Copper(II) and iron(III) complexes of N-nitroso-N- alkylhydroxylamines,and the X-ray crystal structures of bis(N-nitroso-N-isopropylhydroxylaminato)copper(II) and tris(N-nitroso-N-propylhydroxylaminato)iron(III)

N-nitroso-N-alkylhydroxylamines have been prepared by hydrolysis of the mixture obtained by reaction of nitric oxide with Grignard reagents, and stabilized as their copper(II) or iron(III) complexes, Cu(RN₂O₂)₂ and Fe(RN₂O₂)₃, where R is, for example, Me, Et, Prⁱ, Bu^iso, Ph, n-C₈H₁₇ or n-C₁₂H₂₅. The complexes have been characterized by analytical, magnetic and spectroscopic measurements. By single-crystal X-ray methods Cu(PrⁱN₂O₂)₂ has been found to be trans-planar and Fe(PrⁿN₂O₂)₃ has a facial octahedral structure; in each complex the NO bond lengths are equal with no significant variation between the copper and iron complexes.     

Cationic η-benzyl nickel compounds with diphosphine ligands as catalyst precursors for ethylene oligomerization/polymerization: influence of the diphosphine bite angle

The oligomerization and/or polymerization of ethylene catalyzed by the cationic η³-benzylcomplexes [Ni(η³-CH₂C₆H₄-p-CF₃)(P-P)]⁺ BPh₄⁻ (P-P=ⁱPr₂P(CH₂)_nPⁱPr₂, n=1-3) have been studied. The activity of these single component catalysts depends on the length of the (CH₂)_n bridge of the diphosphine ligand. Thus, the dippm derivative (n=1) displays higher activity than compounds of the dippe (n=2) or dippp (n=3) ligands. The molecular weight of the products is also a function of n, and varies in the order dippm > dippe > dippp, with the former two catalysts giving rise to low molecular weight polyethylenes and the latter to oligomers.     

Rotational isomerism of O,O′-dialkyl esters of phosphorodithioic acid

Compounds (RO)₂ P(:S)SH, RPrⁱ, Buⁿ, and Octⁿ, exhibit rotational isomerism about PO and PS bonds. Temperature-dependence studies of band intensities indicate values of ΔH for the equilibria between isomers to be 2.5 kJ mol⁻¹, RPrⁱ; 3.0 kJ mol⁻¹, RBuⁿ; and ∼4.5 kJ mol⁻¹, ROctⁿ.     

Synthesis and characterization of monomeric palladium(II) pyridine-2-chalcogenolate complexes

Mononuclear palladium(II) complexes of the type [Pd(Epy)(S^∩S)(PPh₃)] [E=S or Se; S^∩S=S₂CNEt₂, S₂P(OR)₂ (R=Et, Prⁿ, Prⁱ)] have been prepared. All the complexes have been characterized by elemental analysis and NMR (¹H, ³¹P{¹H}, ⁷⁷Se{¹H}) spectral data. The NMR data indicate that there are two species in solution, i.e. one with chelating S^∩S ligand predominates (∼95%) while the other with chelating Epy and monodentate S^∩S existing in ∼5% concentration. The X-ray crystal structure of [Pd(Spy){S₂P(OPrⁱ)₂}(PPh₃)] has been determined. The square planar palladium atom is coordinated to asymmetrically chelated (PrⁱO)₂PS₂⁻ ligand, PPh₃ and pyS⁻ groups.     

Synthesis,Characterization, and Sol-Gel Behavior of Dichlorotitanium(IV) (O-Alkyl,O-Cycloalkyl,and O-Aryl Trithiophosphates)

Dichlorotitanium(IV) trithiophosphates of the type TiCl₂[(RO)P(S)S₂] (where R = Me, Et, Prⁿ, Prⁱ, Buⁿ, Bu^s, Buⁱ, Amⁱ, Ph and cyclohexyl) have been synthesized for the first time by the reaction of titanium tetrachloride with potassium trithiophosphates in a 1:1 molar ratio in anhydrous benzene. Sol-gel chemistry of these titanium(IV) compounds has been studied in dry benzene by treatment with hydrogen sulfide gas. These newly synthesized derivatives have been characterized by elemental analysis (C, H, S, Cl, and Ti), molecular weight measurement, and spectral [IR and multinuclear NMR (¹H, ¹³C, and ³¹P)] studies. The bonding mode of trithiophosphate ligands and tentative structure around titanium(IV) are discussed.     

