• 분석과학
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• 제13권4호
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• pp.534-538
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• 2000

The title compound, $[Co(H_2O)_6](CH_3C_6H_4SO_3)_2$, has been prepared and characterized by X-ray crystallography. The crystal structure of the compound demonstrates a layered material constituted by hexaaquacobalt (II) cations and p-toluenesulfonate anions. Geometrical environment of the cobalt atom is octahedrally coordinated by water molecules. The p-toluenesulfonate anions are arranged with the sulfonate groups turned toward opposite side of the layer, alternately. The layered structure is stabilized by the hydrogen bondings between the ligated water molecules and the anionic sulfonate oxygen atoms.

• 대한수학회지
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• 제59권5호
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• pp.927-944
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• 2022

Let $\vec{p}{\in}(0,\;1]^n$ be an n-dimensional vector and A a dilation. Let $H^{\vec{p}}_A(\mathbb{R}^n)$ denote the anisotropic mixed-norm Hardy space defined via the radial maximal function. Using the known atomic characterization of $H^{\vec{p}}_A(\mathbb{R}^n)$ and establishing a uniform estimate for corresponding atoms, the authors prove that the Fourier transform of $f{\in}H^{\vec{p}}_A(\mathbb{R}^n)$ coincides with a continuous function F on ℝⁿ in the sense of tempered distributions. Moreover, the function F can be controlled pointwisely by the product of the Hardy space norm of f and a step function with respect to the transpose matrix of A. As applications, the authors obtain a higher order of convergence for the function F at the origin, and an analogue of Hardy-Littlewood inequalities in the present setting of $H^{\vec{p}}_A(\mathbb{R}^n)$.

• Applied Science and Convergence Technology
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• 제26권6호
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• pp.174-178
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• 2017

The reactions of thermal hydrogen atoms H(g) with the Ge(100) surface were examined with temperature-programmed desorption (TPD) mass spectrometry. Concomitant $H_2$ and $CH_4$ TPD spectra taken from the H(g)-irradiated Ge(100) surface were distinctly different for low and high H(g) doses/substrate temperatures. Reactions suggested by our data are: (1) adsorbed mono(${\beta}_1$)-/di-hydride(${\beta}_2$)-H(a) formation; (2) H(a)-by-H(g) abstraction; (3) $GeH_3$(a)-by-H(g) abstraction (Ge etching); and (4) hydrogenated amorphous germanium a-Ge:H formation. While all these reactions occur, albeit at higher temperatures, also on Si(100), H(g) absorption by Ge(100) was not detected. This is in contrast to Si(100) which absorbed H(g) readily once the surface roughened on the atomic scale. While this result is rather against expectation from its weaker and longer Ge-Ge bond as well as a larger lattice constant, we attribute the absence of direct H(g) absorption to insufficient atomic-scale surface roughening and to highly efficient subsurface hydrogenation at moderate (>300 K) and low (${\leq}300K$) temperatures, respectively.

• Bulletin of the Korean Chemical Society
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• 제14권5호
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• pp.603-610
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• 1993

The crystal structure of dehydrated $Ag_{5.6}K_{6.4}-A$, zeolite A ion-exchanged with $K^+\;and\;Ag^+$ as indicated and dehydrated at 360$^{\circ}$C, has been determined by single-crystal X-ray diffraction techniques. Also determined were the structures of the products of the reactions of this zeolite with 0.1 Torr of Cs vapor at 250$^{\circ}$C for 48 h and 72 h, and with 0.1 Torr of Rb vapor at 250$^{\circ}$C for 24 h. The structures were solved and refined in the cubic space group Pm3m at 21(l)$^{\circ}$C (a= 12.255(l) ${\AA}$ , 12.367(l) ${\AA}$, 12.350(l) ${\AA}$, and 12.263(l) ${\AA}$, respectively). Dehydrated $Ag_{5.6}K_{6.4}$-A was refined to the final error indices $R_1= 0.044\;and\;R_2=0.037$ with 202 reflections for which I>3${\sigma}$(I). The crystal structures of the reaction products were refined to $R_1=0.087\;and\;R_2= 0.089$ with 157 reflections, $R_1=0.080\;and\;R_2= 0.087$ with 161 reflections, and $R_1= 0.071\;and\;R_2=0.061$ with 88 reflections, respectively. In the structure of $Ag_{5.6}K_{6.4}-A,\;K^+$ ions block all 8-oxygen rings, and one reduced Ag atom is found per sodalite cavity. Also, ca. 4.6 $Ag^+ ions\;and\;3.4 K^+ ions$ are found at 6-ring sites in the large cavity. The crystal structures of the reaction products show that all $K^+$ and $Ag^+$ ions have been reduced, and that all K^+$ atoms have left the zeolite. Cs or Rb species are found at three different crystallographic sites: 3.0 $Cs^+\;or\;3.0Rb^+$ ions per unit cell occupy 8-ring centers, ca. 8.0 $Cs^+ ions\;or\;5.7 Rb^+$ ions, are found on threefold axes opposite 6-rings deep in the large cavity, and ca. 2.5 $Cs^+\;or\;2.3 Rb^+ ions are found on threefold axes in the sodalite unit. Also, 1 $Rb^+$ ion lies opposite a 4-ring. Silver atoms, corresponding to 75% or 40% occupancy of hexasilver clusters stabilized by coordination to $Cs^+\;or\;Rb^+$ ions, are found at the centers of the large cavities. In the crystal structures of dehydrated Ag_{5.6}K_{6.4}-A$ reacted with Cs vapor, excess Cs atoms are absorbed and these form (locally) cationic clusters such as $(Cs_4)3^+\;and\;(Cs_6)4^+$.

