Vacuum Dehydration Research Articles

Controlled Low-Temperature Vacuum Dehydration and Tunnel Drying: A Comparative Study

Controlled low-temperature vacuum dehydration (CLTVD) and tunnel drying (TD) processes were applied to mashed potatoes and the quality of the dried products was compared for both processes. Slabs of different thickness (0.26, 0.52 and 0.78 mm) were prepared. CLTVD was carried out at a low temperature avoiding freezing the product, at absolute pressure of 0.67, 1.00 and 1.33 kPa. For the TD experiments air temperatures were 40, 50 and 60° C. CLTVD and TD processes were compared using engineering and quality parameters (bulk density, water adsorption and total color difference). During the constant-rate drying period 40 to 70% of moisture was removed. The best quality product was generated at 0.26 mm, 0.67 kPa for CLTVD and 0.26 mm, 40° C for TD. For these treatments, the flux of mass was 7.8 3 1025 and 3.3 3 1024 kg m22s21 for CLTVD and TD, respectively. The mass transfer coefficient was 6.2 3 1026 kg m22s21 ΔY21 for CLTVD and 3.6 3 1022 kg m22s21 ΔY21 for TD. The falling-rate drying period was divided into three sub-periods. The effective diffusivity coefficient ranged from 1.1 3 10211 to 4.8 3 10211 m2/s and from 4.2 3 10211 to 9.6 3 10211 m2/s for CLTVD and TD, respectively. A change in water transport mechanism was achieved and both processes were controlled by mass transfer; internal and external mass transfer resistances were higher for CLTVD than for TD. CLTVD yields a product with lower shrinkage and a color closer to the white standard than the products obtained by TD. CLTVD may be considered as a potential alternative for drying of temperature-sensitive materials.

Endangered sounds: a sound project

endangered sounds is a project that focuses on the exploration of sound marks (trade-marked sounds). the initial stage of this project was funded by arts victoria, and comprised legal searches that resulted in the listings of sound marks registered in australasia and the united states of america. this list was published on the internet with a call for volunteers to collect samples of the listed sounds internationally. the volunteer was sent a specimen tube with label and cap, and asked to collect the sound by placing the specimen tube close to the source (thereby capturing the air through which the sound travelled), securing the cap and then completing the label, documenting the time, place and nature of the sound (sound mark reg. no., sound mark description, time of capture, date of capture, location, etc.). these specimen tubes were collected and displayed in chemistry racks in the exhibition in the biennale of electronic arts, perth in 2004, illustrating the frequency and diversity of the environment into which these ‘private’, protected sounds have been released. the exhibition project consisted of:(1) a web portal listing all the sound marks listed in australasia and the usa, and negotiations are underway to expand that to include the eu.(2) a collection of sound marks in specimen tubes with caps and labels gathered internationally by people who volunteered to collect samples of sound marks in their environment.(3) a number of glass vacuum desiccator vessels containing a small loudspeaker and sound reproduction chip suspended in a vacuum, reproducing sound marks in the vacuum, notionally breaking the law, but as sound does not travel in a vacuum the gallery visitor hears no sound – what then is the jurisdiction of the sound mark?(4) a card index register of lost and deceased sounds.this project questions the legitimacy of privatising and protecting sounds that are released at random in public spaces. if i own a multi-million dollar penthouse in a city, and work night shifts, i have no recourse against the loud harley davidson or australian football league (afl) siren that wakes me from my precious sleep – both sounds are privately protected, making their recording, reproduction and broadcast illegal.while there are legal mechanisms for protection against repeat offenders, and many of us are committed to a culturally conditioned moral obligation re sound dispersion, there are no legal limits – i can call the police, but the football siren is already within legal standards and still permeates the private domain of city dwellings. the noise abatement legislation is only applicable to regular breaches of the law, and takes some time to sort out, but it does not apply to singular occurrences which, although within legislated limits, still disturb. additionally, the laws are based on amplitude and do not really address the issue of propagation. the ownership of the sound is not addressed in these legislative mechanisms – it should be; if the sound is an emblem of corporate identity, we should be able to choose not to be exposed to it, in the same way that we can place a ‘no junk mail’ sign on our letter boxes. acknowledgement of the private domain is sacrosanct in other areas of legislation, in fact heavily policed, but not addressed in discussions of the acoustic environment beyond amplitude limitations.

