A highly distorted hexacoordinated silver(I) complex: synthesis,crystal structure,and DFT studies

A new highly distorted hexacoordinated silver(I) complex [AgL₂NO₃] with 2-(bis(methylthio)methylene)-1-phenylbutane-1,3-dione (L) as ligand is synthesized and characterized using elemental analysis, FTIR, NMR, and X-ray single-crystal structure analysis. The ligand (L) and the nitrate group act as bidentate ligands. The geometry around the silver ion has an intermediate configuration between a trigonal prism (TP) and an octahedron (OCT). Continuous shape measure (CShM) analysis indicated a closer configuration to TP than OCT. Experimentally and theoretically, the Ag–S bonds are shorter than any of the Ag–O bonds, indicating a stronger interaction between Ag⁺ (soft metal) and S-atom as a softer site than oxygen. Natural bond orbital (NBO) analyses showed higher interaction energies between the S-atom lone pairs and the Ag–antibonding NBO (8.61–31.39 kcal/mol) than LP(O)→Ag (3.48–11.46 kcal/mol). The acceptor antibonding NBO of the Ag atom has mainly s-orbital character. The Ag atom has a natural charge of +0.7579 e at the experimental structure, suggesting that negative charge was transferred from the ligand (0.0666 e) and nitrate (0.1090 e) to the Ag ion. Using Hirshfeld surface analysis, the important intermolecular interactions between molecular units within the crystal lattice of the ligand and its Ag-complex were analyzed and compared.     

双重网络嵌入对公司IPO后市场表现的影响研究

将社会网络嵌入理论从单一网络拓展至双重网络,分析上市公司同时嵌入风险投资网络和承销商网络对公司IPO上市后市场表现的影响。利用2004～2017年有风险投资支持的IPO公司数据,实证检验结果表明：(1)单独嵌入风险投资网络中心位置、单独嵌入承销商网络中心位置,均会提高公司IPO后市场表现;(2)同时嵌入风险投资网络中心位置和承销商网络中心位置,对公司IPO后短期市场表现的正向影响会相互替代;(3)同时嵌入风险投资网络中心位置和承销商网络中心位置,对公司IPO后长期市场表现的正向影响会互相补充。     

棱镜转向机构在爆轰测试中的应用

本文阐述了别汉棱镜转向机构的原理和应用技术,并给出了技术要求和爆轰试验中应用转向机构获得的实验数据。     

分时偏振成像系统中光束偏离的补偿方法研究

分时偏振成像系统需要通过旋转检偏器获取场景的偏振信息(I, Q, U), 检偏器的前后表面间不平行(也称为楔角)将导致成像光束发生偏离且随检偏器旋转而旋转, 这将降低偏振成像系统的空间分辨率和偏振测量精度. 本文提出调整检偏器相对于入射主光轴倾斜角的方法来补偿上述光束偏离. 以格兰棱镜作为检偏器, 根据几何光学理论, 推导了分时偏振成像系统光束偏离的一阶近似补偿模型, 获得倾斜角与格兰棱镜楔角之间的函数关系, 并通过仿真模拟验证了该补偿方法的可行性和有效性. 研究结果表明, 将格兰棱镜置于汇聚光路中, 光束偏离的一阶误差可以通过调节格兰棱镜的倾斜角有效补偿; 倾斜角大小与棱镜折射率、楔角及棱镜距电荷耦合元件靶面的距离成正比, 与棱镜厚度成反比. 该结果为研制高精度分时偏振成像系统提供了切实可行的理论依据.     

菲涅耳双棱镜干涉实验中虚光源位置的讨论

讨论了菲涅耳双棱镜实验中虚光源的位置,计算了两虚光源间的距离,并进行了实验测量,理论分析与实验相一致.     

氧化石墨烯在辣根过氧化物酶传感器中的应用研究

本文研究氧化石墨烯的合成方法及其在生物传感器中的应用.通过Hummer法氧化天然石墨粉制得氧化石墨,在蒸馏水中利用超声分散将氧化石墨剥片,从而合成了氧化石墨烯(GO).通过透射电镜图表征了氧化石墨烯的形貌并通过红外光谱证实氧化石墨烯的形成.将所合成的氧化石墨烯与三角形貌的金纳米颗粒(prism AuNPs)、辣根过氧化...     

双棱镜干涉实验中的参量取值研究

本文从理论上推导出双棱镜干涉实验中各参量的取值范围,并通过实验研究找到测量误差小于1%时各参量的取值,这为减小实验误差提供了理论和实验依据.     

Tantalum isocyanide complexes: TaI(CNDipp)6 (Dipp is 2,6‐diisopropylphenyl) and ionic [Ta(CNDipp)7][Ta(CNDipp)6], a formal disproportionation product of the 17‐electron Ta0 metalloradical Ta(CNDipp)6

Treatment of tetraethylammonium hexacarbonyltantalate, [Et₄N][Ta(CO)₆], with 1.1 equivalents of molecular iodine (I₂) in tetrahydrofuran (THF) at 200 K, followed by the addition of 6.0 equivalents of 2,6‐diisopropylphenyl isocyanide (CNDipp) and slow warming to 293 K over a 24 h period gave the tantalum(I) iodide derivative hexakis(2,6‐diisopropylphenyl isocyanide‐κC)iodidotantalum(I), [TaI(C₁₃H₁₇N)₆] or TaI(CNDipp)₆, 1 . Recrystallization of this substance from pentane provided deep‐red nearly black parallelepipeds of the product, which was characterized by single‐crystal X‐ray diffraction. Addition of 1 in THF at 200 K to a suspension of an excess (5.8 equivalents) of caesium graphite (CsC₈), followed by warming, filtration, and solvent removal, afforded a dark‐green oily solid of unknown composition, from which several red–brown rhombohedral plates of the ditantalum salt heptakis(2,6‐diisopropylphenyl isocyanide‐κC)tantalum hexakis(2,6‐diisopropylphenyl isocyanide‐κC)tantalate, [Ta(C₁₃H₁₇N)₇][Ta(C₁₃H₁₇N)₆] or [Ta(CNDipp)₇][Ta(CNDipp)₆], 2 , were harvested. Salt 2 is a unique substance, as it is the only known example of a salt containing a homoleptic cation, [ML_x]⁺, and a homoleptic anion, [ML_y]^?, with the same transition metal and π‐acceptor ligand L. In solution, 2 undergoes full comproportionation to afford the recently reported 17‐electron paramagnetic zerovalent tantalum complex Ta(CNDipp)₆, the only known isolable TaL₆ complex of Ta⁰.     

Risley棱镜在光学侦察中的应用

近年来Risley棱镜在军事侦察领域得到越来越多的应用。介绍Risley棱镜的基本组成,从数学模型上论证了Risley棱镜两种工作原理及其应用技术,分析了工程实现的难点,描述了国内外的工程应用情况,国防科技大学研制的物理样机可实现10光束偏转,实验结果表明已初步实现了扫描成像和光束扫描功能。