A machine learning network based on the combination of empirical parameters and convolutional neural network (CNN) is proposed to recognize the modulation types of radar emitter signals. By using the characteristics of empirical parameters, the neural network can solve the problem that a large number of samples are needed to train when only using convolutional neural network algorithm to achieve automatic classification, and can effectively reduce the training cost of convolutional neural network. The simulation results show that the classification network can effectively classify signals of different modulation types.

Two novel chiral β‐ketoiminate‐based boron hybrid polymers, P‐1 and P‐2, are synthesized from a chiral β‐ketoiminate‐based boron hybrid complex (M‐1), with 1,4‐dioctyl‐2,5‐diethynyl­benzene (M‐2) and 3,6‐diethynyl‐9‐octyl‐9H‐carbazole (M‐3), respectively, via a Pd‐catalyzed Sonogashira coupling reaction. The resulting polymers P‐1 and P‐2 show strong fluorescence emission centered at 525 nm and 534 nm with large Stokes’ shifts and high quantum yields. Most importantly, compared with the circularly polarized luminescence (CPL) dissymmetry factor (glum = +0.042) of chiral small model molecules, P‐1 and P‐2 can exhibit a large glum as high as +0.105 and +0.349 in CH2Cl2 solution, which can be attributed to the amplification effect of CPL arising from the conjugated polymer structure. image

The novel chiral conjugated polymers P-1 and P-3 are prepared from the monomers S-M-2 and S-M-3 with (R,R)-1,2-aminocyclohexane (M-1) via a nucleophilic addition-elimination reaction, respectively. The Eu(III)-grafting chiral polymers P-2 and P-4 could be obtained by direct coordination reaction of Eu(TTA)3 ·2H2 O with P-1 and P-3, respectively. Photoexcitation of P-2 produces pink color emission as a result of the combination of partial blue self-emission chromophore of P-1 along with the red color from the Eu(TTA)3 moiety, whereas P-4 shows the exclusively red color emission from the Eu(III) ((5) D0 →(7) F2 ) transition due to almost complete excitation energy transfer from the macromolecular chain to the Eu(TTA)3 moiety. The choice substitution of phenyl derivative of the polymer plays a crucial role on the efficient energy transfer from the polymer chain to Eu(III) ion center. Meanwhile, the glum value of the dissymmetry factor of circularly polarized luminescence (CPL) for the (5) D0 →(7) F2 transition of Eu(III) for P-4 reaches as high as +0.0207, whereas P-2 exhibits the largest glum value about +0.0464 centered at 434 nm.

Three novel polymers with a bent-core V-shaped chain backbone, P1, P2, and P3, were synthesized by Pd-catalyzed Sonogashira coupling reaction of dibromo substituted B,O-chelated azadipyrromethene (M-1) with 2,5-diethynyl-3,4-dimethylthiophene (M-2), 3,6-diethynyl-9-octadecyl-9H-carbazole (M-3), and 1,4-diethynyl-2,5-bis(octyloxy) benzene (M-4), respectively. On varying the electron donating strength of co-monomer partners, the resulting conjugated polymers exhibited narrow near-infrared (NIR) emission over 820 nm with tunable band gaps in the range of 0.99-1.21 eV. Interestingly, there is a linearly proportional relationship between the experimentally determined energy levels (cyclic voltammetry (CV)) and the theoretically calculated ones for the HOMOs and LUMOs of these polymers. This provides us with a valuable method to predictably tune frontier molecular orbital energy levels and guide the synthesis of NIR emissive materials.

Four donor-pi-acceptor-type copolymers were synthesized via palladium-catalyzed Sonogashira coupling reaction. The resulting donor-pi-acceptor-conjugated copolymers can show fluorescence emission in the range of lambda = 473-568 nm, and the band gaps of the alternating polymers can be tuned in the range 3.09-3.74 eV by using four different donors.

A tetraphenylethene (TPE)-based chiral polymer (TPETyr) was synthesized by the polymerization of 1,2-bis(4-ethynylphenyl)-1,2-diphenylethene (M-1) and 3′,5′-diiodo-N-α-tert-butoxycarbonyl-O-octyl-L-tyrosine methyl ester (M-2) via Sonogashira cross-coupling. Interestingly, the generated luminogen emits weak fluorescence in THF solution, but becomes strongly luminescent as nanoparticle suspensions upon addition of water, demonstrating a novel phenomenon of aggregation-induced emission (AIE). The resulting TPETyr can also exhibit a large CPL dissymmetry factor (glum) in both solution and aggregate states. More importantly, the glum can be tuned in the range of 0.44 to 0.08 by changing the content of water in THF solution.

An Eu(III)-containing polymer can exhibit intense induced circularly polarized luminescence (CPL) in the presence of proline. In addition, the optical anisotropy factor (g(lum)) of the polymer for (5)D0 → (7)F1/(7)F2 transition was much higher than that of a single model molecule, which reveals the amplification effect of CPL arising from the conjugated polymer structure.

A highly regioselective sp3 C–H amination of aryl amides with N-substituted pyrrolidin-2-ones has been developed with a catalyst Fe(II) complex with TBHP as a benign oxidant. This facile method can offer rapid access to the amination reaction of N-substituted pyrrolidin-2-ones in moderate to excellent yields.

