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Transition metal coordination polymers with polycarboxylic acid as bridging ligands:Synthesis and structure characterization of[Fe(μ_(4)-bta)_(0.5)(phen)(OH)]_(n)

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Science china chemistry 2004年第1期47卷 10-16页

作者： XU Jiqing, CHU Deqing, YU Jiehui, WANG Tiegang & TANG AoqingCollege of chemistry and State Key Laboratory of Inorganic Synthesis and Preparative chemistry, jilin university, changchun 13.023, china institute of theoretical chemistry, jilin university, changchun 13.023, china College of chemistry and State Key Laboratory of Inorganic Synthesis and Preparative chemistry Jilin University Changchun China institute of theoretical chemistry Jilin University Changchun China

A new 2D (two-dimensional) coordination polymer, [Fe(μ4-bta)o.5(phen)(OH)]n (1), has been hydrothermally synthesized with FeCl3 6H2, Na4bta (h4bta = 1,2,4,5-benzentetracarboxylic acid), 1,10-phen (1,10-phenanthroline) and H2O as raw materials. The crystals of the compound belong to monoclinic P21/n space group, a = 1.0129(2) nm, b = 0.9265(2) nm, c = 1.5696(3) nm, β=91.37(3)°V=1.4721(5) nm3,Z=3, final R1=0.0292, wR 2=0.0798 for 2572 [/>2σ(/)] observed reflections. The result of structure determination shows that in the compound each bta ligand is connected with four Fe3, forming a new μ4-coordination mode. Four deprotonated carboxylic groups of bta link to Fe3 ions alternatively through monodentate and bidentate coordination fashion, constructing 2D layer network. The measurement of variable temperature magnetic susceptibility indicates that there exist antiferromagnetic interactions between Fe3 ions in the compound. The TGA spectrum displays relatively fine thermal stability of the compound. In addition, IR and UV-Vis spectra of compound 1 have also been measured.

关键词： 2D coordination polymer, 1,2,4,5-benzentetracarboxylic acid, iron, hydrothermal synthesis, crystal structure.

theoretical studies on the spectroscopic properties and the substituent effects of pyridyl triazole Os(Ⅱ) complexes

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Science china chemistry 2009年第3期52卷 261-265页

作者： WU YuHui, ZHOU Xin & ZHANG HongXing State Key Laboratory of theoretical and Computational chemistry, institute of theoretical chemistry, jilin university, changchun 13.023, china State Key Laboratory of theoretical and Computational chemistry Institute of Theoretical Chemistry Jilin University Changchun China

To explore the spectroscopic properties of pyridyl triazole Os(Ⅱ) complexes and how the substituent effects affect the spectroscopic properties of [Os(ptz)2L2] (L=PH3; ptzH=(2-pyridyl)-1,2,4-triazole) (1), [Os(bptz)2L2] (bptzH=3-tert-butyl-5-(2-pyridyl)-1,2,4-triazole) (2), [Os(fptz)2L2] (fptzH=3- (trifluoreomethyl)- 5-(2-pyridyl)-1,2,4-triazole) (3), and [Os(fbtz)2L2] (fbtzH=3-(trifluoreomethyl)-5-(4-tert-butyl- 2-pyridyl)-1,2, 4-triazole) (4), the density functional theory (DFT) method at the B3LYP level was used to optimize the geometrical structures in the ground and excited state. The absorption and emission properties of the dichloromethane solution were predicted at the time-dependent density functional theory (TD-DFT, B3LYP) level associated with the PCM solvent effect model, the transitions characters of them were assigned. Important correlations between substituent effects and emission spectra and the quantum yield have been obtained by comparing and analyzing the calculated results.

关键词： pyridyl triazole Os(Ⅱ) complexes excited state density functional theory TD-DFT substituent effects

Quantifying quantum entanglement via machine learning models

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Communications in theoretical Physics 2024年第7期76卷 52-56页

作者： changchun Feng Lin Chen LMIB(Beihang university) Ministry of EducationBeijing 100191China School of Mathematical Sciences Beihang UniversityBeijing 100191China International Research institute for Multidisciplinary Science Beihang UniversityBeijing 00191China

Quantifying entanglement measures for quantum states with unknown density matrices is a challenging *** learning offers a new perspective to address this *** training machine learning models using experimentally measurable data,we can predict the target entanglement *** this study,we compare various machine learning models and find that the linear regression and stack models perform better than *** investigate the model's impact on quantum states across different dimensions and find that higher-dimensional quantum states yield better ***,we investigate which measurable data has better predictive power for target entanglement *** correlation analysis and principal component analysis,we demonstrate that quantum moments exhibit a stronger correlation with coherent information among these data features.

