 2-propanol rise formation hydrides...