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1.
Mechanically pre-activated K 2PtCl 4 salt consumes methyl iodide producing methyl chloride at room temperature. The reaction mechanism includes the following steps sequence: oxidative addition of methyl iodide to platinum(II) complexes with intermediate formation of methyl platinum(IV) complexes and further decomposition of the latter in the course of innersphere reductive elimination yielding methyl chloride. The first step of the reaction proceeds owing to the assistance of active centers regenerated in the course of each event of MeI into MeCl transformation taking part in the chain halogen substitution process. It could be assumed that the role of active centers is played by coordinatively unsaturated platinum(II) complexes located on the surface. These species bearing a positive efficient charge can render electrophilic assistance for the nucleophilic substitution. The chain termination can be caused by recombination of coordinatively unsaturated platinum(II) complexes and interstitial chloride ions forming an inactive K 2PtCl 4 complex. 相似文献
2.
The reactions of the alkylsulfonated phosphines LM=Ph 2P(CH 2) nSO 3Na/K ( n=2, 3, 4) with K 2PtCl 4 and K 2PdCl 4 have been studied in homogeneous aqueous solution as a function of pH. In homogeneous acidic solution the protonated phosphines react to give cis- and trans-PtCl 2(LH) 2. The biphasic reaction between 1,5-cyclooctadiene platinum(II) chloride in dichloromethane and acidified aqueous LNa/K gives a higher proportion of the cis isomer. In neutral solution the initial reaction to give [PtCl(LNa/K) 3] +Cl − is followed by slow formation of cis-PtCl 2(LNa/K) 2. K 2PdCl 4 reacts more rapidly to give PdCl 2(LNa/K) 2. In homogeneous alkaline solution rapid oxidation of the phosphine occurs with only small amounts of platinum complex being observable. The biphasic reaction yields phosphine oxide in the aqueous layer and a small amount of the chelate complexes PtL 2 in the organic. Representative complexes have been isolated and characterised and the mechanisms for the reactions discussed. The electrospray mass spectra of solutions of the isolated complexes have been recorded in both positive and negative ionisation modes. The positive ionisation spectra are complicated, but platinum and palladium containing ions derived from loss of chloride, H + and HCl are observed in the negative ionisation spectra. 相似文献
3.
Me 3Si-X reagents react to completion at 25°C in a short time to convert Ir(H) 2FL 2 (L=P tBu 2Ph) to Ir(H) 2XL 2. This involves formation of Ir-O, Ir-N, Ir-I, Ir-S and Ir-C(sp) bonds. Products include some η2-X ligands such as carboxylate and acetamide, NHC(O)CH 3. The acetamide is shown to be η2 in the solid state and in solution, but readily rearranges, by a transition state with Ir-O bond cleavage, to effect site exchange of the two inequivalent hydrides. The same synthetic approach succeeds for the more crowded metallated species and these reactions arc shown to fail when F is replaced by Cl in the iridium reagent. Unsaturation at Ir is suggested to be central to the mechanism of these F/X transposition reactions. 相似文献
4.
The water-soluble bisphosphine, 1,2-bis(bis(hydroxymethyl)phosphino)ethane (1), was synthesized in near quantitative yield by the reaction of bisphosphine, H 2PCH 2CH 2PH 2, with an aqueous formaldehyde in the presence of K 2PtCl 4. The reaction of this water-soluble bisphosphine 1 with cis-Pt(COD)Cl 2 affords the mononuclear bischelate complex, [Pt{(HOH 2C) 2PCH 2CH 2P(CH 2OH) 2} 2](Cl) 2 (2), in near quantitative yield. The new ligand and complex have been characterized spectroscopically and the structure of the metal complex, 2, was determined by X-ray crystallography. The Pt(II) complex 2 crystallizes in the orthorhombic space group Pbca( a=14.623(1), B=16.216(2), C=9.319(4) Å) with Z=4. The final R value is 0.024. 相似文献
5.
The synthesis and structure of a monoperoxo vanadate(V) of the formula K 2[VO(O 2)NTA]·2H[ 2O, where NTA = C 6H 6NO 6 3−, the nitrilotriacetate, is described. This stable compound crystallizes in the orthorhombic system (space group Pna2 1): a = 7.621(1), B = 13.002(3), C = 13.155(1) Å. A tetradentate NTA encloses vanadium in a distorted pentagonal bipyramid with an apical V = O group. Cis to it, in the pentagonal plane, a non-symmetrically coordinated peroxo group is located with an (O---O) bond length of 1.438(4) Å. Complex IR spectra display rich absorption due to coordinated NTA, in addition to the characteristic V = O and (O---O) stretching vibrations. Aqueous solutions of the complex show a (peroxo → V(V)) charge transfer band at γ max = 425 nm. 相似文献
6.
