Showing papers in "Inorganic Chemistry in 1986"

Synthesis of 1-(p-isothiocyanatobenzyl) derivatives of DTPA and EDTA. Antibody labeling and tumor-imaging studies

Abstract: To investigate the /sup 111/In labeling of tumor-localizing monoclonal antibodies (MoAb), the chelate 1-(p-isothiocyanatobenzyl)diethylenetriaminepentaacetic acid (p-SCN-Bz-DPTA) (1) and its EDTA analogue (2) have been synthesized. By the use of a MoAb (B72.3) specific for a high molecular weight antigen (TAG-72) on cells of a colorectal carcinoma grown in nude mice, optimal chemical conditions for MoAb conjugation of those ligands and of the dicyclic and isobutylcarboxy carbonic anhydrides of DTPA and subsequent /sup 111/In labeling were determined. All conjugates were shown by a competitive binding assay to retain their specificity and activity in vitro when less than one ligand is protein coupled both prior to and after /sup 111/In labeling. Chemical methods for purification of the MoAb were systematically investigated by injection of purified immunoprotein into athymic mice bearing LS-174T tumors that express the TAG-72 antigen. Tissue distribution studies revealed that simple addition of EDTA to labeled immunoglobulins was ineffective at complexing indium not linked to protein by chelates. Similarly, gel chromatography (Sephadex G-50) was not sufficient; rather, size exclusion HPLC had to be employed to remove unreacted /sup 111/In and aggregated antibody. To compare the relative utility of the four chelates for /sup 111/In diagnostic radioimmunoimaging, scintigraphic images of tumor-bearingmore » mice were obtained and evaluated along with tissue distributions. Results showed that clear images of these solid tissue tumors free of extraneous radiation could be obtained only by using p-SCN-Bz-DTPA purified by HPLC. Methods developed are now being employed in clinical trials for diagnosis of human colorectal cancer. 71 references, 5 figures, 1 table.« less

Catechol-quinone redox series involving bis(bipyridine)ruthenium(II) and tetrakis(pyridine)ruthenium(II)

Abstract: Preparation d'une serie d'especes appartenant a la chaine redox RuN 4 (cat), [RuN 4 (sq)] + , [RuN 4 (q)] 2+ N 4 =unite bis(bipyridine) ou tetrakis(pyridine), les coordinats dioxolene sont: pyrocatechol, di t-butyl-3,5 pyrocatechol, et tetrachloropyrocatechol

Cobalt-catalyzed evolution of molecular hydrogen

Abstract: Solutions of chromium(II), europium(II), or vanadium(II) chloride in hydrochloric acid evolve molecular hydrogen rapidly in the presence of trace concentrations of the cobalt(II) macrocycle Co(dmgBF/sub 2/)/sub 2/. The stoichiometry for Cr(II) corresponds to the net reaction Cr/sup 2 +/ + Cl/sup -/ + H/sup +/ = CrCl/sup 2 +/ + 1/2H/sub 2/. The kinetics are described quite adequately by the Michaelis-Menton scheme. Kinetic studies of the reaction were during the pre-steady-state phase, during which an intensely absorbing intermediate forms, and also at longer times during the steady-state phase when the pseudo-steady-state concentration of the intermediate slowly declined as the substrate was consumed. Arguments are given in support of the intermediate being ((H/sub 2/O)/sub 5/Cr-Cl-Co(dmgFB/sub 2/)/sub 2/)..mu... Its dissociation leads, in acidic solution, to the hydridocobalt complex HCo(dmgBF/sub 2/)/sub 2/, which is responsible for H/sub 2/ formation. Bromide ions, but not perchlorate, also give catalytic H/sub 2/ production, whereas iodide forms a ternary complex that does not decompose. 27 references, 8 figures, 1 table.

