G(FOX-7)的合成、晶体结构及量子化学研究

用1,1-二氨基-2,2-二硝基乙烯（FOX-7）和盐酸胍在KOH水溶液中合成了[HN=C(NH₂)₂]⁺(FOX-7)^---G(FOX-7),并培养出淡黄色单晶。化合物属正交晶系,空间群为P-bca,晶体结构参数为: a=1.0428(3)nm, b=0.73099(18)nm,c=2.2253(5)nm,V=1.6963(7) nm³,D_c=1.542 g/cm³,μ＝0.333 mm^-1,F(000)=864, Z=8。在分析分子晶体结构的基础上,采用B3LYP、HF和MP2三种方法在6-31+G(d)基组水平上对标题化合物进行几何全优化,并对其成键情况、原子电荷分布、分子轨道能量进行了分析。     

Molecular Structure,Theoretical Calculation and Thermal Behavior of DAG(NTO)

A new compound, [DAG(NTO)], was prepared by mixing the NaNTO•H2O aqueous solution and diaminogaunidine hydrochloride aqueous solution. Single crystals suitable for X-ray measurement were obtained by recrystallization from water at room temperature. The crystal belongs to triclinic, space group P-1 with crystal parameters of a＝0.6732(3) nm, b＝0.6745(3) nm, c＝0.9840(4) nm, α＝88.309(7)°, β＝77.255(6)°, γ＝86.520(7)°, V＝4.349(3) nm3, Z＝2, μ＝0.144 mm－1, F(000)＝228, and Dc＝1.674 g/cm3. The theoretical investigation on DAG(NTO) as a structural unit was carried out by B3LYP, MP2 and HF methods with 6-31＋G(d) basis set. The apparent activation energy and pre-exponential constant of the exothermic decomposition reaction of DAG(NTO) are 112.15 kJ•mol－1 and 109.603 s－1, respectively. The critical temperature of thermal explosion is 208.6 ℃.     

Struktur und Eigenschaften von Gd3I3C

Structure and Properties of Gd₃I₃C . The compound Gd₃I₃C is prepared by reaction of Gd, GdI₃ and C (2:1:1 mole) at 1 250 K in sealed Ta tubes. It is obtained as bronze-coloured needles which are air and moisture sensitive. The structure of Gd₃I₃C contains twin chains of C centered Gd₆ octahedra surrounded by I atoms capping all free edges like in the M₆X₁₂ cluster. The one-dimensional units are oriented along [010] and linked according to (GdGd_1/3Gd_2/2Gd_2/3C)₂IIII. Gd₃I₃C is metallic in the temperature range 300 K ≥ T ≥ 120 K, between 120 and 15 K the electrical resistance increases by 6 orders of magnitude. At high temperatures the susceptibility follows the Curie-Weiß law with a paramagnetic Curie temperature θ ≈ - 340 K. Two local maxima in the susceptibility at 100 K and 25 K indicate successive formation of antiferromagnetically ordered structures.     

Stable gem-trifluoromethyl anionic σ-complexes based on 1,3,5-tris(sulfonyl)benzene derivatives and their transformations

A convenient synthetic procedures is described to obtain gem-trifluoromethyl anionic σ-complexes of 1,3,5-tris(fluorosulfonyl)benzene, 1,3,5-tris(β,β,β-trifluoroethoxysulfonyl)benzene, 1,3,5-tris(trifluoromethylsulfonyl)benzene as well as of 1,3,5-trinotrobenzene. Conditions for easy oxidation of these adducts into corresponding 2,4,6-tris(substituted)benzotrifluorides have been found. It is shown that the latter add trifluoromethyl anion to the 1 and 3 positions of the aromatic ring forming new anionic σ-complexes in different ratio. Structures and relative stabilities of the anionic adducts are discussed based on RI-MP2 quantum chemical calculations.     

