• Bulletin of the Korean Chemical Society
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• 제20권8호
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• pp.943-947
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• 1999

Ligand field analyses for tris(biuret)chromium(III) chloride and hexaureachromium(III) bromide were performed and compared to understand the ligand field properties of both ligands. The optimized eσO and eπO values indicate that coordinated oxygen atom in biuret ligand is a moderate s- and strong p-donor, while that in urea ligand is a weak σ- and moderate π-donor. The electronic structures of those two complexes are quite different and they were well accounted by inclusion of an anisotropic p bonding.

• Bulletin of the Korean Chemical Society
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• 제19권5호
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• pp.575-579
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• 1998

The 77 K luminescence and excitation spectra, and 298 K infrared and absorption spectra of $cis-{\Alpha}-[Cr(trien)Cl_2]Cl{\cdot}H_2O$ (trien=triethylenetetramine) have been measured. Ligand field electronic transitions due to spin-allowed and spin-forbidden are assigned. The zero-phonon line in the excitation spectrum splits into two components by $198\; cm^{-1}$, and the large $^2E_g$ splitting can be reproduced by the modern ligand field theory. It is confirmed that nitrogen atoms of the trien ligand have a strong σ-donor character, but chloride ligand has weak σ- and π -donor properties toward chromium(III) ion.

• Bulletin of the Korean Chemical Society
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• 제28권3호
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• pp.421-426
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• 2007

A linking ligand containing sulfur donor atoms in the terminal thiophene rings, 1,2-bis(thiophen-2-ylmethylene) hydrazine (L), was prepared by Schiff-base condensation. Ligand L reacted with [PdCl2(NCPh)2] to produce a molecular Pd compound [PdL2Cl2] (1). On the other hand, it reacted with AgNO3 and AgClO4 to produce a 2-D network [AgL0.5(NO3)] (2) and a 1-D polymer [AgL]ClO4 (3), respectively, whose structures are based on secondary intermolecular forces such as H-bonding, van der Waals interaction, and π-π stacking. Polymer 2 exhibited photoluminescence at room temperature in the solid state.

• Journal of Photoscience
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• 제11권1호
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• pp.19-23
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• 2004

The sharp-line absorption spectrum of microcrystalline samples of cis-[Cr(cycb)$Cl_2$]Cl (cycb=rac-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) has been measured between 13000 and $16000 cm^{-1}$ at temperatures down to 5K. The 77K emission and excitation spectra, and 298 K infrared and visible absorption spectra have also been measured. The nine electronic bands due to spin-allowed and spin-forbidden transitions were assigned. Using the observed transitions, a ligand field analysis has been performed to probe the ligand field properties of coordinated atoms in the title chromium(III) complex. The zero-phonon line in the sharp-line absorption spectrum splits into two components by $240 cm^{-1}$ , and the $large ^2$$_E{g}$ splitting can be reproduced by the modem ligand field theory. It is confirmed that nitrogen atoms of the macrocyclic cycb ligand have a strong $\sigma$-donor character, but chloride ligand has weak $\sigma$- nd $\pi$-donor properties toward chromium(III) ion.n.

• Journal of Photoscience
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• 제7권3호
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• pp.97-101
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• 2000

The 77 K emission and excitation spectra, and 298 K infrared and absorption spectra of mer-[CrCl(en)(dpt)]ZnCl$_4$(en=1,2-diaminoethane; dpt=1,5,9-triazanonane) have been measured. Ligand field electronic transitions due to spin-allowed and spin-forbidden are assigned. The zero-phonon line in the excitation spectrum splits into two components by 151$cm^{-1}$ /, and large$^2$E$^{g}$ splitting can be reproduced by the modern ligand field theory. It is confirmed that nitrogen atoms of the en and dpt ligands have a strong $\delta$-donor character, but chloride ligand has weak $\delta$-and $\pi$-donor properties toward chromium(III) ion.

