Mohan Rao Kollipara

Reactivity studies of η6-arene ruthenium (II) dimers with polypyridyl ligands: isolation of mono, binuclear p-cymene ruthenium (II) complexes and bisterpyridine ruthenium (II) complexes

Abstract The complexes [(η6-p-cymene)RuCl(L2)]+ where L2=2,2′-biquinoline (biqui) (3), 2,9-dimethyl 4,7-diphenyl-1,10-phenanthroline (ddp) (4), and 2,3-bis(α-pyridyl) quinoxaline (bpq) (5) were obtained by halide bridge cleavage of [{(η6-p-cymene)Ru(μ-Cl)}2Cl2] (1) with the corresponding ligands. The ligand bridged binuclear compound [{(η6-cymene)RuCl}2(bpq)]2+ (6) was also obtained by treating 1 with stoichiometric amount of bpq in methanol. The reactions of [{(η6-arene)Ru(μ-Cl)}2Cl2], {arene=p-cymene (1), hexamethylbenzene (2)} with substituted phenylterpyridines (x-phterpy, x=H, CH3, OCH3) yielded bis terpyridine complexes of the type [(x-phterpy)2Ru]2+ by the facile displacement of η6-arene ring as well as chloride ligands. These complexes were characterized by FT-NMR, FT-IR spectroscopy, and analytical data. The molecular structures of [(η6-p-cymene)RuCl(biqui)]PF6 (3) and [(η6-p-cymene)RuCl(bpq)]PF6 (5) have been determined by single crystal X-ray diffraction study.

Syntheses and characterization of arene ruthenium (II) complexes containing N,N′-donor Schiff base ligands. Crystal and molecular structure of [(η6-C6Me6)Ru(C5H4N-2-CHNC6H4-p-NO2)]PF6

Abstract Reaction of [(η6-C6Me6)RuCl2]2 (1a) with N,N′-donor Schiff bases viz., para-substituted N-(2-pyridinylmethylene)phenylamines yielded complexes of the formulation [(η6-C6Me6)Ru(C5H4N-2-CHNC6H4-p-X)Cl]+ 2a–e where C6Me6=hexamethylbenzene, X=H (2a), CH3 (2b), OCH3 (2c), Cl (2d) and NO2 (2e). Reaction of 1a and [(η6-p-cymene)RuCl2]2 (1b) where p-cymene=(CH3C6H4CH(CH3)2) with N-(2-pyridinylmethylene)cyclohexylamine (2-PC) yielded complexes of the type [(η6-arene)Ru(2-PC)Cl]+ (arene=C6Me6 (3a); p-cymene, (3b)) respectively. All these complexes were isolated as their PF6 salt. These complexes were characterized by spectroscopic and analytical data. The molecular structure of [(η6-C6Me6)Ru(C5H4N-2-CHNC6H4-p-NO2)Cl]PF6 2e has been determined by X-ray crystallography.

Syntheses of (η6-p-cymene)ruthenium(II) piano-stool amine complexes: molecular structure of [(η6-C10H14)RuCl2(H2N-C6H4-p-Cl)]

The dimeric complex [{(η6-p-cymene)Ru(μ-Cl)Cl}2] (1) reacts with S,N-donor Schiff base ligands, para-substituted S-(thiophen-2-ylmethylene)phenylamines in methanol to give mononuclear amine complexes of the type [(η6-p-cymene)RuCl2(NH2–C6H4–p-X)] {X = H (2a); X = CH3 (2b); X = OCH3 (2c); X = Cl (2d); Br (2e) X = NO2 (2f), respectively} by hydrolysis of the imine group of the ligand after coordination to the metal. The complexes were characterized by analysis and IR and NMR spectroscopy. The molecular structure of [(η6-C10H14)RuCl2(H2N–C6H4–p-Cl)] (2d) was established by a single-crystal X-ray diffraction study.

