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1.
Zusammenfassung Phosphinboran und Phosphoniumjodid reagieren mit NaBH4 unter H2-Entwicklung zu H2P(BH3)2–Na+(I), Phenylphosphinboran zuPhHP(BH3)2–Na+ (II). Methylphosphinboran, Phenylphosphin und die Anionen von I und II reagieren nicht mit NaBH4, da die Acidität des an Phosphor gebundenen Wasserstoffs zu gering ist. Auch (PhHP·BCl2)3 reagiert mit NaBH4 unter Wasserstoffentwicklung.
Reaction of phosphine borane, phenylphosphine borane and phosphonium iodide with sodium tetrahydridoborate
The reaction of phosphine borane and phosphonium iodide with NaBH4 yields H2P(BH3)2–Na+ (I), of phenylphosphine boranePhHP(BH3)2–Na+ (II) hydrogen being evolved in both reactions. Methylphosphine borane, phenylphosphine and the anions of I and II do not react with NaBH4 on account of the reduced acidity of the hydrogen atoms bound to phosphorus. Likewise hydrogen is evolved if (PhHP·BCl2)3 reacts with NaBH4.相似文献
2.
M. A. Abuzwida A. G. Maslennikov V. F. Peretrukhin 《Journal of Radioanalytical and Nuclear Chemistry》1991,147(1):41-50
The simultaneous determination of U(VI), Pu(VI), Pu(V) in 0.5–4.0 M NaOH has been elaborated by means of classical and differential pulse voltamperometry. U(VI) is determined with a dropping mercury electrode (DME) at the half-wave potential of E1/2=–0.89 V vs. Ag/AgCl reference electrode due to reduction to U(V). The limiting current or peak heights are proportional to uranium(VI) concentration in the range of 1.3.10–7–3·10–4 M U(VI). Deviation from proportionality is observed for higher concentrations due to polymerization of uranates. Pu(VI) and Pu(V) are determined with a platinum rotating electrode at E1/2=–0.02 V due to the reaction Pu(VI)+e–»Pu(V) and with DME at E1/2=–1.1 V due to the reduction to Pu(III). The limiting currents of both Pu(VI) and Pu(V) are proportional to their concentrations in the range of 4·10–6–1.2·10–3 M Pu. The determination of U(VI), Pu(VI), Pu(V) is not interfered by the presence of the following salts: 2M NaNO3, 2M NaNO2, 1.5M NaAlO2, 0.5M NaF and ions of Mo(VI), W(VI), V(V), Cu(II). The presence of CrO
4
2–
and FeO
2
–
ions disturbs the determination of U(VI) in 1–4M NaOH, however, contribution of the reaction Fe(III)+e–»Fe(II) to uranium reduction peak can be calculated from the height of the second peak Fe(II)+2 e–»Fe(0). 相似文献
3.
Summary The bisacetonitrile complexes [MI2(CO)3(NCMe)2] react with an equimolar amount of L in CH2Cl2 at room temperature to give [MI2(CO)3(NCMe)L] which when mixedin situ with an equimolar amount of [NBu
4
n
]X affords the anionic seven-coordinate compounds [NBu
4
n
][MI2X(CO)3L][M=Mo or W,X=I, L=PPh3 (for M=W only), AsPh3 or SbPh3 (for M=Mo only); M=Mo and W, X=Br3 or Br2I, L=PPh3, AsPh3 or SbPh3]. These reactions are likely to occurvia the stepwise dissociative displacement of two acetonitrile ligands. Low-temperature (–70° C, CD2Cl2)13C n.m.r. spectra (CO resonances) are reported for several of the complexes in order to infer the likely stereochemistry of these compounds. 相似文献
4.
