含偶氮苯聚芳亚胺的合成、表征和光谱分析

以4,4＇-二溴二苯甲酮和4,4＇-二氨基偶氮苯为单体,通过钯催化的胺基化反应缩聚合成了含偶氮苯基团的新型结构聚芳亚胺（PAI-A）．PAI-A结构通过FT—IR,^1H NMR和元素分析测定,测试结果和目标产物吻合良好．在不同的条件下测定了聚合物的光学性能．     

Synthesis, structure, and reactivity of palladacycles that contain a chiral rhenium fragment in the backbone: New cyclometalation and catalyst design strategies

The bromocyclopentadienyl complex [(eta5-C5H4Br)Re(CO)3] is converted to racemic [(eta5-C5H4Br)Re(NO)(PPh3)(CH2PPh2)] (1 b) similarly to a published sequence for cyclopentadienyl analogues. Treatment of enantiopure (S)-[(eta5-C5H5)Re(NO)(PPh3)(CH3)] with nBuLi and I2 gives (S)-[(eta5-C5H4I)Re(NO)(PPh3)(CH3)] ((S)-6 c; 84 %), which is converted (Ph3C+ PF6 -, PPh2H, tBuOK) to (S)-[(eta5-C5H4I)Re(NO)(PPh3)(CH2PPh2)] ((S)-1 c). Reactions of 1 b and (S)-1 c with Pd[P(tBu)3]2 yield [{(eta5-C5H4)Re(NO)(PPh3)(mu-CH2PPh2)Pd(mu-X)}2] (10; X = b, Br, rac/meso, 88 %; c, I, S,S, 22 %). Addition of PPh3 to 10 b gives [(eta5-C5H4)Re(NO)(PPh3)(mu-CH2PPh2)Pd(PPh3)(Br)] (11 b; 92 %). Reaction of (S)-[(eta5-C5H5)Re(NO)(PPh3)(CH2PPh2)] ((S)-2) and Pd(OAc)(2) (1.5 equiv; toluene, RT) affords the novel Pd3(OAc)4-based palladacycle (S,S)-[(eta5-C5H4)Re(NO)(PPh3)(mu-CH2PPh2)Pd(mu-OAc)2Pd(mu-OAc)2Pd(mu-PPh2CH2)(Ph3P)(ON)Re(eta5-C5H4)] ((S,S)-13; 71-90 %). Addition of LiCl and LiBr yields (S,S)-10 a,b (73 %), and Na(acac-F6) gives (S)-[(eta5-C5H4)Re(NO)(PPh3)(mu-CH2PPh2)Pd(acac-F6)] ((S)-16, 72 %). Reaction of (S,S)-10 b and pyridine affords (S)-[(eta5-C5H4)Re(NO)(PPh3)(mu-CH2PPh2)Pd(NC5H5)(Br)] ((S)-17 b, 72 %); other Lewis bases yield similar adducts. Reaction of (S)-2 and Pd(OAc)2 (0.5 equiv; benzene, 80 degrees C) gives the spiropalladacycle trans-(S,S)-[{(eta5-C5H4)Re(NO)(PPh3)(mu-CH2PPh2)}2Pd] (39 %). The crystal structures of (S)-6 c, 11 b, (S,S)- and (R,R)-132 C7H8, (S,S)-10 b, and (S)-17 b aid the preceding assignments. Both 10 b (racemic or S,S) and (S)-16 are excellent catalyst precursors for Suzuki and Heck couplings.     

Structural Study on Water-induced Phase Transitions of Poly(ethylene imine) as Viewed from the Simultaneous Measurements of Wide-Angle X-ray Diffractions and DSC Thermograms

Thermal behavior of poly(ethylene imine) [PEI] has been studied using simultaneous WAXD/DSC measurement system. PEI exhibits water-induced and thermally-induced phase transitions among four kinds of crystalline hydrates: anhydrate (EI/water = 1/0), hemihydrate (1/0.5), sesquihydrate (1/1.5), and dihydrate (1/2). The chain conformation changes from a double helix in the anhydrate to a planar zigzag form in the three hydrates. The anhydrate melts at 60 °C while the hydrates melt differently in the temperature region of 70–110 °C. By means of the simultaneous WAXD/DSC measurements, complex DSC thermograms of PEI hydrates were characterized on the basis of X-ray diffractions obtained concurrently.     

