Ruthenium(II) complexes with mono and ditertiary arsines and phosphines and their reaction with small molecules

Dichlorotetrakis(dimethylsulphoxide)ruthenium(II) reacts with AsPh₃ AsMePh₂, AsMe₂Ph and SbPh₃ in ethanolic hydrochloric acid solution to yield the complexes RuCl₂(DMSO)₂(AsPh₃)₂, RuCl₂(DMSO) L₂ (L = AsMePh₂, AsMe₂Ph, SbPh₃) respectively. The treatment of ruthenium(II) blue solution with AsMePh₂, AsMe₂Ph and SbPh₃ in alcohol resulted in the formation of the complexes; RuCl₂L₃ (L = AsMePh₂, AsMe₂Ph and SbPh₂), respectively. The reaction of RuCl₂(DMSO)₄ with the bidentate ligands 1,2 bis (diphenylarsino)methane (DPAM), 1,2 bis(diphenylarsino)ethane (DPAE) and 1,2 bis (diphenylphosphino)methane (DPPM). 1,2 bis(diphenylphosphino)ethane (DPPE), in ethanol gave the complexes RuCl₂(DPAM)₂, RuCl₂(DPAE)₂, RuCl₂ (DPPM)₂ RuCl₂(DPPE)₂, respectively. The complexes thus obtained undergo reaction with carbon monoxide, hydrogen, molecular nitrogen and nitric oxide to yield a variety of mixed ligand complexes.     

Photochemistry of β, γ-unsaturated ketones-V: The direct irradiation of some γ-phenyl β, γ-enones

The photochemistry of some members of the two series of γ-phenyl substituted acyclic β, γ-unsaturated ketones 1 and 2 upon direct irradiation with γ 310nm has been investigated, viz 1c–1h and 2b+2c.The alkyl substituted (E)-5-phenyl-4-penten-2-ones 1c–1h yield the corresponding 1,3-acyl shift products and (Z)-isomers, and 1g and 1h in addition two decarbonylated products. 2b only yields the (Z)-isomer and some benzaldehyde, but 2c yields the 1,3-acyl shift product, the ODPM product, three hydrocarbons formed by disproportionation of the allyl radical, and some benzaldehyde. The β-phenyl β, γ-UK 3a proved to be photostable. The 1,3-acyl shift products of 1c–1h result mainly from the singlet excited state in a cage radical process. The exclusive formation of the (E)-configuration of the 1,3-acyl shift product is explained in terms of conformational preference of the intermediate allyl radical. It is proposed that the formation of the (Z)-isomer proceeds from ¹T(π -π^*) which is populated according to

. Evidence is presented which supports the proposed mechanism.The β,γ-UK 2b containing a benzoyl moiety leads to a higher degree of (E)-(Z) isomerization than the corresponding 1d which has an acetyl moiety.The triplet energies of (E)- and (Z)-1h are 56 and ca 70 kcal/mol respectively.     

Ionic conductivity in Na+, K+, and Ag+ β″-alumina

This paper presents measurements of the ionic conductivity in single crystals of β″-alumina (0.84 M₂O · 0.67 MgO · 5.2 Al₂O₃, M = Na, K, Ag). Single crystals of sodium β″-alumina were grown from a melt of Na₂O, MgO, and Al₂O₃ at 1660 to 1730°C. Selected crystals were converted to the other isomorphs by ion exchange. The conductivity of sodium β″-alumina varies from 0.18 to 0.01 (ohm · cm)^?1 at 25°C depending upon crystal growth conditions. Potassium β″-alumina has the unusually high room temperature conductivity of 0.13 (ohm · cm)^?1. Silver β″-alumina has a slightly lower conductivity, 4 × 10^?3 (ohm · cm)^?1 at 25°C. The activation energies of sodium and potassium β″-alumina decrease with increasing temperature, while that of silver β″-alumina is constant from ?80 to 450°C.     

Molecular structure of carbonyl bromide as studied by gas electron diffraction

The molecular structure of COBr₂ has been determined as follows by an analysis of electron diffraction intensity: r_g(CO) = 1.178 ± 0.009 Å, r_g(C-Br) = 1.923 ± 0.005 Å and θ°_α(Br-C-Br) = 112.3 ± 0.4°. The uncertainties represent estimated limits of error. The observed systematic trends in the bond lengths and bond angles in carbonyl and thiocarbonyl halides are discussed.     

Separation and gravimetric determination of cerium and lanthanum with N-m-tolyl-m-nitrobenzohydroxamic acid

Cerium and lanthanum were determined gravimetrically by selective precipitation with N-m-tolyl-m-nitrobenzohydroxamic acid and separated from several metal ions such as Ag(+), Be(2+) , Pb(2+) , Mn(2+) , Cu(2+), Zn(2+) , Cd(2+) , Hg(2+) , Pd(2+) , Ga(3+) A1(3+) , Bi(3+) , Sb(3+), Sn(4+), Ce(3+) , Pr(3+) , Nd(3+) , Ti(4+), Zr(4+), Th(4+), V(5+) , Mo(6+) and U(6+) . The precipitates were weighted directly after drying at 110 degrees . The analytical results indicated the composition of the complexes to be (C(14)H(11)N(2)O(4))(n)M.     

Valence fluctuation in some Yb intermetallics by X-ray photoemission and X-ray absorption

The valence state of Yb in some of its intermetallics, YbNi₂Ge₂, YbCu₂Si₂ and YbPd₂Si₂ has been investigated by L_III(Yb) absorption edges and X-ray pnotoelectron spectra in the 4f and 4d regions. These studies establish the presence of mixed valence in all three systems and illustrate the utility of 4f and 4d spectra in the study of mixed valence in Yb compounds.     

Mobile Ad Hoc NetWork与Internet互联的技术研究

分析了移动IP和AODV协议的工作机理．对MANET与Internet互联的关键技术，包括协议转换、地址分配、网关发现、路由发现与数据传输等问题进行了详细的讨论．并对今后的研究工作进行了展望。     

Cache中TLB的设计及优化

当今微处理器的设计中，为了加快虚拟地址向物理地址转换的速度，通常使用地址转换后备缓冲器TLB(translation lookaside buffer)来加快地址转化的速度．本论基于逆向设计，提出了一种可行的TLB结构，可完成地址转换的功能，并从硬件上支持了不同大小的页表格式．此外，通过引入DVS技术将TLB存储单元中的漏电功耗减少90％以上．     

基于以太网的数据采集终端设计

具有以太网接口的数据采集终端是以太网数据采集系统的前端设备。采用嵌入式网络单片机来设计以太网接入的数据采集终端,具有结构简单、成本低、体积小、易于实现的特点。主要介绍了以8bit嵌入式网络单片机SF0020为核心,配置512KBytes程序和数据存储空间,通过与A/D转换芯片MAX1263和物理层收发器DM9161的连接,组成一款基于以太网的数据采集终端。它具有250Ksps的最高转换速度,12bit的分辨率和4个输入通道,可以在该数据采集终端基础上,方便地进行网络仪器仪表的开发。     

基于GSM和Internet相结合的远程监控系统的开发

以基于远程无线采集某地下水水位数据的开发系统为例,阐述了以VB6.0为开发环境,基于GSM网络和Internet网络两种通信方式相结合的远程监控系统的开发过程,并给出了基于Winsock的数据传输的部分代码。其设计方法具有一定的新颖性,并且具有可移植的通用性,因此可以广泛地应用于其它计算机监控系统的设计。