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1.
Xiao‐Ping Shen Ai‐Hua Yuan Qiang‐Jin Wu Zi‐Xiang Huang Zheng Xu Yun‐Peng Yu 《中国化学》2001,19(6):627-629
From the reaction of K3[Cr(CN)6] and [NiL](CIO4)2 (L= 1,8‐di(hydroxyethyl)‐l, 3, 6, 8, 10, 13‐hexaazacyclotetradecane), an infinite stair‐like layered assembly [NiL]3 [Cr‐(CN)6]2‐6.5H2O is obtained, in which each hexacyanochromate(III) ion connects three nickel(II) ions using three cis Of groups and the bridging cyanide ligands coordinate to the nickel ion in a trans fashion forming trans‐NiL(N°C)2 moieties. 相似文献
2.
S. Ganguli S. Das M. Bhattacharya 《Journal of Radioanalytical and Nuclear Chemistry》1998,232(1-2):229-231
A simple method to prepare57Fe enriched K4[Fe(CN)6] and K3[Fe(CN)6] is described. The yields of the products are much better than those reported in the literature so far. The enrichment is essential for57Fe Mössbauer investigation in a variety of Prussiate type complexes and other inorganic compounds which are conveniently prepared from K4[Fe(CN)6] and K3[Fe(CN)6]. K4[Fe(CN)6] was obtained by reacting freshly prepared Fe(OH)3 with glacial acetic acid and treating with iron acetate in boiling aqueous solution of KCN. The novel feature of the procedure to obtain K3[Fe(CN)6] is that the oxidation of K4[Fe(CN)6] has been carried out in the solid state by passing chlorine gas over the powdered specimen. K3[Fe(CN)6] was crystallised from alkaline solution of this oxidised powder. The compounds were characterised by Mössbauer spectroscopy. 相似文献
3.
Trigonal Crystallizing Metal(II) Hexacyanoferrates(II) M2II[Fe(CN)6] According to X-ray powder diagrams, Ca2[Fe(CN)6], Cd2[Fe(CN)6], Zn2[Fe(CN)6] · 2 H2O, Pb2[Fe(CN)6] and the firstly described compounds Zn2[Fe(CN)6] · 2 NH3 and Sn2[Fe(CN)6] crystallize trigonal containing one formula unit in the unit cell. Ca2[Fe(CN)6] and Cd2[Fe(CN)6] are belonging to the space group D—P3 1m, the other compounds to D—P3 m1. The latters are described as coordination polymers with a coordination number 4 for Zn and 3 for Sn and Pb, respectively. 相似文献
4.
A. D. Kirk 《Theoretical chemistry accounts》1971,20(2):113-118
The self-quenching of chromium phosphorescence in K3[CrxCo1-x(CN)6] mixed crystals has been studied in the range of very high chromium concentration and a minimum in emission quantum yield has been found at about 80% Cr. Comparison of the Cr emission intensities from K3[Cr(CN)6] doped with 1% of various impurities suggests that the impurity quenching observed in the range 90 to 100% Cr may be a result of the site asymmetry introduced by the impurity. It is suggested that at least two mechanisms of self-quenching are operative in this concentration range and the nature of these is discussed in relationship to present theories of radiationless transitions.
Dedicated to the memory of Professor Hans-Ludwig Schläfer. 相似文献
Zusammenfassung Die Eigenlöschung der Cr(III)-Phosphoreszenz wurde in K3[CrxCo1-x(CN)6]-Mischkristallen im Bereich hoher Cr-Konzentrationen untersucht. Die Quantenausbeuten der Emission zeigten ein Minimum bei etwa 80% Cr. Ein Vergleich der Lumineszenzintensitäten von K3[Cr(CN)6] mit 1% verschiedener Zusätze läßt vermuten, daß die im Bereich von 90–100 % Cr beobachtete Löschung von einer durch die Verunreinigung verursachten Gitterstörung herrührt. — Es wird angenommen, daß in dem untersuchten Konzentrationsbereich mindestens zwei Mechanismen der Eigenlöschung wirksam sind, die anhand der gegenwärtigen Theorien der strahlungslosen Übergänge diskutiert werden.
