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1.
Ion-selective electrodes are proposed on the basis of tetradecylammonium salts for determining [B12H12]2−, [B10H10]2−, and [B10Cl10]2− closoborate anions. Their basic electroanalytical parameters, selectivity, linear response range, detection limit, potential stability, and the pH effect on electrode indications are estimated. The closoborate anions can be arranged in the following series by the selectivity of their determination: [B10Cl10]2− ≫ [B12H12]2− > [B10H10]2−.  相似文献   

2.
Quantum-chemical calculations of the geometry and energies of nine possible isomers of 12-vertex cobaltacarborane CpCoC2B9H11 (1) were carried out by the DFT method (PBEPBE/DGDZVP/DGA1). Thermodynamic stability of the isomers increases with increasing distance between the carbon atoms in the cage and is virtually independent of the position of the CpCo vertex. The relative stabilities of the 1,2,3-(17.57 kcal mol−1), 1,2,4-(3.72 kcal mol−1), and 1,2,9-isomers of 1 (0 kcal mol−1) are similar to the corresponding values for the ortho (17.61 kcal mol−1), meta (3.21 kcal mol−1), and para isomers (0 kcal mol−1) of carborane C2B10H12. The results of the present study confirm a close similarity of the CpCo and BH fragments in metallacarborane chemistry. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1557–1559, July, 2005.  相似文献   

3.
The problem of determining the number and type of X-substituted (where X represents certain substituents) carbometallic derivatives of hydroborons [Co(C2B9H11)2] C 2h and [Co(C5B6H11)2] D 5d (from apexes) was solved on the basis of G. Pólya’s theorem by means of combinatory analysis. The formulae of symmetry Z and generating functions of the number of achiral substitution isomers were determined. The family distributions of isomers (depending on the type and number of substituents) and the sites of possible substitution depending on the number m were determined. Mono and di-X-substituted isomers of [Co(C5B6H11)2] C 2h , as well as mono and di-X-substituted isomers of [Co(C5B6H11)2] D 5d , were identified. The procedure for plotting an additive model of calculating the properties of isomers of apical substitution of [Co(C5B6H11)2] D 5d was described on the basis of splitting of polygonal numbers (K 3, K TE, K 5, and so on) of Pascal triangle, upon use of which there is no randomization in the choice of parameters of calculation model. The additive schemes containing 7 and 25 parameters for the calculation of properties of X-substituted carbometallic derivative of hydroboron [Co(C5B6H11)2] D 5d to various approximations were obtained.  相似文献   

4.
The reaction of the anion B12H122− with [Au(Ph3P)Cl] in acetonitrile was studied. The nature of the initial cation of the closo-dodecaborate and the reagent ratio was shown to affect complexing. The X-ray structures of compounds Au(Ph3P)2[AgB12H12] (I) and [Au9(Ph3P)8]B24H23 (II) were determined. Complex I is the first example where B12H122− is coordinated to silver(I) atoms in the face coordination mode. In complex II, B12H122− is oxidized to the dimeric trianion B24H233− where the two icosahedra are linked by a B-H-B′ bridge.  相似文献   

5.
Reactions between the icosahedral carboranes 1,2-C2B10H12 (1), 1,7-C2B10H12 (2) and 1,12-C2B10H12 (3) and the iminophosphorane HNP(NMe2)3 (4) are described that have afforded a variety of products whose structures have been characterised by X-ray diffraction. They include the adduct between (1) and (4), C2B10H12·HNP(NMe2)3 (5) the 12-atom 14-skeletal pair supra-icosahedral nido structure of which illustrates an early step in the deboronation of ortho-carborane (1) by Lewis Bases, and the C–H⋯N hydrogen-bonded adducts of meta- and para-carborane with the iminophosphorane, [1,7-C2B10H12⋯HNP(NMe2)3] n and 1,12-C2B10H12 2HNP(NMe2)3. The iminophosphorane (4) readily converts ortho-carborane (1) into the nido anion [7,8-C2B9H12] and less readily meta-carborane (2) into the nido-anion [7,9-C2B9H12], which have been isolated from solution as salts of the cations [H2NP(NMe2)3]+ or [{(Me2N)3PN}2BNHP(NMe2)3]+, the latter evidently incorporating a boron atom removed from the carborane cage. Adventitious presence of water in the attempted recrystallization of [{(Me2N)3PN}2BNHP(NMe2)3]+ [7,8-C2B9H12] led to a salt of the cation [{(Me2N)3PNBN(H)P(NMe2)3}2O]2+. Other unexpected products isolated from reactions carried out under moist air included the salt [H2NP(NMe2) 3 + ]2[CO 3 2− ]·2B(OH)3 (from the reaction between 2 and 4) and the salt 1,12-C2B10H12·2H2NP(NMe2) 3 + HCO 3 (from the reaction between 3 and 4).Dedicated to Prof. Brian F.G. Johnson, in recognition of his major contributions to cluster chemistry and warm friendship over the years.  相似文献   