Synthesis, Characterization and Molecular Structure of a new (?6-P-Cymene) Ruthenium(II) Amidine Complex, [(?6-P-Cymene)Ru{NH=C(Me)3,5-Dmpz}(3,5-Hdmpz)](BF4)2·H2O

A new arene ruthenium(II) complex [(η6-p-cymene)Ru(L)(3,5-Hdmpz)](BF4)2⋅H2O (L = 1-methylcarbaldimino-3,5-dimethylpyrazole; 3,5-Hdmpz = 3,5-dimethylpyrazole) has been synthesized. The ligand L has been generated in situ through the condensation of 3,5-dimethylpyrazole and acetonitrile in the presence of [{(η6-p-cymene)RuCl2}2]. The complex [(η6-p-cymene)Ru{NH=C(Me)3,5-dmpz}(3,5-Hdmpz)](BF4)2⋅H2O crystallizes in monoclinic space group P21/c, a = 10.943(2), b = 26.394(7), c = 11.502(1) Å, Β = 115.43(1)°, V = 3000.1(19) Å3 and Z = 4. The compound has been characterized by FTIR, 1H NMR, 2D-COSY NMR spectroscopy and a single-crystal X-ray diffraction study.

Synthesis of indenyl ruthenium triazolato complexes by [3 + 2] cycloaddition of activated nitrile and alkynes to indenyl ruthenium azido complexes: crystal structures of [( η 5-C9H7)Ru(PMe2Ph)2{N3C2(CO2Me)2}] and [( η 5-C9H7)Ru(dppe){N3C2H(CN}]

The indenyl ruthenium(II) azide complexes [(η5-C9H7)Ru(L2)N3], L2 = (PMe2Ph)2 (1), dppe (2) and dppm (3), (where dppe = Ph2PCH2CH2PPh2 and dppm = PPh2CH2PPh2) were readily prepared by the reaction of NaN3 with corresponding chloro complexes [(η5-C9H7)Ru(L2)Cl]. The azido complexes undergo [3 + 2] dipolar cycloaddition reactions with activated alkynes and nitrile (NCCH = CHCN) to yield new indenyl ruthenium triazolato complexes [(η5-C9H7)Ru(L2)(N3C2(CO2R)2)], L2 = (PMe2Ph)2, R = Me (4), Et (5); L2 = dppe, R = Et (6), L2 = dppm, R = Et (7) and [(η5-C9H7)Ru(L2)(N3C2HCN)], L2 = (PMe2Ph)2 (8), L2 = dppe (9), L2 = dppm (10). The complexes were fully characterized on the basis of microanalyses, IR and NMR spectroscopy. The structures of representative complexes 4 and 9 have been determined by single-crystal X-ray methods.

Substitution reactions of diphenyl-2-pyridylphosphine with [(η5-C5Me5)M(μ-Cl)Cl]2 (M = Rh or Ir) dimers: Isolation of mono–, di– and chelating complexes

The reaction of [{(η5-C5Me5)M(μ-Cl)Cl}2] {where M = Rh (1), Ir (2)} with functionalized phosphine viz., diphenyl-2-pyridylphosphine (PPh2Py) in dichloromethane solvent yield neutral ϰ1-P-coordinated rhodium and iridium complexes [(η5-C5Me5)RhCl2(κ1-P-PPh2Py)]3 and [(η5-C5Me5) IrCl2(ϰ1-P-PPh2Py)]4. Reaction of complexes 1 and 2 with the ligand PPh2Py in methanol under reflux give bis-substituted complexes such as [(η5-C5Me5)RhCl(ϰ1-P-PPh2Py)2]+5 and [(η5-C5Me5)IrCl(ϰ1-P-PPh2Py)2]+6, whereas stirring in methanol at room temperature gives P-, N-chelating complexes of the type [(η5-C5Me5)RhCl(ϰ2-P-N-PPh2Py)]+ 7 and [(η5-C5Me5)IrCl(ϰ2-P-N-PPh2Py)]+8. Neutral ϰ1-P-coordinated complexes [(η5-C5Me5)RhCl2(ϰ1-P-PPh2Py)]3 and [(η5-C5Me5)IrCl2(ϰ1-P-PPh2Py)]4 easily undergo conversion to the cationic P-, N-chelating complexes [(η5-C5Me5)RhCl(ϰ2-P-N-PPh2Py)]+7 and [(η5-C5Me5) IrCl(ϰ2-P, N-PPh2Py)]+8 on stirring in methanol at room temperature. These complexes are characterized by FT-IR and FT-NMR spectroscopy as well as analytical methods. The molecular structures of the representative complexes [(η5-C5Me5)RhCl2(ϰ1-P-PPh2Py)]3, [(η5-C5Me5)IrCl2(ϰ1-P-PPh2Py)]4 and hexafluorophosphate salt of complex [(η5-C5Me5)IrCl(ϰ2-P-PPh2Py)2]+6 are established by single-crystal X-ray diffraction methods