维生素K 2(VK 2)是一类具有甲基萘醌结构的脂溶性维生素,越来越多的研究表明VK 2具有多重生理功能,在抗骨质疏松、抑制血管钙化、糖尿病、肿瘤、肝病、慢性肾病、免疫性疾病、神经系统疾病和肥胖等多种疾病中发挥着重要作用。为了更好地指导人们合理地补充VK 2,迫切需要建立简单、可行、准确度和特异性高的VK 2测定方法,确定其正常值范围。本文回顾近年来VK 2的临床检测及其评价方法,对VK 2的体内血药浓度检测、血液标志物检测等进行概述总结,为临床上VK 2的合理应用提供依据。 相似文献
7.
Two ruthenium(II) complexes with polypyridyl, Ru(bipy) 2(phen)](ClO 4) 2·H 2O (1) and [Ru(bipy) 2(Me-phen)](ClO 4) 2 (2), (phen = 1,10-phenanthroline, bipy = 2,2′-bipyridine, Me-phen = 5-methyl-1,10-phenanthroline), were synthesized and characterized by IR, MS and NMR spectra. Their structures were determined by single crystal X-ray diffraction techniques. The strong steric interaction between the polypyridyl ligands was relieved neither by the elongation of the Ru---N bonds nor increase of the N---Ru---N bite angles. The coordination sphere was distorted to relieve the ligand interaction by forming specific angles (δ) between the polypyridyl ligand planes and coordination planes (N---Ru---N), and forming larger twisted angles between the two pyridine rings for each bipy. The bond distances of Ru---N(bipy) and Ru---N(phen) were virtually identical with experimental error, as expected of π back-bonding interactions which statistically involve each of the ligands present in the coordination sphere. 相似文献
8.
Two novel tetracopper(I) and tetrasilver(I) complexes [Cu 4(atdz) 6](ClO 4) 4·2CH 3OH (1) and [Ag 4(atdz) 6](ClO 4) 4 (2), have been prepared using 2-amino-1,3,4-thiadiazole (atdz), and their crystal structures and properties have been determined. On each tetranuclear complex, two Cu or Ag atoms (M) are bridged by two atdz ligands to form a six-membered N 2M 2N 2 framework. The two N 2M 2N 2 frameworks are in parallel linked by another atdz ligand to provide the tetranuclear structure with a rectangular M 4 core. The four Cu or Ag atoms possess a trigonal-square geometry. The two adjacent MM separations are (3.096(1) and 3.412(1) Å) and (3.316(2) and 3.658(2) Å) for 1 and 2, respectively. On both tetranuclear complexes there are two species of hydrogen bonds between the ClO 4 − anions and the NH 2 group of atdz ligands. It is proposed that the hydrogen bonds are related to the stabilization of the tetranuclear structure during the crystallization process. 相似文献
9.
The photochemistry of the diphosphino Pt(II) hydrides [LPtH 2] (L=(t-Bu) 2P(CH 2) 2P(t-Bu) 2 (7); L=(t-Bu) 2P(CH 2) 3P(t-Bu) 2 (8);L=(t-Bu)(Ph)P(CH 2) 2P(Ph)(t-Bu) (9)) is reported. The primary photoevent is the dissociation of H 2 and formation of the 14-e [LPt] species. These coordinatively unsaturated intermediates provide a versatile entry point into the C---H bond activation of hydrocarbons. [LPt] reacts with benzene in an oxidative addition reaction to yield [LPt(H)(C 6H 5)] complexes. The importance of the metal centre and ancillary ligation in the C---H bond activation is discussed. 相似文献
10.
The interaction of a ‘double-hydrophilic’ polyethyleneoxide-polyethyleneimine block copolymer (PEO-b-PEI) with AuCl 3, PdCl 2, Na 2PdCl 4, H 2PtCl 6·6H 2O, Na 2PtCl 6·6H 2O, and K 2PtCl 4 in aqueous medium was studied. Micellar structure formation was observed for all metal compounds except Na 2PdCl 4 where additional protonation of the polymer was required to induce micelle formation. The characteristics of the micelles formed depended strongly on the metal type, the molar ratio polymermetal compound, and the type of reducing agent. Micellization in the presence of AuCl 3·H 2O is accompanied with reduction of the salt and the formation of gold colloid without reducing agent induced by oxidation of the PEI block. The interaction with PtCl 62− ions results in narrowly distributed micelles wi size depending on the metal compound loading. In the case of loading with H 2PtCl 6, it was found that the size and shape of the colloids can be controlled by changing the molar ratio PEI:metal salt. The lower is the metal loading, the smaller are the particles. In addition, differently shaped Pt colloids were observed. This phenomenon can be controlled by the relative ratio of reactants. 相似文献
11.
