Inn Hoe Kim

Metal ion complexation by acyclic polyethers with lipophilic amide, thioamide, and amine end groups

A series of acyclic polyethers with lipophilic amide, thioamide, and amine end groups was synthesized. Metal ion transport across bulk liquid membranes and measurement of thermodynamic parameters for ligand-metal ion complexation by titration calorimetry show strong selectivity for complexation of lead ion over other metal ion species for the diamide ligand. Lead ion complexation by the acyclic polyether diamide involves the amide oxygens and silver ion coordination by a dithioamide analog involves the thioamide sulfurs. With a proper length of the ethereal linkage, the ligand wraps around the metal ion in a pseudocyclic fashion.

Effects of surrounding ion on Eu3+ luminescence in glass

Abstract The energy relaxation of excited Eu 3+ in glass hosts is investigated in this study. Eu 3+ ions are incorporated in both melted glass and sol–gel derived glass. The strong Eu 3+ emission lines from 5 D 0 to 7 F level show that the glass hosts provide the effect of the random structure of the silica network on the Eu 3+ ion. The relative intensities of the Eu 3+ emission depend strongly on the host glass types and excitation wavelengths. The 5 D 0 emissions of Eu 3+ in the sol–gel derived glass are more efficient than in the melted glass due to an excitation to the charge-transfer-state at 250 nm. The promotion of the charge-transfer-state excitation in the sol–gel derived glass, which is annealed at 400°C, comes from the anions encapsulated during the sample preparation step. The energy relaxation processes are identified from the wavelengths of the excitation peaks of Eu 3+ . The roles of UV-absorbing cations, Ce 3+ and Ti 4+ , which are codoped in the glasses, are examined.

Bis(2-amino­benzothia­zole-κN1)bis­(thio­cyanato-κN)zinc(II)

The ZnII ion in the title complex, [Zn(NCS)2(C7H6N2S)2], is tetrahedrally coordinated within an N4 donor set defined by two N atoms of two terminal isothiocyanate ligands and by two heterocyclic N atoms of two different 2-aminobenzothiazole ligands. This arrangement is stabilized by intramolecular N—H⋯N hydrogen bonds. In the crystal structure, molecules are linked through N—H⋯S hydrogen bonds to form a two-dimensional array.

Bis(2-amino-1,3-thia­zole-κN 3)diazido­zinc

In the title complex, [Zn(N3)2(C3H4N2S)2], the ZnII atom is tetrahedrally coordinated by two terminal azide ligands and by the ring N atoms of two different 2-aminothiazole ligands. Intramolecular N—H⋯N hydrogen bonds between the amino groups of both 2-aminothiazole ligands and the N atom of one of the azide ligands ensure that the heterocyclic rings are oriented in the same direction. Intermolecular N—H⋯N hydrogen bonds link the molecules into zigzag sheets in the ac plane.

Bis(2-amino-1,3-thia-zole-κN)diazido-zinc.

In the title complex, [Zn(N3)2(C3H4N2S)2], the ZnII atom is tetrahedrally coordinated by two terminal azide ligands and by the ring N atoms of two different 2-aminothiazole ligands. Intramolecular N—H⋯N hydrogen bonds between the amino groups of both 2-aminothiazole ligands and the N atom of one of the azide ligands ensure that the heterocyclic rings are oriented in the same direction. Intermolecular N—H⋯N hydrogen bonds link the molecules into zigzag sheets in the ac plane.

Bis(2-amino-1,3-thiazole-κN3)diazidozinc

In the title complex, [Zn(N3)2(C3H4N2S)2], the ZnII atom is tetrahedrally coordinated by two terminal azide ligands and by the ring N atoms of two different 2-aminothiazole ligands. Intramolecular N—H⋯N hydrogen bonds between the amino groups of both 2-aminothiazole ligands and the N atom of one of the azide ligands ensure that the heterocyclic rings are oriented in the same direction. Intermolecular N—H⋯N hydrogen bonds link the molecules into zigzag sheets in the ac plane.

Bis(2-amino-1,3-thia­zole-κN3)diazido­zinc

In the title complex, [Zn(N3)2(C3H4N2S)2], the ZnII atom is tetrahedrally coordinated by two terminal azide ligands and by the ring N atoms of two different 2-aminothiazole ligands. Intramolecular N—H⋯N hydrogen bonds between the amino groups of both 2-aminothiazole ligands and the N atom of one of the azide ligands ensure that the heterocyclic rings are oriented in the same direction. Intermolecular N—H⋯N hydrogen bonds link the molecules into zigzag sheets in the ac plane.

Tetra­kis(2-amino­thia­zole-κN3)dichloridocadmium(II)

In the title complex, [CdCl2(C3H4N2S)4],the CdII atom has an trans-Cl2N4 octahedral coordination geometry defined by four N atoms derived from the four 2-aminothiazole ligands and two Cl atoms. The amino groups participate in intra- and intermolecular N—H⋯N and N—H⋯Cl hydrogen bonding that stabilizes both the molecular and crystal structures.

Tetrakis(2-aminothiazole-κN3)dichloridocadmium(II)

In the title complex, [CdCl2(C3H4N2S)4],the CdII atom has an trans-Cl2N4 octahedral coordination geometry defined by four N atoms derived from the four 2-aminothiazole ligands and two Cl atoms. The amino groups participate in intra- and intermolecular N—H⋯N and N—H⋯Cl hydrogen bonding that stabilizes both the molecular and crystal structures.

Tetrakis(2-aminothiazole-kappa N-3)dichloridocadmium(II)

In the title complex, [CdCl2(C3H4N2S)4],the CdII atom has an trans-Cl2N4 octahedral coordination geometry defined by four N atoms derived from the four 2-aminothiazole ligands and two Cl atoms. The amino groups participate in intra- and intermolecular N—H⋯N and N—H⋯Cl hydrogen bonding that stabilizes both the molecular and crystal structures.