膦手性丙炔胺脯氨酸磷酸酯螺旋聚合物的合成与表征

通过添加对映体拆分剂,合成了4种含膦手性的丙炔胺磷酸酯单体[HC帒CC H2NH(PO)R1R2].单体1,R1=OPh,R2=NC4H7COOCH3;单体2,R1=OPh,R2=NC4H7COOCH2CH3;单体3,R1=OPh,R2=NC4H7-COOC(CH3)3;单体4,R1=Ph,R2=NC4H7COOC(CH3)3].1H-NMR和31P-NMR表征可知对映体(单体1)不能被拆分剂拆分,而单体2、单体3、单体4通过拆分剂可以制得单一手性的磷化合物.以(nbd)Rh+[η6-C6H5B--(C6H5)3]为催化剂,以三氯甲烷为溶剂成功得到聚合物分子量范围在0.4×10-4～0.7×10-4,分子量分布在1.26～1.98范围的3种含手性膦侧基的丙炔胺类聚合物.比旋光度([α]D)、圆二色谱(CD)对聚合物的不同侧基及温度对光学活性的影响表明,聚合物具有良好的光学活性且能够形成单一方向的螺旋构象,说明膦手性在构建螺旋聚合物具有重要作用.     

单茂钪催化对氟苯乙烯间规聚合及与乙烯共聚合的研究

采用(C5Me4Si Me3)Sc(CH2C6H4NMe2-o)2(1)和(C5Me4Si Me3)Sc(CH2Si Me3)2(THF)(2)2种单茂钪催化剂,考察了其催化对氟苯乙烯均聚合以及与乙烯共聚合的性能,并通过1H-NMR、13C-NMR、GPC和DSC对所获聚合物的微观结构和热性能进行了分析.结果表明,单茂钪1可以催化对氟苯乙烯均聚合,获得间规聚合物,但聚合活性较低.采用单茂钪2,控制溶剂种类和用量可以获得间规和无规2类聚合物:控制对氟苯乙烯单体在氯苯溶剂中浓度低于2.4 mol/L,可获得间规聚对氟苯乙烯(rrrr≥99%,Tm≥319oC),且聚合活性高达105 g polymer molSc-1 h-1;控制对氟苯乙烯单体在氯苯溶剂中浓度高于4.8 mol/L或者选用氟苯做溶剂,可获得无规聚对氟苯乙烯;固定单体浓度调控对氟苯乙烯和催化剂的比例,可获得分子量(Mn)在3.10×104~2.08×105间调控的间规和无规聚对氟苯乙烯.在常压乙烯下,单茂钪1和2还可以催化对氟苯乙烯与乙烯共聚合,获得了组成(对氟苯乙烯含量41 mol%~88 mol%)和分子量(3.10?104~1.84?105)可控的两元共聚物,共聚合活性高达106 g polymer molSc-1 h-1.当共聚物中乙烯含量高于对氟苯乙烯含量时,共聚物仅有源自聚乙烯嵌段的熔点(119~126oC).当共聚物中对氟苯乙烯含量高于乙烯含量时,共聚物出现聚对氟苯乙烯嵌段;由单茂钪1获得聚对氟苯乙烯嵌段为间规结构,共聚物具有熔点(269~282oC)和玻璃化转变温度(Tg,79~82oC);单茂钪2获得聚氟苯乙烯嵌段为无规结构,共聚物仅有1个Tg(94~96oC).     

