The experimental electron density distribution in the complex of (E)-1,2-bis(4-pyridyl)ethylene with 1,4-diiodotetrafluorobenzene at 90 K

The experimental electron density of the donor-acceptor complex of (E)-1,2-bis(4-pyridyl)ethylene (bpe) with 1,4-diiodotetrafluorobenzene (F(4)DIB) at 90 K has been determined with the aspherical atom formalism and analyzed by means of the topological theory of molecular structure. The bpe and F(4)DIB molecules are connected by intermolecular I.N bonds into infinite 1D chains. F.H bonds link these chains together to form the crystal assembly. The topological analysis reveals that the Cbond;I bond is of the "closed shell" type. Its bond-critical properties run parallel to those found in metal-metal and metal-ligand bonds of organometallic compounds. The integrated net charges show that the I.N halogen bond has an essentially electrostatic nature. F.F, F.C, and C.C intermolecular interactions, for which a bond path was found, contribute to reinforce the crystal structure.     

化学发光法测定I-的研究

研究了高锰酸钾-Ⅰ--甲醛体系化学发光,从而建立了一种测定微量Ⅰ-的新方法.讨论了各种反应物浓度、酸度、干扰离子等因素对测定结果的影响.Ⅰ-浓度在1.0×10-6～4.0×10-5g/mL范围内与化学发光强度有较好的线性关系.对1.0×10-5g/mL的Ⅰ-进行了11次平行测定,相对标准偏差为2.8%,方法的检出限为2.4×10-8g/mL.结果令人满意.     

碘硒缺乏对人体健康的危害与预防

概述了碘、硒缺乏对人体健康的危害与预防措施。建议开发硒碘食品并简单介绍了作者的研究工作。     

2-Iodoxybenzenesulfamides: new pseudobenziodoxole-based hypervalent iodine reagents

Amides of 2-iodoxybenzenesulfonic acid were prepared by the dioxirane oxidation of the corresponding 2-iodobenzenesulfamides and isolated as stable, microcrystalline products. These new representatives of the pseudocyclic hypervalent iodine compounds can selectively oxidize benzylic alcohols to aldehydes.     

用燐光寿命变化测定碘离子与燐光体反应动力学参数

利用I-促进系间窜越，加快发射过程，缩短磷光寿命的特点，研究I-量改变与色氨酸，色胺燐光寿命关系，分别为：τ=3．98e－0.0658x,与τ=3．5e－0.0899x,应用静态分析，推导Stern－Volmer式，计算平衡常数Ka与Ki，分别为：0．109与0．200mmol；0．027与0．051smmol－1。利用本法分析了酪氨酸，苯丙氨酸，L-色氨酸，牛血清白蛋白，葡糖苷酸酶，链霉蛋白酶，硫酸酯酶，顺-雄（甾）酮．吲满氨酯，催醒安，阿托品等的动力学参数。     

新生儿及其乳母碘营养状况探讨

为了解杭州部分地区现行加碘盐含量是否满足孕妇分娩时碘营养需求,采用碘铈催化分光光度法对79对新生儿及其母亲尿碘进行了检测。结果表明,新生儿组尿碘明显高于其母亲组(t=22.62,P<0.01)。新生儿的尿碘与其母亲尿碘含量呈正相关(r=0.862,P<0.01),母亲组尿碘小于100μg/L,有9人,占本组11.4%。新生儿组有10人及其母亲组有57人,尿碘在100~200μg/L,分别占本组的12.7%和72.2%。表明母亲组碘营养轻度不足比例较高。     

Laser-Induced Addition Reactions of Iodine with Acetylene

Laser-induced addition reactions of iodine with acetylene at 5145 and 4880 Å excitation wavelengths are studied, while trans-1,2-diiodoethylene is identified as the exclusive reaction product. A sequential addition reaction mechanism initiated by iodine atoms from the direct photodissociation process or collisional induced dissociation can be inferred.     

Phenyliodine(V) fluorides

The known compound phenyltetrafluoroiodine(V) is shown by X-ray diffraction to have a tetragonal pyramidal structure with an apical phenyl group. This structure is compared to that of IF(OTeF₅)₄, where the apical position is occupied by the fluorine atom. C₆H₅IF₄ adds F⁻, forming C₆H₅IF₅⁻, which has a pentagonal pyramidal structure with an apical phenyl group. Fluoride abstraction from C₆H₅IF₄ by SbF₅ results in the formation of the cation C₆H₅IF₃⁺, which has a pseudotrigonal bipyramidal structure with the phenyl group occupying an equatorial position. Isoelectronic C₆H₅IOF₂ has a similar structure, with the phenyl group and oxygen atom both occupying equatorial positions.     

Fragmentation of carbohydrate anomeric alkoxy radicals: a new synthesis of chiral 1-halo-1-iodo alditols

Treatment of 1,2-fluorohydrins, 1,2-chlorohydrins, 1,2-bromohydrins, and 1,2-iodohydrins of the D-gluco, D-galacto, D-lacto, L-rhamno, D-allo, L-arabino, 3-deoxy-D-gluco, and 3,4-dideoxy-D-gluco families of carbohydrates with the (diacetoxyiodo)benzene/iodine system afforded 1-fluoro-1-iodo, 1-chloro-1-iodo, 1-bromo-1-iodo, and 1,1-diiodo alditols, respectively, in excellent yields. The reaction was achieved by radical fragmentation of the C1bond;C2 bond, triggered by the initially formed anomeric alkoxy radical, and subsequent trapping of the C2-radical by iodine atoms. This methodology is compatible with the stability of the protective groups most frequently used in carbohydrate chemistry. The potential utility of these 1-halo-1-iodo alditols as chiral synthons was evaluated by their transformation into alk-1-enyl iodides and in the Takai E-olefination reaction.     

Selective functionalisation of hydrocarbons by nitric acid and aerobic oxidation catalysed by N-hydroxyphthalimide and iodine under mild conditions

Alkylbenzenes are selectively functionalised to the corresponding acetates by nitric aerobic oxidation catalysed by N-hydroxyphthalimide and iodine. With cyclohexane the oxidation leads to a mixture of cyclohexyl acetate and trans-2-iodocyclohexyl acetate. The mechanism is discussed.