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1.
Zusammenfassung Die Absorptions- und Reflexionsspektren der Oktocyanokomplexe desMo(IV) undW(IV) sowie die Absorptionsspektren der Oktocyanotomplexe desMo(V) undW(V) werden mitgeteilt. Die Spektren werden unter Zugrundelegung der durch Raman- und IR-spektroskopische Untersuchungen gefordertenD 4d-Symmetrie dieser Verbindungen interpretiert. Die beobachteten Banden niedriger Intensität (log<3) werden Übergängen in einem Termsystem zugeordnet, das für die Konfigurationend 2 undd 1 und die SymmetrieD 4d berechnet worden ist. Banden hoher Intensität (log>3) werden auf Übergänge in antibindende Zustände zurückgeführt, an denen höherep-Zustände des Zentralions sowie Ligandenzustände beteiligt sind. Die erhaltenen Werte des Feldparameters stimmen mit ligandenfeldtheoretischen Erwartungen überein.
Absorption and reflection spectra of the octacyanides ofMo(IV) andW(IV) and the absorption spectra of the octacyanides ofMo(V) andW(V) are presented. The spectra are interpreted in terms of theD 4d symmetry of the compounds supported by investigations of Raman and infrared spectra. Bands of low intensity (log<3) correspond to transitions between levels obtained in the case of the configurationsd 2 andd 1 respectively, in a field ofD 4d symmetry. Bands of high intensity (log>3) are attributed to transitions into antibonding levels in which p-orbitals of the central ion and ligand orbitals participate. The values of the field parameter obtained are in accord with ligand field theory.

Résumé Les spectres d'absorption et de réflexion des complexes octocyanurés duMo(IV) et duW(IV) ainsi que les spectres d'absorption des mêmes complexes deMo(V) et de W(V) sont présentés. Les spectres sont interprétés en supposant la symétrieD 4d des molécules indiquée par des analyses des spectres Raman et infrarouges. Les bandes de faible intensité (log<3) sont attribuées à des transitions dans un système de niveaux, calculé pour les configurationsd 2 etd 1, respectivement, en symétrieD 4d. Des bandes de forte intensité (log>3) sont attribuées à des transitions vers des niveaux antiliants auxquels participent des fonctions élevéesp de l'ion central et des fonctions des groupes liés. Les valeurs obtenues pour le paramètre de champ sont en accord avec les prévisions de la théorie.
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2.
Self-assembly of the precursor [Cu(L)]2+ (L = 3,10-dipropyl-1,3,5,8,10,12-hexaazacyclotetradecane) with hexacyanometalate [Fe(CN)6]3− produces a 3-D cyano-bridged Cu(II)–Fe(III) bimetallic assembly, [CuL]2[Fe(CN)6]ClO4 · H2O (1), characterized by single-crystal X-ray diffraction studies, and magnetic measurements. The crystallographic determination reveals that each hexacyanoferromate(III) ion connects four copper(II) ions using four co-planar CN groups which axially coordinate to the copper ion in a trans fashion forming trans-CuL(N≡C)2 moieties in (1). Magnetic studies reveal that (1) displays a ferromagnetic interaction between Cu(II) and Fe(III) through the CN linkage.  相似文献   

3.
K3 [Fe(CN)6] and KFe[Fe(CN)6] are classical coordination compounds. However, the mechanism of decomposition reactions has not been well expounded. The gas products of thermal decomposition were examined by gas chroma tography (GC) , and the structure of the solid products by Mossbauer spectroscopy(MS) and X-ray diffraction(XRD). The findings are explained in terms of the theory of coordination chemistry and a decomposition mechanism is proposed in this study. On the basis of various experimental results, the first stage of the decomposition of K3[Fe(CN)6] in He was found to be the evolution of(CN)2 resulting in the reduction of Fe(Ⅲ)12K3 [Fe(CN)6]→9K4[Fe(CN)6] + Fe2 [Fe(CN)6] + 6 ( CN )For KFe [Fe(CN) 6 ], the first stage of decomposition man be represented as6KFe[Fe(CN)6]→3K2Fe[Fe(CN)6] + 2Fe2[Fe(CN)6 + 3(CN)2At higher temperatures, the decomposition of both K3[Fe(CN)6) andKFe[Fe(CN)6] to form KCN and Fe2C was accomplished by the release of(CN)2 and N2.  相似文献   