Résumé L'auto étouffement du chrome phosphorescent à partir de K3[CrxCo1-x(CN)6], cristaux mélanges avait été étudié dans la région de très haute concentration de chrome et un minimum d'émission quantique, il en résultait environ 80% Cr. Comparé à l'intensité d'émission de chrome à partir de K3[Cr(CN)6] contaminé par 1% de diverses impuretés indique que l'étouffement d'impureté qui était observé dans la région de 90 à 100% Cr, peut être le résultat de l'emplacement assimétrique introduit par l'impureté. — II a été suggéré qu'au moins deux mécanismes d'auto étouffement sont à l'oeuvre dans cette région de concentration et leur nature décrite en relation avec les présentes théories de transitions sans radiation.
Dedicated to the memory of Professor Hans-Ludwig Schläfer. 相似文献
5.
Mária Hvastijová Jiří Kohout Helmut Köhler 《Monatshefte für Chemie / Chemical Monthly》1992,123(6-7):493-500
Summary New dicyanamide complexes of the typeM[N(CN)2]2
L
2 (M=Cu or Ni;L=2-, 3-, 4-aminopyridine, 2-amino-5-nitropyridine) and Co[N(CN)2]2 (2-amino-5-nitropyridine)2 were prepared and studied by spectroscopic methods as well as by room-temperature magnetic moments. The results show that the Cu(II) complexes have elongated pseudooctahedral structures while the Ni(II) and Co(II) complexes are octahedral. In most cases the N(CN)2 groups are in bridging function and through their cyanide nitrogens, or-more rarely-amide and cyanide nitrogens connect the basic structure units into polymeric conglomerates. In the Cu(II) systems exchange coupling is seen from the eff value or ESR spectrum.
Professor Viktor Gutmann zum 70. Geburtstag gewidmet 相似文献
6.
G. V. Markin Yu. A. Shevelev G. A. Domrachev G. K. Fukin E. V. Baranov M. A. Lopatin V. A. Kuropatov A. I. Kirillov A. S. Shavyrin Yu. A. Kurskii 《Russian Chemical Bulletin》2008,57(9):1970-1974
Radical-ion salts bis(biphenyl)chromium(i) 1,4-di(2-cyanoisopropyl)-1,4-dihydrofulleride [(Ph2)2Cr]+·[1,4-(CMe2CN)2C60]−· and bis(biphenyl)chromium(i) 1-(2-cyanoisopropyl)-1,2-dihydrofulleride [(Ph2)2Cr]+·[1,2-(CMe2CN)(H)C60]−·, the salt bis(biphenyl)chromium(i) (2-cyanoisopropyl)fulleride [(Ph2)2Cr]+·[(CMe2CN)C60]−, and neutral 1-(2-cyanoisopropyl)-1,2-dihydrofullerene 1,2-(CMe2CN)(H)C60 have been synthesized for the first time. The compounds [(Ph2)2Cr]+·[1,4-(CMe2CN)2C60]−· and [(Ph2)2Cr]+·[1,2-(CMe2CN)(H)C60]−· decompose in THF to form [(Ph2)2Cr]+·[(CMe2CN)C60]−, whose protonation affords 1,2-(CMe2CN)(H)C60. 1,4-Di(2-cyanoisopropyl)-1,4-dihydrofullerene 1,4-(CMe2CN)2C60 and 1,2-(CMe2CN)(H)C60 are stable in vacuo up to 513 K.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1935–1939, September, 2008. 相似文献
7.
