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161.
本文报道一个光度法测定纳克量锡的新方法。在聚乙烯醇(PVA)存在下锡(Ⅳ)与钨酸盐和耐尔蓝(NB)反应形成离子缔合物,离子缔合物的最大吸收位于580nm,表观摩尔吸光系数ε值2.95×107L·mo1-1·cm-1,服从比耳定律范围0~2.0μg/L,检出限(3σ)0.083μg/L(n=10),对2.0μg/L锡测定的RSD为1.42%(n=11),离子缔合物至少稳定72h。考察了40多种共存离子的影响,大多数常见元素不干扰。测定锡的适宜条件[H2SO4]=1.20mo1/L,[WO2-4]=6.05×10-5mo1/L,[NB]=5.5×10-5mo1/L和PVA0.08%。本法已用于某些合金钢和锌合金中纳克量锡的测定,结果与推荐值吻合,回收率满意。 相似文献
162.
B. Rke F. Zülch Y. Ding J. Prust H. W. Roesky M. Noltemeyer H.‐G. Schmidt 《无机化学与普通化学杂志》2001,627(5):836-840
Synthesis, Structure, and Properties of [nacnac]MX3 Compounds (M = Ge, Sn; X = Cl, Br, I) Reactions of [nacnac]Li [(2,6‐iPr2C6H3)NC(Me)C(H)C(Me)N(2,6‐iPr2C6H3)]Li ( 1 ) with SnX4 (X = Cl, Br, I) and GeCl4 in Et2O resulted in metallacyclic compounds with different structural moieties. In the [nacnac]SnX3 compounds (X = Cl 2 , Br 3 , I 4 ) the tin atom is five coordinated and part of a six‐membered ring. The Sn–N‐bond length of 3 is 2.163(4) Å and 2.176(5) Å of 4 . The five coordinated germanium of the [nacnac]GeCl3 compound 5 shows in addition to the three chlorine atoms further bonds to a carbon and to a nitrogen atom. In contrast to the known compounds with the [nacnac] ligand the afore mentioned reaction creates a carbon–metal‐bond (1.971(3) Å) forming a four‐membered ring. The Ge–N bond length (2.419(2) Å) indicates the formation of a weakly coordinating bond. 相似文献
163.
The single‐crystal X‐ray structure analysis of hexakis(2,4,6‐triisopropylphenyl)cyclotristannoxane, cyclo‐[(2,4,6‐i‐Pr3‐C6H2)2SnO]3 ( 1 ), is reported and reveals this compound to contain an almost planar six‐membered ring. Redistribution reactions of 1 with cyclo‐(t‐Bu2SnO)3 and t‐Bu2SiCl2, respectively, failed and indicate an unusual kinetic inertness of the Sn–O bonds in 1 as compared to related molecular diorganotin oxides containing less bulkier substituents. The redistribution reaction of cyclo‐(t‐Bu2SnO)3 with cyclo‐(t‐Bu2SnS)2 leads to an equilibrium involving the trimeric diorganotin oxysulphides cyclo‐t‐Bu2Sn(OSnt‐Bu2)2S ( 2 a ) and cyclo‐t‐Bu2Sn(SSnt‐Bu2)2O ( 2 b ). 相似文献
164.
Jens Beckmann Klaus Jurkschat Stephanie Rabe Markus Schürmann Dainis Dakternieks 《无机化学与普通化学杂志》2001,627(3):458-464
The syntheses of the asymmetrically substituted tetraorganodistannoxanes [t‐Bu2(X)SnOSn(Y)(CH2SiMe3)2]2 ( 1 , X = Y = OH; 2 , X = Cl, Y = OH; 3 , X = Y = Cl) are reported and their structures in solution and in the solid state are characterized by multinuclear NMR spectroscopy and single crystal X‐ray analyses. In toluene, the tetrahydroxy‐substituted derivative 1 is in equilibrium with the organotin oxides cyclo‐[t‐Bu2Sn{OSn(CH2SiMe3)2}2O] ( 4 ), cyclo[(Me3SiCH2)2Sn(OSnt‐Bu2)2O] ( 5 ), and cyclo‐(t‐Bu2SnO)3, and some additional, undefined species containing pentacoordinated tin atoms. In contrast, the dihydroxydichloro‐substituted derivative 2 is inert in solution. 相似文献
165.
Reaction of the chiral lithium stannate [HC{SiMe2N[(S)–CH(Me)Ph]}3SnLi(thf)] ( 1 ) with Me3SnCl gave the corresponding distannane [HC{SiMe2N[(S)–CH(Me)Ph]}3Sn–SnMe3] ( 2 ) in good yield. Its [2,2,2]bicyclooctane‐related cage structure, comprising the trisilylsilane unit and the triamido‐tin fragment, as well as the Sn–Sn bond (2.7978(15)–2.8020(15) Å in the three crystallographically independent molecules) were established by a single crystal X‐ray structure analysis: Space proup P3, Z = 3, lattice dimensions at 293(2) K: a = 17.724(3), c = 10.597(2) Å, R = 0.0374. 相似文献
166.
