Structural researches on metal complexes with ligands containing the pyridoxal moiety: X-ray structure of chloro(N-pyridoxylidene-N′-salicyloylhydrazinato) copper(II) Monohydrate

Summary The x-ray crystal structure of the title complex is described Crystals are monoclinic, space groupP2₁/n, with unit-cell dimensions:a=18.070(2),b=13.471(2),c=6.788(2) Å,=94.70(1),Z=4. The structure was solved from diffractometer data by Patterson and Fourier methods and refined by least-squares techniques toR=5.0% for 2451 independent reflections. It consists of complex molecules, in which the copper atom square planar coordination comprises the chlorine atom, Cu-Cl=2.240(3) Å, and the organic ligand which acts as terdentate through the oxygen atom [Cu-O=1.948(3) Å] and a nitrogen atom, [Cu-N=1.933(5) Å] from the hydrazidic chain and the oxygen atom, [Cu-O = 1.894(4) Å] from the pyridoxal group.     

X-ray structure of trichloro-oxo-(N-pyridylmethylene-N′-salicyloylhydrazine-NO)molybdenum(V) · acetonitrile (1/1). An example of isomerization by complexation

Summary The synthesis, i.r. spectrum and x-ray crystal structure of the title, complex are described, Crystals are monoclinic space groupP 2₁/n, witha = 19.901(7),b = 13.163(8),c = 7.273(6) A, = 90.58(5)° Z = 4, The structure was solved from diffractometer data by direct methods and refined by least-squares techniques toR = 0.053 for 923 independent reflections. The complex has a distortedmer-octahedral geometry [Mo-O = 1,70(1), 2.15(1), Mo-Cl = 2.340(7), 1.352(7), 2.280(7), Mo-N = 2.19(2) A], The starting ligand Hsip, which is in theE configuration when free and in a number of metal complexes where it is terdentate, assumes here theZ configuration and is hiclentate.     

Synthesis and structure of 1-(2-amino)phenyl-2-phenyl-12H-indolo[3,2-c]carbazole ethylacetate solvate,a new indolocarbazole compound

The structure of a new indolo-carbazole compound, unique in having two indole rings with NH groupstrans-fused to a phenyl ring, has been determined by X-ray crystallography. The crystals are monoclinic, space groupP2₁/n,a=25.548(7),b=8.532(3),c=12.594(4) Å,=93.50(2)°,V _c=2740.1(2) ų,Z=4,D _k=1.240 g cm^–3, (CuK)=1.54178 Å,=5.79 cm^–1,F(000)=1080,R=0.071,R _w=0.080 for 2939 unique significant reflections measured at 298 K. The crystals retain one mole of ethyl acetate per molecule, which shows disorder. Restricted rotation of the phenyl and aminophenyl groups was detected by¹³C nmr. The title Indolo-carbazoles are easily obtained by reaction of 3-bromoindoles with 2,3-biindolyls and show an interesting planar structure which could be investigated for anticancer properties.     

Aroylhydrazones as chelating agents: d10-metal complexes of pyridine-2-carbaldehyde salicyloylhydrazone and x-ray structure of the zinc derivative

The title organic ligands (Hsip) gave, by reaction with d¹⁰-metal acetates, complexes of the type M(sip)₂ (M = Zn, Cd, Hg), in which the ligand behaved as terdentate, producing a distorted octahedral environment around the metal. The ¹H and ¹³C chemical shifts found for these complexes in DMSO are compared with the corresponding ones of the free ligand. The crystal structure of the zinc derivative has been determined from diffractometer data to R = 0.072 for 1086 independent reflections. Crystals are monoclinic, space group C2/c, with unit-cell dimensions a = 18.193(2), b = 24.532(6), c = 11.535(2) Å,β = 103.71(1)° and Z = 8. Coordination occurs through the carbonyl oxygens (Zn?O = 2.10, 2.16(1) Å), the azomethine nitrogens (Zn?N = 2.04, 2.07(1) Å) and the pyridine nitrogen s(Zn?N = 2.24, 2.26(1) Å).     

Molecular inclusion in functionalized macrocycles part 10*: Crystal and molecular structure of ap-tert-butylcalix[6]arene hexapodand

Colourless prismatic crystals of (3) were obtained from ethanol/CH₂Cl₂ (1:1) solution, space groupP2₁/c,a=14.581(5),b=22.517(8),c=11.799(5) , =92.13(4)°. Refinement led to a final conventionalR value of 0.074 for 4247 reflections. The conformation of the molecule, which lies on a center of symmetry, is 1,2,3-alternate with one oligoethereal chain pointing inside the molecular cavity. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. 82011 (30 pages).For part 9, see [1]. Results presented in part at the Second International Symposium of Clathrate Compounds and Molecular Inclusion Phenomena, Parma, Italy, 1982.     

3-(4-iodomethyl-2-oxo-1-azetidinyl)propynoic acidt-butyl ester: a new β-lactam derivative,synthesis of an ynamide by reaction of 4-iodomethylazetidin-2-one with the t-butyl ester of propiolic acid in the presence of copper(i)

The reaction of 4-iodomethylazetidin-2-one (2) with the t-butyl ester of propiolic acid (4) in the presence both of equimolar amounts of copper(I) and oxygen results unexpectedly in the fomation of the β-lactam ynamide 5. Its structure was suggested by spectroscopic data and confirmed by single-crystal X-ray analysis.     

Molecular modeling as a tool to discriminate between enantiomers resolved by derivatized cyclodextrins in gas chromatography

The elution order of a series of enantiomers, determined by gas chromatography using permethylated and trifluoroacetylated- and-cyclodextrins as stationary phases, was tentatively correlated with the lowest energies of the host-guest complex models resulting by including the enantiomers into the cyclodextrin cavity by means of the molecular mechanics method using standard software packagesSybyl andSpartan. The modeling data of cyclic isomers such as proline derivatives and-lactones correlate with the gas chromatographic data. Those of open isomers such as other aliphaticd,l-amino acids and alcohols, give contradictory results.     

The crystal and molecular structure of 10,10-dimethyl-10-germa-9-thio-9,10-dihydroanthracene

The X-ray analysis of 10,10-dimethyl-10-germa-9-thio-9,10-dihydroantracene has been carried out. The crystals are orthorhombic: a 11.130(3), b 7.556(2), c 30.795(5) »; Z = 4; space group Pbca. The structure was solved by a combination of Patterson and Fourier methods and refined to R = 0.047 (R_w = 0.050, w = 1/a²(F₀)). The molecule is not planar and the dihedral angle formed by the two benzene rings is 143.6°. The central ring has the boat conformation. The ¹³C NMR chemical shifts associated with benzene carbon atoms correlate well with bond angles obtained by X-ray methods.