Thermal Decomposition Studies of Selected Transition Metal Polysulfide Complexes. II. Effect of Atmosphere on Decomposition

Initial studies involved the thermal decomposition profile of five polysulfide complexes in air up to 550 °C. Since our first report to the Academy in 1990, we have obtained the capability to run samples up to 1500°C under various gases. Thermal Gravimetric Analysis (TGA) and Differential Thermal Analysis (DTA)of a series of transition metal polysulfide complexes are presented. Compounds analyzed included Cp2TiS5 ,MoS9 2 ,MoOS8 2 , Zn(S x ) 2 , Cd(S x ) 2-, Fe2S122 - and NiS82

Izbor dobavljača primjenom metode višekriterijskog odlučivanja

In the present conditions of market globalization and thus increased market competition, the purchasing department and management structure of the company, in addition to answering questions what, how many and when to buy at what price, has also to be answered the question about an appropriate supplier. Supplier selection as well as the efficient inventory control can bring significant savings to a company. For the purpose of systematic evaluation of suppliers, criteria and multiple criteria AHP model (analytic hierarchy process) for selecting the best supplier have been proposed in the paper. The model is illustrated by the example of supplier selection to purchase parts for assembly of the agricultural machine. Multiple criteria and systematic quantitative approach to the supplier selection problem, significantly improve the decision-making process.U današnjim uvjetima globalizacije tržišta, a time i povećanja tržišnog natjecanja, služba nabave i upravljačke strukture u poduzeću, pored odgovora na pitanja što, koliko i kada nabaviti, te po kojoj cijeni, moraju znati i odgovor na pitanje od koga nabaviti. Izbor dobavljača, uz učinkovito upravljanje zalihama, može donijeti značajne uštede poduzeću. S ciljem sustavnog i objektivnog vrednovanja dobavljača, u radu su predloženi kriteriji i višekriterijski AHP model (analitički hijerarhijski proces) za izbor najpovoljnijeg dobavljača. Model je ilustriran na primjeru izbora najpovoljnijeg dobavljača dijelova za montažu poljoprivrednog stroja. Višekriterijskim i sustavnim kvantitativnim pristupom problemu, olakšano je donošenje objektivne odluke

Comparison of the Molecular Structures of Monovalent Cation Salets of N,N-Dimethyldithiocarbamate. Novel Synthesis and Crystal Structure of (Phi4)(S2CN(CH3)2)2H2O

Crystals of the tetraphenylphosphonium N,N-dimethyldithiocarbamate dihydrate (C₂₇H₃₀NO₂PS₂; F.W. = 495.6) are monoclinic; P2₁/n; a = 13.349(6), b = 20,968(6), c = 9.800(4) Å, β = 109.01(3)°; Z = 4; V = 2593.4(16) Å^3; Dₓ = 1.269 gcm- 3 . Data were collected at ambient temperature using MoKα radiation (λ = 0.71069 Å).F(000) = 1048, linear absorption coefficient, n = 2.80 cm- 1. The structure was solved by direct methods and subsequently refined by full matrix least squares techniques. Final R value = 0.064 for 1 61 0 reflections and 298 varied parameters. Due to the nature of the cation, interactions between the tetraphenylphosphonium group and the sulfur atoms of the anion are absent, unlike previous dimethyldithiocarbamate structures (Na+, Cs+, TI+). Intermolecular interactions between the waters of hydration and the anion are present

Model for the CO Poisoning of Hydrodesulfurization Catalysts. Synthesis and Structure of {Ru(CO)[PPh2SC12H7)]2Cl2}.2CH2Br2

The treatment of {Ru[(PPh2SC12H7)]2Cl2} with CO at ambient conditions results, after work up, in the isolation of the monocarbonylated species {Ru(CO)[(PPh2SC12H7)]2Cl2}, I. Crystals of I(C51H38Br4Cl20P2RuS2; F.W. = 1284.6) are triclinic; Ppa= 11.587(3), b = 13.010(4), c = 17.309(4) A, a = 93.32(2)°, p = 106.51(2)°, y = 91.29(2)°; Z= 2; V=2495(1) A\u27;d^,. = 1.709 gem 1 X(MoKa) = 0.71073 A, = 37.7 cm 1 ;R =0.0748; Rw = 0.0714 for 4141 unique reflections. The geometry about the Ru(II) center is pseudooctahedral, with the phosphine ligands in the trans configuration. The Ru-S bond distance is 2.425(3) A

Neue Aspekte in der Chemie von Übergangsmetallpolysulfidkomplexen: Synthese und Kristallstrukturen von Cp′3Nb3S12 und Cp′3Nb3S10O (Cp′ = t-BuC5H4)

Thermolysis of a mixture of Cp′4Nb2Sn (Cp′ = t-BuC5H4; n = 8, 9) results in the formation of the new niobium polysulfide complexes: Cp′3Nb3S12 (2), Cp′3Nb3S10O (3), Cp′3Nb3S10O (4) and Cp′4Nb4S13 (5). The structures of 2 and 3 have been established by X-ray diffraction studies. The complexes are characterized by an unusual variety of different sulfur ligands (up to five in 2), which is responsible for the absence of any metal-metal interaction