Treatment of a THF solution of trans-[ReCl(N 2)L 4] (L = PMePh 2) with a cyanamide, NCNR 2 (R = Me, Et or H) or with cyanoguanidine, NCNC(NH 2) 2 , yields mer-[ReCl(N 2)(NCNR 2)L 3] (1) or mer-[Re(N 2)[Re(N 2){NCNC(NH 2) 2} 2L 3]Cl (2), respectively, which, to our knowledge, are the first mixed dinitrogen-cyanamide-type complexes to be reported. The former products (1, R=Me or Et) can also be obtained from reaction of the benzoyldiazenido complex [ReCl 2(NNCOPh)L 3] with NCNR 2 in refluxing methanol; the Re(II) complex mer-[ReCl 2(NCNEt 2)L 3] (3) is also formed (conceivably via an unusual homolysis of the C---N bond of the benzoyldiazenido ligand) and its crystal structure is reported. It shows an unusual pyramidal conformation at the amine N atom of the diethylcyanamide ligand which also exhibits a significant structural trans influence on the phosphine, behaving as a stronger net electron donor than the latter ligand. 相似文献
12.
The reaction of the title complex with DNA has been examined. Addition of [(bpy) 2(OH 2)RuORu(OH 2) (bpy) 2] 4+ to DNA leads to the reduction of the complex to Ru(bpy) 2(OH 2) 22+, as indicated by absorption spectroscopy and cyclic voltammetry. The reaction is accelerated by Mg 2+. The combined evidence points to a mechanism where the oxo-bridged dimer is hydrolyzed to a monomeric Ru(III) complex that is capable of oxidizing DNA to effect strand scission. Gel electrophoresis demonstrates nicking of supercoiled /gfX174 DNA by [(bpy) 2(OH 2)RuORu(OH 2) (bpy) 2] 4+, and double-stranded cleavage is observed in the presence of Mg 2+. Linearization of the plasmid prior to treatment with the complex does not lead to further fragmentation, suggesting that supercoiling is required to realize double-stranded cleavage. 相似文献
13.
New manganese(III) complexes of Hphox (2-(2′-hydroxyphenyl)-oxazoline) and HClphox (2-(5′-chloro-2′-hydroxyphenyl)-oxazoline) have been synthesised. The X-ray structures of [Mn(phox) 2(MeOH) 2][Mn(phox) 2(ClO 4) 2](H 2O) 2 and [Mn(Clphox) 2(MeOH) 2](ClO 4) show the manganese(III) ions to be octahedrally coordinated with methanol or perchlorate at the axial coordination sites. The cyclic voltammograms of the complexes, with the exception of [Mn(phox) 2(acac)] (Hacac=2,4-pentanedione), show an irreversible reduction wave of manganese(III) to manganese(II). After addition of an excess of 1-methylimidazole (1-Meim), the reduction process shifts towards lower potentials and becomes (quasi-) reversible, indicating that the presence of 1-Meim affects the catalytic efficiency of the complexes. The complexes catalyse the epoxidation of styrene by dihydrogen peroxide. The cumulative turnover numbers towards styrene oxide obtained after 15 min. vary from 16 for [Mn(Clphox) 2(MeOH) 2](ClO 4) to 26 for [Mn(phox) 2(acac)]. Ligand degradation appears to be the limiting factor for obtaining higher turnover numbers. 相似文献
14.
The labile cations [Cu(F-BF 3)(PCy 3) 2] and [Cu(OTf)(PCy 3) 2] are versatile precursors for the formation of [Cu(X)(PCy 3) 2] (X = Br, I, SCN, N 3) complexes by metathesis with NaX. The azide [Cu(N 3)(PCy 3) 2] is triclinic, space group
, a = 9.755(4), B = 22.78(1), C = 9.284(6) Å, = 96.76(3), β = 115.36(3), γ = 94.20(5)°, Z = 2. 相似文献
15.
