11 resultados para PPH

em Chinese Academy of Sciences Institutional Repositories Grid Portal


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Reaction of [Ph(4)P]2WS4 With NiCl2 in methanol solution in the presence of NaOCH3 leads to the formation of [Ph(4)P](2) [S2W(mu-S)(2)Ni(S-2)] (I) A Similar reaction between (NH4)(2)WS4 and NiCl2 under O-2 atmosphere in the presence of Ph(4)PCl or (n)Bu(4)NCl affords [Ph(4)P](2)([(S-2)W(O)(mu-S)(2)]Ni-2] (IIa) and [(n)Bu(4)N](2)([(S-2)W(O)(mu-S)(2)]Ni-2} (IIb) Under argon the same reaction gives [Ph(4)P](2)[Ni(WS4)(2)] (IIIa) and [(n)Bu(4)N](2)[Ni(WS4)(2)] (IIIb). [Ph(4)P](2)[Ni(WOS3)(2)] (IV) and [Ph(4)P](2)[Ni(WO2S2)(2)] (V) can be prepared from the reaction of [Ph(4)P]2WOS3 and [Ph(4)P]2WO2S2 with NiCl2. Treatment of (NH4)(2)WS4 with CuCl in the presence of PPh(3) in boiling pyridine produces W(mu-S)(4)Cu-2(PPh(3))(3) (VI), which can further react with excess PPh(3) to give W(mu-S)(4)Cu-2(PPh(3))(4) . py (VII). Complex I crystallizes in the space group P2(1)/n with the cell parameters: a = 20.049(4), b = 17.010(4), c = 14.311(7) Angstrom; beta = 110.24(3)degrees and Z = 4; R = 0.058 for 4267 independent reflections. The structural study confirms that complex I contains two terminal sulfide ligands, two bridging sulfide ligands, a side-on disulfide ligand, and a planar central W(mu-S)(2)Ni four membered ring. Complex VII crystallizes in the space group C2/c with the cell parameters: a = 26.436(8), b = 20.542(6), c = 19.095(8) Angstrom; beta = 125.00(3)degrees and Z = 4; R = 0.080 for 3802 independent reflections. The structural study reveals a perfect linear arrangement of the three metal atoms Cu-W-Cu.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

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.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

