• Bulletin of the Korean Chemical Society
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• v.25 no.7
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• pp.977-982
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• 2004

The reaction of $cis-[Cr([14]-decane)(OH_2)_2]^+$ ([14]-decane = rac-5,5,7,12,12,14-hexamethyl-1,4,8,11-teraazacyclotetradecane) with auxiliary ligands {$L_a$ = benzoate(bz) or chlorobenzoate(cbz)} leads to a new compound $[Cr([14]-decane)(bz)_2]ClO_4$ or $[Cr([14]-decane)(cbz)_2]ClO_4$. These complexes have been characterized by a combination of elemental analysis, conductivity, IR and Vis spectroscopy, mass spectrometry, and X-ray crystallography. The crystal structure of $[Cr([14]-decane)(cbz)_2]^+$ was determined. The complex shows a distorted octahedral coordination environment with the macrocycle adopting a folded cis-V conformation. The angle $N_{axial}-Cr-N_{axial}$ deviates by $14.5^{\circ}$ from the ideal value of $180^{\circ}$for a perfect octahedron. The bond angle cis-O-Cr-O between the Cr(III) ion and the two carboxylate oxygen atoms of the monodentate p-chlorobenzoate ligands is close to 90$^{\circ}$. The FAB mass spectra of the $cis-[Cr([14]-decane)(La)_2]ClO_4$ display peaks due to the molecular ions $[Cr([14]-decane)(bz)_2-H]^\;,\;[Cr([14]-decane)(cbz)_2-2H]^$ at m/z 578, 646, respectively.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1675-1680
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• 2012

Three new cyanide-bridged $Cr^{III}Mn^{II}$ binuclear complexes, $[Mn(phen)_2Cl][Cr(bpmb)(CN)_2]{\cdot}H_2O$ ($\mathbf{1}$) (phen = 1,10-phenanthroline, $bpdmb^{2-}$ = 1,2-bis(pyridine-2-carboxamido)-4-methyl-benzenate), $[Mn(phen)_2Cl][Cr(bpmb)-(CN)_2]{\cdot}H_2O$ ($\mathbf{2}$) ($bpdmb^{2-}$ = 1,2-bis(pyridine-2-carboxamido)-4,5-dimethyl-benzenate), and $[Mn(phen)_2Cl]-[Cr(bpClb)(CN)_2]{\cdot}CH_3OH{\cdot}H_2O$ ($\mathbf{3}$) ($bpClb^{2-}$ = 1,2-bis(pyridine-2-carboxamido)-4-chloro-benzenate) were obtained based on $Mn(phen)_2Cl_2$ and a series of dicyanidechromate(III) building blocks. Single crystal X-ray diffraction analysis shows the structures of the three complexes are dimeric type with two different metal centers linked by a cyanide group from corresponding dicyanidechromate(III) building block. Magnetic investigations indicate the existence of relatively weak antiferromagnetic coupling between Cr(III) and Mn(II) ions with best-fit constants $J_{CrMn}=-2.78(5)cm^{-1}$ for $\mathbf{1}$, $J_{CrMn}=-3.02(2)cm^{-1}$ for $\mathbf{2}$ and $J_{CrMn}=-2.27(3)cm^{-1}$ for $\mathbf{3}$ based on the spin exchange Hamiltonian = $-2J_{CrMn}\hat{S}_{Cr}\hat{S}_{Mn}$. The magneto-structural correlation of cyanide-bridged $Cr^{III}Mn^{II}$ complexes has been discussed at last.

• Journal of the Korean Chemical Society
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• v.23 no.4
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• pp.198-205
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• 1979

A valence bond method of calculation of the dipole moments for octahedral $(M(III)0_3S_3)$ type complexes are developed, using $d^2sp^3 $hybrid orbitals of the central metal ions and the single basis set orbital of ligands. (M (III) =V (III), Cr (III), Mn (III), Fe (III), Co (III), Ru (III), Rh (III) and OS (III)). In this method the mixing coefficient of the valence basis sets for the central metal ion with the appropriate ligand orbitals is not required to be the same, differently from the molecular orbital method. The valence bond method is much more easier to calculate the dipole moments for octahedral complexes than the approximate molecular orbital method and the calculated results are also in the range of the experimental vaues.