The Pt 2 (II) isomeric terminal hydrides [(CO)(H)Pt(μ-PBu t 2) 2Pt(PBu t 2H)]CF 3SO 3 (1a), and [(CO)Pt(μ-PBu t 2) 2Pt(PBu t 2H)(H)]CF 3SO 3 (1b), react rapidly with 1 atm of carbon monoxide to give the same mixture of two isomers of the Pt 2 (I) dicarbonyl [Pt 2(μ-PBu t 2)(CO) 2(PBu t 2H) 2]CF 3SO 3 (3-Pt); the solid state structure of the isomer bearing the carbonyl ligands pseudo- trans to the bridging phosphide was solved by X-ray diffraction. A remarkable difference was instead found between the reactivity of 1a and 1b towards carbon disulfide or isoprene. In both cases 1b reacts slowly to afford [Pt 2(μ-PBu t 2)(μ,η 2,η 2-CS 2)(PBu t 2H) 2]CF 3SO 3 (4-Pt), and [Pt 2(μ-PBu t 2)(μ,η 2,η 2-isoprene) (PBu t 2H) 2]CF 3SO 3 (6-Pt), respectively. In the same experimental conditions, 1a is totally inert. A common mechanism, proceeding through the preassociation of the incoming ligand followed by the P---H bond formation between one of the bridging P atoms and the hydride ligand, has been suggested for these reactions. 相似文献
16.
The chloro complexes trans-[Pt(Me)(Cl)(PPh 3) 2], after treatment with AgBF 4, react with 1-alkynes HC---C---R in the presence of NEt 3 to afford the corresponding acetylide derivatives trans-[Pt(Me) (C---C---R) (PPh 3) 2] (R = p-tolyl (1), Ph (2), C(CH 3) 3 (3)). These complexes, with the exception of the t-butylacetylide complex, react with the chloroalcohols HO(CH 2) nCl ( n = 2, 3) in the presence of 1 equiv. of HBF 4 to afford the alkyl(chloroalkoxy)carbene complexes trans-[Pt(Me) {C[O(CH 2) nCl](CH 2R) } (PPh 3) 2][BF 4] (R = p-tolyl, N = 2 (4), N = 3 (5); R=Ph, N = 2 (6)). A similar reaction of the bis(acetylide) complex trans-[Pt(C---C---Ph) 2(PMe 2Ph) 2] with 2 equiv. HBF 4 and 3-chloro-1-propanol affords trans-[Pt(C---CPh) {C(OCH 2CH 2CH 2Cl)(CH 2Ph) } (PMe 2Ph) 2][BF 4] (7). T alkyl(chloroalkoxy)-carbene complex trans-[Pt(Me) {C(OCH 2CH 2Cl)(CH 2Ph) } (PPh 3) 2][BF 4] (8) is formed by reaction of trans-[Pt(Me)(Cl)(PPh 3) 2], after treatment with AgBF 4 in HOCH 2CH 2Cl, with phenylacetylene in the presence of 1 equiv. of n-BuLi. The reaction of the dimer [Pt(Cl)(μ-Cl)(PMe 2Ph)] 2 with p-tolylacetylene and 3-chloro-1-propanol yields cis-[PtCl 2{C(OCH 2CH 2CH 2Cl)(CH 2C 6H 4- p-Me}(PMe 2Ph)] (9). The X-ray molecular structure of (8) has been determined. It crystallizes in the orthorhombic system, space group Pna2 1, with a = 11.785(2), B = 29.418(4), C = 15.409(3) Å, V = 4889(1) Å 3 and Z = 4. The carbene ligand is perpendicular to the Pt(II) coordination plane; the PtC(carbene) bond distance is 2.01(1) Å and the short C(carbene)-O bond distance of 1.30(1) Å suggests extensive electronic delocalization within the Pt---C(carbene)---O moietry. 相似文献
17.
Reactions of [Rh(COD)Cl] 2 with the ligand RN(PX 2) 2 (1: R = C 6H 5; X = OC 6H 5) give mono- or disubstituted complexes of the type [Rh 2(COD)Cl 2{ν 2−C 6H 5N(P(OC 6H 5) 2) 2}] or [RhCl{ν 2−C 6H 5 N(P(OC 6H 5) 2) 2 }] 2 depending on the reaction conditions. Reaction of 1 with [Rh(CO) 2Cl] 2 gives the symmetric binuclear complex, [Rh(CO)Cl{μ−C 6H 5N(P(OC 6H 5) 2) 2} 2, whereas the same reaction with 2 (R = CH 3; X = OC 6H 5) leads to the formation of an asymmetric complex of the type [Rh(CO)(μ−CO)Cl{μ−CH 3N(P(OC 6H 5) 2) 2} 2 containing both terminal and bridging CO groups. Interestingly the reaction of 3 (R = C 6H 5, X = OC 6H 4Br− p with either [Rh(COD)Cl] 2 or [Rh(CO) 2Cl] 2 leads only to the formation of the chlorine bridged binuclear complex, [RhCl{ν 2−C 6H 5N(P(OC 6H 4Br− p) 2) 2}] 2. The structural elucidation of the complexes was carried out by elemental analyses, IR and 31P NMR spectroscopic data. 相似文献
18.