4.
Two supramolecular complexes, {{Ni(H2O)(phen)2[Au(CN)2]}[Au(CN)2]?·?1.5H2O} n (1) (phen?=?1,10-phenanthroline) and [H2teta][Au2(CN)4]?·?2H2O (2) (teta?=?5,7,7,12,14,14-hexamethyl-1,4,8,11-tetra-azacyocloteradeca-4,11-diene) have been synthesized and structurally characterized. Complex 1 was a one-dimensional infinite chain constructed by [Au(CN)2]? building blocks. In complex 2, there are one cation, one anion, and two water molecules in the asymmetric unit. The two complexes are interconnected through a combination of aurophilic attractions and hydrogen bonds and formed into 3D supramolecular structures. The aqueous solutions of 1 and 2 display interesting luminescence at room temperature.  相似文献   

5.
[Fe(CN)5NO]2–, (1) and [Ru(bpy)2(NO)Cl]2+, (2) react with PhCH2NH2 to produce mainly N-benzylphenyl-methanimine and PhCN as oxidation products. (PhCH2)2NH, PhCH2Cl and PhCH2OH are formed as diazotization products. Products derived from the benzyl radical (such as PhMe), are also formed. Since oxidation products are generated even in the absence of oxygen, a mechanism in which the nitrosyl ligand acts as an oxidant is proposed.  相似文献   

6.
The interactions between [M(CN)8]4– (M = Mo or W) and pyrazine (pz) in the solid state and in aqueous solutions have been analysed. In strongly acidic solutions {pzH+, [M(CN)8]4–} ion pair formation is observed; the pyrazinium salts (pzH)2(H3O)2[Mo(CN)8]·0.5pz·3H2O and (pzH)2K(H3O)[W(CN)8]·H2O have been isolated. The X-ray crystal structure of the latter, and the spectroscopic properties of both, are described. The [W(CN)8]4– anion is approximately square antiprismatic (D4d), with different H-bond environments around the N atoms. The ligand-field photolysis of [M(CN)8]4– in the presence of pyrazine in neutral and alkaline solution results in the formation of tetracyanooxometallates(IV) in equilibrium with pentacyanooxometallates(IV) through the [M(CN)7(pz)]3– anions as intermediates. The formation of the [M(CN)6(pz)2]2– ion, postulated in the literature to be the final product of the alkaline photolysis, has definitively been excluded.  相似文献   

7.
The stabilization of nitrogen-rich phases presents a significant chemical challenge due to the inherent stability of the dinitrogen molecule. This stabilization can be achieved by utilizing strong covalent bonds in complex anions with carbon, such as cyanide CN and NCN2− carbodiimide, while more nitrogen-rich carbonitrides are hitherto unknown. Following a rational chemical design approach, we synthesized antimony guanidinate SbCN3 at pressures of 32–38 GPa using various synthetic routes in laser-heated diamond anvil cells. SbCN3, which is isostructural to calcite CaCO3, can be recovered under ambient conditions. Its structure contains the previously elusive guanidinate anion [CN3]5−, marking a fundamental milestone in carbonitride chemistry. The crystal structure of SbCN3 was solved and refined from synchrotron single-crystal X-ray diffraction data and was fully corroborated by theoretical calculations, which also predict that SbCN3 has a direct band gap with the value of 2.20 eV. This study opens a straightforward route to the entire new family of inorganic nitridocarbonates.  相似文献   

8.
Geometry of complexes [Mg(DMF) i (CH3CN)6?i ]2+ (i from 0 to 6) was optimized, IR spectra were calculated, and values of ΔG of the ligand replacement in the cation coordination sphere were estimated by DFT BLYP/6-31G** method. Regularities in variations of spectral and structural characteristics of the complexes at variation in their compositions were elucidated. Quantitative relations between the calculated changes in frequency and intensity of the IR bands νC≡N, νC-C, νC=O, and δOCN of the complexes and the respective values in the IR spectra of solutions CH3CN-Mg(ClO4)2-DMF at varying composition of the binary solvent were established. The main regularities in the changes of the DMF νC=O band contour in the process of resolvation of Mg2+ ions were interpreted.  相似文献   