• Bulletin of the Korean Chemical Society
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• 제24권6호
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• pp.723-727
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• 2003

Recently the ab initio effective valence shell Hamiltonian method $H^v$ has been extended to treat spin-orbit coupling in atoms or molecules. The quasidegenerate many-body perturbation theory based $H^v$ method has an advantage of determining the spin-orbit coupling energies of all valence states for both the neutral species and its ions with a similar accuracy from a single computation of the effective spin-orbit coupling operator. The new spin-orbit $H^v$ method is applied to calculating the fine structure splittings of the valence states of SiH, $SiH^+$, and $SiH^{2+}$ not only to assess the accuracy of the method but also to investigate the spin-orbit interaction of highly excited states of SiH species. The computed spin-orbit splittings for ground states are in good agreement with experiment and the few available ab initio computations. The ordering of fine structure levels of the bound and quasi-bound spin-orbit coupled valence states of SiH and its ions, for which neither experiment nor theory is available, is predicted.

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2603-2608
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• 2012

A novel mononuclear supramolecule of copper(II) has been synthesized with Ippyt ligand (Ippyt=3-(4'-imidazole phenyl)-5-(pyrid-2''-yl)-1,2,4-triazole) (1). Compound 1, namely [$Cu(Ippyt)_2(H_2O)_2$], has been characterized by single-crystal X-ray diffraction, IR spectrum, elemental analysis and thermogravimetric analysis. Structure determination reveals that the elongated-octahedral geometry is formed in the vicinity of the copper (II) atom being coordinated by four nitrogen atoms from two Ippyt ligands occupying the equatorial position and two oxygen atoms from two coordinated water molecules in the axial position, which together form the $N_4O_2$ donor set. Hydrogen bonding interactions between nitrogen and oxygen atoms result in the set up of a supramolecular network architecture. Biological properties including antibacterial activity and superoxide dismutase (SOD) mimetic activity of compound 1 have been investigated by agar diffusion method and the modified Marklund method, respectively. The results indicate that compound 1 exhibits a stronger antibacterial efficiency than the parent ligand and it also has a certain radical-scavenging activity.

• 대한화학회지
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• 제29권4호
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• pp.348-355
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• 1985

본 연구에서는 백금착물, $[PtA_2Cl_2]\;(A:\;NH_3$ 및 en과 그 유도체)형의 항암성 메카니즘의 첫 단계에서 두 개의 염소 원자가 분리된다고 가정하고 이 분리의 용이성을 Extended Huckel법에 의해서 양자화학적 양을 조사하였다. 백금착물의 전체에너지가 높을수록, Pt의 d-전자의 전이가 용이할수록, Cl의 net charge의 (-)값이 클수록, Pt-Cl사이의 Cl의 이탈이 용이하여진다고 생각된다. 그리고 실험적으로 항암성이 있다고 보고된 Pt(II)착물에서 Cl의 이탈용이도가 컸다. 따라서 $PtLCl_2$형 항암제(L:NH$_3$, en)$에서 항암작용의 첫 단계로서 Cl의 해리과정이 중요하다고 예측된다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권9호
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• pp.371-377
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• 2003