金华市地氟病病区摄氟总量调查

金华地区氟污染严重,地氟病病区居民摄氟总量偏高,平均日摄入量可达4.77 mg。饮水和食物是主要的摄氟途径。应该采用综合性的地氟病防治措施,仅仅靠改水是不够的。     

光还原法制备不同形貌银纳米粒子及其形成机理

光还原法制备不同形貌银纳米粒子及其形成机理;光还原;纳米银;形成机理     

Struktur und Eigenschaften von TlZnPO4 und TlZnAsO4

Structure and Properties of TlZnPO₄ and TlZnAsO₄ TlZnPO₄ and TlZnAsO₄ have polymorphic behavior with two phase transitions (TlZnPO₄: 263°C, 450°C; TlZnAsO₄: 562°C, 752°C) between room temperature and the congruent melting point at 1 090°C for TlZnPO₄ and 930°C for TlZnAsO₄. X-ray diffraction powder patterns have shown, that the compounds are isotypic and crystallize in the monoclinic system with the lattice constants a = 882.8(2), b = 546.2(1), c = 872.9(1) pm, β = 90.61(2)° for TlZnPO₄, a = 895.4(1), b = 562.3(1), c = 892.8(1) pm, β = 91.08(2)° for TlZnAsO₄, Z = 4, space group P2₁. TlZnPO₄ and TlZnAsO₄ belong to the „stuffed derivatives”︁ of the Icmm structure type with a [ZnXO₄]⁻ network of corner linked alternating ZnO₄ and XO₄ tetrahedra (X = P, As) with channels of six-membered rings in the direction of the c axis. These cavities contain the Tl cations. The results of ³¹P MAS-NMR measurement of TlZnPO₄ may be correlated with its structure. The Tl⁺ ionic conductivity at 300°C reaches only values of 4.4 × 10⁻⁸ Ω⁻¹ cm⁻¹ for TlZnPO₄ and 4.5 × 10⁻⁸ Ω⁻¹ cm⁻¹ for TlZnAsO₄.     

佛山市儿童铅中毒现状的调查

[目的 ]旨在了解佛山市儿童铅中毒的现状。 [方法 ]采用阳极溶出伏安法 ,测定佛山市41 6名 1～ 1 4岁儿童的血铅值。 [结果 ]儿童铅中毒率为 3 3 41 % ,不同性别儿童铅中毒率有明显差异 (P <0 0 1 ) ,不同年龄组血铅中毒率无明显差异 (P >0 0 5 )。 [结论 ]儿童铅中毒在不同地区存在一定差异。儿童铅中毒已不只是医学问题 ,应引起全社会的广泛关注。     

Structure and catalytic activity of the ruthenium(I) sawhorse‐type complex [Ru2{μ,η2‐CF3(CF2)5COO}2(DMSO)2(CO)4]

The title compound, cis‐di‐μ‐perfluoroheptanoato‐κ⁴O:O′‐bis[dicarbonyl(dimethyl sulfoxide‐κS)ruthenium(I)](Ru—Ru), [Ru₂(C₇F₁₃O₂)₂(C₂H₆OS)₂(CO)₄], is a sawhorse‐type dinuclear ruthenium complex with two bridging perfluoroheptanoate ligands, and with two dimethyl sulfoxide (DMSO) ligands in the axial positions coordinating via the S atoms. It is a new example of a compound with an aliphatic fluorinated carboxylate ligand. The Ru—Ru bond distance of 2.6908 (3) Å indicates a direct Ru—Ru interaction. The compound is an active catalyst in transvinylation of propionic acid with vinyl acetate.     

新型同分异构芘基查尔酮的理论研究和超快三阶非线性光学响应

合成了3个新型同分异构芘基查尔酮:1-(芘-1-基)-3-(吡啶-2-基)-2-丙烯-1-酮(3a)、1-(芘-1-基)-3-(吡啶-3-基)-2-丙烯-1-酮(3b)和1-(芘-1-基)-3-(吡啶-4-基)-2-丙烯-1-酮(3c)。 通过核磁共振波谱仪(NMR)、傅里叶变换红外光谱仪(FTIR)和液-质联用仪(LC-MS)等技术手段表征3个化合物的结构、热稳定性和线性光学性质和三阶非线性光学吸收性能。 结果表明,在532 nm和180 fs条件下,化合物3a-3c均表现出超快三阶非线性光学响应,化合物3c的非线性吸收系数分别是化合物3b和3a的1.14和2.67倍。 运用密度泛函理论方法计算了化合物3a-3c的非线性光学性质及其电子性质,结果表明,化合物3c分子具有最大的静态第一超极化率(β₀)(2830.9 a.u.),并具有最小的最高占据分子轨道(HOMO)-最低空分子轨道(LUMO)之间的能隙(3.11 eV)和最小的跃迁能(ΔE)(2.67 eV),这与N原子在吡啶环上的位置有关;分子内部均存在电荷转移现象。 3个化合物的紫外-可见光谱在450 nm以上无吸收,有良好的热稳定性,在激光防护方面有应用前景。