Hybrid membrane particles from two mutants of Escherichia coli K 12, B v4 and K I1, defective in oxidative phosphorylation, have been prepared, in which ATP-driven membrane energization is restored. A soluble factor of mutant KI1 was found to have properties similar to parental crude coupling factor, ATPase (EC 3.6.1.3). Membrane particles of this mutant could not be reconstituted by parental coupling factor. Either parental coupling factor, or the soluble factor of mutant KI1 could reconstitute both respiration-driven and ATP-driven energization to membrane particles of mutant BV4 or to parental particles depleted of ATPase. Mutant BV4 was found to be devoid of coupling factor activity, while retaining the ability to hydrolyze ATP. Both mutants possess an ATPase with an altered binding to the membrane. Mutant KI1 is impaired in respiration-driven amino acid transport, in contrast to mutant BV4. The three major subunits of parental Escherichia coli ATPase have been isolated and antibodies have been prepared against these subunits. Antibodies against the largestsubunit ( component) or against the intact catalytic subunits ( + β components) inhibit both ATP-Pi exchange in the parent organism as well as ATP hydrolytic activity in parent and mutants. Antibodies against the two other subunits (β or γ components) also inhibit these two reactions, but were found to be less effective. Mutant NI44, which lacks ATPase activity, shows no precipitin lines with anti-, anti-β, anti-γ, or anti-( + β) preparations. In contrast, mutants BV4 and KI1, exhibit cross-reactivity with all of the antisera. 相似文献
19.
Two new spin-crossover complexes, [Fe(Medpq)(py) 2(NCS) 2] · py · 0.5H 2O (1) and [Fe(Medpq)(py) 2(NCSe) 2] · py (2) (Medpq = 2-methyldipyrido[3,2- f:2′,3′- h]-quinoxaline, py = pyridine), have been synthesized. The crystal structures were determined at both room temperature (298 K) and low temperature (110 K). Complexes 1 and 2 crystallize in the orthorhombic space group Pbca and monoclinic space group P2 1/ n, respectively. In both complexes, the distorted [FeN 6] octahedron is formed by six nitrogen atoms from Medpq, the trans pyridine molecules and the cis NCX − groups. The thermal spin transition is accompanied by the shortening of the mean Fe–N distances by 0.194 Å for 2. The mononuclear [Fe(Medpq)(py) 2(NCS) 2] and [Fe(Medpq)(py) 2(NCSe) 2] neutral species interact each other via π-stacking, resulting in a one-dimensional extended structure for both 1 and 2. There exist C–HX (X = S, Se) hydrogen bonds for both complexes. Variable-temperature magnetic susceptibility measurements and Mössbauer spectroscopy reveal the occurrence of a gradual spin transition. The transitions are centered at T1/2 = 120 K for 1 and T1/2 = 180 K for 2, respectively. 相似文献
20.
New mixed metal complexes SrCu 2(O 2CR) 3(bdmap) 3 (R = CF 3 (1a), CH 3 (1b)) and a new dinuclear bismuth complex Bi 2(O 2CCH 3) 4(bdmap) 2(H 2O) (2) have been synthesized. Their crystal structures have been determined by single-crystal X-ray diffraction analyses. Thermal decomposition behaviors of these complexes have been examined by TGA and X-ray powder diffraction analyses. While compound 1a decomposes to SrF 2 and CuO at about 380°C, compound 1b decomposes to the corresponding oxides above 800°C. Compound 2 decomposes cleanly to Bi 2O 3 at 330°C. The magnetism of 1a was examined by the measurement of susceptibility from 5–300 K. Theoretical fitting for the susceptibility data revealed that 1a is an antiferromagnetically coupled system with g = 2.012(7), −2 J = 34.0(8) cm −1. Crystal data for 1a: C 27H 51N 6O 9F 9Cu 2Sr/THF, monoclinic space group P2 1/ m, A = 10.708(6), B = 15.20(1), C = 15.404(7) Å, β = 107.94(4)°, V = 2386(2) Å 3, Z = 2; for 1b: C 27H 60N 6O 9Cu 2Sr/THF, orthorhombic space group Pbcn, A = 19.164(9), B = 26.829(8), C = 17.240(9) Å, V = 8864(5) Å 3, Z = 8; for 2: C 22H 48O 11N 4Bi 2, monoclinic space group P2 1/ c, A = 17.614(9), B = 10.741(3), C = 18.910(7) Å, β = 109.99(3)°, V = 3362(2) Å 3, Z = 4. 相似文献
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