Heteroaromatic Ligands Research Articles

Sulfone-aromatic ligands for thiophilic adsorption chromatography: Purification of human and mouse immunoglobulins

New thiophilic matrices and new procedures were used for the purification of immunoglobulins both from human serum and from hybridoma cell cultures containing fetal calf serum. A range of aromatic and heteroaromatic ligands containing hydroxyl or amino groups have been coupled to divinyl sulfone-activated agarose. The resulting affinity matrices have the general formula M-OCH 2CH 2SO 2CH 2CH 2- X- Y, where M is the agarose matrix, X is oxygen or nitrogen, and Y is an aromatic or heteroaromatic compound. Contrary to earlier expectations these matrices showed pronounced thiophilic binding patterns when tested for the selective binding of immunoglobulins from human serum. The binding is influenced by the structure of the aromatic part of the ligand, the ligand concentration, and the concentration and type of lyotropic salt. 2-Hydroxypyridine coupled to divinyl sulfone-activated agarose was used to purify murine monoclonal antibodies (IgG 1 and IgM) from hybridoma cell cultures containing fetal calf serum. Compared to previous methods, significantly increased binding capacity (300–1500%) was obtained by using 1.0–1.2 m ammonium sulfate. Purity of the monoclonal antibody may be optimized for each individual clone by washing the column with either a low concentration of ammonium sulfate or polyethylene glycol before elution.

Improvement of the photochemical reactivity of [Cu(dmp)P2]+ (dmp = 2,9-dimethyl-1,10-phenanthroline; P = tertiary phosphine) by substituting triphenylphosphine with larger phosphines: application to photoreduction of methylviologen

Cu(I) complexes containing heteroaromatic ligands such as 2,2'-bipyridine (bpy) or 1,10-phenanthroline exhibit a metal-to-ligand charge-transfer (MLCT) band in the visible to near-ultraviolet spectral region and have a triplet MLCT state as the lowest energy excited state like (Ru(bpy)3)S which has been applied extensively to the photochemical reduction of water to hydrogen gas. Nevertheless, application of those Cu(I) complexes to the photochemical reduction of water has not been carried out, excepting only one report of Sauvage et al. Recently, they reported that Cu(I) complexes containing a heteroaromatic ligand, (Cu(NN)(PPh3)2) (NN = 2,9-dimethyl-1,10-phenanthroline (dmp) or 4,4',6,6'-tetramethyl-2,2'-bipyridine), found application as a sensitizer in photocatalytic reduction of methylviologen (MVS ) upon near-UV-light irradiation. Unfortunately, however, the quantum yield for MVS reduction (phi/sub MV /) is lower than that of (Ru(bpy)3)S . In this work, they have succeeded in improving the photoreducing activity of (Cu(dmp)(PPh3)S) by using such bulky and/or donating tertiary phosphines as cyclohexyldiphenylphosphine, PCyPh2, and tris(p-methoxyphenyl)phosphine, P(p-C6H4OMe)3, instead of PPh3. Another emphasis presented here lies in investigating the phosphine ligand effect on the photoreactivity of Cu(I) complexes, because such investigation has not been carried out yet to their knowledge.

ChemInform Abstract: Magnetic and Spectroscopic Study of Some Binuclear and Trinuclear Cobalt(II) Carboxylate Complexes.

AbstractReaction of CoCO3 (I) with the unsaturated acids (II) and the heteroaromatic ligands (III) results in the formation of either the binuclear cobalt complexes (IVa) or (IVb), or the trinuclear complexes (V); on addition of excess ligand (IIIa), the trinuclear complex (Va) is transformed to the dinuclear complex (IVc).

Preparation and reactions of palladium(II) complexes with C2-bonded heteroaromatic ligands trans[PdCl(R N)(PPh 3) 2] (R N = 2-pyridyl, 2-pirazyl, 2-pyrimidyl group). A new reaction pathway in the insertion of isocyanides into the Pdc bond of trans-[PdXR(L) 2] compounds

The complexes trans-[PdCl(R N)(PPh 3) 2] (I) [R N = 2-pyridyl (2-Py), 2-pyrazyl (2-pyz), 2-pyrimidyl (2-pym) group] have been prepared in high yield by deprotonation with NEt 3 of the corresponding cationic compounds trans[PdCl(R NH) (PPh 3) 2] + (R NH = N-protonated C 2-heteroaromatic ligand) in the presence of an excess of PPh 3. In chlorinated solvents, complexes I undergo a slow reversible dimerization into the binuclear derivatives [PdCl(μ-R N)(PPh 3)] 2 (II) (μ-R N = C 2, N 1-bridging ligand). From the 31P NMR spectra in 1,2-dichloroethane the following dissociation constants were obtained: 1.9 mol 1 −1 (R N= 2-py), 5.1 × 10 −2 (2-pym), 6.6 × 10 −3 (2-pyz). The dimerization becomes fast and quantitative if the PPh 3, involved in the equilibrium is removed by oxidation or by reaction with [PdCl(η 3-2-MeC 3H 4)] 2. Only the 2-pyridyl complex Ia reacts (slowly) with CO yielding the migratory insertion product trans-[PdCl{C(2-py)O}(PPh 3) 2], together with the dimer IIa. All the complexes I undergo migratory insertion of t-butylisocyanide with formation of trans-[PdCl{C(R N) = NCMe 3}(PPh 3) 2]] at rates which depend on the heterocyclic group (R N = 2-py > 2-pyz ⪢ 2-pym). The reaction of the 2-pyrazyl complex Ib with CNCMe 3 has been studied in detail by conductivity measurements and by IR and 31P NMR spectroscopy. The data suggest a complex mechanism in which insertion occurs through rearrangement of a four-coordinate intermediate [PdCl(2-pyz)(CNCMe 3)(PPh 3)], and through interaction of a cationic intermediate trans-[Pd(2-pyz)(CNCMe 3)(PPh 3) 2] + (Vb) with Cl − and with the free isocyanide of the initial equilibria. The occurrence of the latter reactions is confirmed by independent experiments in which the cationic complex Vb (isolated as perchlorate salt) is treated with an equimolar amount of [AsPh 4]Cl or CNCMe 3. The isocyanide-promoted insertion step represents a new mechanistic pathway for isocyanide insertion into the PdC bond of trans-[PdXR(L) 2] complexes.