• Bulletin of the Korean Chemical Society
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• v.26 no.7
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• pp.1044-1050
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• 2005

The reaction of cis-[Cr([14]-decane)($OH_2)_2]^+$ ([14]-decane = rac-5,5,7,12,12,14-hexamethyl-1,4,8,11-teraazacyclotetradecane) with auxiliary ligands {$L_a$ = isothiocyanate ($NCS^-$), azide ($N3^-$) or chloroacetate(caa)} leads to a new cis-[Cr([14]-decane)($NCS)_2]ClO_4{\cdot}H_2O$ (1), cis-[Cr([14]-decane)($N_3)_2]ClO_4$ (2) or cis-[Cr([14]-decane)($caa)_2]ClO_4$ (3). These complexes have been characterized by a combination of elemental analysis, conductivity, IR and Vis spectroscopy, mass spectrometry, and X-ray crystallography. Analysis of the crystal structure of cis-[Cr([14]-decane)($NCS)_2]ClO_4{\cdot}H_2O$ reveals that central chromium(III) has a distorted octahedral coordination environment and two $NCS^-$anions are bonded to the chromium(III) ion via the Ndonor atom in the cis positions. The angle $N_{axial}-Cr-N_{axial}$ deviates by 13$^{\circ}$ from the ideal value of 180$^{\circ}$ for a perfect octahedron. The bond angle N-Cr-N between the Cr(III) ion and the two nitrogen atoms of the isothiocyanate ligands is close to 90$^{\circ}$. The bond lengths of Cr-N between the chromium and $NCS^-$groups are 1.964(5) and 2.000(5) $\AA$. They are shorter than those between chromium and nitrogen atoms of the macrocycle. The IR spectra of 1, 2 and 3 display bands at 2073, 1344 and 1684 $cm^{-1}$ attributed to the $NCS^-$, ${N_3}^-$ and caa groups stretching vibrations, respectively.

• Journal of the Korean institute of surface engineering
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• v.21 no.4
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• pp.160-167
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• 1988

Electrochemical behaviors od chromium electrodeposition from 0.05M chromium (III) sulface complexes in aqueous solutions using sodium formate-glycine mixtures as a complexing agent were studied. In the cathodic current-potential cures, it is found that the intial limiting current of Cr(III) is proportional to square root of scan rate and activiation energy from Arrhenius plot is s obtained 3.05Kcal/mol. From this results, the reaction is considered, Cr3++e longrightarrow Cr2+, which is controlled diffusion of Cr (III). It is also found that the chromium is deposited when the potential reaches to hydrogen evolution potential. Effects of NaSCN as a catalyser in the electrolyte were investigated NCS- anion seems to react strongly by specific absorption at the inner HelmholtZ layer, so that, it is considered to suppress the electrodeposition reaction reaction for chromjum, and also it is considered multipe-bridge such as Cr(III)-NCS---M(M;cathode).

• Bulletin of the Korean Chemical Society
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• v.26 no.9
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• pp.1395-1402
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• 2005

The reaction of cis-[Cr([14]-decane)$(OH)_2]^+$ ([14]-decane = rac-5,5,7,12,12,14-hexamethyl-1,4,8,11-teraazacyclotetradecane) with auxiliary ligands {$L_a$ = acetylacetonate (acac), oxalate (ox) or malonate (mal)} leads to a new cis-[Cr([14]-decane)(acac)]$(ClO_4)_2{\cdot}(1/2)H_2O\;(1),\;cis-[Cr([14]-decane)(ox)]ClO_4{\cdot}(1/2)H_2O\;(2)\;or\;cis-[Cr([14]-decane)(mal)]ClO_4{\cdot}(1/4)H_2O\;(3)$. These complexes have been characterized by a combination of elemental analysis, conductivity, IR and Vis spectroscopy, mass spectrometry, and X-ray crystallography. Analysis of the crystal structure of cis-[Cr([14]-decane)(acac)]$(ClO_4)_2{\cdot}(1/2)H_2O$ reveals that central chromium(III) has a distorted octahedral coordination environment and two acetylacetonate-oxygen atoms are bonded to the chromium(III) ion in the cis positions. The angle $N_{axial}-Cr-N_{axial}$ deviates by $11^{\circ}$ from the ideal value of $180^{\circ}$ for a perfect octahedron. The bond angle O-Cr-O between the chromium(III) ion and the two acetylacetonate-oxygen atoms is close to $90^{\circ}$. The bond lengths of Cr-O between the chromium and the acetylacetonate-oxygen atoms are 1.950(3) and 1.954(2) $\AA$. They are shorter than those between chromium and nitrogen atoms of the macrocycle. The IR spectra of 1, 2 and 3 display bands at 1560 {ν (C=O)}, 1710 {${\nu}_{as}$(OCO)} and 1660 $cm^{-1}$ {${\nu}_{as}$(OCO)} attributed to the acac, ox and mal auxiliary ligands stretching vibrations, respectively.

