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Construction of a New Versatile Hydrazonic Ligand and Its Chemical and Structural Behaviour Towards Metal Ions
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REACTIONS OF MANGANESE AND RHENIUM COMPLEXES WITH ORGANIC AZIDES: PREPARATION OF 1,4-TETRAAZABUTADIENE DERIVATIVES
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Tetraphenyl derivatives of phosphorus, arsenic and antimony exchange reaction and reduction. Crystal and molecular structure of [(C4H8O2)NaAsPh2]n.
No full textThe tetraphenyl derivatives of phosphorus(I1) and arsenic(I1) P2Ph4 and As2Ph4 were found to undergo a relatively fast
exchange reaction to the mixed product Ph2PAsPh2, and the corresponding equilibria were studied in benzene, diethyl ether,
and chloroform. By measurements of equilibrium constants at different temperatures in benzene as solvent, the reaction
was found to be slightly endothermic (W = 1.3 * 0.3 kcal/mol of mixed product formed) with a positive entropy contribution
(AS' = +3.5 * 1.0 eu). The corresponding phosphorus and antimony compounds P2Ph4 and Sb2Ph4 undergo exchange
to an even lower extent, presumably due to an even more endothermic character of the reaction. Crystal data: CI6Hl8AsNaO2,
M,= 340.23, orthorhombic, a = 10.280 (1) A, b = 15.053 (2) A, c = 10.735 (1) A, Z = 4, d(ca1cd) = 1.360 g.~m-~T.h e
structure consists of an alternating sequence of dioxane-coordinated sodium atoms and Ph2As groups, giving rise to infinite
-Na-As-Na-As- chains parallel to [100]. The chains are almost linear (173.6 (1)') at arsenic and bent (121.5 (1)')
at sodium. The geometry around arsenic approximates closely that of a trigonal bipyramid. An electron deficient 2e-3c
bond involving arsenic and sodium is suggested, which appears to account also for solvation by more polar solvents such
as tetrahydrofuran
Reactivity of molecules containing element–element bonds. I.Non transitional elements.
No full textA new method for preparing Bi2Ph4 consists of reducing BiPh21 with bis(cyclopentadienyl)cobalt(II) in tetrahydrofuran as solvent,
with yields as high as 80%. The mixed products Ph2BiEPh (E = S, Se, Te) were obtained by reacting Bi2Ph4 with &Ph2 in toluene
as solvent at room temperature. The crystal and molecular structure of BiSePh, has been solved. Crystal data: CI8Hl5BiSe,
M, = 519.3, orthorhombic, space group P212121a, = 15.936 (3) A, 6 = 11.550 (3) A, c = 8.855 (2) A, Z = 4, d(calcd) = 2.116
g cm-,. The structure consists of tricoordinated and bicoordinated bismuth and selenium, respectively, paired by a Bi-Se bond
2.704 (3) A long. The tellurium and selenium mixed species undergo diazomethane insertion with formation of the Ph2BiCH2-EPh
species. Tetraphenyldibismuthine is oxidized by elemental selenium, giving (BiPh2)2Se
Crystal and Molecular Structure of an Unsubstituted Bis(phenoxo)-derivative of Copper(II), the [{Cu(OPh)2(en)}2] •2PhOH Dimer, with a 'Normal' Magnetic Moment at Room Temperature
No full textThe title compound has been shown by X-ray diffraction methods to be a centrosymmetric phenoxo-bridged dimer with terminal phenoxo- and ethylenediamine groups and hydrogen-bonded phenol molecules. The crystals are monoclinic, space group P21/n, and the unit cell has dimensions a = 19.000(13), b = 10.930(9), c = 8.968(5) Å, β = 89.90(2)°, U = 1 862.4 Å3, and Z = 4. The structure was refined by three-dimensional Patterson and Fourier techniques up to a conventional R value of 0.0437. The copper atoms are five-co-ordinate and the co-ordination geometry is that of a distorted square pyramid. The Cu ⋯ Cu distance is 3.215 Å. The compound has a nearly normal magnetic moment at room temperature and the results of the present investigation are discussed in connection with the known magnetic and structural data for dimeric oxygen-bridged copper(II) complexes
REDOX REACTIONS INVOLVING HEXACARBONYLVANADIUM(0) AND COMPOUNDS CONTAINING ELEMENT HALIDE, ELEMENT HYDROGEN AND ELEMENT CARBON BONDS - SYNTHESIS, AND CRYSTAL AND MOLECULAR-STRUCTURE OF PH3PBV(CO)6
No full textTETRANUCLEAR COPPER(II) COMPLEXES WITH POLYDENTATE HYDRAZONE LIGANDS - SYNTHESIS AND X-RAY STRUCTURE
No full textThe synthesis and X-ray crystal structure of two copper(II) complexes, [Cu2(dappc)(OH2)3]2-[Cu2(dappc)(OH2)2(ClO4)6.2H2O (I) (H2dappc = 2,6-diacetylpyridine bis(2-pyridinecarbonylhydrazone)) and [Cu2(dapip')Br]2.2H2O, (II) (H3dapip' = 2,6-diacetylpyridine 2-pyridinecarbonylhydrazone 2-(2'-pyridine carbonylhydrazono)phenylacetohydrazone) are reported. The interest of both structures pertains mainly to their tetranuclear nature with dimeric units related by an imposed center of symmetry. The structure of compound I is built up from two different complex cations, ClO4- anions and uncoordinated H2O molecules, while that of compound II consists of neutral complex molecules and solvating H2O molecules. During the formation of the latter complex the original H4dapip ligand (H4dapip = 2,6-diacetylpyridine bis[2-(2'-pyridinecarbonylhydrazono)phenylacetohydrazone] has undergone a modification through a hydrolysis process, resulting in partial cleavage of one arm to give H3dapip'
THE METHYLENE BLUE SENSITIZED PHOTO-OXIDATIVE REARRANGEMENT TO 5-HYDROXYPYRIMIDINES OF SOME 3-ACYL-5-ARYL-4-BENZALAMINO-2-METHYLPYRROLES
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