• Journal of Photoscience
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• 제7권1호
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• pp.21-26
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• 2000

The photoemission and excitation spectra of cis-[Cr(cyclam)F$_2$]ClO$_4$ (cyclam = 1,4,8,11-tetraazacy-clotetradecane) taken at 77 K are reported. The 298 K mid- and far-infrared spectra are also measured. The vibrational intervals of the electronic ground state are extracted from the far-infrared and emission spectra. The ten electronic bands due to spin-allowed and spin-forbidden transitions are assigned. The zero-phonon line In the excitation spectrum splits into two components by 169 cm$^{1}$, and the large $^2$E$_{g}$ splitting can be reproduced by the ligand field theory. According to the ligand field analysis, we can confirm that nitrogen atoms of the cyclam ligand have a strong c-donor character, and fluoride ligand also has strong $\sigma$- and $\pi$-donor properties toward chromium(III) ion.n.

• Journal of Photoscience
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• 제4권3호
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• pp.121-125
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• 1997

The 77 K emission and excitation, and room-temperature visible spectra of cis[Cr(cyclam)Br$_2$]Br (cyclam=1,4,8,11-tetraazacyclotetradecane) are reported. The mid- and far-infrared spectra at room-temperature are also measured. The vibrational intervals of the electronic ground state are extracted from the far-infrared and emission spectra. The ten electronic bands due to spin-allowed and spin-forbidden transitions are assigned. It is found that nitrogen atoms of the cyclam ligand have strong $\sigma$-donor characters, but bromide ligand has weak $\sigma$- and $\pi$-donor properties toward chromium(III) ion. The zerophonon line in the excitation spectrum splits into two components by 172 cm$^{2-}$, and the large $^2E_g$ splitting can be reproduced by the ligand field theory.

• Bulletin of the Korean Chemical Society
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• 제24권3호
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• pp.384-388
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• 2003

The emission and excitation spectra of $cis-[Cr(cyclam)(NCS)_2]NCS$ (cyclam = 1,4,8,11-tetraazacyclotetradecane) taken at 77 K are reported. The infrared and visible spectra at room temperature are also measured. The vibrational intervals due to the electronic ground state are extracted from the far-infrared and emission spectra. The ten pure electronic origins due to spin-allowed and spin-forbidden transitions are assigned by analyzing the absorption and excitation spectra. Using the observed transitions, a ligand field analysis has been performed to determine the bonding properties of the coordinated ligands in the title chromium(Ⅲ) complex. According to the results, it is found that nitrogen atoms of the cyclam ligand have a strong σ-donor character, while the NCS ligand has medium σ- and π-donor properties toward chromium(Ⅲ) ion.

• Bulletin of the Korean Chemical Society
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• 제26권6호
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• pp.903-908
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• 2005

The sharp-line absorption and emission spectra of $(H_{13}O_6)${$trans-[Cr(Me_2tn)_2Br_2]$}$_2Br_2(ClO_4)\;(Me_2$tn = 2,2-dimethyl-1,3-diaminopropane) have been measured between 13000 $cm^{-1}$ and 16000 $cm^{-1}$ at 5 K. The 298 K infrared and visible absorption spectra have also been measured. The nine electronic bands due to spin-allowed and spin-forbidden transitions were assigned. Using observed transitions, a ligand field analysis has been performed to probe the ligand field properties of coordinated atoms in the title chromium(III) complex ion. The zero-phonon line in the sharp-line absorption spectrum splits into two components by 286 $cm^{-1}$, and the large $^2E_g$ splitting can be reproduced by the modern ligand field theory. It is confirmed that nitrogen atoms of the Me2tn ligand have a strong $\sigma$-donor character, but the bromide has weak $\sigma$- and $\pi$-donor properties toward chromium(III) ion.

• 대한화학회지
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• 제55권4호
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• pp.590-593
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• 2011

새로운 유기주석(IV) 착물을 $Bu_2SnCl_2$과 N, O 및 S 주개 리간드인 5-(p-dimethylaminobenzylidene)rodanine(HL)로 부터 제조하였다. 염기 존재 하에 리간드는 탈양성자화되며, SnBuCl2L의 분자식을 갖는 착물이 형성되었다. 이 착물은 IR, $^1H$ NMR, $^{119}Sn$ NMR 및 원소분석을 통하여 전반적으로 특성을 분석하였다. 분광학적인 데이터로부터 리간드는 산소원자를 통하여 주석에 배위됨을 알았으며, 배위수가 4임을 용액에서 $^{119}Sn$ NMR 데이터에 의해 결정하였다.