Ram C. Maurya Rajesh Shukla Raj K. Shukla Nalamas Anandam Shri K. Srivastava Mannar R. Maurya 《Transition Metal Chemistry》1987,12(3):203-205
Summary New compounds of chromium(I), from the interaction of potassium pentacyanonitrosylchromate(I) monohydrate, K3[CrNO(CN)5]·H2O with 2-, 3- and 4-aminopyridines, pyridine-2-hydrazide, 2(2-aminoethyl)pyridine and 4(2-aminoethyl)pyridine are described. The products possess the empirical formula, CrNO(CN)2(L)2, for which a cyano-bridged polymeric structure is proposed. Chromium(I) has a low-spin-d5 configuration in these complexes. 相似文献
8.
Egorova T. V. Voitenko Z. V. Zatovsky I. V. Wolf J. G. 《Russian Journal of Coordination Chemistry》2002,28(8):557-559
The interaction of K3[Fe(CN)6] and K2[Ni(CN)4] with cyanine dyes of the tetrazoloisoindole series in nonaqueous media was established. This process involved both ion-exchange reactions and several other interactions. Four compounds were isolated and studied by electronic absorption spectroscopy, IR spectro-scopy, and mass spectrometry. 相似文献
9.
Ahmed A. Abdel-Khalek Alaa E. -D. M. Abdel-Hady Mohamed F. El-Shahat 《Transition Metal Chemistry》1994,19(2):169-172
Summary A kinetic study of the oxidation of chromium(III) by N-bromosuccinimide (NBS) in aqueous solutions and H2O-MeOH solvent mixtures were performed. The kinetics in aqueous solutions obeyed the rate law: d[CrVI]/dt = {k
4
K
h
K
2[NBS][CrIII]T}/[+]{1 + K
h/[H+] + (K
1 + K
h
K
2/[H+][NBS])} where K
h, K
1 and K
2 are the hydrolysis constant of [CrIII(H2O)6]3+, and pre-equilibrium formation constants for the protonated and deprotonated precursor complexes, respectively. An innersphere
mechanism is proposed. An argument based on isokinetic correlations among activation parameters for the oxidation of a series
of cobalt(II) and chromium(III) complexes including [Cr(H2O)6]3+ is presented in support of a common mechanism for these reactions.
Abstracted from the Ph.D. Thesis (Ain Shams University) of A. E.-D. M. Abdel-Hady. 相似文献
10.
《Journal of Coordination Chemistry》2012,65(4):605-617
Reactions of 2-(L-carboxyl-2-hydroxyphenyl)thiazolidine with different chromium(III) salts [CrCl3?·?6H2O, K3[Cr(SCN)6], NH4[Cr(NH3)2(SCN)4]?·?H2O, [Cr(urea)6]Cl3?·?3H2O and [Cr(CH3COO)2H2O]2] under varied reaction conditions afforded many new mixed-ligand chromium(III) complexes. The ligand is a tridentate dibasic NSO donor except for complexes 1 and 4 where two moles of the ligand are present for each molecule of complex, one functioning as a dibasic tridentate (NSO) and the other as a monobasic bidentate (NS) (phenolic OH and carboxylic COOH groups remaining uncoordinated). The complexes have been characterized by elemental analyses, magnetic susceptibilities, molar conductances, molecular weights and spectroscopic (IR, Uv-vis) data. The ligand field parameters and NSH Hamiltonian parameters suggest tetragonal geometries of the complexes. 相似文献
11.
Mössbauer- and IR Spectra from the Addition Compounds of K4[Fe(CN)6] with Antimony Trihalides By the reaction of K4[Fe(CN)6] with SbX3 in the melt (X = Cl, Br) or in SO2 solution (X = F) the addition compounds K4[Fe(CNSbX3)6] (X = F, Cl) and K4[Fe(CNSbX3)4(CN)2] (X = Cl, Br) are formed. The IR spectra of these compounds have been interpreted. The MÖSSBAUER spectra are single lines which exhibit a slight broadening compared with K4[Fe(CN)6] · 3 H2O. The values of the isomer shifts following the order of the LEWIS acid strengths of the SbX3 molecules correspond to a small but significant increase of the s-electron density, which is explained by the increasing influence of the π-acceptor function of the ligands. 相似文献
12.
