• Bulletin of the Korean Chemical Society
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• v.16 no.5
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• pp.406-409
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• 1995

The complex formation from Cu(Ⅱ) ion and 2,2-bis(hydroxymethyl)-2,2',2"-nitrilotriethanol (Bistris) in aqueous solution has been studied potentiometrically and spectrophotometrically. Bistris (L) coordinates to Cu(Ⅱ) as tridentate. The complex CuL2+ undergoes deprotonation in neutral and basic media. The deprotonated complexes involve metal-alcoholate coordinate bond in stable chelate structures.

• Bulletin of the Korean Chemical Society
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• v.27 no.7
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• pp.1005-1008
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• 2006

The reaction of $AgClO_{4}$ with acyclic potential tridentate N,N,N',N',N''-pentamethyldiethylenetriamine (pmdeta) has given colorless crystals suitable for X-ray crystallography. The crystal structure ($P2_{1}$/n, a = 14.413(1) $\AA$, b = 25.270(2) $\AA$, c = 16.130(1) $\AA$, b = $103.012(1){^{\circ}}$, V = 5723.7(8) A$\AA^{3}$, Z = 4, R = 0.0349) has been solved and refined. Three silver(I) ions connect four pmdeta ligands to produce discrete complex of $[Ag_3(pmdeta)_4](ClO_4)_3$. A pmdeta ligand is bridged to three silver(I) ions, and three other pmdeta ligands are chelated to each silver(I) center in a tridentate mode. Thus, the product is a rare tri-nuclear silver(I) complex with two different chemical environments. $^{13}C$ NMR and $MAS\;^{13}$C NMR indicate that the tri-nuclear silver(I) complex is not rigid in solution. The contact angles and thermal analyses of the complex are measured and discussed.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3615-3620
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• 2013

Two novel copper(II) bromide complexes with pyridine containing Schiff base ligands, $Cu(pmed)Br_2$ and $Cu(pmed)Br_2$ where pmed = N'-((pyridin-2-yl)methylene)ethane-1,2-diamine (pmed) and dpmed = N,N-diethyl-N'-((pyridin-2-yl)methylene)ethane-1,2-diamine (dpmed) were synthesized and characterized using X-ray single crystal structure analysis, optical and magnetic susceptibility measurements. Crystal structural analysis of $Cu(pmed)Br_2$ showed that the copper(II) ion has a distorted square-pyramidal geometry with the trigonality index of ${\tau}=0.35$ and two intermolecular hydrogen bonds, which result in the formation of two dimensional networks in the ab plane. On the other hand, $Cu(pmed)Br_2$ displayed a near square-pyramidal geometry with the value of ${\tau}=0.06$. In both compounds, the NNN Schiff base and one Br atom occupy the basal plane, whereas the fifth apical position is occupied by the other Br atom at a greater Cu-Br apical distance. The reported complexes show $g_{\mid}$ > $g_{\perp}$ > 2.0023 with a $d_{x2-y2}$ ground state and a penta-coordinated square pyramidal geometry. Variable temperature magnetic susceptibility measurements showed that the developed copper(II) complexes follow the Curie-Weiss law, that is there are no magnetic interactions between the copper(II) ions since the Cu--Cu distance is too far for magnetic contact.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2537-2543
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• 2011

A self-assembled Al-bridged diiminopyridine-based ligand (3) was synthesized and characterized by FT-IR, ESI-MS and NMR spectroscopy. Electron spectral titrations were performed to confirm the formation of a novel trinuclear bis(imino)pyridyl iron(II) complex (4) upon addition of $FeCl_2$ into Al-bridged ligand 3 in methanol solution. Simultaneously, a typical bis(imino)pyridine-iron(II) complex (2) was synthesized and fully characterized. The X-ray crystal study of the iron(II) complex 2 disclosed a five-coordinate, distorted square-pyramidal structure with the tridentate N^N^N ligand and chlorides. The optimal molecular structure of 4 was obtained by means of molecular mechanics, which showed that each iron atom in the complex 4 is surrounded by two chlorides, a tridentate N^N^N ligand and one oxygen atom, supporting considerations about the possibility of six-coordinate geometry from MMAO or the ethylene access. A comparison of 4 with the reference 2 revealed a remarkable decrease of the catalytic activity and MMAO consumption (activity up to $0.41{\times}10^3\;kg\;{mol_{Fe}}^{-1}h^{-1}bar^{-1}$, Al/Fe = 650 for 4 and $7.02{\times}10^3\;kg\;{mol_{Fe}}^{-1}h^{-1}bar^{-1}$, Al/Fe = 1600 for 2).

• Journal of the Korean Chemical Society
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• v.17 no.3
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• pp.169-173
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• 1973

The tridentate schiff base ligand, salicyliden amino-o-hydroxy benzene, has derived from salicylaldehyde and o-amino phenol. This ligand reacts with a series of Mo (VI), Mo (V), Mo (IV), and Mo (III) oxidated states and forms a new complexes; [Mo O$_2(H_2O)\;(C_{13}H_9O_2N)]$, [MoO Cl$(H_2O)\;(C_{13}H_9O_2N)]$, [Mo(SCN)$_2(H_2O)\;(C_{13}H_9O2_N)]$ 및 $[Mo(H_2O)_2\;(C_{13}H_9O_2N)]_2O$. The Mo (VI), Mo(V) and Mo(Ⅳ) ions in these complexes are octahedron, hexa coordinate, and the mole ratio of these ions to the ligand are 1 : 1, but Mo (III) Complex is a Mo-O-Mo oxygen bridge bond and polynuclear, and the mole ratio of Mo (III) to the ligand 1 : 1 above facts are identified from the data of Infrared spectra, visible spectra, and elemental analysis.

