A study has been made of the dissolution of naturally occurring α-iron oxide hydrate in acidified aqueous solutions of sulphur dioxide at 110°C. The dissolution was found to be independent of acidity at low concentrations of sulphur dioxide and inversely dependent on acidity at higher concentrations of sulphur dioxide. Both homogeneous and heterogeneous control of the reaction was observed. The addition of cupric ion to the system catalysed the rate. Dissolution is thought to occur via hydration of the oxide surface and subsequent reaction of undissociated sulphurous acid at the surface to form a ferric-sulphite complex. The rate determining step is considered to be the desorption of the complex from the surface. A limited study of the direct dissolution of iron oxide hydrate in sulphuric and perchloric acids at temperatures between 120 and 150°C is included. Under these conditions, the hydrated oxide surface is thought to undergo anion exchange during dissolution. Work carried out on the preparation and identification of the isomeric α- and γ-iron oxide hydrates is reported. / Applied Science, Faculty of / Materials Engineering, Department of / Graduate

Analysis of the sulfur dioxide long wavelength band, appearing in n-ROH or benzene and carbontetrachloride solutions, has been obtained in terms of the system:- donor + SO₂ ⇌ complex The characteristic constants for the MeOH , EtOH , n-PrOH, n-BuOH and benzene complexes and the heat of formation of the benzene and ethanol complexes with sulfur dioxide in carbontetrachloride have been estimated. Structures for the n-ROR – SO₂ complexes have been proposed along the lines of Mulliken's simple charge transfer theory. It has been shown that the spectroscopic behaviour of sulfur dioxide in mixed benzene - ethanol solutions is adequately explained in terms of the binary donor system:- benzene + SO₂ ⇌ (complex)₁ ethanol + SO₂ ⇌ (complex)₂ if it is assumed that the characteristic constants for both complexes and the molar extinction curve of free sulfur dioxide remains unchanged in passing from non - polar to polar solvents. From a similar analysis of the new band appearing in hydroquinone - sulfur dioxide - ethanol solutions, the characteristic constants and heat of formation of the hydroquinone - sulfur dioxide complex have been obtained. The value for the heat of formation of this complex is in good agreement with the reported value of the heat of decomposition of the hydroquinone - sulfur dioxide clathrate compound. This fact, together with the evidence of the binary donor character of the ethanol - benzene - sulfur dioxide system is strong evidence in favour of the proposed theory of the formation of liquid lattice penetration complexes (by penetration of the liquid lattice by sulfur dioxide). From studies of the temperature dependence of the long wavelength band in sulfur dioxide - water solutions, it has been concluded that neither Ley and Konig nor Boyd Campbell and Maass’ theories adequately describe the behaviour of the sulfur dioxide - water system. A new theory has been proposed which qualitively describes the behaviour of this system. However, attempts to obtain values for the constants involved from the absorption spectra of water-ethanol-sulfur dioxide solutions, have been unsuccessful. This has been attributed to the simultaneous formation of ethanol - water interpenetration complexes (water penetrating the ethanol lattice). / Science, Faculty of / Chemistry, Department of / Graduate

Efficient preparative routes to several new rhodium complexes and some iridium compounds containing sulfoxide ligands are described. Chiral sulfoxide complexes of rhodium were tested as possible catalysts for the homogeneous asymmetric hydrogenation of prochiral olefins. Also tested were chiral sulfoxide-iridium complexes as potential catalysts for H2 transfer from isopropanol to prochiral olefins and ketones. The sulfoxides used include: the monodentate ligands dimethyl (DMSO), tetramethylene (TMSO), di-n-propyl (NPSO), methyl phenyl (MPSO), and diphenyl sulfoxide (DPSO); the monodentate chiral ligands (+)-(R)-methyl-p-tolyl sulfoxide (MPTSO), (+)-(R)-t-butyl-p-tolyl sulfoxide (TBPTSO), (-)-(S)-o-tolyl-p-tolyl sulfoxide (OTPTSO), and (+)-(S)-2-methylbutyl-(S,R)-methyl sulfoxide (MBMSO); and the potentially chelating ligands meso-l,2-bis(methyl sulfinyl)ethane (MSE), (R,R)-1,2-bis(p-tolyl sulfinyl)ethane (PTSE), and (-)-(2R,3R)-2,3-0-isopropylidene-2,3-dihydroxy-1,4-bis(methyl sulfinyl)butane (DIOS). Displacement of the labile acetone ligand from [Rh(diene)(PPh₃) (acetone)]A (diene=l,5-cyclooctadiene (COD), norbornadiene (NBD); A=PF₆ ⁻, SbF₆ ⁻ ) allows facile coordination of dialkyl or diaryl sulfoxides, and [Rh(diene)(PPh₃)L]⁺ complexes (L=DMSO,TMSO,NPSO,MBMSO,MPSO,MPTSO, and TBPTSO) have been synthesized; compounds with L=AsPh₃, py and (CO)₂ also form. Diaryl sulfoxides and DIOS coordinate, but no solids were isolated. The upfield shifts of the sulfoxide resonances (¹H nmr), reflecting shielding by the adjacent phenyl groups of PPh₃, and the decrease in v(SO) on coordination, are indicative of O-bonding in all cases. NMR data on the olefinic diene protons suggest the occurrence of some disproportionation of the mixed ligand complexes to [Rh(diene) (PPh₃)₂]⁺ and [Rh(diene)(L)2]⁺ depending on L, and the presence of 3-coordinate, and 5-coordinate (for diene=NBD only) intermediates. The hydrogenation of itaconic acid using catalysts with L=R-MPTSO or DIOS resulted in no asymmetric induction in the a-methyl succinic acid product because of disproportionation and catalysis via the bis(triphenylphosphine) system. Efficient hydroformylation of 1-alkenes is effected using [Rh(diene) (PPh₃)(CO)₂j⁺ as catalyst precursors. Aqueous isopropanol solutions of RhCl₃-3H₂O on treatment with sulfoxides provide an efficient route to RhCl₃L₃ complexes (L=DMSO, R-MPTSO,MPSO,TMSO) that contain in solution, at least for the first three systems, two S-bonded sulfoxides trans to a chloride, and an 0-bonded ligand. The 0-bonded sulfoxide is displaced by amides, amine oxides, and phosphine oxides to give mer- RhCl₃ (DMSO)₂(OL) complexes. The DMSO cis to OL in RhCl₃DMSO)₂(OL) or RhCl₃ (DMSO)₃(OL) can be identified in the nmr by using the ring current shielding effects of OPPh₂Me. RhCl₃L₃ react with H₂ (1:1) in base promoted reactions to yield Rh(I) presumably via undetected Rh(III)-H species. RhCl₃.3H₂O reacts with DPSO in isopropanol to give Rh(I) as the chloride-bridged species [RhCl(DPSO)₂]₂. The reaction with NPSO gives a Rh(I) dimer (indirect evidence) and a Rh(III) product, isolated as [H(NPSO)₂][RhCl₄(NPSO)₂] containing a symmetrical hydrogen-bridged cation. A crystal structure of trans-[H(DMSO)₂] [RhCl₄(DMSO)₂] reveals the short oxygen-oxygen distance (~2.45Å) in the cation expected for strong H-bonds. Such cations display intense v[sub a] (OHO) bands at 1700- 1100 and 900-600 cm⁻¹. The air-sensitive complexes [RhCl(C₈H₁₄)(DPSO)]₂, [RhCl(DMS0)₂]₂, [RhCl(DIOS)₂]₂ and [RhCl(MPSO)(PPh₃)]₂, isolated from [RhCl(cyclooctene)₂]₂/ ligand solutions, contain very labile Rh-S bonds that do not appear to involve Rh(dπ)+S (d-π) backbonding. Attempts at generating hydride complexes by oxidative addition of H₂ or HCl to Rh(I) resulted normally in either metal formation or sulfoxide reduction; even in the presence of prochiral olefins these complications occurred rather than catalytic asymmetric hydrogenation. The compound [Rh(MSE) ₂]PF₆ was isolated from the reaction of H₂ with [Rh(NBD) ₂]PF₆, and 2 MSE in alcohol solutions. The compounds mer-IrCl₂(H)(DMS0)₃ with trans chlorides, and mer-IrCl(H)₂(DMSO)₃ with cis hydrides, were obtained from oxidative addition reactions involving HCl and H₂, respectively, with [IrCl(C₈H₁₄)₂]₂ in DMSO. The former catalyzes the efficient selective reduction of α,β-unsaturated aldehydes to the unsaturated alcohols. Attempts at asymmetric synthesis using as catalysts IrCl₃H₂0/chiral sulfoxide mixtures failed. A simple bent M<-O=L vibrational model is used to estimate from v(M0) and v(S0) the force constants F[sub MO] and F[sub OL] using data for seventy 0-bonded DMSO, DMSO-D₆, and TMSO complexes of several metals. The correlation F[sub OL]=-(1.24±0.12)F[sub MO].+(8.78±0.12) mdyne/Å appears to hold for all metal complexes excepting those of group IVA and VA elements. / Science, Faculty of / Chemistry, Department of / Graduate

