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Thiocyanate Ions (thiocyanate + ion)

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Chemistry100%

Selected Abstracts

Ion-Selective Electrodes for Thiocyanate Based on the Dinuclear Zinc(II) Complex of a Bis- N,O -bidentate Schiff Base

ELECTROANALYSIS, Issue 12 2004
Philippe Bühlmann
Abstract An ion selective electrode based on the dinuclear complex formed by two zinc(II) ions and two molecules of the bis- N,O -bidentate Schiff base 2,2,-[methylenebis(4,1-phenylenenitrilomethylidyne)]bisphenol exhibits thiocyanate selectivity with a good discrimination of nitrite, nitrate, and azide. The selectivities of electrode membranes with various compositions indicate that this potentiometric selectivity is based on the formation of a 1,:,1 complex between the thiocyanate anion and the dinuclear ionophore. The 2,:,1 ratio of thiocyanate ions and the dinuclear ionophore that results from higher ratios of cationic sites and ionophore worsens the selectivity, suggesting that binding of a thiocyanate to both zinc(II) centers of the dinuclear ionophore is not favorable. Interestingly, the selectivity patterns of these electrodes differ radically from that of a highly sulfate selective electrode based on a compound reported previously to be the analogous mononuclear 1,:,1 complex of zinc(II) and the same Schiff base. It is suggested that the previously reported 1,:,1 complex with zinc(II) may indeed have been a polymer of the same elemental composition. [source]

Nonequilibrium solvent polarization in kinetics of SN2 reactions

INTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 2 2003
J. S. JaworskiArticle first published online: 21 NOV 200
The solvent effect on the experimental activation barriers for the reactions of methyl iodide with chloride and thiocyanate ions was analyzed according to the Marcus and Shaik theories, considering SN2 mechanism in terms of a single electron shift. The linear increase in the solvent reorganization energy of the Marcus theory (after removing contributions from the specific solvation) with the solvent Pekar factor, describing the effect of the nonequilibrium solvent polarization, was observed for six aprotic solvents. The direct support of the title effect based on the Shaik theory was less evident; however, in general, the calculated activation barriers in 10 solvents change parallel with the experimental ones. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 35: 61,66, 2003 [source]

An unusual chain cadmium(II) coordination polymer: catena -poly[[(2,2,-bipyridyl-,2N,N,)cadmium(II)]-di-,-chlorido-[(2,2,-bipyridyl-,2N,N,)cadmium(II)]-di-,-thiocyanato-,2N:S;,2S:N]

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 12 2007
Min Chen
The title complex, [CdCl(NCS)(C10H8N2)]n, represents an unusual CdII coordination polymer constructed by two types of anionic bridges and 2,2,-bipyridyl (bipy) terminal ligands. These two types of bridges are arranged around inversion centers. The distorted octahedral coordination of the CdII center is provided by two chloride ions, one N- and one S-donor atom from two thiocyanate ions, and a pair of N atoms from the chelating bipy ligand. Interestingly, adjacent CdII ions are interconnected alternately by paired chloride [Cd...Cd = 3.916,(1),Å] and thiocyanate bridges [Cd...Cd = 5.936,(1),Å] to generate an infinite one-dimensional coordination chain. Furthermore, weak interchain C,H...S interactions between the bipy components and thiocyanate ions lead to the formation of a layered supramolecular structure. [source]

Synthesis and Crystal Structure of a Two-dimensional Silver(I)-Iron(III) Heteronuclear Coordination Polymer: {[Ag,Fe2(SCN)12(H2O)2] [(inaH)2(H2O)2]}n

CHINESE JOURNAL OF CHEMISTRY, Issue 1 2004
Xiu-Ling Li
Abstract The 2-D heteronuclear coordination polymer {[Ag4Fe2(SCN)12(H2O)2] (inaH)2(H2O)2}n (1) (inaH is the abbreviation of protonated isonicotinic acid) with chemical formula C24Ag4Fe2N14O8S12 has been synthesized and characterized by single crystal X-ray diffraction, elemental analysis and IR spectroscopy. The Ag2S2 rings connect two kinds of octahedral geometries of Fe(III) ions, [Fe(NCS)6]3, and Fe(H2O)2(NCS)4], units with bridging thiocyanate ions leading to 2-D [Ag4Fe2(SCN)12(H2O)22, anion framework. Four kinds of rings including the unprecedented thirty-two membered Ag4Fe4(SCN)8 rings share comers or edges in the 2-D anion layer structure. All thiocyanates coordinate to the metal ions according to the HSAB principle with N atoms binding to the Fe(III) ions and with S atoms binding to Ag(I) ions. Pronoated ina cations stabilize the layer structure as counter ions and hydrogen bonds were formed within the pronoated in a cations dimer and between the dimers and the lattice waters. Crystal data: Mr= 1560.44, triclinic, P1, a=0.76082(1) nm, b=0.9234 nm, c= 1.85611(4) nm, a= 103.0170(10)°, ,=93.7780(10)°, y=97.4080(10)°, V= 1.25385(3) nm3, Z=1, ,(Mo K,)=2.650 mm,1, Dc,=2.067 g · cm,3, F(000)=758, R1=0.0412. wR2=0.1003. [source]