6.
The redox aptitude of a series of cobalt(III) or cobalt(I) sandwich complexes bearing a charge compensated dicarbollide ligand ([9-L-7,8-C2B9H10]) as a constant unit and different counterparts (varying from classical [7,8-C2B9H11]2− to charge-compensated [9-L-7,8-C2B9H10] dicarbollides, from cyclopentadienyl [C5R5] (R = Me, H) to cyclobutadiene [C4Me4]0 ligands) has been studied. All the Co(III) complexes display the reversible sequence Co(III)/Co(II)/Co(I). In contrast, the Co(I) complexes (namely, those capped by tetramethylcyclobutadiene) accede reversibly only to the Co(II) oxidation state, the passage to Co(III) being irreversible. When possible, the Co(II) intermediates have been characterized by EPR spectroscopy. The molecular structures of the monocation [Co(η-9-SMe2-7,8-C2B9H10)2]+ in its DD/LL and meso diastereomeric forms as well as that of heteroleptic (η-7,8-C2B9H11)Co(η-9-SMe2-7,8-C2B9H10) have been obtained by single-crystal diffraction. Presented at the 3rd Chianti Electrochemistry Meetings July 3−9, 2004, Certosa di Pontignano, Italy  相似文献   

7.
Molecular and electronic structure of four polyhydrogenated (n,0)-tubulenes, namely, [−C24H4−] m (1), two isomers of composition [−C28H4−] m (2 and3), and [−C32H4−] m (4) withn benzene rings in the cross section (n=6, 7, 7, and 8, respectively), was simulated atm>1 (m is the number of repeating fragemnts). It was assumed that hydrogen atoms are attached to all carbon atoms lying on the two most distant elements of the cylinders of the corresponding tubulenes. The energy band structures of macromolecules1–4 and their Li-intercalated analogs [−C24H4Li−] m (5) [−C28H4Li−] m (two isomers,6 and7), and [−C32H4Li−] m (8), containing one Li atom per repeating unit at each center, were obtained in the EHT approximation by the crystal orbital method. Geometric parameters of repeating units of structures1–8 were found after MNDO/PM3 optimization of the energies of hydrocarbon molecules C72H24, C84H26 (two geometric isomers), and C96H28, containing three repeating units of corresponding tubulenes1–4 each. The conductivity types of polyhydrogenated tubulenes1–4 are the same as those of their precursors, (6,0)-, (7,0)-, and (8,0)-tubulenes. Dispersion curves of systems5–8 are much the same as those of macromolecules1–4; however, electron energy spectra of5–8 possess metallic conductivity type and the positions of Fermi levels for these systems are higher than for compounds1–4. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2061–2067, November, 1999.  相似文献   

8.
The reaction of the [B10H9O2C4H8], [B10H9OC4H8], and [B10H9OC5H10] anions with negatively charged S-nucleophiles, such as SH, SCN, and S2O3 2−, resulted in the ring opening of the cyclic substituent and the formation of derivatives with the terminal thiol, thiocyanate, and thiosulfate groups. The structures of the products were confirmed by the IR, mass, and 1H, 11B, and 13C NMR spectra.  相似文献   