Development of portable device for measuring accumulation rate of sea salt particles

We have developed a new portable device for measuring the accumulation rate of sea salt particles. This device is composed of two sets of handy QCM devices, a handy vacuum desiccator and a handy moistening. QCM sensor used was Ag-coated one with 30 MHz in resonant frequency. The resonant frequency change with the relative humidity was measured under different size and amount of attached sea salt particles. The result shows that the resonant frequency was decreased as the relative humidity increased. The decrease of resonant frequency was caused by the weight increase of MgCl 2 solution in the sea salt particles. QCM sensor was exposed on outdoor and the amount of attached sea salt was estimated by the resonant frequency change with the relative humidity.

Fixed and Incremental Levels of Microwave Power Application on Drying Grapes under Vacuum

ABSTRACT: Microwave vacuum drying has been investigated as promising potential for high‐quality dried fruits. In this study, a batch microwave vacuum dryer was used to understand the effect of levels of microwave power on the drying characteristics and moisture content of grapes. Thompson seedless grapes were treated 1st for 30, 60, and 90 min at fixed levels of 500, 750,1000,1250, and 1500 W at a reduced pressure of 2.7 kPa and then treated by 3 staged microwave power levels: a higher level of power during the initial stages of dehydration and 2 subsequently lower levels of power applied as the moisture content decreased. A typical temperature profile was found during the drying process, linearly increasing at the start of drying, followed by a nearly constant value during the drying period while water was evaporating. The total specific energy estimated by the energy balance model was 0.97 to 1.01 W‐h/g of fresh grapes and agreed well with the experimental specific energy of 0.85 to 0.90 W‐h/g for the fixed power tests. The multiple regression results showed that the specific energy was the most influential parameter on the final moisture content of grapes both in fixed and incremental power levels. Further research is needed to further improve the process with high efficiency and good product quality using product temperature as a control measure. Keywords: microwave vacuum dehydration, specific energy, fruits, grapes

Investigating HIV-1 Polypurine Tract Geometry via Targeted Insertion of Abasic Lesions in the (–)-DNA Template and (+)-RNA Primer

A variety of biochemical and structural studies indicate that two regions of the human immunodeficiency virus type 1 (HIV-1) polypurine tract (PPT)-containing RNA/DNA hybrid deviate from standard Watson-Crick geometry. However, it is unclear whether and how these regions cooperate to ensure PPT primer selection by reverse transcriptase-associated ribonuclease H and subsequent removal from nascent (+)-DNA. To address these issues, we synthesized oligonucleotides containing abasic lesions in either the PPT (+)-RNA primer or (-)-DNA template to locally remove nucleobases, although retaining the sugar-phosphate backbone. KMnO(4) footprinting indicates such lesions locally alter duplex structure, whereas thermal melting studies show significantly reduced stability when lesions are positioned around the scissile bond. Substituting the (-)-DNA template between positions -15 and -13 altered cleavage specificity, whereas equivalent substitutions of the (+)-RNA had almost no effect. The unpaired base of the DNA template observed crystallographically (-11C) could also be removed without significant loss of cleavage specificity. With respect to the scissile -1/+1 phosphodiester bond, template nucleobases could be removed without loss of cleavage specificity, whereas equivalent lesions in the RNA primer were inhibitory. Our data suggest an interaction between the p66 thumb subdomain of HIV-1 reverse transcriptase, and the DNA template in the "unzipped" portion of the RNA/DNA hybrid could aid in positioning the ribonuclease H catalytic center at the PPT/U3 junction and also provides insights into nucleic acid geometry around the scissile bond required for hydrolysis.

Ion Exchange/Vacuum Dehydration Treatment of Phosphate Esters in Industrial Applications

Phosphate esters are widely used in a variety of hydraulic systems in industrial applications. These fluids typically exhibit good lubricity and oxidative stability. The fire‐retarding characteristics of phosphate esters make them attractive for use in applications where petroleum‐based fluids would constitute a fire hazard. However, in the presence of water, these fluids hydrolyse and form acidic partial phosphates. Because this process accelerates in an acidic environment, the reaction is referred to as autocatalytic. Moreover, fluid degradation becomes extremely difficult to reverse once acidity reaches an acid number of I mg KOH/g. From that point on, it is increasingly hard to stabilise the fluid with conventional treatment methods such as fuller's earth or activated alumina. In contrast, fluid treatment based on a combined application of ion exchange and vacuum dehydration (IX/VD) was found to be highly effective in arresting fluid degradation and restoring fluid properties to within limits acceptable for continued operation. This paper presents data collected over a period of several years at a number of power plants throughout the USA and Europe. The data confirm that fluids that initially exceeded manufacturer specifications even by a wide margin were successfully stabilised through a combined treatment of IX/VD under normal operating conditions.