• Bulletin of the Korean Chemical Society
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• v.27 no.5
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• pp.687-693
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• 2006

Chromium(III) complexes, cis-[Cr([14]-decane)$(HOC _6H _4COO) _2$]$ClO _4$ I and cis-[Cr([14]-decane)(OH) $(OC _6H _4NO _2)$]$ClO _4{\cdot}H _2O$ II ([14]-decane = rac-5,5,7,12,12,14-hexamethyl-1,4,8,11-teraazacyclotetradecane) are synthesized and structurally characterized by a combination of elemental analysis, conductivity, IR and VIS spectroscopy, and X-ray crystallography. The complexes crystallizes in the monoclinic space groups, $C2 _1$/a in I and $P2 _1$/n in II. Analysis of the crystal structure of complex I reveals that central chromium(III) ion has a distorted octahedral coordination environment and two hydrogensalicylato ligands are unidentate to the chromium(III) ion via the carboxyl groups in the cis-position. For monomeric complex I the hydrogensalicylato coordination geometry is as follows: Cr-O(average) = 1.984(3) $\AA$;Cr-N range = 2.105(3)-2.141(4) $\AA$;C(24)-O(4) = 1.286(5) $\AA$;N(2)-Cr-N(4) (equatorial position) = 96.97(15)${^{\circ}}$; N(1)-Cr-N(3) (axial position) = 168.27(15)${^{\circ}}$; O(1)-Cr-O(4) = 85.70(13)${^{\circ}}$. The crystal structure of II has indicated that chromium(III) ion is six-coordinated by four secondary amines of the macrocycle, hydroxide anion and nitrophenolate anion.

• Journal of Environmental Science International
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• v.3 no.4
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• pp.439-443
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• 1994

In aqueous acid solution ${[Cr(CN)_6]}^{3-}$ aquates via a series of stepwise stereospecific reactions to give ${[Cr{(H_2O)}_6]}^{3+}$as the final product.Some of the intermediate cyanoaquo complexes in the sequence have been isolated.These complexes aquate by both acid independent and acid denpendent pathways, the latter involving protonation of the cyano ligands followed by aquation of the singly protonated species. The kinetic data for the aquation of {[CrCN{(H_2O)}_5]}^{2+}$ are consistent with the transition state structure ${[{(H_2O)}_4Cr(CN)-OH-Cr{(H_2O)}_5]}^{3+}$. Addition of $Cr^{2+}$ to solutions of cyanocobalt(III) complexes produces the metastable intermediate${[CrNC{(H_2O)}_5]}^{2+}$ This isomerizes to in a $Cr^{2+}$-catalyzed reaction which occurs by a ligand-bridged electron-change mechnism. From acid catalysis on these aquation reactions, it product HCN. Especially, $HSO_3$-ions do the role of catalyst in the formation of HCN from $CrCN^{3-}$

• Journal of the Korean Chemical Society
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• v.25 no.4
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• pp.270-274
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• 1981

Al(III) and Cr(III) were determined selectively by colorimetry of Bismark Brown R {4,4'[(4-methyl-1,3-phenylene)bis(azo)]-bis(6-methyl-1,3-benzenediamine) dihydrochloride} in the presence of the various cations and anions without the using of any masking agents, but tartrate and citrate ions were interfered. The ligand of Bismark Brown R and complexes of Al(III) and Cr(III) were shown the maximum absorbance at the same wavelength together and both metallic ion were interfered to determine each other, but Al(III) were able to determine after oxidation of Cr(III) to Cr(VI).

• Bulletin of the Korean Chemical Society
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• v.14 no.2
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• pp.179-183
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• 1993

Template condensation of ${\alpha}$-diketones such as 2,3-butanedione or benzil with diaminoalkanes such as 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, 1,8-diaminooctane or 1,12-diaminododecane in the presence of Cr(III) results in the formation of complexes of the type $[CrI,X_2]X$ (where L = tetraazamacrocycle having 12 to 32-membered ring and $X={NO_3}^- or Cl^-).$ The complexes have been characterized by elemental analyses, magnetic measurements and IR and diffuse reflectance spectra.