9.
Reduction of the R2P-functionalized zirconocene dichlorides [C5Me4(CH2)2PR2] (C5Me5)ZrCl2 (R = Me (1) and Ph (2)) and [C5Me4(CH2)2PMe2][C5Me4(CH2)2PR2]ZrCl2 (R = Me (3) and Ph (4)) with amalgamated magnesium was studied. In the reduction of compounds 1 and 2, intramolecular C-H activation highly selectively afforded the fulvene hydride complexes Zr(H)(η5−C5Me5)[η52(C,P)−(CH2)C5Me3CH2CH2PR2] (R = Me (7), Ph (8)); in the case of compound 2, the aryl hydride Zr(H)(η5:C5Me5)[η51(C)−C5Me4CH2CH2PPh(o−C6H4)] (9) was also formed. The reduction of complexes 3 and 4 gave the ZrII derivatives Zr[η51(P)− C5Me4CH2CH2PMe2]2 (12) and Zr[η51(P)−C5Me4CH2CH2PMe2][η51(P)−C5Me4CH2 CH2PPh2] (14) stabilized by two phosphine groups. The second product in the reduction of compound 4 was the fulvene hydride complex Zr(H)(η5−C5Me4CH2CH2PPh2)[η52(C,P)−(CH2)C5Me3CH2CH2PMe2] (15). The reaction of compound 7 with an excess of MeI resulted selectively in replacement of the hydride ligand by iodide to give the complex ZrI(η5−C5Me5)[η52(C,P)−(CH2)C5Me3CH2CH2PMe2] (10). In contrast, in the reaction of compound 7 with Me2Si(H)Cl, the Zr-CH2 bond underwent cleavage to give the chloride hydride complex Zr(H)Cl(η5−C5Me5)[η51(P)−C5Me3(CH2SiMe2H)CH2CH2PMe2] (11). In the reaction of complex 12 with CO, a phosphine group was replaced by CO to form the complex Zr(CO)(η5−C5Me4CH2CH2PMe2)[η51(P)−C5Me4CH2CH2PMe2] (13). The results obtained were compared with analogous reduction reactions of MeO-, MeS-, and Me2N-functionalized zirconocene dichlorides. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 65–74, January, 2008.  相似文献   

10.
New liquid-crystalline heteropolynuclear complexes L2M (M=Cu2+ (2a), Pd2+ (2b)) were synthesized by the reactions of C5H5FeC5H4−C6H4NH−C2H2−(CO)−C6H4OC12H25 (1, LH) with copper(ii) and palladium(ii) acetates. Compound2b was found to possess monotropic nematic and smectic phases;2a exhibits the monotropic nematic phase and a phenomenon of “double melting”. The compositions and structures of compounds1 and2a,b were established by elemental analysis,1H and13C NMR, ESR, and IR spectroscopy. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 381–383, February, 1999.  相似文献   

11.
Solvothermal synthesis method has been successfully introduced into the diphosphine carborane system, and two new nickel complexes containing nido-carborane diphosphine ligand [7,8-(PPh2)2-7,8-C2B9H10] with the formula [Ni2(μ-Cl)(μ-OOPPh2){7,8-(PPh2)2-7,8-C2B9H10}2]·CH2Cl2 (1) and [H3O][NiBr2] {7,8-(PPh2)2-7,8-C2B9H10}·C6H6 (2) were obtained by the reactions of 1,2-(PPh2)2-1,2-C2B10H10 with NiCl2·6H2O or NiBr2·6H2O in CH2Cl2 under the solvothermal condition. Both of the two complexes have been characterized by the elemental analysis, FT-IR, 1H and 13C NMR spectroscopy and single crystal X-ray diffraction. The X-ray structure analysis for these two complexes reveals the nido-nature of the carborane diphosphine ligand, indicating that the solvothermal synthesis is an efficient method for the degradation of the closo-carborane diphosphine ligand.  相似文献   

12.
The reactions of the oxalate complexes [M3Q7(C2O4)3]2− (M = Mo or W; Q = S or Se) with MnII, CoII, NiII, and CuII aqua and ethylenediamine complexes in aqueous and aqueous ethanolic solutions were studied. The previously unknown heterometallic complexes [Mo3Se7(C2O4)3Ni(H2O)5]·3.5H2O (1) and K3{[Cu(en)2H2O]([Mo3S7(ox)3]2Br)}·5.5H2O (2) were synthesized. In these complexes, the oxalate clusters serve as monodentate ligands. The K(H2en)2[W3S7(C2O4)3]2Br·4H2O salt (3) was isolated from solutions containing CoII, NiII, or CuII aqua complexes and ethylenediamine. The reaction of [Mo3Se7(C2O4)3]2− with HBr produced the bromide complex [Mo3Se7Br6]2−, which was isolated as (Bu4N)2[Mo3Se7Br6] (4). Complexes 1–3 were characterized by X-ray diffraction, IR spectra, and elemental analysis. The formation of 4 was detected by electrospray mass spectrometry. Dedicated to Academician G. A. Abakumov on the occasion of his 70th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1645–1649, September, 2007.  相似文献   