9.
Binary complex salts, [Co(En)3][Fe(CN)6] · 2H2O and [Co(En)3]4[Fe(CN)6]3 · 15H2O, are synthesized. The properties of the salts and their thermolysis in air, dihydrogen, and argon are studied. Oxides of the central ions of the binary complex salts are found to be the thermolysis products in an oxidative atmosphere. Solid solutions (intermetallic compounds) CoFe are the thermolysis products in the reductive atmosphere, whereas intermetallides containing considerable amounts of C and N and an impurity of Co and Fe oxides are the thermolysis products in an inert atmosphere. Gaseous thermolysis products in dihydrogen and argon are NH3, hydrocarbons, and ethylenediamine.  相似文献   

10.
《Polyhedron》1999,18(26):3533-3544
[Tris(1,3-dithiole-2-thione-4,5-dithiolato)stannate]2−, [Q]2[Sn(C3S5)3], [tris(1,3-dithiole-2-one-4,5-dithiolato)stannate]2−, [Q]2[Sn(C3S4O)3], and [tris(1,3-dithiole-2-thione-4,5-diselenolato)stannate]2− [Q]2[Sn(C3S3Se2)3], complexes, have been synthesised and characterised. Crystal structure determinations of [Q]2[Sn(C3S5)3] (Q=1,4-dimethylpyridinium, monoclinic and orthorhombic forms; NMe4, NEt4, and PPh4) and [NEt4]2[Sn(C3S4O)3] revealed variations in the overall dianion structures. The geometry about tin in each case is essentially octahedral with the chelate bite angles in the range 80.7(5)–87.45(4)°: the range of Sn–S distances is 2.5207(18)–2.571(17) Å. A statistical analysis, carried out on the crystal structure data for the six complexes, indicated that the most critical factors in controlling the overall shape of the dianion were the distances of the Sn atom from the dithiolate ligand planes [Sn–OOP]. Interanionic S⋯S interactions, within the sum of the van der Waals’ radii for two S atoms, are affected by the size of the cation, Q; the secondary connectivity is 3-dimensional for the smallest cations, Q=1,4-dimethylpyridinium and NMe4, in chains for the somewhat larger cation, NEt4 and is absent for the still larger, PPh4 cation.  相似文献   

11.

Two ion pair complexes, [Ru(bpy)3]2[Fe(CN)6]I [sdot] 7H3O (1) and [Ru(bpy)3][Fe(CN)5NO](CH3OH) [sdot] H2O (2) (bpy = 2,2-bipyridine) have been synthesized and structurally characterized. X-Ray crystallographic structures of 1 and 2 both show Fe(III) and Ru(II) in distorted octahedral environments. In both complexes, H-bonding interactions between an uncoordinated water molecule and the nitrogen atom of a cyano group exist.  相似文献   

12.
The [Ni36Pt4(CO)45]6- and [Ni37Pt4(CO)46]6- clusters have been obtained in mixture upon reaction in acetonitrile of [Ni6(CO)12]2- salts with K2PtCl4 in a 2.5:1 molar ratio. The two hexaanions were indistinguishable by spectroscopic techniques. Crystallization of their trimethylbenzylammonium salts led to crystals of composition 0.5[NMe3CH2Ph]6[Ni36Pt4(CO)45]-0.5[NMe3CH2Ph]6[Ni37Pt4(CO)46]·C3H8O, hexagonal,space group P63 (No. 173), a=17.853(9), c=27.127(13) Å, Z=2; final R=0.057. The metal core of the [Ni36Pt4(CO)45]6- anion consists of a Pt4 tetrahedron fully encapsulated in a shell of 36 Ni atoms belonging to a very distorted and incomplete 5 tetrahedron. The [Ni37Pt4(CO)46]6- hexaanion derives from the former by capping the unique triangular face of the metal polyhedron with an additional Ni(CO) fragment. The [Ni36Pt4(CO)45]6--[Ni37Pt4(CO)46]6- mixture is rapidly degraded to the known [Ni9Pt3(CO)21]4- cluster by exposure to carbon monoxide. Its reaction with protic acids initially affords the corresponding [H6-nNi36Pt4(CO)45]n--[H6-nNi37Pt4(CO)46]n- (n=5, 4) derivatives, and eventually leads to rearrangement to the known [H6-n Ni38Pt6(CO)48]n- species. Both [Ni36Pt4(CO)45]6--[Ni37Pt4(CO)46]6- and [HNi36Pt4(CO)45]5--[HNi37Pt4(CO)46]5- mixtures have been chemically and electrochemically reduced to their corresponding [Ni36Pt4(CO)45]n--[Ni37Pt4(CO)46]n- (n=7–9) and [HNi36Pt4(CO)45]n--[HNi37Pt4(CO)46]n- (n=6–8) mixtures.  相似文献   

