• Bulletin of the Korean Chemical Society
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• v.20 no.10
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• pp.1200-1204
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• 1999

The reactions of Ru(tpy)Cl3 (tpy = 2,2';6',2"-terpyridine) with new N,N,C-terdentate ligands, 3,2'-annulated-6-(2"-pyridyl)-2-phenylpyridines (1, HL) and the properties of their Ru(II) complexes are described. The distribution ratio of the two possible Ru(II) complexes, a pentaaza-coordinated complex [Ru(tpy)(1-N,N')Cl]+ and a cycloruthenated complex [Ru(tpy)(La-N,N',C)]+ are highly dependent on the length of the polymethylene unit. The trimethylene bridge of the N,N,C-terdentate in pentaaza-coordinated complex is rigid enough to induce an asymmetry in the complex.

• Journal of the Korean Chemical Society
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• v.49 no.6
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• pp.609-612
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• 2005

• Bulletin of the Korean Chemical Society
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• v.19 no.1
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• pp.79-82
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• 1998

Novel coordination polymers of general form $[Co(NCS)_2(Py_2L)_2]_n\; (Py_2L=trans-1,2-bis(4-pyridyl)ethylene$ (bpee), 1; 1,2-bis(4-pyridyl)ethane (bpea), 2) have been synthesized by slow diffusion of aqueous solution of $Co(NCS)_2$ with ethanolic solution of appropriate spacer ligand, $Py_2L$, in a mole ratio of 1 : 2. X-ray analyses on both 1 and 2 have provided similar unit and infinite structures with space group Ibam. The local geometry around the cobalt(Ⅱ) atoms is an octahedral arrangement with two NCS groups in trans position (N-Co-N, 180.0° (1); 180.0°(2)) and four pyridine units in propeller fashion. Each spacer ligand connects two cobalt(Ⅱ) ions defining the edges of a $[Co(II)]_4$ rhombus. The most fascinating feature is the occurrence of perpendicular interwoven of independent square grid sheets: this is, one molecular network is perpendicularly interpenetrated through the centers of the $[Co(II)]_4$ rhombuses of another independent network with all of the cobalt(Ⅱ) atoms in a coplanar sheet. The physicochemical properties of the present unique structures were studied.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2338-2340
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• 2009

Ionic palladium(II) complex containing a long aliphatic chain, [(tmeda)$PdL]_2(PF_6)_4$ (tmeda = N,N,N',N'-tetramethylethylenediamine; L = decylmethylbis(m-pyridyl)silane) allowed to form a puckered submicrosphere morphology without any template or additive. The puckered spheres reversibly adsorb and desorb dioxane molecules. Coligand and cosolvent effects on the formation of submicrospherical morphology were observed.

• Bulletin of the Korean Chemical Society
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• v.23 no.12
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• pp.1839-1841
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• 2002

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2325-2329
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• 2013

Second-order rate constants $k_N$ have been measured for reactions of benzyl 2-pyridyl thionocarbonate (4b) and t-butyl 2-pyridyl thionocarbonate (5b) with a series of cyclic secondary amines in MeCN at $25.0{\pm}0.1^{\circ}C$. The $k_N$ values for the reactions of 4b and 5b have been compared with those reported previously for the corresponding reactions of benzyl 2-pyridyl carbonate (4a) and t-butyl 2-pyridyl carbonate (5a) to investigate the effect of changing the electrophilic center from C=O to C=S on reactivity and reaction mechanism. The thiono compound 4b is more reactive than its oxygen analogue 4a. The Br${\o}$nsted-type plots for the reactions of 4a and 4b are linear with ${\beta}_{nuc}=0.57$ and 0.37, respectively. The reactions of 4a were previously reported to proceed through a concerted mechanism, while those of 4b in this study have been concluded to proceed through a stepwise mechanism with formation of an intermediate being the rate-determining step on the basis of the ${\beta}_{nuc}$ value of 0.37. Enhanced polarizability upon changing the C=O in 4a by C=S has been suggested to be responsible for the reactivity order and the contrasting reaction mechanisms. In contrast, the reactivity of 5a and 5b is similar, but they are much less reactive than 4a and 4b. Furthermore, the reactions of 5a and 5b have been concluded to proceed through the same mechanism (i.e., a concerted mechanism) on the basis of linear Bronsted-type plots with ${\beta}_{nuc}=0.45$ or 0.47. It has been concluded that the strong steric hindrance exerted by the t-Bu in 5a and 5b causes a decrease in their reactivity and forces the reactions to proceed through a concerted mechanism.