Stable organomercury compounds containing an o-iminosemiquinone radical ligand

A series of stable paramagnetic organomercury compounds containing the 4,6-di-tert-butyl-N-(2,6-diisopropylphenyl)-o-iminobenzosemiquinone ligand (imSQ) with the general formula imSQHgR (R = Ph, Et, Prⁿ, Buⁿ, Prⁱ, Hex^c, CH₂SiMe₃, p-FPh, Fc, p-Me₂NPh) were synthesized. The molecular and electronic structures of the synthesized compounds were investigated by EPR spectroscopy and X-ray diffraction. The o-iminosemiquinone ligand shows the unusual amidophenoxy-type coordination mode. In the EPR spectra of the compounds imSQHgR, the hyperfine coupling constant of magnetic mercury isotopes (^199,201Hg) depends on the nature of the substituent R, the temperature, and the nature of the solvent. Voltammetric investigations showed that the complex imSQHgFc undergoes three reversible one-electron redox steps related to the redox transformations of both the o-iminoquinone ligand and the metallocene moiety of the molecule.     

O-Alkyl Trithiophosphate Derivatives of Triorganotin(IV) and S-Alkyl Trithiophosphate Derivatives of Diorganotin(IV) Chloride

Reactions of triorganotin chlorides with potassium salt of O-alkyl trithiophosphate [ROP(S)(SK)₂; R = Me, Prⁱ, Ph] in 2:1 molar ratio in anhydrous benzene yield triorganotin O-alkyl trithiophosphate of the type ROP(S) [SSnR′₃]₂ R = Me, Prⁱ; Ph, R′ = Prⁿ, Buⁿ, Ph] which are found to be monomeric in nature. These complexes are soluble in common organic solvents. Similar reactions of diorganotin chloride with dipotassium salt of S-alkyl trithiophosphate yield diorganotin-S-alkyl trithiophosphate of the type [(RS)P(O)S₂]₂SnR′₂; R = Me, Prⁱ; R′ = Me, Et, Ph, which also are found to be monomeric in nature and are soluble in common organic solvents. The newly synthesized derivatives have been characterized by physicochemical and spectroscopic techniques, IR, NMR (¹H, ³¹P, and ¹¹⁹Sn).     

Synthesis and spectral studies of diorganotin(IV) dialkyldithiophosphates

Two series of diorganotin(IV) dialkyldithiophosphates, [RR′Sn{SSP(OR″)₂}₂](R = Me or Et; R′= Ph; R″ = Et, Prⁿ, Prⁱ or Buⁿ) and [RR′Sn(Cl){SSP(OR″)₂}] (R = R′= Me, Et or Ph; R″ = Ph; R″ = Et, Prⁱ or Buⁿ) were prepared and characterised by i.r. and NMR (¹H, ¹³C, ³¹P, ¹⁹⁹Sn) spectroscopy. The NMR data indicate five and six coordinate geometries for [RR′Sn(Cl){SSP(OR″)₂}] and [RR′Sn{SSP(OR″)₂}₂] complexes, respectively. The chloro complexes showed ²J (PSn) whereas such couplings were not observed in the spectra of [RR′Sn{SSP(OR″)₂}₂].     

Synthesis and separation of stereoisomeric 2,4,6,8-tetrasubstituted 3,7-dithia-1,5-diazabicyclo[3.3.0]octanes

Heterocyclization of hydrazine with aldehydes R-CHO (R = Me, Et, Prⁿ, Buⁿ, n-C₅H₁₁, Ph, 4-MeOC₆H₄, 3-Py) and H₂S leads to stereoisomeric 2,4,6,8-tetrasubstituted 3,7-dithia-1,5-diazabicyclo[3.3.0]octanes, which were separated by column chromatography. The trans-transoid-trans-configuration of tetramethyl(-ethyl,-propyl)-3,7-dithia-1,5-diazabicyclo-[3.3.0]octanes was inferred from the X-ray diffraction and ¹H and ¹³C NMR spectroscopic data.     

