A solid state e.s.r. study of manganese(II) halide-triphenylphosphine oxide complexes

Summary Ph₃PO adducts with manganese(II) halides, viz. MnX₂-(OPPh₃) ₂ (X = Cl or Br) were heated for 1 h and their X-band e.s.r. spectra recorded at room temperature. The chloride adduct, MnCl₂(OPPh₃)₂ completely transformed into the symmetrised product, [Mn(OPPh₃)₄] [MnCl₄] at 175 and 225° C. The bromide adduct, MnBr₂-(OPPh₃)₂, which is probably a mixture of its nonionic and ionic forms at room temperature, showed hyperfine coupling in the g = 2.029 region.     

Crystal structure of [bis 1,2-(diphenylphosphino)ethane]-bis(pyridine-2-thiolato)ruthenium(II)

The Ru atom in the title compound, [Ru(dppe)(2-pyS)₂] exists in a distorted octahedral geometry defined by a dppe ligand and two 2-pyS anions which function as bidentate ligands via their N- and S-atoms. Important interatomic parameters are Ru-P2.240(3), 2.256(3); Ru-N 2.131(8), 2.136(8); Ru-S 2.413(3), 2.428(3) Å; P-Ru-P 84.1(1), S-Ru-S 155.0(1) and N-Ru-N 87.5(3)°. Crystals are monoclinic, space groupP2₁/c, with unit cell dimensionsa=10.342(1),b=31.145(6),c=11.107(2) Å,=113.80(1)° andZ=4. The structure was refined to finalR=0.064 for 3057 reflections withI2.5(I).     

X-ray crystal and molecular structure of dichlorobis [2(1H)-pyridinethione-S]iron(II)

Attempts to prepare the mixed ligand complex, FeCl₂(pyS)(Ph₃P)₂ from the reaction of iron(III) chloride with 2(1H)-pyridinethione-S(HpyS) and triphenylphosphine(Ph₃P) in ethanol instead formed FeCl₂(HPyS)₂ characterized by X-ray crystallography. The structure was determined by the heavy atom method, using MoK diffractometer data, and refined by full-matrix least squares toR=0.049 for 1123 observed reflections. The molecule possesses twofold symmetry with a distorted tetrahedral geometry about the iron(II) center with S-Fe-S and Cl-Fe-Cl bond angles of 98.76(5)° and 115.79(5)° and Fe-S and Fe-Cl bond distances 2.345(1) Å and 2.288(1) Å, respectively. Hydrogen bonding between NH and chlorine atoms leads to a polymeric type structure of linked molecules running approximately parallel to thea axis.     

Inclusive and exclusive measurements in the projectile breakup of 7Li

The inclusive and exclusive measurements were carried out for ⁷Li projectile breakup on ²⁷Al target at 48 MeV. In the inclusive data we have observed a broad peak around the beam velocity for alphas and tritons. The exclusive data for alpha-triton coincidences show good agreement with the post-form DWBA theory of breakup reactions.     

Chemistry of iron complexes—III. X-ray diffraction,ESR and other spectral studies of new iron(II) and iron(III) complexes with tri-p-tolylarsine oxide

Reactions of iron(II) and iron(III) salts with tri-p-tolylarsine oxide(L) in suitable organic solvents yield complexes of formulas: (i) [FeL₂Cl₂(OH₂)₂] [FeCl₄].2H₂O, [FeL₂Br₂] [FeBr₄].2H₂O; (ii) [Fe(NCS)₃L₂].H₂O; (iii) [FeL(O₂ClO₂)₂(OH₂)] (ClO₄).0.25C₆H₆; (iv) [FeL₃I] [FeI₃].H₂O and (v) [Fe(CO)₃LI]I. Characterization has been done through elemental analyses, IR, far IR, ESR, and reflectance spectra, molar conductance, magnetic moments, t.g.a. and X-ray diffraction (powder) data. The species [FeL₂Cl₂(OH₂)₂]⁺, [FeL₂Br₂]⁺, [Fe(NCS)₃L₂], [FeL(O₂ClO₂)₂OH₂]⁺, [FeL₃I]⁺ and [Fe(CO)₃LI]⁺ have been assigned trans-octahedral, trans-square planar, trans-trigonal bipyramid, trans-octahedral, tetrahedral and cis-trigonal bipyramid structures respectively.     

A Sandmeyer type reaction for bromination of 2-mercapto-1-methyl-imidazoline (N2C4H6S) into 2-bromo-1-methyl-imidazole (N2C4H5Br) in presence of copper(I) bromide

2-Mercapto-1-methyl-imidazoline (N(2)C(4)H(6)S) is converted at room temperature into 2-bromo-1-methyl-imidazole (N(2)C(4)H(5)Br) in presence of copper(I) bromide in acetonitrile-chloroform mixture via extrusion of sulfur as sulfate and oxidation of Cu(I) into Cu(II). 2-Bromo-1-methyl-imidazole was isolated as its self assembled tetranuclear Cu(II) cluster, [Cu(4)(η(1)-N-(N(2)C(4)H(5)Br)(4)(μ(4)-O)(μ-Br)(6)] 1 {η(1)-N-(N(2)C(4)H(5)Br) = 2-bromo-1-methyl-imidazole}.