Synthesis of Chain‐End Functionalized Polyolefins with a Bis(phenoxy imine) Titanium Catalyst

Polyethylenes and highly syndiotactic poly(propylene)s possessing chain end hydroxyl groups were synthesized by living polymerizations using L₂TiCl₂ [ 1 , L: C₆F₅NCH(2 O C₆H₃ 3 ^tBu)]/MAO and functionalized α‐olefins, H₂CCH(CH₂)_n Y [ 2 ; YOAlMe₂, n = 4 ( 2a ); YOSiMe₃, n = 9 ( 2b )]. Because the primary insertion of 2 to a cationic species L₂Ti⁺ Me ( 3 ) derived from 1 /MAO is much faster than the successive secondary insertion of 2 , addition of an equimolar amount of 2 to 3 resulted in the quantitative formation of L₂Ti⁺ CH₂ CH(Me) (CH₂)_n Y [ 4 ; YOAlMe₂, n = 4 ( 4a ); YOSiMe₃, n = 9 ( 4b )]. These cationic species 4 served as functionalized initiators for the living polymerization of both ethylene and propylene and afforded polyolefins having extremely narrow molecular weight distributions and a hydroxyl group at the initiating chain end. The terminating chain end of the syndiotactic poly(propylene)s was also functionalized by adding an excess amount of 2b as a chain end capping agent to the living L₂Ti–polymeryl species. Due to much slower insertion of the second molecule of 2b relative to the first one, the obtained polymers were end capped quantitatively by a single molecule of 2b . Telechelic syndiotactic poly(propylene)s were successfully synthesized through a living polymerization initiated by 4b and an end capping using 2b .

     

Role of cyclic dithiocarbonate as a promoter in the reaction of epoxide and imine in the presence of water

It was demonstrated that the reaction of epoxide and imine as a latent initiator under highly humid conditions was accelerated by addition of 5‐phenoxymethyl‐1,3‐oxathiolane‐2‐thione ( 1 ). When 1 was added to a mixture of glycidyl phenyl ether and an imine, the reaction of the epoxide with an amine released from the imine became faster than was the case without 1 , that is, 1 worked as a promoter of the reaction. The curing rate and initial adhesive strength of epoxy resin increased compared with that without 1 . © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4276–4283, 2004     

HBF4·DEE-catalyzed formation of sulfinyl imines: Synthesis and mechanistic studies

A mild acid-catalysed method is reported for the formation of sulfinyl imines from tert-butanesulfinamide and aromatic or aliphatic aldehydes using tetrafluoroboric acid diethyletherate (10?mol%) in dichloromethane. Reactions were performed at room temperature and gave the corresponding sulfinyl imines in excellent yield after 2?h. A DFT study was performed and a mechanism for the reaction is postulated.     

Three component reaction of aryl diazonium salt with sulfonamide & actonitrile to synthesize N-sulfonyl amidine

A new method was developed to prepare N-sulfonyl amidine compounds through three-component reaction of aryl diazonium salts with sulfonamides and acetonitrile, in which, nitrilium ion intermediate, generated from the reaction of aryldiazonium salt with nitrile, was subsequently trapped by sulfonamides. A series of N-sulfonyl amidine derivatives were synthesized by using various types of aryl diazonium salts, sulfonamides and nitriles. In addition, indolyl imine products could also be prepared by using indole as the nucleophile to trap nitrilium ion intermediate.     

Tautomerism of bis(2,4-benzyloxy)-6-(5H)-one-1,3,5-triazine: A combined crystallographic and quantum-chemical investigation

In order to study the keto and enol forms of cyanuric acid derivatives in the solid state, we have synthesized bis(2,4-benzyloxy)-6-(5H)-one-1,3,5-triazine, 1. Computational investigations indicate that keto form is more stable than enol form in both gas phase and solution phase by 9.69–11.18 kcal mol⁻¹ IR and crystallographic analysis shows that 1 exists in keto form in the solid state also. To obtain the enol form in the solid state, we adopted co-crystallization with an organic base. The crystal structures of both keto/amine and the enol/imine forms (in a co-crystal) are reported. IICT Communication No. 2505/CMM-0022.     

Lewis acid promoted alkynylation of imines with terminal alkynes: simple, mild and efficient preparation of propargylic amines

A mild and efficient addition of terminal alkynes to imines in the presence of ZnCl₂, Et₃N and TMSCl gives propargylamines in good yields.     

Substituent effects on the polycondensation of quinones with aromatic amines to form poly(quinone imine)s

The effect of alkyl groups on the polycondensation of aromatic diamines and quinones to form poly(quinone imine)s was investigated. Models were synthesized under standard conditions: 1 equiv of quinone was reacted with 2 equiv of aniline in the presence of titanium tetrachloride and 1,4‐diazabicyclo[2.2.2]octane. Only modest yields of diimines were obtained when alkyl substituents were introduced. Likewise, alkyl substituents were harmful in the polycondensation of both anthraquinones and benzoquinones with aromatic diamines. As for fluorine substituents, model reactions with either 1,5‐difluoroanthraquinone or 1,4‐difluoroanthraquinone with aniline proceeded in high yields. These model compounds for aromatic poly(quinone imine)s were characterized with ¹H NMR spectroscopy, ¹⁹F NMR spectroscopy, variable‐temperature ¹H NMR spectroscopy, and X‐ray crystal structure determination. Polymers of the difluoroanthraquinones with aromatic diamines were obtained in high yields, although not in high molecular weights, and no stereocontrol was found. Both p‐benzoquinones and anthraquinones were used as monomers in these polymerizations, and a fundamental difference in reactivity was observed. With the former, the polymerization behaved as a classical polycondensation and demanded exact reagent equivalence. With the anthraquinones, however, the polymerization proceeded by a condensation chain polymerization and was much more forgiving. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 43–54, 2002