Asymmetric acetylenic thioethers in ruthenium cluster chemistry

The compounds [Ru₃(CO)₉(μ,η²-SCCR)(μ₃,η²-CCR^′)] (R=SiMe₃, R^′=SiⁱPr₃ (1); R=SiⁱPr₃, R^′=SiMe₃ (2); R=SiⁱPr₃, R^′=H (3); R=H, R^′=SiⁱPr₃ (4)) have been obtained by cleavage of one S-C bond of the thioethers ⁱPr₃SiCCSCCR (R=H, SiMe₃) in the presence of Ru₃(CO)₁₂. Thermal treatment of [Ru₃(CO)₉(μ,η²-SCCSiⁱPr₃)(μ₃,η²-CCH)] yields to the cluster [Ru₄(CO)₉(μ-CO)₂(μ₄-S)(μ₄-η²-C(H)C)(CCSiⁱPr₃)] (5) which contains a bridging sulfur atom and a polycarbon chain as a consequence of the rupture of the S-C bond and a C-C coupling reaction. All derivatives have been characterized by spectroscopic data. An X-ray diffraction study was carried out on the species [Ru₃(CO)₉(μ,η²-SCCSiⁱPr₃)(μ₃,η²-CCSiMe₃)] and of [Ru₃(CO)₉(μ,η²-SCCSiⁱPr₃)(μ₃,η²-CCH)].     

SYNTHESIS AND CHARACTERIzATION OF TRIPHENYLANTIMONY (V) (O-ALKYL,O-CYCLOALKYL AND O-ARYLTRITHIOPHOSPHATES)

Triphenylantimony (V) (O-alkyl,O-cycloalkyl and O-aryltrithiophosphates) of the type Ph ₃ Sb[S ₂ (S)P(OR)] (R = Me, Et, Pr ⁿ , Pr ⁱ , Bu ⁿ , Bu ^s , Bu ⁱ , Am ⁱ , Ph and C.h. = cyclohexyl) have been synthesized for the first time by the reaction of triphenylantimony (V) dibromide with potassium trithiophosphates in 1:1 molar ratio in methanol. These new compounds have been characterized by elemental analysis, molecular weight determinations, and spectroscopic (IR,¹³C and ³¹P NMR) studies. On the basis of these data trigonal bipyramidal geometry has been proposed for these compounds.     

SYNTHESIS AND CHARACTERIZATION OF DICHLORODIMETHOXYMOLYBDENUM (V) 0,0′-DIALKY L(ALKYLENE) DITHIOPHOSPHATE COMPLEXES

Abstract

Dichlorodimethoxymolybdenum(V) 0.0′-dialkyl dithiophosphates, MoCI₂(OMe)₂S₂,P(OR)₂ (where R = Et, Prⁿ, Prⁱ,Buⁱ) and dichlorodimethoxymolybdenum (V), 0,0′-alkylene dithiophosphates, MoCI₂(OMe)₂S₂POGO (where G = CH₂CMe₂-, -CMe₂,CMe₂-,-CHMeCHMe-) have been synthesized by the reactions of MoCI₃ (OMe)₂, with sodium (or ammonium) salts of the corresponding dithiophosphoric acids.

These complexes have been characterized on the basis of elemental analyses, ³¹P NMR spectral data, magnetic studies and molecular weight determinations, which show their paramagnetic as well as dimeric nature. Based on these data, plausible structures containing hepta-coordinated molybdenum have been suggested for these compounds.     

Lanthanide triiodide-catalyzed amination of phthalonitrile. The structure of 1-isopropylamino-3-(isopropylimino)isoindole

The reactions of phthalonitrile with MeNH₂, PrⁿNH₂, and PrⁱNH₂ in the presence of catalytic amounts of LnI₃ (Ln = Nd or Dy) or LnI₃(THF)₃ (Ln = Gd or Nd) afford 1,3-bis(alkylimino)isoindolines (Alk = Me (1), Prⁿ (2), or Prⁱ (3), respectively). Under analogous conditions, 2-aminopyridine gives 1,3-bis(2-pyridylimino)isoindoline (4). The X-ray diffraction study of compound 3 showed that, in the crystalline state, this compound exists as the isomer, 1-isopropylamino-3-(isopropylimino)isoindole.     

