Synthesis and structures of mercury and cadmium complexes: [Ph4Sb] 2 + [Hg2I6]2−·Ph2Hg, [Ph4Sb] 2 + [E2I6]2− (E = Hg, Cd), and [Ph4Sb] 2 + [Hg4I10]2−

The reaction of pentaphenylantimony with mercury iodide affords the ionic complex [Ph₄Sb] ₂ ⁺ [Hg₂I₆]^2?·Ph₂Hg (I). The [Ph₄Sb] ₂ ⁺ [Hg₂I₆]^2? (II) and [Ph₄Sb] ₂ ⁺ [Cd₂I₆]^2? (III) complexes are synthesized from tetraphenylantimony iodide and mercury and cadmium iodides. The [Ph₄Sb] ₂ ⁺ [Hg₄I₁₀]^2? complex (IV) is prepared from tetraphenylantimony 2,4-dimethylbenzenesulfonate and mercury iodide. According to the X-ray diffraction data, the Sb atom in the [Ph₄Sb]⁺ cations of complex I has virtually ideal tetrahedral coordination (the CSbC angles are 108.09°–109.64°). In the central square fragment Hg₂I₂ of the [Hg₂I₆]^2? anion, the Hg-I_br bond lengths are 2.825 and 3.075 Å, and the terminal iodine atoms are more strongly bonded to the mercury atoms (Hg-I_term 2.691 and 2.700 Å). The [Cd₂I₆]^2? anion in complex III has a similar structure (the Cd-I_bridg and Cd-I_term distances are 2.865, 2.872 and 2.723, 2.748 Å, respectively). The anions in complex IV are joined by I…Hg (3.651 Å) and I…I (4.058 Å) interactions into an infinite dimeric network.     

Tail behavior of conditional sojourn times in Processor-Sharing queues

We investigate the tail behavior of the sojourn-time distribution for a request of a given length in an M/G/1 Processor-Sharing (PS) queue. An exponential asymptote is proven for general service times in two special cases: when the traffic load is sufficiently high and when the request length is sufficiently small. Furthermore, using the branching process technique we derive exact asymptotics of exponential type for the sojourn time in the M/M/1 queue. We obtain an equation for the asymptotic decay rate and an exact expression for the asymptotic constant. The decay rate is studied in detail and is compared to other service disciplines. Finally, using numerical methods, we investigate the accuracy of the exponential asymptote. AMS 2000 Subject Classifications Primary:60K25,Secondary: 60F10,68M20,90B22     

Synthesis and structure of 2,4,6-tribromophenoxytetraphenylbismuth

Four new complexes of pentavalent bismuth are synthesized: Ph₃Bi[OC₆H₂(Br₃-2,4,6)]₂, Ph₃Bi[OC₆H₂(Cl₃-2,4,6)]₂, Ph₄BiOC₆H₂(Br₃-2,4,6), and Ph₄BiOC₆H₂(Cl₃-2,4,6). Tetraphenylbismuth aroxides are produced by the disproportionation reaction of ligands from pentaphenylbismuth and triphenylbismuth diaroxides in toluene or from pentaphenylbismuth and phenol. Triphenylbismuth diaroxides are synthesized from phenol, triphenylbismuth, and hydrogen peroxide taken at a molar ratio of 2 : 1 : 1, respectively, in diethyl ether. According to the X-ray diffraction data, the bismuth atom surrounding in 2,4,6-tribromophenoxytetraphenylbismuth has the configuration of a trigonal bipyramid with the aroxyl ligand in the axial position. The Bi-C and Bi-O bond lengths are 2,184, 2.190, 2.234, and 2.514 Å, respectively, and the equatorial CSbC angles are equal to 111.4°, 121.3°, and 121.3°.Translated from Koordinatsionnaya Khimiya, Vol. 30, No. 12, 2004, pp. 935–938.Original Russian Text Copyright © 2004 by Sharutin, Egorova, Tsiplukhina, Gerasimenko, Pushilin.     

Effect of NH-restructuring on the electronic spectra of the tetrapropylchlorin molecule

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 52, No. 4, pp. 586–592, April, 1990.     

New Method of Synthesis of Tetraphenylbismuth Aroxides

Russian Journal of General Chemistry -     

New Method for Preparing Tetraphenylbismuth Arenesulfonate

Russian Journal of General Chemistry -     

Adduct of Triphenylphosphine Oxide and Sulfuric Acid: Synthesis and Structure

Adduct of triphenylphosphine oxide and sulfuric acid was synthesized by reacting arenesulfonic acids with triphenylphosphine oxide (1 : 2) in the presence of the moisture of air. According to the X-ray diffraction data, the phosphorous atom has a distorted tetrahedral coordination. The sulfuric acid molecule is disordered over two sites and is linked with two triphenylphosphine oxide molecules through hydrogen bonds.     

Synthesis of 4,2′-iodonio-3-phenyl-1,2-benzisoxazole tetrafluoroboride and the crystal structure of its monohydrate

Conclusions 4,2-Iodonio-3-phenyl-l,2-benzisoxazole tetrafluoroboride monohydrate (IV) was synthesized and an x-ray diffraction structural study showed that the cation (IV) is a tetracyclic system and the crystal structure is insular with I...F and I...OH₂2 ionic and ion-dipole interactions.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2309–2314, October, 1985.