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991.
992.
This paper reports the reaction of Ag2(mnt) and [(NEt4)Ag(mnt)] (mnt2? = maleonitriledithiolate) with PPh3 and 1,2-bis(diphenylphosph 相似文献
993.
The 195Pt and 13C chemical shifts (δPt and δc) are reported for platinum(II), platinum(IV) and class II mixed-valence complexes, with general formula [PtL4]X2, cis- and trans-PtL2X2, PtL2X4 and Pt2L4X6 (where L may be thiourea, 2-imidazolidine-thione, tetrahydro 2-pyrimidinethione, thiocaprolactam, pyridine-2-thione and tetramethylthiourea, and X may be Cl or Br). The 195Pt chemical shifts can be understood in view of 13C data in terms of variations of electronegativities and σ-donor abilities of ligands attached to platinum. 相似文献
994.
Mixed complexes of Pb(II) with some carboxylate ions, viz. tartrate (tart2?), malonate (mal2?) and citrate (citr3?); and imidazole (im) have been studied polarographically at 25°C and at constant ionic strength μ = 2.0 (NaNO3) and at pH 6. The polarographic reduction of the complexes in each case is reversible and diffusion-controlled. Pb(II) forms a single mixed complex with tartrate and imidazole, viz [Pb(tart)(im)] with stability constant log β11 = 4.19; with mal2? and im, three mixed complexes, [Pb(mal)(im)], [Pb(mal)(im)2] and [Pb(mal)2(im)]2? with stability constants log β11 = 4.3, log β12 = 7.3 and log β21 = 5.5 respectively are formed. With citr3? and im a single mixed species, [Pb(citr)(im)]? with stability constant log β11 = 8.0 is formed. Various equilibria involved in the mixed systems have been discussed. 相似文献
995.
996.
The reaction of LiA1H4 with CO2 or NaHCO3 at elevated temperatures has been investigated. Methane and ethylene are the primary products of each reaction. These molecules are probably the “explosive” reaction products formed when CO2 fire extinguishers are used on LiAlH4 fires. 相似文献
997.
Ph3TeF is ionic and no evidence is obtained for a covalent form in solvents of relatively low polarity. By contrast significant covalent interaction is seen for Ph2(CH3)Te(OOCR)(R=Ph, o-CH3O·C6H4-, m-NO2·C6H4). Factors influencing the formation and stability of covalent forms of telluronium “salts” are discussed. Phenyl(methyl)telluronium-ortho-phthalate is shown to be a monomer in chloroform solution. The structure of the compound is discussed in relation to NMR and IR data and against the background of previous literature reports of both dimeric and monomeric diorganotellurium-ortho-phthalates. 相似文献
998.
R.F. Suddendorf D.E. Gutzler M.B. Denton 《Spectrochimica Acta Part B: Atomic Spectroscopy》1976,31(5):281-287
A pulse ultrasonic nebulizer system capable of reproducibly introducing small sample volumes into a flame for analysis by flame emission spectrometry i 相似文献
999.
The action of Na2Fe(CO)4 with tin(IV) and germanium(IV) porphyrins affords metal(II) porphyrin complexes [(por)M(II)Fe(CO)4] (por = porphyrinate, M - Sn(II) or Ge(II)). The molecular structure of [(oep)Sn(II)Fe(CO)4] was solved by X-ray diffraction techniques. The molecular structure of [(oep)Sn(II)Fe(CO)4] was solved by X-ray diffraction techniques : the Sn coordination is square pyramidal with the iron in axial position (Sn-Fe = 2.492(1)Å) whereas the Fe coordination is trigonal bipyramidal. Mössbauer parameters provide convincing evidence for the formal zero oxidation state of the iron atom. 相似文献
1000.
Substitution reactions take place following the photonic excitation of aqueous K4M(CN)8 (where M = Mo or W) in the presence of 1,10-phenanthroline and 2,2bipyridyl. Changes in absorbance with time show that the overall reaction is dependent on photochemical activation of potassium octacyanomolybdate(IV) and -tungstate(IV). The species [K2Mo(CN)4(OH)2(phen)], [K2W(CN)4(OH)2(phen)], [K2Mo(CN)4(OH)2(bipy)] and [K2W(CN)4(OH)2(bipy)] exist in solution. The final photosubstitution products [Mo(OH)3(CN)(phen)2] · 2H2O], [Mo(OH)3(CN)(bipy)2] · 3H2O, [W(OH)3(CN)(phen)2] · 2H2O and [W(OH)3(CN)(bipy)2] · H2O have been isolated in the solid state. Their IR spectra have been discussed. The quantum yield of the photosubstitution reactions has been determined and its variation with change of concentration of the complex as well as the H+ ion concentration has been studied. 相似文献