<p>Sulfur (S) demand has increased as atmospheric deposition of S decreased and soybean (<i>Glycine max</i> (L.) Merr.) production has increased. Soybean growers have invested into agronomic practices to maximize production and alleviate potential S shortfalls including the use of starter fertilizer. For this reason, this study was designed to quantify and qualify the effects of fluid starter S fertilizer on soybean yield. The objectives were to determine an optimum source, rate, and placement of fluid starter fertilizer. A split-plot design of S source-rate and placement was used in 2019 and 2020 at West Lafayette and Wanatah, Indiana. Three starter S fertilizers were used: ammonium thiosulfate (ATS, 12-0-0-26S, Hydrite Chemical), potassium thiosulfate (KTS, 0-0-25-17S, Hydrite Chemical), and K-Fuse (derived from potassium acetate, ammonium thiosulfate and urea 6-0-12-12S, NACHURS) as well as broadcast granular ammonium sulfate (AMS, 21-0-0-24S), and an untreated control. Starter S products were applied at four S rates: 5.6, 11.2, 16.8, and 22.4 kg S ha^-1 to determine optimal S rate and in two placements (single: 0x5x1-cm; dual: 0x5x2-cm). AMS was broadcast at 22.4 kg S ha^-1</p> <p>Placement did not affect a majority of the factors analyzed and was largely factored out when not significant. Leaf concentrations of essential macro-nutrients, including S, were above critical levels and were not affected by starter fertilizer at any site-year. ATS increased manganese (Mn) in 2019 and 2020 and Wanatah. In West Lafayette 2020 (timely planting), all three starter sulfur fertilizers increased yield and protein, while broadcast AMS did not. Yield and protein did not change with starter S fertilizer in the remaining site-years, which was likely due to plantings later than recommended.</p> <p>To evaluate and quantify the effects of fluid starter fertilizer across early and late planting dates, a split-plot design was used with an earlier (May 13, 2020) and late (June 8, 2020) planting dates at West Lafayette, IN, as well as early (P24A80X) and late (P35A33X) maturing soybean varieties at Wanatah, IN. These were crossed with six fertility treatments: ammonium thiosulfate (ATS, 12-0-0-26S), potassium thiosulfate (KTS, 0-0-25-17S), K-Fuse (6-0-12-12S, NACHURS), 28% urea ammonium nitrate (UAN, 28-0-0), ammonium sulfate (AMS, 21-0-0-24S), and an untreated control. Starter S fertilizers were applied at 16.8 kg S ha^-1 and 28% UAN was applied at a 7.9 kg Nitrogen (N) ha^-1rate, all in a single (0x5x1-cm) placement.</p> <p>The earlier planting had greater stand and yield than the later planting. Starter fertilizers did not impact yield, protein or oil compared to untreated control. Earlier-planted soybean with KTS had higher S concentration in the leaves than UTC and other fertility treatments. Variety impacted leaf nutrient and seed protein concentration. Leaf nutrient concentrations was generally higher in the 3.5 variety compared to the 2.4 variety. Protein was higher in the 2.4 variety compared to the 3.5 variety. However, yield was not affected by variety, fertilizer, or a variety x fertilizer interaction. There was also no fertilizer effect on any essential nutrient concentration. </p> <p>Soybean positive response to starter S fertilizer aligned with timely plantings rather than later plantings. Earlier plantings were cool and wet field conditions, which limited mineralization of soil organic matter and the supply of N and S. The highest yield was 4308 kg ha^-1 with KTS in West Lafayette 2020, applied at a rate of 7.5 kg S ha^-1, followed by K-Fuse and ATS, respectively. Given the minimal response to different placements, it can be concluded that the difference between single and dual placements on soybean growth and yield is negligible.</p>

The kinetics of the reaction of atomic sulfur with acetylene (S (3P) + C2H2) were investigated experimentally via the flash photolysis resonance fluorescence method, and the theoretical potential energy surface for the reaction CN + SO was modeled via the density functional and configuration interaction computational methods. Sulfur is of interest in modern chemistry due to its relevance in combustion and atmospheric chemistry, in the Claus process, in soot and diamond-film formation and in astrochemistry. Experimental conditions ranged from 295 – 1015 K and 10 – 400 Torr of argon. Pressure-dependence was shown at all experimental temperatures. The room temperature high-pressure limit second order rate constant was (2.10 ± 0.08) × 10-13 cm3 molecule-1 s-1. The Arrhenius plot of the high-pressure limit rate constants gave an Ea of (11.34 ± 0.03) kJ mol-1 and a pre-exponential factor of (2.14 ± 0.19) × 10-11 cm3 molecule-1 s-1. S (3P) + C2H2 is likely an adduct forming reaction due to pressure-dependence (also supported by a statistical mechanics analysis) which involves intersystem crossing. The potential energy surface for CN + SO was calculated at the B3LYP/6-311G(d) level and refined at the QCISD/6-311G(d) level. The PES was compared to that of the analogous reaction CN + O2. Notable energetically favorable products are NCS + O, CO + NS, and CS + NO. The completed PES will ultimately be modeled at the CCSD(T) level (extrapolated to infinite basis set limit) for theoretical reaction rate analysis (RRKM).

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