Weak Agostic Interaction Research Articles

Optical resolution of racemic stilbenediamine using N*-chiralortho-palladated matrix

Optical resolution of racemic stilbenediamine (Stien) was performed by recrystallization of its diastereomeric adducts withortho-palladated(S)-N-isopropyl-α-methylbenzylamine. The less soluble (S C R N′,SS) diastereomer was stuided by X-ray diffraction analysis. It was established that the crystal of this diastereomer consists of dimers formedvia association of two molecules of the mononuclear cationic complex with an additional molecule of free diamine of the same absolute configuration. The association occurs through a system of hydrogen bonds and weak agostic interactions. The association occurs through a system of hydrogen bonds and weak agostic interactions. Based on the X-ray diffraction data, the procedure was improved for the resolution of stilbenediamine due to the more profitable use of theortho-palladated reagent. The Stien/Pd ratio in the diastereomer isolated was inceased up to 3∶2. The conformational features of the complex are discussed on the basis of1H NMR spectroscopy data.

Intramolecular CH activation and oxidative addition reactions of iridium complexes containing arylamines with bulky substituents on n itrogen; X-ray structures of [Ir I(C 6H 4CH 2NEt 2-2- C, C)] and [Ir III(C 6H 4CH 2Net(CHMe)-2- C, N, C′)I(cod)] (cod = cycloocta-1,-5-diene)

Square-planar iridium(I) complexes [Ir(C 6H 4CH 2NRR′)(cod)] (R=R′=Et; R=Me, R′=t-Bu; cod=cycloocta-1,5-diene) containing C,N-chelating arylamine ligands have been synthesized and characterized by NMR spectroscopy. An X-ray diffraction study of [Ir9C 5H 4CH 2NEt 2-2- C, N)(cod)] shows a weak agostic interaction between the d 8 metal center and a methyl H atom of one ethyl group. An oxidative addition reaction of this complex with Mel affords an If(III) complex [ Ir( C 6H 4CH 2NEt ( CHMe)-2-C,N,C′) I ( cod) ] which results from an intramolecular methylene CH activation process. This latter complex has been characterized with 2D NMR techniques and an X-ray diffraction study . The activity of the new iridium(I) complexes as well as [Ir(C 6H 4CH 2NMe 2-2- C, N)(cod)], Ir(1-C 10H 6NMe 2-8- C, N)(cod)] and [Ir(C 6H 4]CH 2N(Me)CH 2CH 2NMe 2-2- C, N)(cod)] towards H 2 is reported; the different products obtained are discussed with reference to reaction pathways influenced by the steric bulk on the nitrogen donor atom. Crystals of [Ir(C 6H 4CH 2NEt 2-2- C, N)(cod)] are triclinic, space group P 1 with unit-cell dimensions a = 9.154(1), b = 9.992(1), c = 10.846(1) A ̊ , α = 93.46(1), β = 113.03(1), γ = 109.84(10)°, Z = 2 , final R = 0.0234, wR = 0.0295 for 3465 refelctions with I>2.5 σ( I) and 197 parameters. Crystals of [ Ir( C 6H 4CH 2NEt ( CHMe)-2-C,N,C′) I ( cod) ] are triclinic, space group P 1 with dimensions a = 7.591(1), b = 11.406(1), c = 13.511()1) A ̊ , α = 65.63(1), β= 88.34(1), γ = 83.29°, Z = 2 , final R = 0.0319, wR = 0.0402 for reflections with I>2.5 σ( I) and 228 parameters.

Intramolecular carbon-hydrogen bond activation: preparation, structure, and properties of a unique cobalt(III) complex, K[Co(III)(dacoda)(SO3).cntdot.5H2O, containing a weak agostic interaction in aqueous solution

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIntramolecular carbon-hydrogen bond activation: preparation, structure, and properties of a unique cobalt(III) complex, K[Co(III)(dacoda)(SO3).cntdot.5H2O, containing a weak agostic interaction in aqueous solutionWilliam E. Broderick, Kan Kanamori, Roger D. Willett, and J. Ivan LeggCite this: Inorg. Chem. 1991, 30, 20, 3875–3881Publication Date (Print):October 1, 1991Publication History Published online1 May 2002Published inissue 1 October 1991https://doi.org/10.1021/ic00020a020RIGHTS & PERMISSIONSArticle Views241Altmetric-Citations37LEARN 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 (914 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts