Showing papers by "Bryan M. Gatehouse published in 1978"

Organometallic compounds containing a guanidinium group. Phenylmercury(II) derivatives of creatine and creatinine

Abstract: Phenylmercury(II) replaces a proton of creatine, H2NC+(NH2)NMeCH2C02-, in basic solution to form the zwitterionic complex PhHgNHC+(NH2)NMeCH2CO2-. Creatine and creatinine (C4H7N30) react with PhHg((OH)N03)I/2 in aqueous ethanol to form a 2:l complex [(PhHg)2(C4H6N30][N03] which exists in two crystalline forms. Creatinine forms a 1:l complex [PhHg(C4H7N30)][N03].1/2H20 at pH 1.4 on reaction with PhHg((OH)N03)l/2 in the presence of nitric acid. The 1:l and 2:l complexes may be interconverted. Creatinine hydronitrate, [H2NCNMeCH2CONH][NO3], and the PhHg(II) complexes of creatinine have similar infrared (including deuterated derivatives) and 1H NMR spectra, consistent with retention of the creatinine ring and presence of a guanidinium group in the complexes. An X-ray structural analysis of one crystalline form of the 2:l complex shows bonding of PhHg(II) groups to the exocyclic and ring nitrogens of creatinine to form the cation [PhHgNHCNMeCH2CONHgPh]+.

Crystal and molecular structure of (3,3'‐dimethyl‐2,2'‐bipyridyl)methylmercury(II) nitrate; a complex that may have weak intramolecular π‐coordination

Abstract: The structure of the methylmercury complex of 3,3'-dimethyl-2,2'-bipyridyl(L), [MeHg(L)]NO3, was solved by Patterson and Fourier techniques using 1560 counter-measured observed reflections and refined by the full-matrix least-squares method to R = 0·061. The complex has a bent C(1)-Hg-N(1) group [172·7(5)] with Hg-C(1) 2·01(1) and Hg-N(1) 2·11(1) A, weak interaction between mercury and nitrate oxygen atoms, and evidence suggesting the presence of a weak intramolecular-interaction between mercury and the second pyridyl ring, with Hg-C(2') 3·11(1), Hg-N(l') 3·29(1) A and an angle of 100·5 between the planes of the pyridyl rings.

Structure, absolute configuration and electrochemical properties of Tris(N-methylformothiohydroxamato)iron(III), an antibacterial metal chelate and potential iron siderochrome

Abstract: The title compound, which previously had been isolated from bacteria and shown to possess anti-bacterial activity, has been chemically synthesized. The molecular structure has a cis (facial) arrangement of the asymmetric {S,O} bidentate ligands (Fe-S 2.441(1) Ǻ, Fe-O 2.010(1) Ǻ) as required by the crystallographic C3 molecular symmetry. (Crystal data: C6H12N3O3S3Fe, rhombohedral, space group R3, a 7.094(2)Ǻ, α 102.00(1)°, Z 1.) The complex was spontaneously resolved into enantiomers on crystallization and the absolute configuration in the crystal studied was established as Λ by the anomalous dispersion technique. Magnetic, e.s.r. and Mossbauer studies are compatible with a distorted octahedral complex of high-spin iron(III). Cyclic voltammetric studies in acetone of the title compound and some related iron(III) thiohydroxamates were carried out. A reversible FeIII/FeII reduction wave was observed for the N-methylformothiohydroxamato chelate, in contrast to the irreversible reduction of tris(benzohydroxamato)iron(III), a related complex containing an {O,O} chelate. The tris(benzothiohydroxamato) chelate, Fe(PhC(S)NHO)3, which possesses a non-alkylated nitrogen, also showed an irreversible reduction wave.

Methyleneketenes and methylenecarbenes. XIII. Cycloaddition of ketenes and of a 1-pyrroline 1-oxide to isopropylideneketene

Abstract: Isopropylideneketene (3-methylbuta-1,2-dien-1-one), Me2C=C=C=O, reacts with ketene and substituted ketenes to give oxetanones or cyclobutane-1,3-diones formed by [2+2] cycloadditions involving the central C=C bond of the methyleneketene. By contrast Me2C=C=C=O reacts with 5,5- dimethylpyrroline 1-oxide to give a spirooxazolidinone (13) and an oxetanone (17), both of which appear to be formed by initial cycloaddition of the pyrroline 1-oxide to the terminal C=C bond of the methyleneketene and formation of an intermediate bicyclic ketene (15). The structure of the oxetanone (17) has been confirmed and its stereochemistry established by X-ray crystallography.