Chemistry of heterocyclic compounds series. 94. Square-planar cis- and trans-C-palladium(II) complexes of N electron-deficient heteroaromatic ligands. Ligand synthesis, complexation, and spectral analyses and complex interaction with phage PM2 DNA

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemistry of heterocyclic compounds series. 94. Square-planar cis- and trans-C-palladium(II) complexes of N electron-deficient heteroaromatic ligands. Ligand synthesis, complexation, and spectral analyses and complex interaction with phage PM2 DNAGeorge R. Newkome, Wallace E. Puckett, Garry E. Kiefer, Vinod K. Gupta, Frank R. Fronczek, Daniel C. Pantaleo, Gregory L. McClure, Janell B. Simpson, and Walter A. DeutschCite this: Inorg. Chem. 1985, 24, 6, 811–826Publication Date (Print):March 1, 1985Publication History Published online1 May 2002Published inissue 1 March 1985https://doi.org/10.1021/ic00200a005RIGHTS & PERMISSIONSArticle Views393Altmetric-Citations45LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (2 MB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

ChemInform Abstract: SYNTHESIS AND STUDY OF HETEROAROMATIC LIGANDS CONTAINING A PYRIMIDINE RING

Chemischer InformationsdienstVolume 12, Issue 16 Heterocyclic Compounds ChemInform Abstract: SYNTHESIS AND STUDY OF HETEROAROMATIC LIGANDS CONTAINING A PYRIMIDINE RING A. V. IVASHCHENKO, A. V. IVASHCHENKOSearch for more papers by this authorO. N. GARICHEVA, O. N. GARICHEVASearch for more papers by this authorL. V. SHMELEV, L. V. SHMELEVSearch for more papers by this authorYU. S. RYABOKOBYLKO, YU. S. RYABOKOBYLKOSearch for more papers by this authorG. M. ADAMOVA, G. M. ADAMOVASearch for more papers by this author A. V. IVASHCHENKO, A. V. IVASHCHENKOSearch for more papers by this authorO. N. GARICHEVA, O. N. GARICHEVASearch for more papers by this authorL. V. SHMELEV, L. V. SHMELEVSearch for more papers by this authorYU. S. RYABOKOBYLKO, YU. S. RYABOKOBYLKOSearch for more papers by this authorG. M. ADAMOVA, G. M. ADAMOVASearch for more papers by this author First published: April 21, 1981 https://doi.org/10.1002/chin.198116268Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume12, Issue16April 21, 1981 RelatedInformation

Synthesis and study of heteroaromatic ligands containing a pyrimidine ring

5-Hexyl-3-[2-(1H-pyrazol-1-yl)pyrimidin-4-yl]amino-1(2)H-1,2,4-triazoles and 2-(3,5-dipropyl-4-ethyl-1H-pyrazol-1-yl)-6-methyl-4-(5-methyl-1H-pyrazol-1-yl)-aminopyrimidine were synthesized by the reaction of 4-chloropyrimidines with 3-araino-5-hexyl-1H-1,2,4-triazole and 3-amino-5-methyl-1H-pyrazole. Their IR, UV, and PMR spectra were investigated. New methods for the preparation of the intermediates, viz., 2-hydrazino-4(3H)-pyrimidinones and 2-(1H-pyrazol-1-yl)-4(3H)-pyrimidinones, that make it possible to obtain these compounds in higher yields are described.

Nucleophilic addition of .alpha.-hydroxyalkyl radicals to polypyridyl complexes of chromium(III), cobalt(III), rhodium(III), and ruthenium(II) in aqueous solution

The reactions of radiolytically generated ..cap alpha..-hydroxyalkyl radicals of the form R/sub 1/R/sub 2/COH, where R = H and CH/sub 3/ with M(NN)/sub 3//sup n+/ complexes, where M = Cr(III), Co(III), Rh(III), and Ru(II) and NN = 2,2'-bipyridine (bpy) and 1,10-phenanthroline (phen), proceed via electron transfer and/or addition of the radicals to the complex. The distribution of the products is controlled by the relative rate constants of electron transfer and addition which, in turn, are affected by the redox potential of the radical-complex couple and by the nature of the ligand. The overall rate constants for the radicals increase always in the order .CH/sub 2/OH < CH/sub 3/CHOH < (CH/sub 3/)/sub 2/COH. The radical adducts show lambda/sub max/ 475 nm and are discussed in terms of the known nucleophilic character of the ..cap alpha..-hydroxyalkyl radicals and the electron-deficient nature of these nitrogen heteroaromatic ligands. The limitations to the utilization of methanol, ethanol, and 2-propanol as H and OH radical scavengers and as sources of reducing radicals in the presence of polypyridyl complexes is discussed.