A new cardo bisphenol monomer containing pendant azido group and the resulting aromatic polyesters

Expanding on our strategy to synthesize aromatic step‐growth polymers containing pendant clickable azido groups via functional monomer approach, we have now designed and synthesized a new cardo bisphenol, viz., 2‐(2‐azidoethyl)‐3, 3‐bis(4‐hydroxyphenyl) isoindolin‐1‐one (PPH‐N₃). PPH‐N₃ was conveniently synthesized starting from commercially available phenolphthalein by a three‐step route in an overall yield of 65% using simple organic transformations. Aromatic (co)polyesters bearing pendant azido groups were synthesized by low‐temperature solution polycondensation of PPH‐N₃ or different molar ratios of PPH‐N₃ and bisphenol‐A (BPA) with aromatic diacid chlorides in dry dichloromethane in the presence of triethylamine (TEA) as a base. The formation of medium to reasonably high‐molecular‐weight (co)polyesters was evidenced from intrinsic viscosity and number‐average molecular‐weight measurements that were in the range 0.52–0.85 dL/g and 16,700–28,200, respectively. Tough, transparent, and flexible films could be cast from chloroform solutions of these (co)polyesters. (Co)polyesters were characterized using FTIR, ¹H NMR, ¹³C NMR spectroscopy, XRD, and TGA. The thermal curing reaction of (co)polyesters involving decomposition of azido groups was studied by DSC analysis. The chemical modification of a representative copolyester containing pendant azido groups was carried out quantitatively using catalyst‐free azide‐maleimide cycloaddition reaction with two maleimides, namely, N‐methylmaleimide and N‐hexylmaleimide. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1516–1526     

Synthesis and characterization poly(ϵ-caprolactone-b-ethylene glycol-b-ϵ-caprolactone) ABA type block copolymers via “Click” chemistry and ring-opening polymerization

Synthesis of poly(?-caprolactone-b-ethylene glycol-b-?-caprolactone) ABA type block copolymer by “click” chemistry and ring-opening polymerization (ROP) was reported by using propargyl polyethylene glycol (propargyl-PEG) and terminally azido poly(?-caprolactone) ester (PCL-N₃). For this purpose, primarily propargyl-PEG was synthesized by using reaction of PEGs (3000 Da, 2000 Da, 1500 Da, 1000 Da, 600 Da ve 400 Da) and propargyl chloride. 3-azido-1-propanol was obtained by using chemical interaction of 3-chloro-1-propanol and sodium azide. Synthesis of PCL-N₃ was carried out by means of ROP of ?-caprolactone and 3-azido-1-propanol. Finally, poly(?-caprolactone-b-ethylene glycol-b-?-caprolactone) ABA type block copolymers were synthesized by using PCL-N₃ and propargyl-PEG. The primary parameters such as concentration, time, and temperature that influenced the reactions were assessed. The product characterization was achieved using NMR, FT-IR, GPC, elemental analysis, and fractional precipitation [non-solvent (petroleum ether-mL)/solvent (THF-mL)] techniques.     

Nickelatetrazoles as Intermediates in the Course of the Photolysis of Nickel(II) Azido Complexes? – A Theoretical Study

The primary photoreactions due to charge transfer excitation of d⁸ transition metal complexes of [MP₂(N₃)₂] constitution (P₂: mono‐ or diphosphane ligands) are strongly influenced by the central ion. While [MP₂(N₃)₂] complexes of both palladium(II) and platinum(II) yield primarily the corresponding metal(I) species and azidyl radicals, nickel(II) complexes of the same constitution lead to intermediate generation of nitrenes as has been indirectly shown by various scavenging reactions. During the course of the succeeding reactions, the intermediate generation of nickelatetrazoles is assumed. Both nitrene and metallatetrazole intermediates could not be identified directly so far. Therefore, the proposed reaction pathway has been modeled theoretically to get indications regarding the probability of the formation of such intermediates. Based on density functional theory (DFT) calculations, the energetics of the proposed pathway is compared with those of possible other pathways. The calculations support the proposed reaction pathway and point to possible reasons for the different behaviour of nickel(II) compared to palladium(II) and platinum(II).     