酚酞型聚醚砜(C-PES)是一种综合性能优异的工程塑料和功能材料,具有良好的成膜性、机械性能、热稳定性、化学稳定性和可加工性等。作为一种高性能的膜材料,酚酞型聚醚砜已被广泛的用于气体分离和水处理等领域。酚酞型聚醚砜侧链上含有可修饰的酯基,可通过各种方法,引入功能基团,对其进行化学改性,从而改善C-PES的各种性能,并扩展其应用领域。本论文设计制备了含有烷基、芳基、胺基以及磺酸基等功能基团的新型酚酞型聚醚砜材料,并对其性质进行了深入的研究: 1.通过各种基团修饰的二酚单体和二氯二苯砜的缩聚,合成了新型的含有不同酞侧基的Cardo型聚醚砜高分子材料,并对其性能进行了详细的研究。结果表明,所有聚合物都表现出极好的溶解性、耐热稳定性、成膜性、力学性能和气体分离性能;通过在酞侧基上引入了大体积的对叔丁基苯基,大大改善了材料的透气性和氧氮分离选择性;通过引入仲胺基,增大了聚合物链间作用力,从而提高了气体的分离选择性。此外,我们还对不同基团的引入对聚合物各种性能的影响作了详细的探讨,着重研究了聚合物的结构-性能关系。 2.利用含有胺基的双酚单体PPH-NH2、PPH和二氯二苯砜的共聚反应,成功合成了含有胺基的Cardo型聚醚砜高分子材料(PES-NH2),并对材料的各种性质进行了表征。结果表明,由于胺基的引入,酚酞型聚醚砜的亲水性得到了大幅度的提高。 3.利用含胺基的Cardo双酚和磺化二氯二苯砜在碳酸钾作用下的缩聚反应,成功合成了含胺基的磺化Cardo型聚醚砜 (SPES-NH2),并用于制备反渗透复合膜。通过优化制膜条件,我们利用界面聚合的方法成功制备了高水通量的TMC/ MPDA/SPES-NH2反渗透复合膜,并对复合膜的性能和结构进行了研究,重点讨论了膜的性能和结构、形貌之间的关系。结果表明,通过在复合膜活性层中引入强亲水性的磺酸基和全刚性主链的Cardo型聚醚砜,复合膜在保持较高盐截留率(97.3%)情况下,水通量得到了大幅度的提高,达到了51.2 L/m2.h。 4.合成了新型的全刚性芳香主链的两性聚电解质SPES-NH3+,并对其溶液性质和自组装行为进行了详细的研究。结果表明,在一定的溶液pH值下,两性聚电解质SPES-NH3+表现出聚阴离子的性质。另外,通过引入[BMIM]+离子屏蔽磺酸根负离子,我们在没有加入其它聚电解质的情况下,成功地制备了[BMIM]SPES-NH3+多层膜,并对多层膜表面性质进行了研究。结果表明,多层膜的厚度可由层数来控制,并且膜表面较平滑,其RMS值为6 nm。这种新的组装方式为构筑刚性主链的两性聚电解质多层膜提供了新的方法。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: How to promote the formation of the gamma-form in a certain propylene-ethylene copolymer (PPR) under atmospheric conditions is significant for theoretical considerations and practical applications. Taking the epitaxial relationship between the alpha-form and gamma-form into account, it is expected that incorporation of some extrinsic alpha-crystals, developed by propylene homopolymer (PPH), can enhance the crystallization of the gamma-form of the PPR component in PPR/PPH blends.RESULTS: The PPH component in the blends first crystallizes from the melt, and its melting point and crystal growth rate decrease with increasing PPR fraction. On the other hand, first-formed alpha-crystals of the PPH component can induce the lateral growth of PPR chains on themselves, indicated by sheaf-like crystal morphology and positive birefringence, which is in turn responsible for enhanced crystallization of the gamma-form of the PPR component.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Dinuclear complexes [Mo-2(mu-pyS)(2)(CO)(4)(PPh(3))(2)] (1), [Mo-2(mu-pyS)(2)(CO)(5)(PPh(3))] (2) and a trace quality of trinuclear complex [Mo-3(mu-pyS)(2)(mu(3)-pyS)(2)(CO)(6)] (3) were obtained from the reaction of [Mo(CO)(3)(MeCN)(3)] with pyridine-2-thione (pySH) and PPh(3) in THF. The crystal structures of 1.2C(7)H(8) and 3.7 C7H8 have been determined by X-ray diffraction studies. Crystals of 1.2C(7)H(8) are monoclinic, space group C2/c and Z = 4, with a = 18.797(3), b = 11.143(4), c = 28.157(7) Angstrom, beta = 101.23(2)degrees. The structure was refined to R = 0.050 and Rw = 0.057 for 3146 observed reflections, Crystals of 3.7 C7H8 are monoclinic, space group P2(1)/a and Z = 4, with a = 13.912(2), b = 17.161(2), c = 15.577(3) Angstrom, beta = 101.17(1)degrees. The structure was refined to R = 0.046 and Rw = 0.051 for 4357 observed reflections. The molecule of 1 consists of two Mo(CO)(2)(PPh(3)) fragments linked by an Mo-Mo bond (2.974(2)Angstrom) and by two doubly-bridging pyS ligands. The compound 3 contains a bent open geometry of three molybdenum atoms (Mo(1)-Mo(2)-Mo(3) angle 122.99(3)degrees) linked by two Mo-Mo bonds (2.943(1) and 2.950(1) Angstrom) and by two doubly- and two triply-bridging pyS ligands.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The interaction of [(C(5)H(4)R)(2)NdCl.2LiCl] (R = H, Bu(t)) with one equivalent of Li[(CH2)(CH2)PPh(2)] in refluxing tetrahydrofuran gave the purplish-blue complex [(C(5)H(4)R)(3)NdCH2P(Me)Ph(2)] in 50% yield. The compounds have been fully characterized by analytical, spectroscopic and X-ray diffraction methods. Variable temperature P-31{H-1} NMR spectroscopy indicated the existence of the following equilibrium: [(C(5)H(4)R)(3)NdCH2P(Me)Ph(2)] + THF reversible arrow (C(5)H(4)R)(3)Nd(THF) + CH2=P(Me)Ph(2). At room temperature, the exchange between the coordinated and free ylide ligand is slow on the NMR time scale.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

把非线性光学(NLO)发色基团引入到聚合物主链中,既可以增大聚合物中NLO基团的含量,从而提高聚合物的宏观NLO系数,又能够提高NLO聚合物的极化稳定性。本文报道一种由酚酞环氧树脂(PPh)与对硝基苯胺(NA)得到的NLO聚合物的合成及其极化松弛。 所用酚酞环氧树脂系自制,环氧值0.427。对硝基苯胺北京化工厂产,分析纯。N,N-二甲基甲酰胺为中国医药公司售品,化学纯,用前减压蒸馏精制,乙醇、丙酮均为北京化工厂生产,分析纯。在氮气保护下将等当量的PPh与NA溶于DMF中于150℃反应6~8小时后,倒

Relevância:

10.00% 10.00%

Publicador:

Resumo:

由亲核缩聚反应合成了酚酞(PPh)-二氯二苯酮(DCBP)-对苯二酚(HQ)三元共聚物并对结构和性能作了初步鉴定。随PPh/HQ组成的不同可得到结晶或无定形聚芳醚酮。聚合物的玻璃化转变温度在143~228℃之间,且随pph含量而异。三元共聚物较酚酞聚芳醚酮(PEK-C)均聚物有更好的耐溶剂性及热稳定性。