Paul K. Baker Lesley L. Howells Stuart G. Fraser Gordon W. Rogers Martin J. Snowden 《Transition Metal Chemistry》1990,15(1):71-74
Summary The seven-coordinate complexes [MI2(CO)3(NCMe)2] (M=Mo or W) react with two equivalents of L(L=py, 4Me-py, 3Cl-py or 3Br-py) or one equivalent of NN {NN=2,2-bipyridine(bipy), 1,10-phenanthroline(phen), 5,6-dimethyl-1, 10-phenanthroline (5,6-Me2-1, 10-phen), 5-Nitro-1, 10-phenanthroline (5-NO2-1, 10-phen) and C6H4(o-NH2)2 (o-diam) (for M=Mo only)} in CH2Cl2 at room temperature to give the substituted products [MI2(CO)3L2] or [MI2(CO)3(NN)] (1–17) in high yield. The compounds [MI2(CO)3(NCMe)2] react with two equivalents of NN (for M=W, NN=bipy; for M=Mo, NN=phen) to give the dicationic salts [M(CO)3(NN)2]2I(18–19). The compounds [MI2(CO)3(NCMe)2] (M=Mo or W) react with two equivalents of 5,6-Me2-1, 10-phen to yield the monocationic dicarbonyl compounds [MI(CO)2(5,6-Me2-phen)2]I (20 and21). The dicationic mixed ligand complexes [M(CO)3(bipy)(5,6-Me2-phen)]2I (22 and23) are prepared by reacting [MI2(CO)3(NCMe)2] with one equivalent of bipy, followed by anin situ reaction with 5,6-Me2-1, 10-phen to afford the products22 and23. The complexes (1–23) described in this paper have been characterised by elemental analysis (C, H and N), i.r. spectroscopy and, in selected cases,1Hn.m.r. spectroscopy. Magnetic susceptibility measurements show the compounds to be diamagnetic. 相似文献
5.
Dhanpat Rai Yuanxian Xia Linfeng Rao Nancy J. Hess Andrew R. Felmy Dean A. Moore David E. McCready 《Journal of solution chemistry》2005,34(4):469-498
The objectives of this study were to address uncertainties in the solubility product of (UO2)3(PO4)2⋅4H2O(c) and in the phosphate complexes of U(VI), and more importantly to develop needed thermodynamic data for the Pu(VI)-phosphate system in order to ascertain the extent to which U(VI) and Pu(VI) behave in an analogous fashion. Thus studies were conducted on (UO2)3(PO4)2⋅4H2O(c) and (PuO2)3(PO4)2⋅4H2O(am) solubilities for long-equilibration periods (up to 870 days) in a wide range of pH values (2.5 to 10.5) at fixed phosphate concentrations of 0.001 and 0.01 M, and in a range of phosphate concentrations (0.0001–1.0 M) at fixed pH values of about 3.5. A combination of techniques (XRD, DTA/TG, XAS, and thermodynamic analyses) was used to characterize the reaction products. The U(VI)-phosphate data for the most part agree closely with thermodynamic data presented in Guillaumont et al.,(1) although we cannot verify the existence of several U(VI) hydrolyses and phosphate species and we find the reported value for formation constant of UO2PO−4 is in error by more than two orders of magnitude. A comprehensive thermodynamic model for (PuO2)3(PO4)2⋅4H2O(am) solubility in the H+-Na+-OH−-Cl−-H2PO−4-HPO2−4-PO3−4-H2O system, previously unavailable, is presented and the data shows that the U(VI)-phosphate system is an excellent analog for the Pu(VI)-phosphate system. 相似文献
6.
New binuclear complexes with [Cu(PPh3)3]+ and [Cu(PPh3)(N—N)]+ (N—N – 2,2-bipyridine, 1,10-phenanthroline) moieties connected via the isocyanide group to [Ru(bpy)2(py)]+ and [Ru(phen)2(py)]+ have been prepared and isolated as PF6
– salts. In addition, new trinuclear complexes, [{(PPh3)3Cu(-NC)}2Ru(bpy)2](PF6)2 and [{(N—N)-(PPh3)Cu(-NC)}2Ru(bpy)2](PF6)2, have been synthesized using [Ru(bpy)2(CN)2]. The complexes have been characterized by elemental analyses, i.r., n.m.r., u.v.–vis., FAB mass spectra and by conductivity measurements. The i.r. spectra reveal an increase in v;(CN) in the isocyano-bridged complexes compared to the mononuclear parent complexes. The complexes are luminescent with emission wavelengths in the 458–550 and 600–636 nm ranges. The half wave reduction potentials in MeCN are always more positive than those of the parent complexes. It is observed that the isocyano-bridged complexes are more powerful excited state reductants than the cyano-bridged, Cu(I)(-CN)Ru(II) complexes. 相似文献
7.
Conclusions The anionic vanadium borohydride complex NaV(BH4)4,·3DME was obtained and studied employing spectrophotometry, IR spectroscopy, and derivatography.DME = 1,2-dimethoxyethane.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2822–2823, December, 1978.The authors express their gratitude to V. I. Berestenko for taking the derivatograms and discussing the obtained results. 相似文献
8.