Structural Relationship of Potassium Hexahydroxoscandate(III), K3[Sc(OH)6] with the Isotypic Hydroxometallates Rb3[Sc(OH)6], K3[Cr(OH)6], and Rb3[Cr(OH)6] Ternary hydroxides M}MIII(OH)6{ with MI ? K, Rb and MIII ? Sc, Cr were obtained in the same way as K3[Cr(OH)6] [1] from alkali metal amides and d-metal nitrates by a comproportionation reaction of amide and nitrate ions in supercritical ammonia to elementary nitrogen and hydroxide ions at 523 K and 3 ≤ p(NH3) ≤ 6 kbar within 1 to 3 months. Their structures were determined by single crystal x-ray methods inclusive the positions of the hydrogen atoms. The ratio of size of r(MI)/r(MIII) is related to the symmetry of these hydroxometallates. Structural relationships between K3[Sc(OH)6] and Rb3[Sc(OH)6], K3(Cr(OH)6], Rb3[Cr(OH)6]) and K4[CdCl6] [4] are discussed. 相似文献
13.
Compounds of the type M3[Fe(CN)6]2XH2O (M = Co(II), Ni(II), Cu(II), and Zn(II)) were prepared and magnetic properties of their powders were investigated by means of EPR spectra, Mössbauer effect and magnetic susceptibility measurements. The temperature dependence of the magnetization for the complexes Co3[Fe(CN)5]2- 10H2O, Ni3[Fe(CN)6]2-10H2O and Cu3[Fe(CN)6]2-4H2O revealed that below the critical temperatures 15, 22 and 20 K respectively, these complexes have zero-field magnetization. The magnetic hysteresis at 10 K for Co(II), Ni(II) and Cu(II) complexes was observed. Mössbauer spectra at 4.2 K for the compounds are discussed. 相似文献
14.
Catherine DeBlase 《Tetrahedron》2010,66(5):1098-529
A methodology for the cyanation of aryl iodides is reported using copper iodide as the catalyst, K4[Fe(CN)6] as the cyanide source, and small quantities of water and tetraethylene glycol as the solvent. Reactions are complete within 30 min of microwave heating at 175 °C. A simple work-up procedure has also been devised. 相似文献
15.
The decomposition of solid K3[Fe(C2O4)3] · 2 H2O and K3[Cr(C2O4)3] · 3 H2O has been studied using TGA and DSC. After dehydration, the chromium compound was found to decompose by the loss of CO in two steps, the loss of CO2 and additional CO, and finally the loss of CO2. The final product appears to be either K3CrO3 or the mixed oxides of chromium and potassium. Kinetic parameters and enthalpy data are presented for these reactions. In the case of K3[Fe(C2O4)3] · 2 H2O, dehydration is followed by the loss of CO2 and CO, CO2 alone, and finally CO. The final product appears to be a basic carbonate of the type K3[FE(O)2(CO3)]. Kinetic and thermal data are presented for most of these decomposition reactions. 相似文献
16.
The palladium(II) and platin(II) 1, 1‐dicyanoethylene‐2, 2‐dithiolates [(L–L)M{S2C=C(CN)2}] (M = Pd: L–L = dppm, dppe, dcpe, dpmb; M = Pt: dppe, dcpe, dpmb) were prepared either from[(L–L)MCl2] and K2[S2C=C(CN)2] or from [(PPh3)2M{S2C=C(CN)2}] and the bisphosphane. Moreover, [(dppe)Pt{S2C=C(CN)2}]was obtained from [(1, 5‐C8H12)Pt{S2C=C(CN)2}] and dppeby ligand exchange. The 1, 1‐dicyanoethylene‐2, 2‐diselenolates[(dppe)M{Se2C=C(CN)2}] (M = Pd, Pt) were prepared from[(dppe)MCl2] and K2[Se2C=C(CN)2]. The oxidation potentials of the square‐planar palladium and platinum complexes were determined by cyclic voltammetry. The reaction of [(dcpe)Pd(S2C=O)] with TCNE led to a ligand fragment exchange and gave the 1, 1‐dicyanoethylene‐2, 2‐dithiolate [(dcpe)Pd{S2C=C(CN)2}] in good yield. 相似文献
17.
