Search results for "Polymerization"
showing 10 items of 1689 documents
One-dimensional and two-dimensional anilate-based magnets with inserted spin-crossover complexes.
2014
The syntheses, structures, and magnetic properties of a family of bimetallic anilate-based compounds with inserted spin-crossover cationic complexes are reported. The structures of 1-4 present a two-dimensional anionic network formed by Mn(II) and Cr(III) ions linked through anilate ligands with inserted [Fe(III)(sal2-trien)](+) (1), [Fe(III)(4-OH-sal2-trien)](+) (2), [Fe(III)(sal2-epe)](+) (3), or [Fe(III)(5-Cl-sal2-trien)](+) (4) complexes. The structure of 5 is formed by anionic [Mn(II)Cl2Cr(III)(Cl2An)3](3-) chains surrounded by [Fe(II)(tren(imid)3)](2+), Cl(-), and solvent molecules. The magnetic properties indicate that 1-4 undergo a long-range ferrimagnetic ordering at ca. 10 K. On t…
Cationic Iron Aminocarbene Complexes as Dienophiles in Diels‐Alder Reaction with Cyclopentadiene
1996
The cationic iron (alkynyl)aminocarbene complexes [Cp(CO)2Fe(C(NHR)CCSiMe3][PF6], (R C6H5, p-CH3C6H4) 1 derived from aromatic amines smoothly react with cyclopentadiene in dichloromethane to yield the cycloadducts 2. No reaction was observed for complexes derived from sterically demanding aliphatic amines, like L-alanine tert-butyl ester. For comparison, the alkynyl-substituted acyl iron compounds Cp(CO)2Fe(CO)CC (R SiMe3, C6H5) 3 were investigated, requiring TiCl4 catalysis to undergo the cycloaddition reaction. The structures of the cycloadducts 4 were determined by X-ray crystallography.
Anionic Polymerization of Terpene Monomers: New Options for Bio-Based Thermoplastic Elastomers
2021
[CoII(4-terpyridone)2]X2: a novel cobalt(II) spin crossover system [4-terpyridone = 2,6-bis(2-pyridyl)-4(1H)-pyridone].
2001
[EN] The cationic complex [Co(4-terpyridone)(2)](2+) where 4-terpyridone is the terpy-like ligand 2,6-bis(2-pyridyl)-4-(1H)-pyridone has been synthesized. High-spin and different spin crossover behaviors have been observed in the solid state depending on the counterion SO42-, Cl-, or ClO4-. The room temperature crystal structure of the spin crossover compound [Co(4-terpyridone)(2)](ClO4)(2).H2O is described.
Molecular-Programmed Self-Assembly of Homo- and Heterometallic Tetranuclear Coordination Compounds: Synthesis, Crystal Structures, and Magnetic Prope…
2009
New homo- and heterobimetallic tetranuclear complexes of formula [Cu4(mpba)(Me4en)4(H2O)4](ClO4)4·3H2O (1), [Cu4(mpba)(Me4en)4(H2O)4](PF6)4·2H2O (2), [Cu4(ppba)(Me4en)4(H2O)4](ClO4)4·2H2O (3), [Cu4(mpba)(dipn)4](ClO4)4·3H2O (4), [Cu4(ppba)(dipn)4](ClO4)4·2H2O (5), and [Cu2Ni2(ppba)(dipn)4(H2O)2](PF6)4 (6) [mpba = N,N′-1,3-phenylenebis(oxamate), ppba = N,N′-1,4-phenylenebis(oxamate), Me4en = N,N,N′,N′-tetramethylethylenediamine, and dipn = dipropylenetriamine] have been synthesized and structurally and magnetically characterized. Complexes 1−6 have been prepared following a molecular-programmed self-assembly method, where a heteropolytopic tetranucleating phenylenedioxamato bridging ligand (…
About the relevance of anion-π interactions in water.
2021
Anion-π interactions are emerging as exotic features with potential applications in chemistry. In the last years, their relevance in living systems has been outlined, and so far there is no concluding significant evidence recognized about the participation of anion-π interactions in water because anion-π sensors contain large aromatic hydrophobic surfaces with limited solubility. By transforming a neutral heterocycle (for example quinoline) into its corresponding salt (quinolinium), we have been able to overcome these solubility issues, and new cationic water-soluble fluorophores have been prepared. Herein, we used N-alkylated heterocycles as π-acidic surfaces to shed light on the nature of…
Darstellung und Zerfall von tertiären Hyponitriten
1971
Dicumylhyponitrit (1a), substituierte Dicumylhyponitrite (1b1f) (p-Br, p-Cl, p-CH3, m-CH3, p-CH3O), Bis-[1.1-diphenyl-athyl]-hyponitrit (1h) und Bis-[1.1-dimethyl-pentyl]-hyponitrit (1g) wurden dargestellt. Die tertiaren Hyponitrite zerfallen bereits rasch bei-40 in Stickstoff und freie Alkoxyradikale, die dann zu den entsprechenden Alkoholen und Ketonen weiter reagieren. Die relativen Reaktivitaten von tert.-Butyloxy-und Cumyloxyradikalen hinsichtlich Wasserstoffabstraktion und β-Spaltung wurden fur verschiedene Losungsmittel bestimmt; Cumyloxyradikale neigen starker zur β-Spaltung als tert-Butyloxyradikale. Die freien Alkoxyradikale konnen Polymerisations- und Autoxydationsreaktionen init…
Herstellung von 1,5‐Cyclooctadiin und 1,3,5,7‐Cyclooctatetraen aus 1,5‐Cyclooctadien
1994
Preparation of 1,5-Cyclooctadiyne and 1,3,5,7-Cyclooctatetraene from 1,5-Cyclooctadiene Bromination of 1,5-cyclooctadiene (1) and stepwise dehydro-bromination first with KOtBu and then with KOtBu/18-crown-6 yields 1,5-cyclooctadiyne (5). A prolonged interaction of the base causes a complete transformation to cyclooc-tatetraene (6). Diyne 5 and even more the intermediate enyne 4 are highly reactive dienophiles. The cycloadducts 10–14 formed with 1,3-cyclohexadiene, carbon disulfide, and tetraphenylcyclopentadienone were isolated and characterized. Treatment of 5 with titanium tetrachloride induces a vigorous polymerization.
2D and 3D bimetallic oxalate-based ferromagnets prepared by insertion of different FeIII spin crossover complexes
2010
The syntheses, structures and magnetic properties of the compounds of formula [Fe(III)(5-NO(2)sal(2)-trien)][Mn(II)Cr(III)(ox)(3)]·CH(3)NO(2).0.5H(2)O (1) and [Fe(III)(5-CH(3)Osal(2)-trien)][Mn(II)Cr(III)(ox)(3)] (2) are reported. The structure of 1, that crystallizes in the P2(1) chiral space group, presents a 2D honeycomb anionic layer formed by Mn(II) and Cr(III) ions linked through oxalate ligands and a cationic layer of [Fe(III)(5-NO(2)sal(2)-trien)](+) complexes intercalated between the 2D oxalate network. The structure of 2, that crystallizes in the Pna2(1) acentric space group, presents a 3D achiral anionic network formed by Mn(II) and Cr(III) ions linked through oxalate ligands wit…