ChemInformVolume 43, Issue 49 Preparative Organic Chemistry ChemInform Abstract: A Highly Regioselective sp3 C—H Amination of Tertiary Amides Based on Fe(II) Complex Catalysts. Xuerong Mao, Xuerong Mao Sch. Chem. Chem. Eng., Nanjing Univ., Nanjing 210093, Peop. Rep. ChinaSearch for more papers by this authorYuanzhao Wu, Yuanzhao Wu Sch. Chem. Chem. Eng., Nanjing Univ., Nanjing 210093, Peop. Rep. ChinaSearch for more papers by this authorXiaoxiang Jiang, Xiaoxiang Jiang Sch. Chem. Chem. Eng., Nanjing Univ., Nanjing 210093, Peop. Rep. ChinaSearch for more papers by this authorXunhua Liu, Xunhua Liu Sch. Chem. Chem. Eng., Nanjing Univ., Nanjing 210093, Peop. Rep. ChinaSearch for more papers by this authorYixiang Cheng, Yixiang Cheng Sch. Chem. Chem. Eng., Nanjing Univ., Nanjing 210093, Peop. Rep. ChinaSearch for more papers by this authorChengjian Zhu, Chengjian Zhu Sch. Chem. Chem. Eng., Nanjing Univ., Nanjing 210093, Peop. Rep. ChinaSearch for more papers by this author Xuerong Mao, Xuerong Mao Sch. Chem. Chem. Eng., Nanjing Univ., Nanjing 210093, Peop. Rep. ChinaSearch for more papers by this authorYuanzhao Wu, Yuanzhao Wu Sch. Chem. Chem. Eng., Nanjing Univ., Nanjing 210093, Peop. Rep. ChinaSearch for more papers by this authorXiaoxiang Jiang, Xiaoxiang Jiang Sch. Chem. Chem. Eng., Nanjing Univ., Nanjing 210093, Peop. Rep. ChinaSearch for more papers by this authorXunhua Liu, Xunhua Liu Sch. Chem. Chem. Eng., Nanjing Univ., Nanjing 210093, Peop. Rep. ChinaSearch for more papers by this authorYixiang Cheng, Yixiang Cheng Sch. Chem. Chem. Eng., Nanjing Univ., Nanjing 210093, Peop. Rep. ChinaSearch for more papers by this authorChengjian Zhu, Chengjian Zhu Sch. Chem. Chem. Eng., Nanjing Univ., Nanjing 210093, Peop. Rep. ChinaSearch for more papers by this author First published: 19 November 2012 https://doi.org/10.1002/chin.201249036Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume43, Issue49December 4, 2012 RelatedInformation

The conjugated polymer P-1 was synthesized by the polymerization of 5,5'-divinyl-2,2'-bipyridine (M-1) and N,N'-bis(octyl)-1,7-dibromoperylene diimide (M-2) via Heck cross coupling. The bipyridyl moiety in P-1 can further incorporate Eu(TTA)(3)center dot 2H(2)O/Gd(TTA)(3)center dot 2H(2)O to generate polymer complexes P-2 and P-3, respectively. Interestingly, P-2 exhibits exceptional emissive properties which can be tuned by excitation wavelengths. For example, a green fluorescence can be obtained when P-2 is excited at 440 nm, whereas a red emission with a huge Stokes shift of 248 nm is observed when it is excited at 365 nm. The red fluorescence can be attributed to Eu(III) (D-5(0)-> F-7(2)), which is caused by an effective photoinduced energy transfer process between P-1 and the Eu(TTA)(3) moiety. However, P-3 only emits green fluorescence, and emission intensities depend on the selected excitation wavelengths. The rare excitation induced emission color change of P-2 has led to a better understanding the correlation of photophysical properties between perylenyl moiety and Eu(TTA)(3) moiety.

A polymer-based fluorescent sensor was synthesized by polymerization of (S)-6,6'-dibutyl-3,3'-(di-5-salicylde-ethynyl)-2,2'-binaphthol (M-1) with (R,R)-1,2-diaminocyclohexane (M-2) via nucleophilic addition elimination reaction. The responsive optical properties of the polymer on transition metal ions were investigated by fluorescence and UV vis spectra. The polymer (1.0 x 10(-5) mol/L in THF) could emit fluorescence at 550 nm and exhibit high selectivity for sensing Zn2+ with 36.1-fold fluorescence enhancement. Three logic gates were designed according to the different fluorescence responses of this polymer sensor to Zn2+ and Cu2+. (C) 2011 Elsevier Ltd. All rights reserved.

Two coumarin salen-based sensors CS1 and CS2 can exhibit a pronounced fluorescence enhancement response toward Mg(2+) as high as 36-fold (CS1) and 111-fold (CS2) in the presence of Na(+) as a synergic trigger. More importantly, the fluorescent color of CS1 was bright green instead of weak yellow after the addition of Mg(2+) and Na(+) together, which can be easily detected by the naked eye.

Mg(2+) can lead to the fluorescence enhancement of a dye molecule as high as 47.3-fold while L-proline acts as a promoter in this multicomponent sensory system. The fluorescence color could be easily detected by the naked eye under a UV-lamp.