13.
Abstract

The properties of PF5, HPF4, H2PF3, and H3PF25[sgrave]5P derivatives of (HO)3PO, (HO)2HPO, (HO)H2PO, and of the hypothetic H3PO) and the formation of the related Δ5[sgrave]6P anions PF6 , HPF5 , and trans-H2PF4 have been studied some years ago 1–4. The mono and spirocyclic dioxa and tetraoxa analogues, 1 and 2 available from the corresponding precursor phosphoranes by fluoride addition could be found also as products in the reaction of phosphite 35 and K+(CF3)2CFO together with two other phosphates, 4 and 5. A 19F–19F homocorrelated 2 D NMR spectrum of 2 indicated coupling of the P–F fluorine nuclei with two CF3 groups by a non bond mechanism.  相似文献   

14.
Mossbauer spectroscopy has been applied to the investigation of reaction of Sn[Fe(CN)6] on magnesia, 7-alumina, silica and activated carbon. It was found that the thermal decomposition products of supported Sn[Fe(CN)6] are quite different from those of the unsupported one as a result of the interaction between the complex and supports. The supports could promote the oxidation in the air atmosphere and their effect led to high dispersion of the decomposition products on the surface.  相似文献   

15.
The kinetics of the reaction between [ReN(H2O)-(CN)4]2− with different κ2 N,O-donor ligands (quin and 2,3-dipic, respectively) have been studied in the pH 4–12 range in aqueous solution. Two consecutive reaction steps with the formation of the [ReN(η1-quin)(CN)4]3− and [ReN(μ2-quin) (CN)3]2− complexes, respectively, were spectrophotometrically observed and kinetically investigated. The same reaction mechanism is proposed for these two ligands. The first fast reaction (for quin) is attributed to the aqua substitution of [ReN(H2O)(CN)4]2− with forward and reverse rate constants of 1.96(5) × 10−1 M−1 s−1 and 5.6(3) × 10−2 s−1, while a rate of 2.64(3) M−1 s−1 was observed for the reaction between the conjugate base [ReN(OH)(CN)4]3− and quin at 40.2 °C. Due to small absorbance changes, it was difficult to obtain any good quality data for the fast reactions for 2,3-dipic. The second, slower reaction is attributed to cyano substitution with rate constants (k 3 K 1) of 4.17(4) × 10−3 for quin and 4.68(7) × 10−3 M−1 s−1 for 2,3-dipic, at 80.02 °C, respectively. The acid dissociation constant for the aqua complex was spectrophotometrically determined as 11.58(3) and 11.54(2) and kinetically as 11.51(8) and 11.41(1), at 80.4 °C, respectively. Negative values of −83.5(2) and −144.1(2) J K−1 mol−1 as well as the of 71.4(3) and 47.3(3) kJ mol−1, for the slow quin and 2,3-dipic reactions, respectively, point to an ordered transition state where bond formation is responsible for the major driving force of the reaction. The and for the fast forward reaction of quin is indicative of expected associative activation in the transition state. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

16.

The oxidation reaction of phenyl hydrazine (Phh) by hexacyanoferrate ([Fe(CN)6]3?) has been studied in water‐in‐oil (w/o) microemulsion media. The kinetic profile of the reaction was investigated as a function of [Phh], droplet size, and droplet concentration. Comparison of the kinetic profiles of the reaction in microemulsion, water‐urea, and water‐AOT‐urea media indicates that the kinetic profile of the reaction in microemulsion shows a behavior similar to that of the reaction in water‐AOT‐urea medium at 4 M urea. An initial increase and then a decrease in kobs is observed with increasing molar ratio, Wo(=[H2O]/[AOT]) at constant [AOT] (=0.4 M), whereas kobs decreases upon increasing the AOT concentration at constant molar ratio.  相似文献   