单茂钪催化合成高顺式异戊二烯/苯乙烯共聚物的研究

合成了5种单茂双烷基稀土配合物Cp'Ln(CH2C6H4NMe2-o)2(1:Cp'=C5Me4Si Me3,Ln=Sc;2:Cp'=C9H7,Ln=Sc;3:Cp'=C5H5,Ln=Sc;4:Cp'=C5H5,Ln=Lu;5:Cp'=C5H5,Ln=Y)在助剂[Ph3C]-[B(C6F5)4]的活化下,考察了稀土金属和配体结构对异戊二烯和苯乙烯的均聚合活性和立体选择性的影响规律.结果表明小空间位阻的单茂钪(C5H5)Sc(CH2C6H4NMe2-o)2(3)催化异戊二烯聚合时,聚合活性和顺式立体选择性较优;催化苯乙烯聚合时获得无规聚苯乙烯.因此选用单茂钪催化剂3/[Ph3C][B(C6F5)4],考察了其催化异戊二烯/苯乙烯共聚合的性能,高活性地获得了组成和分子量可控、分子量窄分布的异戊二烯/苯乙烯多嵌段共聚物.通过1H-NMR,13C-NMR,GPC以及DSC对共聚物进行分析表征,结果表明,通过调控苯乙烯与异戊二烯的加料比例,共聚物中苯乙烯摩尔含量可以在1%~75%间调控,聚苯乙烯嵌段为无规聚苯乙烯;共聚物中聚异戊二烯顺-1,4选择性均大于91%;通过调控单体与催化剂的比例,共聚物分子量(Mn)可以在3.5×104~8.3×104间调控,分子量分布保持窄分布(Mw/Mn=1.71~1.94).     

单茂钪催化乙烯与苯乙烯衍生物共聚合的研究

以(C5Me4Si Me3)Sc(CH2C6H4NMe2-o)2和[Ph3C][B(C6F5)4]组成的单茂钪催化体系,考察了其催化不同取代基团苯乙烯衍生物均聚合以及与乙烯共聚合的性能.结果表明单茂钪催化体系可以催化对甲基苯乙烯和对乙烯苯基二甲基硅烷均聚合,高活性(106g聚合物(mol Sc)-1h-1)地获得高间规聚合物;催化二乙烯基苯和乙烯苯基-1-丁烯聚合会发生不同程度的交联反应.在1.01×105Pa乙烯压力下,单茂钪催化体系分别催化对甲基苯乙烯、对乙烯苯基二甲基硅烷与乙烯与共聚合,获得了组成和分子量可控的乙烯/对甲基苯乙烯、乙烯/对乙烯苯基二甲基硅烷共聚物,共聚合活性高达106g聚合物(mol Sc)-1h-1.通过1H-NMR、13CNMR、GPC和DSC对共聚物组成、结构和热性能进行了分析表征.结果表明,在1.01×105Pa乙烯压力下改变苯乙烯衍生物的用量,共聚物中对甲基苯乙烯或对乙烯苯基二甲基硅烷的摩尔含量可以在8 mol%~55 mol%间调控,共聚物含有间规聚对甲基苯乙烯嵌段或间规聚对乙烯苯基二甲基硅烷嵌段、聚乙烯嵌段和乙烯-苯乙烯衍生物的链接序列,共聚物分子量(Mn)可以在3×104~16×104间调控,共聚物具有约127℃的熔点.     

α-二亚胺镍(Ⅱ)催化甲基丙烯酸甲酯聚合

以4种不同结构的α-二亚胺镍(Ⅱ)催化剂[(t-Bu)—N CH—CH N—(t-Bu)]NiBr2(C1),[C6H5—N C(Me)—C(Me)N—C6H5]NiBr2(C2),[(2,6-C6H3(Me)2)—N C(Me)—C·(Me)N—(2,6-C6H3(Me)2)]NiBr2(C3)和[(2,6-C6H3(i-Pr)2)—N C(An)—C(An)N—(2,6-C6H3(i-Pr)2)]NiBr2(An=acenaphthyl)(C4),在甲基铝氧烷(MAO)作用下,对甲基丙烯酸甲酯(MMA)进行催化聚合.以C2为模型催化剂系统研究了Al/Ni摩尔比、单体浓度、聚合温度、聚合时间和反应溶剂对催化活性及聚合物分子量的影响.在较适合的聚合条件(催化剂用量为1.6μmol,Al/Ni摩尔比为800,MMA浓度为2.9 mol/L,甲苯为溶剂,聚合温度为60℃,聚合时间为4 h)下,讨论了催化剂结构对催化活性和聚合物分子量的影响.研究发现,催化剂C1~C3催化MMA聚合均得到富含间规结构的聚甲基丙烯酸甲酯(PMMA).催化剂结构中空间位阻增大导致催化活性降低,空间位阻最小的C1催化活性最高[达107.8 kg/(mol Ni·h)];而空间位阻最大的C4催化活性仅为7.8 kg/(mol Ni·h).催化剂结构中给电子效应增加有利于催化活性及聚合物分子量的增加.C2催化活性为62.5 kg/(mol Ni·h),所得聚合物的分子量为5.0×104;而具有较强给电子效应的C3催化活性达到96.9 kg/(mol Ni·h),并得到更高分子量的聚合物(7.6×104).     

含芴聚亚胺酮的合成与表征

以4,4'-(9-芴基-9,9-二基)二苯胺和含羰基的二溴化合物为单体,通过钯催化的Buchwald-Hartwig交叉偶联反应,缩聚合成了3种不同结构的含芴聚亚胺酮(1a～1c),其结构经UV-Vis, 荧光光谱,1H NMR, IR和热分析表征.分析结果表明,1的重均分子量5×104,分子量分散系数3.0,玻璃化转变温度250 ℃,热分解温度520 ℃.1在二甲基乙酰胺中的UV-Vis最大吸收波长271 nm和369 nm,最大荧光发射波长491 nm和522 nm.     

引发转移终止剂技术合成含有聚异戊二烯链段的三嵌段共聚物

含聚异戊二烯 (ＰＩＰ)链段的嵌段共聚物有着广泛的应用[1～ 3 ] ,有关它的合成、性能表征及应用方面的研究一直是学术及工业界的研究热点 .传统上 ,含有ＰＩＰ链段的嵌段共聚物用活性负离子聚合的方法来合成 ,例如 :聚苯乙烯 聚异戊二烯嵌段共聚物[3 ,4 ] .这是由聚合物增长链端的特殊活性所决定的 ,采用活性负离子聚合方法 ,不但能很好地控制共聚物的分子量和分子量分布 ,而且能控制共聚物中各组分的比例 .但是 ,负离子聚合通常需在较苛刻的条件下进行 ,如低温高真空、高纯度的单体和溶剂 ,而且能用于负离子聚合的单体也有限 .相对而言 ,…     

以双硫酯为链转移剂的活性自由基聚合

合成并研究了两种双硫酯链转移剂的纯化方法 ,进行了多种单体以双硫酯为链转移剂的活性自由基聚合及嵌段共聚 .发现以PhC(S)SC(CH3) 2 Ph为链转移剂的效果比PhC(S)SCH(CH3)Ph好 ,聚合产物的多分散性系数较小 .引发剂与链转移剂的摩尔数比为 1∶3 5～ 1∶4 2时 ,得到多分散性系数小 ,实测分子量与理论分子量相近的聚合产物 .聚合物的分子量随时间和转化率的增加而增加 ,加入第二单体形成嵌段共聚物 ,具有活性聚合特征 .聚甲基丙烯酸酯大分子引发剂引发丙烯酸酯单体聚合时 ,聚合速度最快 .     

合l，4—萘基结构的聚芳醚酮的合成与表征

以无水A1Cl3为催化剂，N-甲基毗咯烷酮为助剂，ClCH2CH2Cl为溶剂，将一种含萘环的新芳醚单体——4，4’-二(α-萘氧基)二苯酮(DNBP)分别与对苯二甲配氯、间苯二甲配氯、2，5-二氯对苯二甲配氯等芳二酰氯通过低温溶液亲电共缩聚反应合成了6种主链含1，4-萘基结构的新型聚芳醚酮醚酮酮无规共聚物。考察了溶剂体系、反应温度、反应时间、单体摩尔浓度等聚合反应条件对聚合物分子量的影响，并用对数比浓粘度(ηnl3)，IR，DSC，TG和WAXD等方法对其进行了分析表征。结果表明：它们均为非晶态聚合物，有较高的玻璃化温度和优良的耐热性，可溶于一些强权性非质子溶剂中。并以CHCl3为溶剂，甲酵和正已烷为沉降剂用浊度滴定法测定了上述6种聚合物的溶度参数(δ)。     

高分子化8-羟基喹啉锂的合成和发光特性的研究

以LiOH与5(2甲基丙烯酰乙氧基甲基)8羟基喹啉反应合成8羟基喹啉锂(Liq)配合物单体,并与甲基丙烯酸甲酯共聚合成含有高分化的8羟基喹啉锂.1HNMR、TGA、元素分析确定了单体的组成为Li(C9H5NO)CH2OCH2CH2OOCC(CH3)CH2·H2O.与聚甲基丙烯酸甲酯比较,共聚物热稳定性高.Liq含量<15wt%时共聚物能够溶于普通溶剂.紫外吸收、激发光谱、光致(PL)发光谱说明单体和共聚物的发光来自于Liq基团.单体和共聚物发蓝光.同时对共聚物的二甲基甲酰胺、二甲亚砜和四氯乙烷溶液制备的薄膜的光致发光光谱进行了比较,证明溶剂影响Liq基团上共轭电子的离域程度,对发光光谱有调节作用.     

Helical structures of N-alkylated poly(p-benzamide)s

Poly(p-benzamide)s 1 bearing a chiral side chain on the nitrogen atom were synthesized by chain-growth polycondensation methodology. The polyamides exhibited well-defined molecular weights with narrow polydispersities. Solutions of the polyamides in several organic solvents (CH(3)CN, CHCl(3), and CH(3)OH) showed dispersion type CD signals characteristic of coupled-oscillator and much larger as compared with the corresponding monomer. The CD signals were dependent on the temperature and molecular weight of the polyamides but independent of the solvent, as far as examined. An exciton model analysis of the absorption and CD spectra provided a clear-cut picture for the secondary structure of these polyamides in solution that the N-alkylated poly(p-benzamide)s possess a right-handed helical conformation ((P)-helix). In the solid states, the results of X-ray crystallographic analysis of 4-(methylamino)benzoic acid oligomers substantiated that they have a helical conformation with three monomer units per turn.     

Control of helix sense by composition of chiral-achiral copolymers of N-propargylbenzamides

N-Propargylbenzamides 1-7 were polymerized with (nbd)Rh(+)[eta(6)-C(6)H(5)B(-)(C(6)H(5))(3)] to afford polymers with moderate molecular weights (M(n) = 26,000-51,000) in good yields. The (1)H NMR spectra demonstrated that the polymers have fairly stereoregular structures (81-88 % cis). The optically active polymers, poly(1) and poly(2), were proven by their intense CD signals and large optical rotations to adopt a stable helical conformation with an excess of one-handed screw sense when heated in CHCl(3) or toluene. The sign of Cotton effect could be controlled by varying the content in the copolymers of either chiral bulky 1 and achiral nonbulky 3, or chiral nonbulky 2 and achiral bulky 7. The smaller the pendant group in the copolymerization of achiral monomers with 1, the more easily did the preferential helical sense change with the copolymer composition. However, the copolymers of chiral nonbulky 2 and achiral nonbulky 3 did not change the helical sense, irrespective of the composition. The free energy differences between the plus and minus helical states, as well as the excess free energy of the helix reversal, of those chiral-achiral random copolymers were estimated by applying a modified Ising model.     

Synthesis and helicity of optically active poly(N‐propargylphosphonamidates) having chiral phosphorus center