Crystal growth, structure and magnetic properties of the double perovskites Ln2MgIrO6 (Ln=Pr, Nd, Sm-Gd)

Single crystals of double-perovskite type lanthanide magnesium iridium oxides, Ln₂MgIrO₆ (Ln=Pr, Nd, Sm-Gd) have been grown in a molten potassium hydroxide flux. The compounds crystallize in a distorted 1:1 rock salt lattice, space group P2₁/n, consisting of corner shared MO₆ (M=Mg²⁺ and Ir⁴⁺) octahedra, where the rare earth cations occupy the eight-fold coordination sites formed by the corner shared octahedra. Pr₂MgIrO₆, Nd₂MgIrO₆, Sm₂MgIrO₆, and Eu₂MgIrO₆ order antiferromagnetically around 10-15 K.     

Reactions of bis(isopropylxanthato)nickel(II) with nitrogen-donor ligands—II

New complexes of bivalent nickel with isopropylxanthates and nitrogen-donor ligands of composition [Ni(Prⁱxa)₂(L)], [Ni(Prⁱxa)₂(L¹)₂], [Ni(L²)₂](Prⁱxa)₂, and [Ni(L³)₃] (Prⁱxa)₂ have been synthesized, where Prⁱxa = i-C₃H₇OCS₂⁻, L = 1,2-diaminopropane (1,2-pn), N,N,N′,N′=tetramethylethylenediamine (tmen) or 4,4′-bipyridine (4,4′-bipy), L¹ = pyridine (py), L² = diethylenetriamine (dien) and L³ = ethylenediamine (en), 1,2-diaminopropane or 1,10-phenanthroline (phen). The compounds have been characterized by elemental analysis, IR and UV-vis spectroscopy, magnetochemical measurements, molar conductivity and thermal analysis. The compounds containing the complex cation have been one-electron irreversibly oxidized using cyclic voltammetry. The crystal and molecular structures of [Ni(Prⁱxa)₂(tmen)] and [Ni(phen)₃](Prⁱxa)₂ have been elucidated.     

Synthetic,spectroscopic, thermal,and structural studies of antimony(III) bis(pyrrolidinedithiocarbamato)alkyldithiocarbonates

An account of the synthesis, spectroscopic, thermal and structural behavior of antimony(III) bis(pyrrolidinedithiocarbamato)alkyldithiocarbonates is presented. The reaction of antimony(III) bis(pyrrolidinedithiocarbamate) chloride with potassium organodithiocarbonate in equimolar ratio yielded the corresponding mixed derivatives of the type [(CH₂)₄NCS₂]₂SbS₂COR [where R = Me, Et, Pr ⁿ , Pr ⁱ , Bu ⁿ , and Bu ⁱ ]. These newly synthesized complexes have been characterized by physicochemical [molecular weight determination, melting points, and elemental analysis], spectral [UV, IR, far-IR, NMR (¹H and ¹³C)], thermal [TG, DTA, and FAB⁺ mass], and structural [powder XRD and SEM] studies. Analytical studies leads to purity and structural properties of the synthesized complexes on the other hand powder X-ray diffraction and SEM studies show that multiphase, polycrystalline, and rod-shaped complexes have been formed having nanorange crystallite size and monoclinic crystal system.     

Studies pertaining to the mechanism of “Pt(PCy3)“ addition. The reaction of MPt(μ-H)(μ-PnPr2)Pt(CO)(PCy3) with Pt(C2H4)2(PCy3)

The reaction of Pt(C₂H₄)₂(PCy₃) with (OC)₄M(μ-H)(μ-PⁿPr₂)Pt(CO)(PCy₃, (1: M  Cr, Mo, W) occurs in a highly specific, kinetically controlled manner to give MPt₂(μ²_MPt-CO)(η²_PtPt-H)(μ²_MPt-PⁿPr₂)(CO)₄ (PCy₃)₂ (5), as the first formed trimer. The trimer 5 (M  Mo, W) isomerizes to give MPt₂(μ²_PtPt-CO) ((μ²_MPtH)(μ²_MPt-PⁿPr₂)(CO)₄)PCy₃)₂ (6) which in turn isomerizes to MPt₂μ²_MPtCO)(μ²_MPt (μ²_PtPt-PⁿPr₂)(CO)₄(PCy₃)₂ (7, as the final isolable product. These results provide a detailed insight into the mechanism of “Pt(PCy₃) addition”, a cluster assembly process.     