Redox potentials: E(UO
2
2+
/UO
2
+
)=60±4 mV/NHE, E(U4+/U3+)=–630±4mV/NHE measured at 25°C in acidic medium (HClO4 1M) using cyclic voltametry are in accordance with the published data. From 5°C to 55°C the variations of the potentials of these systems (measured against Ag/AgCl electrode) are linear. The entropies are then constant: [S(UO
2
2+
/UO
2
+
)–S(Ag/AgCl)]/F=0±0.3 mV/°C, [S(U4+/U3+)–S(Ag/AgCl)]/F=1.5±0.3 mV/°C. From 5°C to 55°C, in carbonate medium (Na2CO3=0.2M), the Specific Ionic Interaction Theory can model the experimental results up to I=2M (Na+, ClO
4
–
, CO
3
2–
): E(UO2(CO3)
3
4–
/UO2(CO3)
3
5–
)=–778±5 mv/NHE (I=0, T=25°C, (25°C)=(UO2(CO3)
3
4–
, Na+)–(UO2(CO3)
3
5–
, Na+)=0.92 kg/mole, S(UO2(CO3)
3
4–
/UO2(CO3)
3
5–
=–1.8±0.5 mV/°C (I=0), =(Cl–, Na+)=(1.14–0.007T) kg/mole. The U(VI/V) potential shift, between carbonate and acidic media, is used to calculate (at I=0,25°C):
相似文献
9.
Reactions of dimethyl(dimethylsulphoxide)pentamethylcyclopentadienyl-rhodium and -irridum with acids
Manuel Gómez Paul I.W. Yarrow Amelio Vázquez De Miguel Peter M. Maitlis 《Journal of organometallic chemistry》1983,259(2):237-243
The complexes [C5Me5MMe2(Me2SO)] (Ia, M = Rh; Ib, M = Ir) react with p-toluenesulphonic acid in acetonitrile to give [C5Me5MMe(Me2SO)(MeCN)]+, (II), and with trifluoroacetic acid to give first [C5Me5MMe(Me2SO)(O2CCF3)] and then [C5Me5M(Me2SO)(O2CCF3)2]. Complexes II react with halide (X?) to give the halomethyl complexes [C5Me5MMe(X)(Me2SO)]. The IR, far-IR, 1H and 13C NMR spectra are all in agreement with structures proposed. 相似文献
10.
Reaction of α-amino acids (HL) with [Ru(PPh3)3Cl2] in the presence of a base afforded a family of complexes of type [Ru(PPh3)2(L)2]. These complexes are diamagnetic (low-spin d6, S=0) and show ligand-field transitions in the visible region. 1H and 31P NMR spectra of the complexes indicate the presence of C2 symmetry. Cyclic voltammetry on the [Ru(PPh3)2(L)2] complexes show a reversible ruthenium(II)–ruthenium(III) oxidation in the range 0.30–0.42 V vs. SCE. An irreversible ruthenium(III)–ruthenium(IV) oxidation is also displayed by two complexes near 1.5 V vs. SCE. 相似文献
11.
In this study, the mononuclear complexes of cadmium(II) and dinuclear complexes of uranyl(VI) with five vic-dioximes have been obtained. Cadmium(II) forms, with ligands, complexes [(L xH)(Cl)(H2O)(Cd)] with x=1–5. Mononuclear complexes with a metal: ligand ratio of 1:1 were obtained for cadmium(II) with the ligands, and a chloride ion and a water molecule are also coordinated to the cadmium(II) ions. Uranyl(VI) complexes of these ligands are a dinuclear structure with μ-hydroxo-bridges. Uranyl(VI) forms, with ligands, complexes [(LxH)2(OH)2(UO2)2] with x=1–5, which have a 2:2 metal:ligand ratio. The structures of the complexes were identified by elemental analysis, i.r., and 1H-n.m.r. spectra, u.v.–vis. spectroscopy, magnetic susceptibility measurements, conductivity measurements and thermogravimetric analysis (t.g.a.). 相似文献
12.
Summary The HFe3(CO)9S– and Fe3(CO)9S2– anions [prepared from H2Fe3(CO)9S by deprotonation] react with M(CO)5(THF) (M=Cr or W) to form the anionic capped clusters, HFe3(CO)9SM(CO)
5
–
and Fe3(CO)9SM(CO)
5
2–
, which can be isolated as their Et4N salts. The M-S bonds of these complexes are cleaved by ligands such as PPh3 or MeCN. The dianionic clusters are more stable than their monoanionic analogues. Alkylation of Fe3(CO)9S2– with alkyl halides followed by protonation yields HFe3(CO)9SR complexes, among them the first member of the series with R=Me. 相似文献
13.