17.
Two Keggin-type heteropolyanions were synthesized and characterized by X-ray crystal structure and elemental analysis as well as infrared spectroscopy. Both K3[VMo12O40]19H2O (1) and [N i (H2O)6][H3PMoVMoVI 11O40]230 H2O (2) were prepared in aqueous solution. Compound 1 crystallized in the space group Pm-3m, a=10.6513(1) Å, V=1208.4(3) Å3, Z=1. Compound 2 crystallized in the space group R-3 with a=b=13.9669(2) Å, c=42.0075(5) Å, V=7096.71(2) Å3, Z=3. The compound 1 contains a {K6VMo12O40} group in which six potassium ions form a regular {K6} octahedron. The heteropolyanion [VMo12O40]3– was capped by six potassium ions and enclosed by {K6} octahedron. A three-dimensional structure was formed by the buildup of {K3[VMo12O40]} n . Compound 2 contains a one-electron reduced heteropolyanion [H3PMoVMoVI 11O40]1–. Ni2+ coordinated by six water molecules as the counter cation balances the negative charge of the molecule.  相似文献   

18.
The reaction of AgNO3 with [(“Bu4N2 i-MNT)]3 in CH3CN produces a new silver cluster anion [Ag4(i-MNT)4]4? ,3, a species having a tetrahedral arrangement of silver atoms bridged by fouri-MNT ligands which has been isolated and characterized by X-ray crystallography as [Bu4N]2[(PPh3)2]2 [Ag4(i-MNT)4],4. The reaction of two or three equivalents of Ag(PPh3)2NO3 with [BzEt3N]6[Ag6(i-MNT)6] in CH3CN produces two new clusters, [BzEt3N]4[Ag8(i-MNT)6(PPh3)4],6, and [BzEt3N]3[Ag4(i-MNT)6(PPh3)6], 7, having the common structural feature of an octahedral Ag6S12 core. The octanuclear Ag8 cluster also can be synthesized from the reaction of 4 and PPh3 in CH2Ck2 and compound 5 has been structurally characterized as [Bu4N]2[(PPh3)2N]2[Ag8(i-MNT)6(PPh3)4]. The31P{1H} NMR spectrum of 6 in CD3CN at ?43° shows two sets of two doublets. The corresponding chemical shift and coupling constant of each species is 9.32 ppm (354, 408.8 Hz) and 9.45 ppm (346.7, 401.7 Hz), respectively. Pertinent crystallographic data are as follows: Compound 4 crystallizes in the orthorhombic space group Cc2a, witha=18.668(3)A,b=36.793(4) A,c=17.836(3)A, Z=4, andV= 12250(3)A3. Compound 5 crystallizes in the triclinic space group P1, witha=16.506(3)A,b=17.280(3)A,c=19.144(4) A,x=98.485(14)°, β= 105.44(2)°.y=94.63(2),Z= 1, andV = 5164(2)A3. Compound6 crystallizes in the monoclinic space group C2/m, witha= 25.341(9)A,b= 25.289(9)A,c= 15.076(7)A, β= 107.19(5)°,Z=2, and V=9230(6)A3. Compound7 crystallizes in the monoclinic space group C2/c, witha=25.872(6)A,b=21.288(4) A,c=35,928(5), β=100.98(1)°,Z-4, andV=19426(6)A3.  相似文献   

19.
A dinuclear complex Cu2(bpca)2(H2O)2(Ag2(CN)3) (1) and a 1D complex [Cu2(bpca)2(H2O)2(Au(CN)2)2] n (2) (bpca = bis(2-pyridylcarbonyl)amide anion) have been prepared, structurally characterized and 2 has been magnetically characterized. The magnetic properties show an antiferromagnetic interaction between the two Cu(II) ions. Based on the Hamiltonian ? = ?2J Σ (Si · Si +1), best fitting for the experimental data leads to J = ?0.045 cm?1.  相似文献   

20.
K4[Fe(CN)6]-K3[Fe(CN)6]体系催化分光光度法测定痕量汞   总被引:1,自引:0,他引:1  
建立了一种测定痕量汞的催化分光光度新方法,它是基于汞能催化亚铁氰化钾分解生成Fe2 ,生成的Fe2 又与铁氰化钾反应生成兰色胶体溶液.方法的相对标准偏差≤5.3%,回收率为98.8%~104.8%之间,检出限为9.8×10-7 g/L;线性范围为0~0.050 μg/mL.  相似文献   

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