Search results for "cationic polymer"
showing 10 items of 441 documents
A Bis(tridentate)cobalt Polypyridine Complex as Mediator in Dye‐Sensitized Solar Cells
2015
Dye-sensitized solar cells equipped with cationic and neutral RuII-based sensitizers [Ru(ddpd){tpy(COOH)3}]2+ [12+; ddpd = N,N′-dimethyl-N,N′-di(pyridin-2-yl)pyridin-2,6-diamine, tpy(COOH)3 = 2,2″6′,2″-terpyridine-4,4′,4″-tricarboxylic acid] and [Ru(ddpd){tpy(COOH)(COO)2}] (2) with and without the coadsorbent chenodeoxycholic acid were constructed with I3–/I– or the CoIII/II-based redox mediators [Co(bpy)3]3+/2+ (33+/2+; bpy = 2,2′-bipyridine) and [Co(ddpd)2]3+/2+ (43+/2+) in the presence of LiClO4 and 4-tert-butylpyridine. The best photovoltaic performance was achieved by using the 43+/2+ shuttle and the neutral sensitizer 2 without coadsorbent. The higher short-circuit photocurrent densit…
Solution Chemistry of Element 106: Theoretical Predictions of Hydrolysis of Group 6 Cations Mo, W, and Sg
2001
Fully relativistic molecular density-functional calculations of the electronic structure of hydrated and hydrolyzed complexes have been performed for the group 6 elements Mo, W, and element 106, Sg. By use of the electronic density distribution data, relative values of the free energy changes and constants of hydrolysis reactions were defined. The results show hydrolysis of the cationic species with the formation of neutral molecules to decrease in the order Mo > W > Sg, which is in agreement with experiments for Mo, W, and Sg. For the further hydrolysis process with the formation of anionic species, the trend is reversed: Mo > Sg > W. A decisive energetic factor in the hydrolysis process …
Thiophen—Mangantricarbonyl-Komplexe
1967
Abstract Cationic thiophenemanganese tricabonyl complexes of the formula [C 4 (CH 3 ) x H 4- x S Mn(CO) 3 ] + have been prepared with 2-methyl-, 3-methyl-, 2,5-dimethyl-, 2,3,5-trimethyl-, tetramethylthiophene, and with thiophene by the reaction of Mn(CO) 5 Cl+AlCl 3 or AlBr 3 with the thiophenes in petrol ether, at 100–110°. The complexions give yellow solutions which are fairly stable. Their IR and some NMR spectra are given and discussed.
General Kinetic Analysis and Comparison of Molecular Weight Distributions for Various Mechanisms of Activity Exchange in Living Polymerizations
1997
The molecular weight distributions in many living (e.g. anionic, group transfer, cationic, and radical) polymerizations strongly depend on the dynamics of various equilibria between chain ends of d...
Synthesis, Spectroscopic Characterization, and Crystal Structure Determination of Cationic [(Cyclopentadienyl)dicarbonyliron](alkynyl)‐aminocarbene C…
1996
(Alkynoyl)iron complexes 1, Cp(CO)2Fe(OCCCR) (R = CH3, Ph, SiMe3), were synthesized by applying a mixed anhydride procedure and transformed into the cationic methoxycarbene complexes 2, [Cp(CO)2 Fe(C(OMe)CCR)+]-[PF6–]. Primary amines H2NR′ react with the methoxycarbene complexes to furnish exclusively cationic aminocarbene complexes 3, [Cp(CO)2 Fe(C(NHR′)CCR)+][PF6–], or (2-methoxyvinyl)aminocarbene complexes 5. The spectroscopic properties of the new complexes are discussed. The (alkynyl)-aminocarbene complexes 3e and 3f were characterized by X-ray crystal structure analysis.
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.
[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…