Synthesis and study of mononuclear ruthenium(II) complexes of sterically hindering diimine chelates. Implications for the catalytic oxidation of water to molecular oxygen

Abstract: Preparation des complexes bis (diimine) de Ru(II), les chelates etant dimethyl-6,6' bipyridine-2,2' ou dimethyl-2,9 phenanthroline-1,10. Comportement electrochimique

Bis axially coordinated (phthalocyaninato)ruthenium(II) compounds

Abstract: Preparation et caracterisation des polymeres (phtalocyaninato) ruthenium (II) avec comme coordinat pontant (pyrazine, bipyridyle-4,4p et diisocyano-1,4 benzene) la coordination a ete etudiee avec les complexes monomeres correspondants. Les derives polymeres presentent une plus haute conductivite que les complexes monomeres correspondants

High-spin .fwdarw. low-spin relaxation kinetics and cooperative effects in the hexakis(1-propyltetrazole)iron bis(tetrafluoroborate) and [Zn1-xFex(ptz)6](BF4)2(ptz = 1-propyltetrazole) spin-crossover systems

Abstract: [Fe(ptz)6l(BF4)2 (ptz= 1-propyltetrazole) and the mixed crystals [Znl,Fe,(ptz)6] (BF4)2 are Fe(I1) spin-crossover compoundsthat exhibit light-induced excited-spin-state trapping. It is shown that (a) for x I 0.1 a single-ion treatment of both the spinequilibrium ( M H L = 510 (12) cm-', ASHL = 5.1 (2) cm-'/K at T = 100 K) and the relaxation from the excited high-spin state (.Eao = 810 (30) cm-I, A - 105/s) is appropriate and (b) for 0.2 I x I 1 cooperative effects observed in the relaxation from the high-spin state are of long-range nature and therefore of elastic rather than of electronic origin.

Crystal and molecular structure of the silver(II) and zinc(II) derivatives of meso-tetraphenylporphyrin. An exploration of crystal-packing effects on bond distance

Abstract: The crystal and molecular structures of four-coordinate silver(I1) and zinc(I1) tetraphenylporphyrinates have been determined. Both complexes crystallize in the triclinic system and are isomorphous with the triclinic modification of the parent macrocycle H2TPP. Bond distances in the centrosymmetric coordination groups of both complexes are found to be statistically nonequivalent. Features of the crystal packing of the compounds suggest that this inequivalence arises from asymmetric lattice packing. The average Ag-N distance is 2.092 A (individual values 2.082 (3) and 2.101 (3) A), and that for Zn-N is 2.037 A (individual values 2.045 (2) and 2.029 (2) A). Crystal data for AgTPP: triclinic, a = 10.503 (2) A, b = 12.485 (2) A, c = 6.351 (2) A, a = 97.72 (l)', P = 100.68 (l)', y = 97.150 (9)', 2 = 1, space group Pi, 5616 observed data, R, = 0.059. Crystal data for ZnTPP: triclinic, a = 10.382 (1) A, b = 12.421 (2) A, c = 6.443 (1) A. 01 = 98.30 (I) ' , P = 101.15 (l)', y = 96.47 (I) ' , 2 = 1, space group Pi, 3729 observed data, R, = 0.036.

Disubstituted tungstosilicates. 1. Synthesis, stability, and structure of the lacunary precursor polyanion of a tungstosilicate .gamma.-SiW10O368-

Abstract: Rb 8 SiW 10 O 36 •10H 2 O cristallise dans le systeme monoclinique, groupe d'espace P2 1/c et sa structure est affinee jusqu'a R=0,070

Coordination of lanthanides by two polyamino polycarboxylic macrocycles: formation of highly stable lanthanide complexes

Abstract: The formation constants of a few lanthanide complexes with DOTA (1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid) and TETA (1,4,8,11-tetraazacyclotetradecane-N,N',N'',N'''-tetraacetic acid) have been measured by potentiometric and competition methods. The ligand DOTA forms the most stable lanthanide chelates known so far (log K/sub ML/ = 28.2-29.2) while the stability of the TETA compounds at 80 /sup 0/C (log K/sub ML/ = 14.5-16.5) is comparable to the stability of the EDTA complexes. A competition method with the oxalate anion as a probe had to be used for determining the formation constants of the DOTA lanthanide chelates because of the high stability of these compounds. The relative stability of the DOTA and TETA complexes in accounted for by steric factors with reference to known solution- and solid-state structures. 20 references, 2 tables.