• Analytical Science and Technology
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• v.12 no.5
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• pp.397-402
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• 1999

The open-chain hexadentate $N_6$, ligand containing two pyridyl groups, 1,15-bis(2-pyridyl)-2,6,10,14-tetraazapentadecane (bpyped) has been synthesized as its tetrahydroehloride salt and characterized by EA, IR, NMR, and Mass. Its proton dissociation constants($logK{^n}_H$) and stability constants ($log\;K_{ML}$) for Co(II), Ni(II), Cu(II) and Zn(II) ions were determined at $25^{\circ}C$ and ionic strength 0.10 M($KNO_3$) in aqueous solution by potentiometry and compared with those or analogous $N_6$ ligands contain one or two propylenic spacers, which make six-membered chelate rings, between the aliphatic nitrogen atoms.

• Korean Journal of Crystallography
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• v.6 no.1
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• pp.36-42
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• 1995

Two types of single crystals of the title compound [6-(2-pyridyl)-3, 5-hexadiyn-ol, PyHxD] were obtained by solution of n-hexane/CH2C12 and n-hexane/Et2O, and their molecular conformations are proved identical in spite of different of space groups; C22H18N2O2 (I), Mr=343.70, Monoclinic, Pa, a=14.595(2), b=5.413(2), c=12.218(2)Å, β=96.86(1)°, V=958.3Å3, Z=2, Dx=1.19 Mgm-3, λ(MoKα)=0.71069Å, μ=0.072mm-1, F(000)=360.0, T=292K, R=0.104 for 756 unique observed reflections. An asymmetric unit contains a dimer connected by two N-H…O intermolecular hydrogen bonds. C11H9NO (II), Mr=171.85, Monoclinic, P21/a, a=14.611(2), b=5.423(6), c=12.191(2)Å, β=96.89(1)°, V=959.0Å3, Z=4, Dx=1.19 Mgm-3, λ(MoKα)=0.71069Å, μ=0.072mm-1, F(000)=360.0, T=293K, R=0.066 for 824 unique observed reflection. The structural asymmetric unit contains a molecule, but two N-H…O hydrogen bonds related by controsymmetry make the molecules form a dimer. In both structure, the dihedral angle between the planar pyridyl ring and the plane defined by C(10)-C(11)-O connected by linear diyne chain is approximately normal, and the molecules are stacked along b-axis with the unit repeat of b-axis.

• Bulletin of the Korean Chemical Society
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• v.30 no.1
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• pp.257-260
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• 2009

• Macromolecular Research
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• v.15 no.4
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• pp.302-307
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• 2007

The living radical polymerization of methyl methacrylate (MMA) by atom transfer radical polymerization, (ATRP) employing a $Fe(II)X_2/diphenyl-2-pyridyl$ phosphine (PyP) catalytic system (X=Cl, Br), was investigated using several initiators and solvents at various temperatures. Most of the polymerizations with the PyP ligand were well controlled, with a linear increase in the number average molecular weights ($M_n$) vs. conversion, with relatively low molecular weight distributions ($M_w/M_n=1.2-1.4$) throughout the reactions. The measured weights matched those of the predicted values. The ethyl-2-bromoisobutyrate (EBriB) initiated ATRP of MMA, with the $Fe(II)X_2/diphenyl-2-pyridyl$ phosphine catalytic system (X=Cl, Br), was better controlled in p-xylene at $80^{\circ}C$ than the other solvents used in this study.