13.
A novel family of electrochemical anion sensors operating in aqueous media, based on the heterometallic Au(I)–Cu(I) [{Au3Cu2(C2R)6}Au3(PPh2C6H4PPh2)3](PF6)2 (L1, R = Fc; L2, R = C6H4Fc) alkynyl cluster complexes, is presented. Upon attachment to graphite and gold electrodes, these compounds exhibit a well-defined, essentially reversible, solid-state electrochemistry in contact with aqueous media, based on ferrocenyl-centered oxidation processes involving anion insertion, leading to distinctive pH-independent electrochemical responses for fluoride, chloride, bromide, perchlorate, bicarbonate, carbonate, phosphate, hydrogen phosphate, dihydrogen phosphate, and nitrate anions. Cluster-modified electrodes can be used as potentiometric sensors as a result of the reversible, diffusion-controlled electrochemistry obtained for the anion-assisted electrochemical oxidation of L1 and L2.  相似文献   

14.
Polyhedral borane anions and carboranes that can be constructed formally from the interaction of rings and caps will be stable with six interstitial electrons. Interstitial electron count is obtained by summing the number of π electrons of the ring and the electrons of the caps involved in ring cap binding. Thus B7H7 −2 (D5h) has 6 interstitial electrons (none from the B5H5 ring, two each from the twobh caps and two negative charge),mndo calculations on isoelectronic pyramidal molecules B6H6 −4 (C5v), B5H5CH−3 (C5v), B5H5 −4 (C4v), B4H4CH−3 (C4v), B4H4 −4 (T d) and B3H3CH−3 (C3v) suggests a criterion based on the out-of-plane bendings of the ring B-H bonds to select the best combination of borocycles and BH or CH caps. Three-membered borocycle prefers CH cap, five-membered borocycle prefers BH cap. The preference of four-membered ring for BH or CH cap is not as pronounced. The extra stability of B12H12 −2 arises from the geometry of the icosahedron. The relative stabilities ofnido andcloso carboranes follow from these rules.  相似文献   

15.
Single crystals of Cs4[(UO2)2(C2O4)(SO4)2(NCS)2] · 4H2O (I) and (NH4)4[(UO2)2(C2O4)(SO4)2(NCS)2] · 6H2O (II) have been synthesized and studied by X-ray diffraction. The crystals of both compounds are orthorhombic with the space group Pbam, Z = 2, and unit cell parameters a = 12.0177(3) ?, b = 18.6182(5) ?, c = 6.7573(10) ?, R = 0.0376 (I); a = 11.6539(9) ?, b = 18.3791(13) ?, c = 6.7216(5) ?, R = 0.0179 (II). The main structural units of crystals I and II are [(UO2)2(C2O4)(SO4)2(NCS)2]4− chains belonging to the crystal-chemical group A2K02B22M21 (A = UO22+, K02 = C2O42−, B2 = SO42−, M1 = NCS) of the uranyl complexes. The uranium-containing chains are joined into a three-dimensional framework due to a system of electrostatic interactions with the cesium or ammonium ions in the structure of I. In the structure of II, this framework is additionally stabilized by hydrogen bonds involving the outer-sphere water molecules and ammonium ions. Original Russian Text ? I.V. Medrish, A.V. Virovets, E.V. Peresypkina, L.B. Serezhkina, 2008, published in Zhurnal Neorganicheskoi Khimii, 2008, Vol. 53, No. 7, pp. 1115–1120.  相似文献   