Template syntheses involving carbon acids. Synthesis and characterization of (3,10-dimethyl-3,10-dinitro-1,4,8,11-tetraazacyclotetradecane)copper(II) and (1,9-diamino-5-methyl-5-nitro-3,7-diazanonane)copper(II) cations and nitro group reduction products

Abstract: Preparation des complexes du titre et des complexes des formes reduites des coordinats, soit: (diammonio-3,10 dimethyl-3,10 tetraaza-1,4,8,11 cyclotetradecane)-Cu(II) et (ammonio-5 deamino-1,9 methyl-5 diaza3,7 nonane)-Cu(II). Structure cristalline

Structure determination and investigation of the high-spin .tautm. low-spin transition of tris[2-(aminomethyl)pyridine]iron(2+) dibromide.monoethanol

Abstract: Le complexe du titre cristallise dans le systeme monoclinique, groupe P2 1 /n et sa structure est affinee jusqu'a R=0,050. La variation des dimensions reticulaires avec la temperature est interpretee en terme de tenseur de dilatation thermique et de tenseur de deformation du a la transition haut spin→bas spin

Structural studies of the hydrogen storage material magnesium nickel hydride (Mg2NiH4). 2. Monoclinic low-temperature structure

Abstract: The structure of the low-temperature phase of Mg/sub 2/NiD/sub 4/ was determined from time-of-flight neutron powder diffraction data collected at 298 K It has monoclinic symmetry (space group C2/c, a = 14343 (5) A, b = 64038 (10) A, c = 64830 (13) A, beta = 11352 ()/sup 0/, Z = 8) and contains four symmetry-independent D atoms As expected, the D atoms surround the Ni atoms in a nearly regular tetrahedral configuration (average bond lengths Ni-D = 154 A, average bond angles D-Ni-D = 1094/sup 0/) Microtwinning parallel to (011) leads to severe anisotropic broadening of the diffraction peaks

Atom-transfer redox kinetics: general-acid-assisted oxidation of iodide by chloramines and hypochlorite

Abstract: L'ordre de reactivite pour l'oxydation est OCl − >>NH 2 Cl>>NHCl 2 . La reactivite depend de la force de l'acide et est reliee a la basicite du site accepteur de proton de l'espece chloree

Tetrakis(phenanthroline)di-.mu.-oxodimanganese(III,IV) tris(hexafluorophosphate).cntdot.acetonitrile and tetrakis(phenanthroline)di-.mu.-oxodimanganese(IV) tetraperchlorate.cntdot.acetonitrile: crystal structure analyses at 100 K, interpretation of disorder, and optical, magnetic, and electrochemical results

Abstract: [(phen) 2 Mn IV (μ-O) 2 Mn III (phen) 2 ](PF 6 ) 3 •CH 3 CN cristallise dans le systeme orthorhombique groupe d'espace Pbcn. [(phen) 2 Mn IV (μ-O) 2 Mn IV (phen) 2 ](ClO 4 )•CH 3 CN cristallise dans le systeme monoclinique groupe d'espace P2 1 /c et sa structure est affinee jusqu'a R=0,035

Hexaaza macrocyclic complexes of the lanthanides

Abstract: The authors systematically investigate the conditions leading to the metal-templated macrocyclic synthesis and obtain by an appropriate combination of counterions and experimental conditions, two series of complexes of the macrocyclic ligand L = C/sub 22/H/sub 26/N/sub 6/, with every lanthanide(III) ion except radioactive Pm. Their synthesis, characterization, and properties are described here. 13 references, 2 figures.