关键词： quantum information entanglement predict machine learning coherence

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Finite-time composite learning control for nonlinear teleoperation systems under networked time-varying delays

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Science china(Information Sciences) 2024年第6期67卷 279-296页

作者： Yana YANG Huixin JIANG changchun HUA Junpeng LI institute of Electrical Engineering Yanshan University

The robust finite-time synchronization control problem is investigated for master-slave networked nonlinear telerobotics systems(NNTSs) in this article. Although there have been some research achievements on finite-time control for the NNTSs, these studies are based on the strong assumptions of communication time delays or can only achieve finite-time bounded convergence even when the external forces are *** and in view of the importance of these issues, a novel robust composite learning adaptive control scheme rendering the finite-time master-slave synchronization is proposed in this paper. In particular, the influence of time delays on finite-time convergence of the system is analyzed by employing the multi-dimension finite-time small-gain framework. Meanwhile, in order to achieve accurate and fast estimation of uncertain parameters of the system, both the online historical and the instantaneous data of the estimation data are explored to derive the new parameter adaptive law under a more realizable interval-excitation(IE) ***, the convergence of the position/force synchronization errors and the adaptive parameter estimation errors is obtained in finite time, and enhanced robustness of the closed-loop system will also be ***, the superior performance of the proposed control algorithms is validated by numerical simulations and hardware experiments.

关键词： networked teleoperation systems finite-time control exact parameter estimation small-gain theorem unknown communication delays

theoretical study of the electronic structures and spectroscopic properties of [(4'-XC≡Ctrpy)PtCl]^+ (trpy=2,2':6',2"-terpyridine;X=H,Me and Ph)

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Science china chemistry 2009年第12期52卷 2226-2236页

作者： WANG Xin,BAI FuQuan,ZHOU Xin,LIU Tao & ZHANG HongXing State Key Laboratory of theoretical and Computational chemistry,institute of theoretical chemistry,jilin university,changchun 13.023,china State Key Laboratory of theoretical and Computational chemistry Institute of Theoretical Chemistry Jilin University Changchun China

The electronic structures and spectroscopic properties of [(4'-XC≡Ctrpy)PtCl]+(trpy = 2,2':6',2″-terpyridine; X = H (1),methyl (Me) (2),and phenyl (Ph) (3) were studied by the ab initio method. The structures at the ground and excited state were optimized at the B3LYP and CIS levels,respectively. The absorption and emission spectra in the dichloromethane solution were obtained by using the TD-DFT (B3LYP) method associated with the PCM model. The molecular orbital energy of the HOMOs of 1-3 with the d(Pt),p(Cl),π(trpy),and π(XC≡C) character is sensitive to the substituents on the acetylide ligand,but that of the trpy-based LUMOs with the π*(trpy) character varies slightly. The lowest lying emission at 503 nm for 1 is mainly attributed to the 3ILCT perturbed by the 3MLCT and 3LLCT transitions,but that at 535 nm for 2,and that at 558 nm for 3 are mainly attributed to the 3LLCT perturbed by the 3ILCT and 3MLCT transitions. The different electron-donating ability of H,Me,and Ph is responsible for the differences in emission character. Moreover,the calculation results show that the phosphorescent color can be turned by adjusting the substituents. Both the lowest energy absorption and emission of 1―3 are red-shifted in the order of 1<2<3,consistent with the electron-donating of H

关键词： platinum(Ⅱ) complexes TD-DFT absorption spectra charge transfer luminescence

DFT evaluation of the electronic structures and spectroscopic properties of the self-assembled [Pt_2M_4(C≡CH)_8](M=Cu,Ag) clusters

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Science china chemistry 2009年第11期52卷 1954-1960页

作者： BAI FuQuan1,XIA BaoHui1,2,ZHANG HongXing1,YANG BaoZhu1,WANG Jian1 & SUN Lei1 1 State Key Laboratory of theoretical and Computational chemistry,institute of theoretical chemistry,jilin university,changchun 13.023,china 2 College of chemistry,jilin university,changchun 13.023,china State Key Laboratory of theoretical and Computational chemistry Institute of Theoretical Chemistry Jilin University Changchun China College of chemistry Jilin University Changchun China