Novel chiral N‐propargylphosphonamidate monomers (HC?CCH₂NHP(?O)R? O? menthyl, 1 : R = CH₃, 2 : R = C₂H₅, 3 : R = n‐C₃H₇, 4 : R = Ph) were synthesized by the reaction of the corresponding phosphonic dichlorides with menthol and propargylamine. Pairs of diastereomeric monomers 1 – 4 with different ratios were obtained due to the chiral P‐center and menthyl group. One diastereomer could be separated from another one in the cases of monomers 1 and 2 . Polymerization of 1 – 4 with (nbd)Rh⁺[η⁶‐C₆H₅B^?(C₆H₅)₃] as a catalyst in CHCl₃ gave the polymers with number‐average molecular weights ranging from 5000 to 12,000 in 65–85%. Poly( 1 )–poly( 4 ) exhibited quantitative cis contents, and much larger specific rotations than 1 – 4 did in CHCl₃. The polymers showed an intense Cotton effect around 325 nm based on the conjugated polyacetylene backbone. It was indicated that the polymers took a helical structure with predominantly one‐handed screw sense, and intramolecular hydrogen bonding between P?O and N? H of the polymers contributed to the stability of the helical structure. Poly( 1a ) and poly( 2a ) decreased the CD intensity upon raising CH₃OH content in CHCl₃/CH₃OH. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1515–1524, 2007     

具有光学活性的两亲性聚炔-聚乙二醇单甲醚接枝共聚物的合成与表征

设计并合成了含手性侧基和含亲水性大分子侧基的接枝聚炔共聚物[聚(丙炔酸薄荷醇酯-co-丙炔酸聚乙二醇单甲醚酯)(poly(a-co-b),(a:propiolic acid L-menthol ester;b:propiolic acid polyethylene glycol monomethyl ether est...     

A novel type of optically active helical polymers: Synthesis and characterization of poly(N‐propargylureas)

This article presents two novel artificial helical polymers, substituted polyacetylenes with urea groups in side chains. Poly( 4 ) and poly( 5 ) can be obtained in high yields (≥97%) and with moderate molecular weights (11,000–14,000). Poly( 4 ) contains chiral centers in side chains, and poly( 5 ) is an achiral polymer. Both of the two polymers adopted helical structures under certain conditions. More interestingly, poly( 4 ) exhibited large specific optical rotations, resulting from the predominant one‐handed screw sense. The helical conformation in poly( 5 ) was stable against heat, while poly( 4 ) underwent conformational transition from helix to random coil upon increasing temperature from 0 to 55 °C. Solvents had considerable influence on the stability of the helical conformation in poly( 4 ). The screw sense adopted by the helices was also largely affected by the nature of the solvent. Poly( 4 ‐co‐ 5 )s formed helical conformation and showed large optical rotations, following the Sergeants and Soldiers rule. By comparing the present two polymers (with one ? N? H groups) with the three polymers previously reported (with two ? N? H groups in side chains), the nature of the hydrogen bonds formed between the neighboring urea groups played big roles in the formation of stable helical conformation. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4112–4121, 2008     

Unusual behavior in light scattering experiments of poly(<Emphasis Type="Italic">N</Emphasis>-vinylimidazole) prepared by precipitation polymerization

Poly(N-vinylimidazole) (PVI) was synthesized by the precipitation polymerization using 2,2’-azobis(isobutyronitrile) (AIBN; initiator) and benzene (solvent) at two different monomer/initiator ratios. The solution polymerization was also performed with the following initiator/solvent systems: AIBN/water–methanol mixture (1:1 by volume) and 4,4’-azobis(4-cyanovaleric acid)/aqueous HCl solution (pH 0.8). All the four preparations of PVI in ethanol and in 0.2 M NaCl (pH 3 with HCl) were examined by dynamic light scattering (DLS). The CONTIN analysis of DLS data for each preparation from the solution polymerization showed a unimodal distribution in both ethanol and aqueous solvents. A good agreement was obtained between the molar masses in these different solvents by static light scattering (SLS). However, the polymers from the precipitation polymerization exhibited a heterogeneous bimodal distribution in DLS under the same conditions as above, indicating that the SLS data as in reference [6] (Savin et al. Macromolecules 37:6565) cause a serious error in the understanding of solution behavior of PVI.     

