نتایج جستجو برای: crown complexes

تعداد نتایج: 155290  

Journal: :Journal of molecular modeling 2012
Hockseng Nguan Sara Ahmadi Rauzah Hashim

A theoretical study of a series of five glucose based glycolipid crown ethers and their complexes with Na(+) and K(+) was performed using the density functional theory with B3LYP/6-31 G* to obtain the optimized geometrical structures and electronic properties. The local nucleophilicity of the five molecules was investigated using Fukui function, while the global nucleophilicity was calculated f...

Journal: :Inorganic chemistry 2004
Marisa C Buzzeo Amber H Iqbal Charli M Long David Millar Sonal Patel Matthew A Pellow Sahar A Saddoughi Abigail L Smenton John F C Turner Jay D Wadhawan Richard G Compton James A Golen Arnold L Rheingold Linda H Doerrer

Two series of homoleptic phenolate complexes with fluorinated aryloxide ligands A2[M(OAr)4] with M=Co2+ or Cu2+, OAr-=(OC6F5)- (OArF) or [3,5-OC6H3(CF3)2]- (OAr'), A+=K (18-crown-6)+, Tl+, Ph4P+, Et3HN+, or Me4N+ have been synthesized. Two related complexes with nonfluorinated phenoxide ligands have been synthesized and studied in comparison to the fluorinated aryloxides demonstrating the drama...

Journal: :Inorganic chemistry 2005
Sherri A McFarland Douglas Magde Nathaniel S Finney

Tris(bipyridyl)ruthenium(II) complexes modified such that one of the bipyridines is appended with a crown ether display luminescence that is responsive to complexation with metal ions. The parent species, Ru(bpy)3(2+), is moderately luminescent, with an emission lifetime of about 1 micros in fluid solution at room temperature. The modified complexes are much less emissive, with lifetimes near 1...

Journal: :Chemical communications 2007
William Clegg Sophie H Dale David V Graham Ross W Harrington Eva Hevia Lorna M Hogg Alan R Kennedy Robert E Mulvey

The first sodium-magnesium and sodium-zinc ketimido complexes display contrasting inverse crown ring and pseudo-cubane structures respectively, while a sodium-zinc heterotrianionic alkide-alkoxide-amide adopts a third type of structure with a stepped ladder motif.

Journal: :Chemical communications 2010
Jing Cao Hai-Yan Lu Jun-Feng Xiang Chuan-Feng Chen

Pentiptycene-based mono(crown ether)s and tetracationic cyclobis(paraquat-p-phenylene) can form 1 : 1 stable complexes in solution and in the solid state, in which both of the components act as the host as well as the guest.

Journal: :Science 1988
C J Pedersen

The discovery of the crown ethers stemmed from efforts to control the catalytic activity of vanadium and copper by complexation with multidentate ligands. The first crown ether, 2,3,11,12-dibenzo-1,4,7,10,13,16-hexaoxacyclo-octadeca-2,11-diene, was obtained in 0.4% yield during an attempt to prepare a phenolic ligand from catechol and bis(2-chloroethyl)ether. This compound, which complexed with...

Journal: :Dalton transactions 2011
Adrián Roca-Sabio Marta Mato-Iglesias David Esteban-Gómez Andrés de Blas Teresa Rodríguez-Blas Carlos Platas-Iglesias

The coordination properties of the macrocyclic receptor N,N'-bis[(6-carboxy-2-pyridyl)methylene]-1,10-diaza-15-crown-5 (H(2)bp15c5) towards the lanthanide ions are reported. Thermodynamic stability constants were determined by pH-potentiometric titration at 25 °C in 0.1 M KCl. A smooth decrease in complex stability is observed upon decreasing the ionic radius of the Ln(III) ion from La [log K(L...

2015
Hayley Jane Clayton

A series of multidentate N-donor ligands have been synthesised all containing pyridyl and pyridyl/thiazole units and their coordination behaviour is described. The ligands are classified into four types; i) terpyridine containing pyridyl/thiazole ligands (L); ii) pyridyl/thiazole ligands containing a 3,3′-disubstituted bipyridine core. (L); iii) 2,2′-bipyridine containing a crown ether moiety (...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده علوم پایه 1390

abstract the cr(iii) and zn(ii) complexes with 2-((9,10-dihydro-1-hydroxy-9,10-dioxaanthracen-4-yloxy)carbonyl)benzoic acid as ligand have been prepared by reacting cr(no3) and zn(no3)2 and ligand in cloroform. the cr and zn complexes with 2-((9,10-dihydro-1-hydroxy-9,10-dioxaanthracen-4-yloxy)carbonyl) were also prepared in chloroform and aceton solutions. the uv-visible and ft-ir spectra of...

A. Sadjadi J. Narafpour

The DO1(18c6)fi (MwLi. Na. K and I 8c6=18-crown-6) complexes have been chosen as the model systems toinvestigate the nature of chemical bonds between alkali metal cations and large mffitidentaie orgmnic ligands.The B3LYP/6-3I+G(d,p) level of calculation has been used for obtaining equilibrium geernetnes and p(r)functions (electron density distributions). By the aid of fundamental physical theor...

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