Elmar Hecht 《无机化学与普通化学杂志》2000,626(3):759-765
Preparation, Properties, and Molecular Structures of Dimethylaminomethyl Ferrocenyl Compounds of selected Elements of Group 13 and 14 Dimethylmetalchlorides of gallium and indium react with dimethylaminomethylferrocenyllithium (FcNLi) to give the corresponding dimethylmetaldimethylaminomethylferrocenes 1 and 2 [Me2MFcN; M=Ga, In]. In a similar manner dialkylmetaldichlorides of germanium and tin yield the expected chlordialkylmetaldimethylaminomethylferrocenes 3 – 5 [R2(Cl)MFcN; M=Ge; R = Me ( 3 ), M=Sn; R=Me ( 4 ), Ph ( 5 )]. In a reaction of Me3Al and Me2AlCl with dimethylaminomethylferrocene the formation of the 1 : 1 adducts 7 and 8 could be observed. All compounds were characterised by 1H and 13C nmr spectroscopy. The molecular structures of 1 , 3 , 4 and 7 were determined. 3 and 4 build in contrast to 1 monomeric molecules with chelat rings as a result of the M–N coordination. Compound 7 consist of monomeric molecules with 4 coordinated Al atoms. 相似文献
167.
Pnictogenidostannates(IV) with Discrete Tetrahedral Anions: New Representatives (E1)4(E2)2[Sn(E15)4] (with E1 = Na, K; E2 = Ca, Sr, Ba; E15 = P, As, Sb, Bi) of the Na6[ZnO4] Type and the Superstructure Variant of K4Sr2[SnAs4] The silvery to dark metallic lustrous compounds (E1)4(E2)2[Sn(E15)4] (E1 = Na, K; E2 = Ca, Sr, Ba; E15 = P, As, Sb, Bi) were prepared from melts of stoichiometric mixtures of the elements. They crystallize in the Na6[ZnO4]‐type structure (hexagonal, space group: P63mc, Z = 2; Na4Ca2[SnP4]: a = 938.94(7), c = 710.09(8) pm; K4Sr2[SnAs4]: a = 1045.0(2), c = 767.0(1) pm; K4Ba2[SnP4]: a = 1029.1(6), c = 780.2(4) pm; K4Ba2[SnAs4]: a = 1051.3(1), c = 795.79(7) pm; K4Ba2[SnSb4]: a = 1116.9(2), c = 829.2(1) pm; K4Ba2[SnBi4]: a = 1139.5(2), c = 832.0(2) pm). The anionic partial structure consists of tetrahedra [Sn(E15)4]8– orientated all in the same direction along [001]. In the cationic partial structure one of the two cation positions is occupied statistically by alkali and alkaline earth metal atoms. Up to now only for K4Sr2[SnAs4] a second modification could be isolated, forming a superstructure type with three times the unit cell volume (hexagonal, space group: P63cm, Z = 6; a = 1801.3(2), c = 767.00(9) pm) and an ordered cationic partial structure. 相似文献
168.
Charles M. Marson Jon Campbell Michael B. Hursthouse K. M. Abdul Malik 《Angewandte Chemie (International ed. in English)》1998,37(8):1122-1124
Ring contraction of a 3,4-epoxyalcohol, then lactolization and electrophilic attack are the steps in the domino cyclization protocol for the formation of 8-oxabicyclo[3.2.1]octane systems [Eq. (a)]. 相似文献
169.
Synthesis and Structures of Novel Ring Compounds of Bismuth with Tris(trimethylsilyl)silyl and ‐stannyl Substituents – [(Me3Si)3Si]4Bi4 and [(Me3Si)3Sn]6Bi8 A bicyclo[3.3.0]octane‐like core consisting of eight bismuth atoms is found in the novel octabismuthane Bi8[Sn(SiMe3)3]6. It is prepared like Bi4[Si(SiMe3)3]4 by reduction of BiBr3 with Li(thf)3E(SiMe3)3 (E = Si, Sn) together with (Me3Si)6E2. Both bismuth ring compounds have been characterized by single crystal X‐ray crystallography. 相似文献
170.
This paper reports on studies on the reactivity of metallic Sn in a solid state reaction in the system In‐Sn‐Cl. The reaction route is investigated by thermoanalysis and XRD measurements. The reaction of InCl3 with Sn to form InSnCl3 does not proceed directly but in several steps giving 4 intermediate phases. It can be interpreted as a kinetically controlled reaction where intermediate phases with a smaller degree of order and higher diffusivity are preferentially formed outside thermodynamic equilibria. 相似文献