A NEW METHOD FOR THE SYNTHESIS OF LN(ETA-6-C6ME6)(ALCL4)3 (LN=ND, SM, GD, YB), AND THE X-RAY CRYSTAL-STRUCTURE OF YB(ETA-6-C6ME6)(ALCL4)3.MEC6H5

A series of neutral eta6-C6Me6 complexes of lanthanide elements Ln(176-C6Me6)(AlCl4)3 . MeC6H5(Ln = Nd, Sm, Gd, Yb) has been prepared directly in good yields from the reaction of LnCl3, AlCl3 and C6Me6 in toluene. The complexes have been characte

FRACTIONATED CRYSTALLIZATION IN POLYOLEFINS-NYLON-6 BLENDS

The crystallization behavior of polyolefins-nylon 6 polymer blends was studied by differential scanning calorimetry (DSC) measurements. In these blends, the crystallization of the minor component often starts with distinctly deeper supercooling than that

吡啶－2，6－二甲酸镧钇异核配合物的合成及晶体结构

合成了吡啶－２，６－二甲酸镧钇异核配合物晶体。元素分析结果表明，化学式为ＬａＹ（ＨＤＰＡ）＿２·（ＤＰＡ）＿２．１２Ｈ＿２Ｏ，ＤＰＡ为吡啶－２，６－二甲酸根。用Ｘ射线衍射法测定了配合物的单晶结构，其结构式为［ＬａＹ（ＨＤＰＡ）＿２（ＤＰＡ）＿２（Ｈ＿２Ｏ）＿４」·８Ｈ＿２Ｏ，属单斜晶系，Ｐ２＿１／ａ空间群。晶胞参数：ａ＝１．２９７５（４）ｎｍ，ｂ＝１．１２６６（３）ｎｍ，ｃ＝１．４０７９（３）ｎｍ；β＝１０２；１５（２）°，Ｖ＝２．０１１９０（１）ｎｍ￣３，Ｚ＝４，Ｄｃ＝１．８３ｇ／ｃｍ￣３，稀土离子的配位数为９，其配位多面体为扭曲的三冠三角棱柱体。

ELECTROCHEMICAL DETECTION OF COBALT IN HAIR FOLLOWING ON-COLUMN DERIVATIZATION WITH 1-(2-PYRIDYLAZO)-2-NAPHTHOL-6-SULFONIC ACID AND REVERSED-PHASE LIQUID-CHROMATOGRAPHY

A method for the specific determination of cobalt based on reversed-phase liquid chromatography with amperometric detection via on-column complex formation has been developed. A water-soluble chelating agent, 1-(2-pyridylazo)-2-naphthol-6-sulphonic acid (PAN-6S), is added to the mobile phase and aqueous cobalt solutions are injected directly into the column to form in situ the cobalt-PAN-6S chelate, which is then separated from other metal PAN-6S chelates and subjected to reductive amperometric detection at a moderate potential of -0.3 V. Because the procedure eliminates the interference of oxygen and depresses the electrochemical reduction of the mobile phase-containing ligand PAN-6S, by virtue of the quasi:reversible electrode process of the cobalt-PAN-6S complex, a low detection limit of 0.06 ng can be readily obtained. Interference effects were examined for sixteen common metal species, and at a 5- to 8000-fold excess by mass no obvious interference was observed. The feasibility of the method as an approach to the specific analysis of cobalt in a hair sample has been demonstrated.

THE CLEAVAGE REACTION OF THE MO-MO TRIPLE BOND - THE CRYSTAL-STRUCTURES OF MOLYBDENUM COMPLEXES [CPMO(CO)(2)(C(5)H(4)NS)], [CPMO(CO)(2)(C(9)H(6)NS)]O=PPH(3) AND [CPMO(CO)(2)(S(2)CNME(2)]

The reactions of [Cp2Mo2(CO)4] (1) with 2,2'-dipyridyl disulphide (C5H4NS-)2, 8,8'-diquinolyl disulphide (C9H6NS-)2 and tetramethyl thiuram disulphide (Me2NC(S)S-)2 in toluene solution resulted in the cleavage of the Mo-Mo triple bond to yield molybdenum complexes [CpMo(CO)2(C5H4NS)] (2), [CpMo(CO)2(C9H6NS)] (3) and [CpMo(CO)2(S2CNMe2)] (4), respectively. The molecular structures of 2, 3 . O=PPh3 and 4 were determined by X-ray diffraction studies. Crystals of 2 are monoclinic, space group P2(1)/n, with Z = 4, in a unit cell of dimensions a = 6.448(1), b = 12.616(2), c = 14.772(2) angstrom, beta = 92.85(1)-degrees. The structure was refined to R = 0.028 and R(w) = 0.039 for 1357 observed reflections. Crystals of 3 . O=PPh3 are triclinic, space group P1BAR, with Z = 2, in a unit cell of dimensions a = 11.351(3), b = 13.409(3), c = 9.895(2) angstrom, alpha = 94.59(2), beta = 90.35(2), gamma = 78.07(2)-degrees. The structure was refined to R = 0.033 and R(w) = 0.037 for 3260 observed reflections. Crystals of 4 are monoclinic, space group P2(1)/a and Z = 4 with a = 12.468(5), b = 7.637(2), c = 13.135(4) angstrom, beta = 96.62(3). The structure was refined to R = 0.032 and R(w) = 0.042 for 1698 observed reflections. Each of complexes 2-4 contains a cyclopentadienyl ligand, a cis pair of carbonyls and a chelate ligand (S,N donor or S,S donor). All the compounds have distorted square-pyramid structures.