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

AGE DEPENDENCE OF SPIRAL GRAIN IN WHITE OAKS (QUERCUS ALBA) IN SOUTHCENTRAL ILLINOIS

Spiral grain, the alignment of wood fibers (trachejds) to the longitudinal axis of h·ees, is thought to be an indicator of old age and is a phenomenon that has been only stndied with destrnctive sampling methods (cutting down trees). In this study, the usefulness of non-fatal sampling methods and existing methods to quantify spiral grain patterns in Jiving and dead deciduous trees are examined, particularly in white oaks (Qi1ercus alba). 111e overall goal is to detem1ine if spiral grain growth is a reasonable indicator of h·ee age. Methods that were tested included the use of a 12 mm increment borer (non-fatal sampling method) and Brazier's method ( 1965) of analyzing grain angles along just one diagonal to get a representative grain angle for the whole circumference at a certain height on a tree. The 12 mm increment borer did not produce consistent results in this study; therefore, . destructive sampling is necessary to study spiral grain in white oaks. Brazier's method (1965) should not be used in white oaks and should not be applied universally to all tree species. Samples from living and dead trees vary in severity and direction of spiral grain. The climatic factors that are roost limiting to tree growth do not influence spiral grain growth in white oaks in this stand. Severe spiral grain does in general seem to be an indicator of age in white oaks, although most trees have severe left spiral grain and not right spiral grain. However, a tree without severe spiral grain is not necessarily young. To judge the severity of spiral grain, grain angles have to be examined in the outermost layer of the wood and not in the bark

Исследование влияния природы растворителя, используемого при получении электродной мембраны, на работу Ni-селективного электрода при определении ионов никеля (LL) в водных средах

Исследовано влияние природы растворителей (бензиловый спирт и хлорфенол), используемых для изготовления полимерной электродной мембраны твердофазного никельселективного электрода на основе никельгексационоферратов ({Ni2[Fe(CN)6]}), иммобилизованных в полиэтилентерефталатную (ПЭТФ) матрицу для определения ионов никеля в водных средах. Установлено, что мембраны, полученные на основе бензилового спирта имеют более высокие электродные показатели по сходимости и воспроизводимости потенциалов, стабильности работы, низком дрейфе и времени отклика электрода по сравнению с мембранами на основе хлорфенола и могут быть рекомендованы к использованию в никель селективных электродах.The influence of the nature of the solvents (benzyl alcohol and chlorophenol) used to fabricate a polymer electrode membrane of a solid-phase nickel selective electrode based on nickelhexacetanoferrates ({Ni2 [Fe (CN) 6]}) immobilized in a polyethylene terephthalate (PET) matrix for the determination of nickel ions in aqueous media . It has been established that membranes obtained on the basis of benzyl alcohol have higher electrode indices for the convergence and reproducibility of potentials, stability of operation, low drift and electrode response time compared to chlorophenol-based membranes, and can be recommended for use in nickel selective electrodes

Synthesis and vibrational spectroscopy of Fe-57-labeled models of [NiFe] hydrogenase: first direct observation of a nickel-iron interaction

A new route to iron carbonyls has enabled synthesis of 57Fe-​labeled [NiFe] hydrogenase mimic (OC)​357Fe(pdt)​Ni(dppe) (pdt = 1,​3-​propanedithiolate)​. Its study by nuclear resonance vibrational spectroscopy revealed Ni-​57Fe vibrations, as confirmed by calcns. The modes are absent for [(OC)​357Fe(pdt)​Ni(dppe)​]​+, which lacks Ni-​57Fe bonding, underscoring the utility of the analyses in identifying metal-​metal interactions