• Analytical Science and Technology
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• v.15 no.2
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• pp.135-141
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• 2002

The new tridentate poly-amine ligands, N,N-Bis(2-amino-ethyl)-methyl amine${\cdot}$2HBr (BAMA${\cdot}$2HBr), N,N-Bis(2-amino-ethyl)-ethylamine${\cdot}$2HBr (BAEA${\cdot}$2HBr), N,N-Bis(2-amino-ethyl)-propylamine${\cdot}$2HBr (BAPA${\cdot}$2HBr) and N,N-Bis(2-amino-ethyl)-butylamine${\cdot}$2HBr (BABA${\cdot}$2HBr) were synthesized as their dihydrobromic-salt and characterized by EA, IR, NMR and Mass spectroscopy. The protonation constants of the ligands and stability constants of transition metal(II) complexes were determined in aqueous solutions by potentiometry and compared with diethylenetriamine. Stability constants for transition metal complexes of ligands are in the order of BAMA < BAEA < BAPA > BABA. The larger value of stability constants of BAPA compared to these BABA, may be attributed to the more distorted structure of the complex due to the increased steric crowding caused by the presence of the bulky N-butyl group.

• Journal of the Korean Chemical Society
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• v.39 no.1
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• pp.47-56
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• 1995

Tridentate Schiff base molybdenum(V) complexes such as [Mo(Ⅴ)2O(SOHB)4], [Mo(Ⅴ)2O3(SOIP)2(NCS)2] and [Mo(Ⅴ)2O3(SOTB)2(H20)2](SOHB: Salicylidene-o-imino hydroxybenzene, SOIP; Salicylidene-o-imino pyridine, SOTB; Salicylidene-o-imino thiolbenzene) were synthesized and identified by elemental analysis, spectroscopy, and thermogravimetric analysis (TGA). It was found that the mole ratio of Schiff base ligand to the metal in these complexes is 1 : 1 or 1 : 2. The redox processes of the complexes were investigated by cyclic voltammetric and differential pulse polarographic techniques in nonaquous solvent containing 0.1 M tetraethylammonium perchlorate (TEAP) as supporting electrolyte at glassy carbon electrode. It was found that diffusion controlled reduction processes with one electron were Mo(Ⅴ)Mo(Ⅴ)e-→ Mo(Ⅴ)Mo(Ⅳ)e-→Mo(Ⅳ)Mo(Ⅳ)e-→Mo(Ⅳ)Mo(Ⅲ).

• Korean Journal of Environmental Biology
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• v.33 no.2
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• pp.201-204
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• 2015

A sea urchin was collected from 140 m deep at Gapado which is nearby Moseulpo in Jejudo Island, Korea on 30 June 2010. This specimen was classified as Echinolampas koreana H.L. Clark 1925, belonging to family Echinolampadidae of order Echinolampadoida based on its morphological characteristics. This order and lower categories are newly recorded from Korea. Distinct morphological characters of this species are as follows: test is relatively high. Abactical system has four large genital pores. Periproct is slightly sunken and situated below equator line. Peristome is very small and rather deeply sunken. Tridentate and ophiocephalous pedicellariae are present. Color in alcohol is light purple. These morphological characters are re-described with illustrations.

• Animal Systematics, Evolution and Diversity
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• v.34 no.3
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• pp.152-158
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• 2018

Two new records of spionid polychaetes, Prionospio pulchra Imajima, 1990 and Scolelepis (Scolelepis) sagittaria Imajima, 1992, collected from Korean waters are reported here with detailed descriptions and illustrations. Prionospio pulchra can be distinguished from its relatives by remarkably long and apinnate branchiae, the first chaetiger with notopodial chaetae, and the presence of ventral sabre chaetae. Scolelepis (Scolelepis) sagittaria is characterized by a sagittate prostomium, an occipital tentacle, and bi- or tridentate hooded hooks. In this paper, photographs of scanning electron microscopy for characteristic features of each species are presented. Keys to Prionospio and Scolelepis species from Korean waters are also provided.

• Journal of Environmental Science International
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• v.12 no.4
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• pp.497-501
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• 2003

The new tridentate ligands of nitrogen donor atoms N,N-Bis(2-amino-ethyI)-benzyl-amine 2HCI(BABEA. 2HCI) and 2,6-Bis(amino-methyl)-pyridien. 2HCI(BAMP. 2HCI) were synthesized as their dihydrochloride salts and characterized by TA, IR. Mass and NMR spectroscopy. The protonation constants of the ligands and stability constants for Cd$^{2+}$, Pb$^{2+}$, Zn$^{2+}$and Cu$^{2+}$ ions were determined by potentiometric titration in aqueous solutions and compared with those of analogous ligands. The effect stability constants of ligands and metal ions for removal of heavy metals in aqueous solution were described.