Hari C. Bajaj Surendra Prasad Radhey M. Naik Prem C. Nigam 《Transition Metal Chemistry》1991,16(5):511-517
Summary The kinetics and mechanism of ligand substitution reactions of tetraethylenepentamine nickel(II), Ni (Teren), and triethylenetetraamine nickel(II), Ni(Trien), with 4-(2-pyridylazo)resorcinol (parH2) have been studied spectrophotometrically at I=0.1 M (NaClO4) at 25°C. In both systems two distinct reaction steps are observed. The rapid first step follows the rate law d[Ni(Polyamine)(ParH2)]/dt=k1 [Ni(Polyamine)] [ParH2]. The formation of ternary complexes of Ni (Polyamine) with ParH2 has been investigated under second order equal concentration conditions. The values of second order rate constants for the Trien and Teren reactions are (2.1±0.2)×104 M–1s–1 and (7.8±0.6)×103 M–1s–1 respectively at pH=9.0, I=0.1 M and 25°C.The rate law for the second step may be written as d[Ni(Par)2]/dt=k2[Ni(Polyamine)(ParH2)]. Values of k2 for the Trien and Teren systems are (2.5±0.1)×10–4 s–1 and (4.76±0.3)×10–5 s–1 respectively. 相似文献
14.
The kinetics of electroreduction of ethylenediamine and hydroxyethylenediamine complexes of zinc(II) on a dropping-mercury electrode (DME) in 1 M NaClO4 solutions of pH 9–11.5 is studied at different ethylenediamine concentrations at 25, 35, and 50°C. One wave with a diffusion limiting current is observed at an overall concentration of zinc(II) complexes of 2 × 10–5 M and current recording times t
1 = 0.3–4 s. The polarographic peak that distorts the wave at t
1 0.5 s, pH 11.5, and 25°C is due to the accumulation of insoluble reduction products on the electrode surface. The slow electrochemical step on DME involves complexes Znen2+, which form in preceding reversible chemical steps from complexes present in solution.__________Translated from Elektrokhimiya, Vol. 41, No. 4, 2005, pp. 397–405.Original Russian Text Copyright © 2005 by Kurtova, Kravtsov, Tsventarnyi. 相似文献
15.
Ramesh C. Kapoor Raj N. Mehrotra Shared K. Vajpai Purnima Chaudhary 《Transition Metal Chemistry》1991,16(1):65-70
Summary The kinetics of the OsVIII-catalysed oxidation of glycols by alkaline hexacyanoferrate(III) ion exhibits zerothorder dependence in [Fe(CN)
6
3–
] and first-order dependence in [OsO4]. The order with respect to glycols is less than unity, whereas the rate dependence on [OH–] is a combination of two rate constants; one independent of and the other first-order in [OH–]. These observations are commensurate with a mechanism in which two complexes, [OsO4(H2O)G]– and [OsO4(OH)G]2–, are formed either from [OsO4(H2O)(OH)]– or [OsO4(OH)2]2– and the glycol GH, or by [OsO4(H2O)2] and [OsO4(H2O)(OH)]– and the glycolate ion, G–, which is in equilibrium with the glycol GH through the reaction between GH and OH–. Hence there is an ambiguity about the true path for the formation of the two OsVIII-glycol complexes. A reversal in the reactivity order of glycols in the two rate-determining steps, despite the common attack of OH– ion on the two species of OsVIII-complexes, indicates that the two complexes are structurally different because S changes from the negative (corresponding to k11) to positive (related to k2). 相似文献
16.
Asymmetric 7-formyanil-substituted-imino-4-(4-methyl-2-butanone)-8-hydroxyquinoline-5-sulphonic acid (Schiff bases), react with CoII, NiII and CuII ions to give 1:2, 1:1 and 2:1 complexes as established by conductometric titrations in 1:1 DMF:H2O. The complexes were investigated by elemental analyses, molecular weight determinations, molar conductance, magnetic moments, thermal analysis, i.r., u.v.–vis. and e.s.r. spectra. The complexes have an octahedral crystal structure and general formula [ML·(OH2)2], where MII = Co, Ni and Cu, and L = Na[7—X—HL], (—X— = (CH2)2, (CH2)3, p-C6H4, o-C6H4). Antimicrobial activity of these new ligands and their transition metal complexes has been screened in vitro on common fungi and bacteria. 相似文献
17.