Syntheses of [(η 6- p -cymene)Ru(EPh3)2Cl]+ complexes and molecular structure of chloro(η 6- p -cymene)-bis(triphenylphosphine)ruthenium(II) tetrafluoroborate (E = P, As and Sb)

The reaction of [(η6-p-cymene)RuCl2]2 with excess EPh3 (E = P, As, Sb) in methanol in the presence of ammonium tetrafluoroborate leads to the formation of complexes of the type [(η6-p-cymene)Ru(EPh3)2Cl]BF4, E = P (1), As (2), Sb (3), which arise through cleavage of the chloride bridges. These complexes were characterized by spectral and analytical data. The crystal structure of 1 was solved by single-crystal X-ray crystallography in order to establish the exact structure in the solid state. The complex crystallizes in monoclinic space group P21/n (#14) with a = 12.42500(10), b = 30.1925(3), c = 11.06530(10) Å, β = 103.1470(10)°.

Study of reactivity ofp-cymene ruthenium(II) dimer towards diphenyl-2-pyridylphosphine: Synthesis, characterization and molecular structures of [(η6-p-cymene)RuCl2(PPh2Py)] and [(η6-p-cymene)RuCl(PPh2Py)]BF4

The reaction of [(η6-p-cymene)Ru(μCl)2Cl2] with functionalized phosphine viz, diphenyl-2-pyridylphosphine yielded complexes of the type: (a) P-bonded complex [(η6-p-cymene)RuCl2(PPh2Py)] (1), (b) P-, N-chelated complex [(η6-p-cymene)RuCl-(PPh2Py)]BF4 (2) and [RuCl2(PPh2Py)2] (3) resulting from the displacement of thep-cymene ligand. These complexes were characterized by1H NMR,31P NMR and analytical data. The structures of complexes1 and2 have been confirmed by single crystal X-ray diffraction study. Complex1 crystallised in triclinic space groupP 1 witha = 10.9403 (3) Å,b= 13.3108 (3) Å,c= 10-5394 (10) Å, α=88.943 (2)°, β = 117.193 (2)°, γ= 113.1680 (10)°, Z=2 andV= 1230.39 (5) Å3. The complex2 crystallises in monoclinic space group P21 witha = 9.1738 (4) Å,b = 14.0650 (6) s, c = 10.7453 (5) Å, β= 106.809 (1)°, Z = 2 andV= 1327.22 (10) Å3

Mono- and di-nuclear azido η6-p-cymene ruthenium(II) complexes; synthesis, reactivity, and structures

The azide bridge complex [(η6-p-cymene)Ru(µ-N3)Cl]2 (2) was prepared from the reaction of sodium azide with [(η6-p-cymene)RuCl]2 in ethanol. The molecular structures and spectroscopic properties of the various azido ruthenium complexes so obtained from the reaction with monodentate and bidentate ligands are described.

Synthesis and reactivity studies of cyclopentadienyl bis(triphenylphosphine)osmium(II) complexes. Crystal and molecular structure of [CpOs(PPh3)(phen)]BF4

Abstract Reaction of [CpOs(PPh3)2Br] (1) with acetonitrile ligand or monodentate anions yielded complexes of the type [CpOs(PPh3)2(CH3CN)]+ (2), [CpOs(PPh3)2X], X=CN (3) and NCS (4). Treatment of 1 with NaNO2–HCl in the presence of NH4BF4 yielded the dicationic complex [CpOs(PPh3)2(NO)](BF4)2 (5). Reactions of the complex [CpOs(PPh3)2(CH3CN)]BF4 (2) with chelating ligands L2 yielded cationic complexes of the type [CpOs(L2)(PPh3)]BF4, where L2=2,2′-bipyridine (bipy) (6), 1,10-phenanthroline (phen) (7). These compounds were characterized by 1H NMR, 31P NMR and IR spectral data. The X-ray crystal structure of the complex [CpOs(PPh3)(phen)]BF4 has been determined.