End‐capping of polystyrene by aliphatic primary amine by derivatization of precursor hydroxyl end group

A new and very efficient route for the synthesis of aliphatic primary amine terminated polystyrene (PS) is reported. In contrast to most known methods, only traditional commercially available reagents are used. PS is synthesized by anionic polymerization with a lithium counter ion and the living chains are end‐capped by a hydroxyl group upon addition of ethylene oxide followed by protonation. The ω‐hydroxyl end group is tosylated and the tosylate is then reacted with sodium azide. The azide terminal group is finally reduced into primary amine. The different steps of functionalization have been fully characterized by SEC, ToF‐SIMS, FTIR, and ¹H NMR. The amine content (= 98%) has been determined by acid‐base titration with perchloric acid. It clearly shows the efficiency of the synthetic method reported in this article although it is a multistep method. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1618–1629, 2000     

基于End-On叠氮桥联的混合价Co(Ⅱ/Ⅲ)和一维Cu(Ⅱ)链-席夫碱化合物的合成、结构及磁学性质

合成了2个化合物[Co^ⅡCo₄^Ⅲ（salhn）₄（N₃）₆（CH₃OH）₂（H₂O）₂]·4CH₃OH·2H₂O （1）和[Cu₂（salhn）（N₃）₂]_n（2）（H₂salhn=N,N''-bis （salicylidene） hydrazine）,并用X射线单晶衍射进行结构表征。化合物1是一个五核的[Co^ⅡCo₄^Ⅲ]钴簇,而化合物2是一个具有结构单元为[Cu₂（salhn）（N₃）₂]的一维链结构。2个化合物中叠氮均具有end-on （EO,μ-1,1）的配位模式。化合物1和2的磁学性质测试表明它们都具有反铁磁行为。     

O,O-二(β-叠氮乙基)-a-对甲苯磺酰胺基-对甲氧基苄基磷酸酯的合成与晶体结构

合成了标题化合物 C19H24N7O6PS,通过元素分析、IR和1H NMR对化合物进行了表征,用X-射线单晶衍射法测定了该化合物的晶体结构。结果表明,晶体属三斜晶系,P`1空间群,a = 9.236(1), b = 10.805(1), c = 14.113(1)? a = 109.29(1), b = 98.16(1), g = 106.30(1), V = 1232.3(2)?, Mr = 509.48, Z = 2, Dc = 1.373g/cm3, m (MoKa) = 0.24mm-1, F(000) = 532, 0 < 2q < 50范围内收集3238个独立衍射点,其中可观测衍射点3121个(F2≥8.0sF2)。晶体结构用直接法解出,经全矩阵最小二乘法修正,最终偏离因子R = 0.073,Rw = 0.074。化合物的分子中,2个取代苯环位于分子主链的同一侧,2苯环平面近于平行。2个取代的叠氮乙基分别位于分子主链的两侧,几乎相互垂直地指向同一个点,形成一种“钳式”构型。2个独立的分子之间以一对NH…O氢键连接形成中心对称的二聚体,成为晶体结构的基本重复单元。     

New heterocyclic furazano[3,4-d ][1,2,3]triazine system as a platform for energetic compound engineering

Novel 7-azidofurazano[3,4-d ][1-3]triazine 5-oxide was synthesized from 3-amino-4-(tetrazol-5-yl)furazan and nitronium salt. Its characterization including energetic properties is described.     

15N NMR spectra and reactivity of 2,4,6‐triazidopyridines, 2,4,6‐triazidopyrimidine and 2,4,6‐triazido‐s‐triazine

2,4,6‐Triazido‐s‐triazine, 2,4,6‐triazidopyrimidine and six different 2,4,6‐triazidopyridines were studied by ¹⁵N NMR spectroscopy. The assignment of signals in the spectra was performed using the gauge‐independent atomic orbital (GIAO)–Tao‐Perdew‐Staroverov‐Scuseria exchange‐correlation functional (TPSS)h/6‐311+G(d,p) calculations on the M06‐2X/6‐311+G(d,p) optimized molecular geometries. The Truhlar and coworkers' continuum solvation model called SMD was applied to treat solvent effects. With this approach, the root mean square error in estimations of the ¹⁵N chemical shifts for the azido groups was just 1.9 ppm. It was shown that the different reactivity of the α‐ and γ‐azido groups in pyridines correlates well with the chemical shifts of the N_α signals of these groups. Of two nonequivalent azido groups of azines, the azido group with the most shielded N_α signal is the most electron‐deficient and reactive toward electron‐rich reagents. By contrast, the azido group of azines with the most deshielded N_α signal is the most reactive toward electron‐poor reagents. Copyright © 2013 John Wiley & Sons, Ltd.