Summary A new series of spin-paired hexa-coordinated mixed-ligand cyanonitrosyl complexes of chromium (having {CrNO}5 electron configuration(1)) of the type [Cr(NO)(CN)2(L)2(H2O)] (where L=4-methyl-2-pyrazoline-5-one(1), 2,3-dimethyl-1-phenyl-3-pyrazoline-5-one(2) or 4-dimethylamino-2,3-dimethyl-1-phenyl-3-pyrazoline-5-one(3) have been synthesized in the solid state by the interaction of potassium pentacyanonitrosylchromate(I) monohydrate, K3[Cr(NO)(CN)5]· H2O with L in aqueous acetic acid. The products, which have been characterized by elemental analyses, molar conductances, thermogravimetric analyses, magnetic measurements, electron spin resonance and infrared spectral studies, contain low-spin chromium(I). An octahedral structure has been suggested for the complexes. 相似文献
18.
This study describes a general palladium-catalyzed cyanation of aryl bromides using K4[Fe(CN)6] as the cyanide surrogate. The reactions can be successfully conducted under mild reaction conditions (at 50 °C) in mixed solvents (water/MeCN = 1:1) without any surfactant additives, and afford the desired aryl nitriles in good-to-excellent yields. Particularly noteworthy is that this system allows the mildest reaction temperature reported so far for palladium-catalyzed cyanation of aryl bromides with K4[Fe(CN)6] source in general. Common functional groups, including keto, aldehyde, free amine, and heterocyclic substrates are compatible under this system. Interestingly, the phosphine ligands bearing -PCy2 moiety, which usually show excellent activity in aryl halide couplings, are found less effective than the corresponding ligands with -PPh2 group. 相似文献
19.
Deceleration of gold electrowinning from model cyanide solutions on porous cathode of graphitized carbon felt was investigated.
It was established that calcium ions present in the solution did not negatively affect the electrolysis rate. The main reason
of the termination of gold electrowinning on the graphitized cathode was the corrosion of the stainless steel anode resulting
in penetration into the cathode chamber of the electrolyzer of CrO42− anions further reduced to Cr(III) and probably Cr(II) compounds. X-ray Photoelectron Spectroscopy investigation of the passivated
carbon cathode showed that the film formed thereon consisted of Cr(III) compounds containing cyanide and hydroxy ligands.
This film covers the active sites on the surface of the porous carbon cathode preventing the deposition thereon of ad-ions
of gold(I). Inert aqua and hydroxo complexes of chromium(III) stronger impede the rate of gold(0) deposition on the porous
carbon cathode than chromium(III) cyanide compounds. This fact originates presumably from the requirement of lower cathode
potentials for the reduction of the former to labile chromium(II) complexes than those necessary for the thermodynamically
stable anions [Cr(CN)6]3−. 相似文献
20.
Shen Xiaoping Li Baolong Zou Jianzhong Xu Zheng Yu Yunpeng Liu Shixiong 《Transition Metal Chemistry》2002,27(4):372-376
K3[Cr(CN)6] reacts with the mononuclear MnIII complex Mn(salen)ClO4 · 2H2O [salen: N,N-ethylenebis(salicylideneiminato)dianion] to give a bimetallic heptanuclear complex cation salt [Cr{(CN)Mn(salen · H2O)}6][Cr(CN)6]6H2O. In the complex anion, [Cr{(CN)Mn(salen · H2O)}6]3+, six MnIII ions coordinate to a CrIII center via cyano bridges, forming a spherical species with 3 symmetry. A study of magnetic properties shows the presence of antiferromagnetic interaction through the cyanide bridge between CrIII (S = 3/2) and MnIII (S = 4/2) and results in a ground state S = 21/2. 相似文献