16.
Triphenylmethyl salts of the very weakly-coordinating borate anions [CN{B(C6F5)3}2] (1), [H2N{(C6F5)3}2] and [M{CNB(C6F5)3}4]2− (M = Ni, Pd) have been prepared in simple one-pot reactions. Mixtures of (SBI)ZrMe2/1/AlBu 3 i (SBI = rac-Me2Si(Ind)2) are 30–40 times more active in ethylene polymerizations at 60–100°C than (SBI)ZrCl2/MAO. The quantification of anion effects on propene polymerization activity at 20°C gives the order [CN{B(C6F5)3}2] > [H2N{(C6F5)3}2] ≈ B(C6F5) 4 ≫ [MeB(C6F5)3]. The highest productivities were of the order of ca. 3.0 × 108 g PP (mol Zr)−1 h−1 [C3H6]−1, about 1.3–1.5 times higher than with B(C6F5) 4 as the counter anion. The titanium system CGCTiMe2/1/AlBu 3 i gave activities that were very similar to the zirconocene catalyst. The concentration of active species [C*] as determined by quenched-flow kinetic techniques indicates typical values of around 10%, independent of the counter anion, for both the borate and MAO systems. Pulsed field-gradient spin echo and nuclear Overhauser effect NMR experiments on systems designed to be more realistic models for active species with longer polymeryl chains, (SBI)M(CH2SiMe3)(μ-Me)B(C6F5)3 and [(SBI)MCH2SiMe 3 + ...B(C6F5) 4 ] (M = Zr, Hf), demonstrated the influence of bulky alkyl chains on the ion pair solution structures: while the MeB(C6F5)3 compound exists as a simple inner-sphere ion-pair, the B(C6F5) 4 compound is an outer-sphere ion pair (OSIP), a consequence of the relegation of the anion into the second coordination sphere by the γ-agostic interaction with the alkyl ligand. The OSIP aggregates to ion hextuples (10 mM) or quadruples (2 mM). Implications for the polymerization mechanism are discussed; the process follows an associative interchange (I a) pathway. The text was submitted by the authors in English.  相似文献   

17.
Solubility product (Lu(OH)3(s)⇆Lu3++3OH) and first hydrolysis (Lu3++H2O⇆Lu(OH)2++H+) constants were determined for an initial lutetium concentration range from 3.72·10−5 mol·dm−3 to 2.09·10−3 mol·dm−3. Measurements were made in 2 mol·dm−3 NaClO4 ionic strength, under CO2-free conditions and temperature was controlled at 303 K. Solubility diagrams (pLuaq vs. pC H) were determined by means of a radiochemical method using 177Lu. The pC H for the beginning of precipitation and solubility product constant were determined from these diagrams and both the first hydrolysis and solubility product constants were calculated by fitting the diagrams to the solubility equation. The pC H values of precipitation increases inversely to [Lu3+]initial and the values for the first hydrolysis and solubility product constants were log10 β* Lu,H = −7.92±0.07 and log10 K*sp,Lu(OH)3 = −23.37±0.14. Individual solubility values for pC H range between the beginning of precipitation and 8.5 were S Lu3+ = 3.5·10−7 mol·dm−3, S Lu(OH)2+ = 6.2·10−7 mol·dm−3, and then total solubility was 9.7·10−7 mol·dm−3.  相似文献   

18.
The benzene complex [1-(η-C6H6)-12-ButNH-1,2,4,12-FeC3B8H10]+ (3a) was synthesized by the photochemical reaction of [(η5-C6H7)Fe(η-C6H6)]+ (1) with the anion [7-ButNH-7,8,9-C3B8H10] followed by the treatment of ferracarborane 1-(η5-C6H7)-12-ButNH-1,2,4,12-FeC3B8H10 (2) with hydrochloric acid. The benzene ligand in cation 3a is replaced by alkyl-substituted benzenes under visible light irradiation in CH2Cl2 to form [1-(η-C6R6)-12-ButNH-1,2,4,12-FeC3B8H10]+ (3b–e; C6R6 is toluene (b), mesitylene (c), hexamethylbenzene (d), or anisole (e)). The structure of [3c]PF6 was established by X-ray diffraction.  相似文献   

19.
A conjugate of the bacteriochlorophyll a derivative with the cobalt bis(dicarbollide) anion [3,3′-Co(1,2-C2B9H11)2] was synthesized.  相似文献   

20.
The reactions of the tetranuclear hydroxo complexes [M42-OH)8(H2O)16]8+ (M = Zr or Hf) with the lacunary Keggin-type ([α-PW11O39]7−) and Dawson-type ([α 2-P2W17O61]10−) phosphotungstates in aqueous solutions produce the sandwich polyoxometalate complexes [M(α-PW11O39)2]10− (M = Zr (1) or Hf (2)) and [M(α 2-P2W17O61)2]16− (M = Zr (3) and Hf (4)). The complexes were isolated and structurally characterized as salts with potassium and dimethylammonium cations. The zirconium and hafnium atoms have a square antiprismatic coordination environment (coordination number is 8). In all complexes, the mutual arrangement of the ligands corresponds to the syn isomer. Hafnium complexes 2 and 4 are the first structurally characterized polyoxometalate complexes of this metal. The structures of the resulting compounds were confirmed also by 31P NMR spectroscopy in solution. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 214–218, February, 2007.  相似文献   

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