Electronic structures and spectroscopic properties of self-assembled [Pt2M4(C≡CH)8](M=Cu,Ag) clusters have been studied by the TD-DFT(time-dependent density functional theory) calculations with the polarizable continuum model(PCM).The ground-and excited-state structures were optimized by the DFT(density functional theory) *** calculated structures and spectroscopic properties are in agreement with the corresponding experimental *** [Pt2Ag4(C≡CH)8] clusters have two stable ground state geometries(D4 and D4h symmetry).The calculated Pt-M distances suggest only very weak *** Cu-Cu distances are larger than the van der Waals radii of two Cu atoms and the Ag-Ag distances are analogous with the sum of van der Waals radii of two Ag *** excitation,the interaction of Pt…M,Ag…Ag is strengthened,while the Cu…Cu distances are shortened but they are still larger than the sum of van der Waals radii of two Cu *** lowest-energy absorptions are at 450,365 and 375 nm and the emissions are at 611,431 and 435 nm for [Pt2Cu4(C≡CH)8],[Pt2Ag4(C≡CH)8](A) and(B),*** transitions are all perturbed by the Cu or Ag composition through the UV-Vis spectra region;therefore,there are not pure ILCT or MPtLCT characteristics(ILCT:intraligand charge transfer;MLCT:metal-to-ligand charge transfer) in absorptions of heteropolynuclear [Pt2M4(C≡CH)8] *** the emissions and the lowest-absorptions have different transition characteristics for each complex,the emissions should not come from the lowest-energy *** the M…M interactions in the excited state of [Pt2Ag4(C≡CH)8] are augmented,the emissions of [Pt2Ag4(C≡CH)8] clusters bear prominent ILCT character,which is the reason why the emission wavelengths of [Pt2Ag4(C≡CH)8] have a small hypsochromic shift relative to the emission wavelength of homoleptic [Pt(C≡CH)4]2-precursor.

关键词： electronic structures luminescence behavior heteropolynuclear complexes TDDFT

Au-chin Tang——A prestigious scientist,outstanding educator and distinguished leader

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Science china chemistry 2008年第12期51卷 1142-1145页

作者： institute of theoretical chemistry, jilin university, changchun 13.023 Prof. Zhang Hongxing institute of theoretical chemistry Jilin University

Au-chin Tang (1915-2008), member of the Chinese Academy of Sciences (CAS), was born in Yixing, Jiangsu Province on November 18th, 1915. During his lifetime, he held various positions such as president

关键词： Au-chin Tang A prestigious scientist,outstanding educator and distinguished leader

theoretical studies of the transport property of oligosilane

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Science china chemistry 2010年第12期53卷 2571-2580页

作者： ZHANG GuiLing 1,YUAN HongLiang 1,ZHANG Hui 1,SHANG Yan 1,SUN Miao 1,LIU Bo 1 & LI ZeSheng 2 1 College of Chemical and Environmental Engineering,Harbin university of Science and Technology,Harbin 150080,china 2 State Key Laboratory of theoretical and Computational chemistry institute of theoretical chemistry,jilin university,changchun 13.023,china College of Chemical and Environmental Engineering Harbin University of Science and Technology Harbin China State Key Laboratory of theoretical and Computational chemistry institute of theoretical chemistry Jilin University Changchun China

The transport mechanisms of four-conjugated systems were comparatively studied by combining ATK and Gaussian 03 *** was found that the charge-doped oligosilane behaved in a different way from the boron doped and phosphorus doped oligosilanes in terms of the transmission *** charge-doped oligosilane showed almost no conductivity owing to the damage of the electron transfer path by *** contrast,the boron doped and phosphorus doped oligosilanes were demonstrated to be good semiconductors and NDR behavior was observed for *** is a reasonable result after the analysis of the transmission spectra,MPSH states,energy gap,conjugation effect,and scattering effect.

关键词： theoretical study transport property oligosilane

Studies on the Interaction of 12-Tungstophosphoric Acid and Diethylene Glycol

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Chemical Research in Chinese Universities 1993年第4期9卷 317-323页

作者： ZHAO Yu-sheng, HUA Shi-ying , WU Tong-hao and WEI Quan (Department of chemistry, jilin university, changchun, 13.023) Worked in institute of theoretical chemistry, jilin university, changchun.

The homogeneous system of 12-tungstophosphoric acid and diethylene glycol was studied using IR and NMR spectra. It was found that the protons in 12-tungstophosphoric acid formed proton oxonium ions with the hydroxyl oxygen in diethylene glycol by hydrogen-bonds, and the formed proton oxonium ions could react with the terminal oxygens of heteropoly anions. The dehydration-cyclization mechanism of diethylene glycol in the presence of heteropoly acid was also proposed.

关键词： IR NMR Diethylene glycol Proton oxonium ions