Triorganotin(IV) benzoates and aminobenzoates

Complexes of the general formula R₃SnX, where X is the anion of benzoic acid, o-, m-, p-amino- or N-phenyl-o-amino-benzoic acid, have been prepared and characterised. A combination of molecular weight, infrared, ¹H NMR and ¹¹⁹Sn Mössbauer measurements show that, the amino-nitrogen atoms are not coordinated to tin. When R = phenyl or cyclohexyl, the compounds are monomeric and four-coordinate, and when R is alkyl (Me, Prⁿ, Buⁿ) they are monomeric and five-coordinate, with a bidentate carboxylate in the equatorial position of a trigonal bipyramidal structure.     

A one-pot method to prepare the carbene complex [TpRhCl2(CHNiPr2)] from [TpRh(CO)2], CHCl3, and NHiPr2

The complex [Tp^Me₂,ClRh(CO)₂] reacts with chloroform to give quantitatively the rhodium(III) complex [Tp^Me₂,ClRhCl(CHCl₂)(CO)] resulting from the oxidative addition of a C-Cl bond. Further reaction with diisopropylamine gives the aminocarbene complex [Tp^Me₂,ClRhCl₂(CHNiPr₂)], whose X-ray crystal structure has been solved. Addition of an excess of diisopropylamine to [Tp^Me₂,ClRh(CO)₂] in chloroform provides directly [Tp^Me₂,ClRhCl₂(CHNiPr₂)].     

Neue arsinidenverbrückte Mehrkern-Clusterkomplexe des Ag und Au. Die Kristallstrukturen von [Ag14(AsPh)6Cl2(PR3)8], (PR3 = PEt3, PMenPr2, PnPr3), [M4(As4Ph4)2(PR3)4], (M = Ag,PR3 = PEt3, PnPr3; M = Au,PR3 = PnPr3), [Au10(AsPh)4(PhAsSiMe3)2(PnPr3)6]

New Arsinidene-bridged Multinuclear Cluster Complexes of Ag and Au. The Crystal Structures of [Ag₁₄(AsPh)₆Cl₂(PR₃)₈], (PR₃ = PEt₃, PMeⁿPr₂, PⁿPr₃), [M₄(As₄Ph₄)₂(PR₃)₄], (M = Ag, PR₃ = PEt₃, PⁿPr₃; M = Au, PR₃ = PⁿPr₃), [Au₁₀(AsPh)₄(PhAsSiMe₃)₂(PⁿPr₃)₆] The reaction of AgCl with PhAs(SiMe₃)₂ in presence of tertiary phosphines (PR₃) leads to arsinidene-bridged silver clusters with the composition [Ag₁₄(AsPh)₆Cl₂(PR₃)₈], (PR₃ = PEt₃ 1 , PMeⁿPr₂ 2 , PⁿPr₃ 3 ). Further it is possible to obtain the multinuclear complexes [Ag₄(As₄Ph₄)₂(PR₃)₄], (PR₃ = PEt₃ 4 , PMeⁿPr₂ 5 ). In analogy to that [PMe₃AuCl] reacts with PhAs(SiMe₃)₂ and PⁿPr₃ to form the compound [Au₄(As₄Ph₄)₂(PⁿPr₃)₄] 6 , which is isostructurell to 4 and 5 . The gold cluster [Au₁₀(AsPh)₄(PhAsSiMe₃)₂(PⁿPr₃)₆] 7 was obtained from the same solution. The structures were characterized by X-ray single crystal structure analysis. (Crystallographic data see “Inhaltsübersicht”)