不同溶剂对聚醚砜酮基炭膜结构及气体分离性能的影响

为考察不同溶剂对聚醚砜酮(PPESK)炭膜结构和性能的影响,以PPESK为前驱体,分别以NMP,CHCl3,C2H2Cl4,DMAc为溶剂制备气体分离炭膜。并采用红外光谱、热重分析、X射线衍射和气体渗透等测试手段对所制膜的化学结构、炭膜的微结构和气体的分离性能进行了表征。结果表明,溶剂的溶度参数、沸点、挥发性以及原膜中溶剂的含量等导致所制备聚合物膜形成不同的化学结构,改变它在预氧化和炭化过程的结构变化规律,使形成炭膜表现出不同的炭结构、孔隙结构和表观柔韧性,最终影响炭膜的气体渗透性和分离选择性。     

Solvent effect on infrared spectra of methyl methacrylate in CCl4/C6H14, CHCl3/C6H14 and C2H5OH/C6H14 binary solvent systems

Research of methyl methacrylate (MMA) in three kinds of binary solvent systems (CCl4/C6H14, CHCl3/C6H14 and C2H5OH/C6H14) on the infrared (IR) spectra was reported. Two types of carbonyl stretching vibration bands for MMA in CHCl3/C6H14 or C2H5OH/C6H14 mixtures were found with the changing of the mole fraction of CHCl3 (XCHCl3) or C2H5OH (XC2H5OH). The carbonyl stretching vibration bands at lower frequencies in the above two mixtures were attributed to the formation of hydrogen bonding between MMA and CHCl3 or C2H5OH. While in CCl4/C6H14 mixtures there was only one type of carbonyl stretching vibration band of MMA. Good linear correlations between the frequencies of C=O or C=C stretching vibration band of MMA and XCCl4, XCHCl3 or XC2H5OH were found, respectively. The solute-solvent interactions in the three different binary solvent systems were discussed in detail.     

Structures, photoluminescence, and reversible vapoluminescence properties of neutral platinum(II) complexes containing extended pi-conjugated cyclometalated ligands

Reacting K2PtCl4 with the tridentate R-C(wedge)N(wedge)C-H2 ligands 2,6-di-(2'-naphthyl)-4-R-pyridine (R = H, 1a; Ph, 1b; 4-BrC6H4, 1c; 3,5-F2C6H3, 1d) in glacial acetic acid, followed by heating in dimethyl sulfoxide (DMSO), gave complexes [(R-C(wedge)N(wedge)C)Pt(DMSO)] (2a-d). In the crystal structures of 2a-c, the molecules are paired in a head-to-tail orientation with Pt...Pt separations >6.3 A, and there are extensive close C-H...pi (d = 2.656-2.891 A), pi...pi (d = 3.322-3.399 A), and C-H...O=S (d = 2.265-2.643 A) contacts. [(Ph-C(wedge)N(wedge)C)Pt(PPh3)] (3) was prepared by reacting 2b with PPh3. Reactions of 2a-d with bis(diphenylphosphino)methane (dppm) gave [(R-C(wedge)N(wedge)C)2Pt2(mu-dppm)] (4a-d). Both head-to-head (syn) and head-to-tail (anti) conformations were found for 4a.6CHCl3.C5H12, whereas only one conformation was observed for 4b.2CHCl3 (syn), 4c.3CH2Cl2 (syn), and 4d.2CHCl3 (anti). In the crystal structures of 4a-d, there are close intramolecular Pt...Pt contacts of 3.272-3.441 A in the syn conformers, and long intramolecular Pt...Pt separations of 5.681-5.714 A in the anti conformers. There are weak C-H...X (d = 2.497-3.134 A) and X...X (X = Cl or Br; d = 2.973-3.655 A) interactions between molecules 4a-d and occluded CHCl3/CH2Cl2 molecules, and their solvent channels are of varying diameters (approximately 9-28 A). Complexes 2a-d, 3, and 4a-d are photoluminescent in the solid state, with emission maxima at 602-643 nm. Upon exposure to volatile organic compounds, 4a shows a fast and reversible vapoluminescent response, which is most intense with volatile halogenated solvents (except CCl4). Powder X-ray diffraction analysis of desolvated 4a revealed a more condensed molecular packing of syn and anti complexes than crystal 4a.6CHCl3.C5H12.