We perform the physical analysis such that Si/W composition ratios and phosphorus distribution change in the W/S $i_{x}$ thin films according to phosphorus concentration of polysilicon and W $F_{6}$ flow rate for the formation of WS $i_{x}$ polycide used as a gate electrode. We report that these physical characteristics have effects on the contact resistance between word line and bit line in DRAM devices. RBS measurements show that for the samples having phosphorus concentrations of 4.75 and 6.0${\times}$10$^{2-}$ atoms/㎤ in polysilicon, by applying W $F_{6}$ flow rates decreases from 4.5 to 3.5 sccm, Si/W composition ratio has increases to 2.05∼2.24 and 2.01∼2.19, respectively. SIMS analysis give that phosphorus concentration of polysilicon for both samples have decreases after annealing, but phosphorus concentration of WS $i_{x}$ thin film has increases by applying W $F_{6}$ flow rates decreases from 4.5 to 3.5 sccm. The contact resistance between word line and bit line in the sample with phosphorus concentration of 6.0 ${\times}$ 10$^{20}$ atoms/㎤ in polysilicon is lower than the sample with 4.75 ${\times}$ 10$^{20}$ atoms/㎤ After applying W $F_{6}$ flow rates decreases from 4.5 to 3.5 sccm, the contact resistance has been improved dramatically from 10.1 to 2.3 $\mu$ $\Omega$-$\textrm{cm}^2$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1993년도 춘계학술대회 논문집
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• pp.134-136
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• 1993

Using the extended H$\ddot{u}$ckel molecular orbital method in connection with the tight binding model, we have studied electronic structure and related properties of superconducting $YBa_2Cu_3O_{7-x}$ crystals in which O-atoms in regular sites were selectively replaced with F atoms. The calculations are based on the crystal structure of Y-Ba-Cu-O obtained by Beno et al.. We use atomic coordinates that refer to the unrelaxed Y-Ba-Cu-O system. In analogy to the isomerism problem with molecules, we discuss all possible combinations of F-substitutions in O-sites with one, two, and four F atoms. The calculations are carried out within charged clusters model for the analogues of the YBa-free copperoxide. Our results suggest that the electronic structure of the symmetrically F-substituted or F-added compound is closer to that of the oxygen-deficient superconducting compound than that obtained from unsymmetrical substitution. This applies in particular if O is replaced with in an O(1) site. This suggests that superconductivity is very sensitive to the oxygen content of the $CuO_2$ layers.

• Bulletin of the Korean Chemical Society
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• 제6권4호
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• pp.202-206
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• 1985

The crystal structure of The crystal structure of $Ag^+$-Exchanged Zeolite A, $Ag_{4.6}Na_{7.4}-A$, dehydrated, treated with $H_2$, and evacuated, all at $350^{\circ}C$, has been determined by single crystal x-ray diffraction methods in the cubic space group Pm3m at $24(1)^{\circ}C;$ a = $12.208(2)\AA.$ The structure was refined to the final error indices R1 = 0.088 and R2 (weighted) = 0.069 using 194 independent reflections for which II_0$ > $3{\sigma}(I_0)$. On threefold axes near the centers of 6-oxygen rings, $7.4 Na^+$ ions and $0.6 Ag^+$ ions are found. Two non-equivalent 8-ring $Ag^+$ ions are found off the 8-ring planes, each containing about $0.6 Ag^+$ ions. Three non-equivalent Ag atom positions are found in the large cavity, each containing about 0.6 Ag atoms. This crystallographic analysis may be interpreted to indicate that $0.6 (Ag_6)^{3+}$ clusters are present in each large cavity. This cluster may be viewed as a nearly linear trisilver molecule $(Ag_3)^0$ (bond lengths, 2.92 and 2.94 $\AA;$ angle, $153^{\circ})$ stabilized by the coordination of each atom to a Ag^+$ ion at 3.30, 3.33, and 3.43 $\AA$, respectively. In addition, one of the silver atoms approaches all of the 0(1) oxygens of a 4-ring at $2.76\AA.$ Altogether $7.4 Na^+$ ions, $1.8 Ag^+$ ions, and 1.8 Ag atoms are located per unit cell. The remaining $1.0 Ag^+$ ion has been reduced and has migrated out of the zeolite framework to form silver crystallites on the surface of the zeolite single crystal.