Herbert Schumann Markus R. Keitsch Stefan H. Mühle 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(1):48-49
The lanthanidocene complex [Sm(BH4)(C12H19)2(C4H8O)], (I), shows a distorted tetrahedral arrangement around the central SmIII atom. It consists of two η5‐isopropyltetramethylcyclopentadienyl ligands, one tetrahydroborato (BH4?) ligand bridging via H atoms to the lanthanide atom and one coordinating tetrahydrofuran (thf) molecule. The BH4? unit of (I) coordinates as a tridentate ligand with three bridging H atoms and one terminal H atom [Sm—B—H4 176 (2)°]. The η5‐isopropyltetramethylcyclopentadienyl ligands of this bent‐sandwich complex [Cp1—Sm—Cp2 133.53 (1)° where Cp denotes the centroid of the cyclopentadienyl ring] adopt staggered conformations. 相似文献
18.
The formation of complexes between Mo(VI) and 8-hydroxy-quinoline (oxine) and four oxine derivatives were investigated by multiwavelength molecular absorption spectrometry, potentiometry, and polarography. The following pKOH- and pKNH- values of the ligands and logK
211-values of the complexes MoO2(OH)2L
x– (x=1 or 2) were obtained at 25° C and an ionic strength of 1M(NaClO4): 5,7-dinitro8-hydroxyquinoline 4.59, <0, 14.50; 7-nitro-8-hydroxyquinoline-5-sulfonic acid 5.34, 0.41, 15.70; 7-iodo-8-hydroxyquinoline-5-sulfonic acid 6.98, 2.62, 17.65; 8-hydroxyquinoline-5-sulfonic acid 8.33, 4.13, 18.71; and 8-hydroxyquinoline 9.62, 5.28, 19.69. A good linearity was found between logK
211 and the sum of the pK-values of the OH- and NH+-groups. The dependence of the peak current of Mo(VI)-determinations by adsorption polarography of the 7-nitro-8-hydroxyquinoline-5-sulfonate complex of Mo(VI) MoO(OH)3L– can quantitatively be described at pH 0.8–2 using the corresponding pK-values and the log K311 of 18.54±0.03, determined by polarography. 相似文献
19.
Superhalogens are species whose electron affinity (EA) or vertical detachment energy (VDE) exceeds those of halogens. These species typically consist of a central electropositive atom with electronegative ligands. The EA or VDE of species can be further increased by using superhalogens as ligands, which are termed as hyperhalogens. Having established BH4− as a superhalogen, we have studied BH4 − x(BH4)x− (x = 1–4) hyperhalogen anions and their Li-complexes LiBH4 − x(BH4)x using density functional theory. The VDE of these anions is larger than that of BH4−, which increases with the increase in number of peripheral BH4 moieties (x). The hydrogen storage capacity of LiBH4 − x(BH4)x complexes is higher but binding energy is smaller than that of LiBH4, a typical complex hydride. The linear correlation between the dehydrogenation energy of LiBH4 − x(BH4)x complexes and the VDE of BH4 − x(BH4)x− anions is established. These complexes are found to be thermodynamically stable against dissociation into LiBH4 and borane. This study demonstrates the role of superhalogens in designing new materials for hydrogen storage and should also motivate experimentalists to synthesize LiBH4 − x(BH4)x (x = 1–4) complexes. 相似文献
20.
《Journal of organometallic chemistry》1987,336(3):377-383
The complexes [WI2(CO)(NCMe)(η2)-RC2R)2] (R = Me and Ph) react in CH2Cl2 with an excess of carbon monoxide to give initially the acetonitrile substituted products [WI2(CO)2(η2-RC2R) 2]. For R= Me, the complex [WI2(CO)2(η2- MeC2Me)2] (1) was isolated and its structure determined by X-ray crystallography. However, for R = Ph, dimerisation occurs to give the iodide-bridged compound [W(μ-I)I(CO)(η2-PhC2Ph)2]2 (2) with loss of carbon monoxide. These reactions are reversible as 1 and 2 react with acetonitrile to give [WI2(CO)(NCMe)(η2-RC2R)2]. The 13C NMR spectra of I and 2 indicate that the two alkyne ligands donate a total of six electrons to the tungsten in these complexes. 相似文献
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