Polycrystallization of a Hole Transport Material on Indium-Tin-Oxide Substrates

We studied polycrystallization phenomena of naphthyl-substituted diamine derivative (NPD) on three kinds of ITO substrates. While keeping specimens in vacuum desiccator, the growth rate of NPD films fabricated by 2 nm/s was twice that of NPD fabricated by 0.2 nm/s. In addition, the smooth ITO substrate supports a higher growth rate than the rough ITO substrate. The number of nucleations was concluded to depend on the kind of ITO, but not on deposition. The introduction of CuPc between ITO and NPD suppressed polycrystallization. The reduction of molecular motion, i.e. migration, was found to be effective for suppression of polycrystallization.

Time Dependence of Optical Properties of Vacuum-Evaporated Poly(di-methyl silane) Thin Films

In this paper, we show an interesting change in the optical properties of poly(di-methyl silane) thin films prepared by vacuum evaporation. We have found that the strength of the optical absorption peak at ∼300 nm is changed depending on the substrate temperature during the deposition. The strength of the optical absorption peak at ∼300 nm decreases with increasing time when the thin film is prepared at a high substrate temperature. On the other hand, the peak does not appear when the thin film is prepared at a low substrate temperature. However, in the latter case, the optical absorption peak appears at ∼300 nm with time. Moreover, the change of the optical absorption strength of the specimen held in a vacuum desiccator is different from that of the specimen held in atmosphere. It is considered that the decrease of the optical absorption strength at ∼300 nm is due to the decrease of the molecular weight of polysilanes, and the increase is due to the structural relaxation of polysilane chains.

Low-Cost "Vacuum Desiccator"

Described are individualized, low-cost, and safe that can be efficiently and rapidly made with an inexpensive kitchen aid sold for shrink-wrapping food. The device can be used for enclosing small vials or bottles and also jars that are too large to be placed in conventional glass or plastic desiccators. This shrink-wrapping device is proposed for producing vacuum desiccators in large undergraduate chemistry laboratories or in graduate and research laboratories.

Sterilized ibuprofen-loaded poly(D,L-lactide-co-glycolide) microspheres for intra-articular administration: effect of γ-irradiation and storage

The aim of this study was to prepare and characterize a controlled-release system (microspheres) loaded with ibuprofen, for intra-articular administration, to extend its anti-inflammatory effect in the knee joint cavity. Among the bioresorbable polymers employed, poly(D,L-lactic-co-glycolic) acid (PLGA) (13 137 Da) was chosen because of its high biocompatiblity. Microspheres were produced by the solvent evaporation process from an O/W emulsion. Labrafil M 1944 CS was included in the formulation as an additive in order to modulate the release rate of the non-steroidal anti-inflammatory drug (NSAID). Once prepared, the microspheres were sobre-sterilized by γ-irradiation. The effect of the irradiation dose (25 kGy) exposure, at low temperature, on the formulation was evaluated. The sterilization procedure employed did not alter the physico-chemical characteristics of the formulation. Dissolution profiles of formulations behaved similarly and overlapped (f2 = 87.23, f1 = 4.2) before and after sterilization. Size Exclusion Chromatography (SEC) revealed no significant changes in the polymer molecular weight. Additionally, a stability study of the sterilized formulation was carried out using microsphere storage conditions of 4°C in a vacuum desiccator for 1 year. The results obtained after storing the sterilized microspheres show no significant alterations in the ibuprofen release rate (f2 = 85.06, f1 = 4.32) or in the molecular weight of the PLGA (12 957 Da). The employment of low molecular weight PLGA polymers resulted as advantageous, due to the practical absence of degradation after gamma irradiation (25 kGy) exposure at low temperature.

Tomato spotted wilt tospovirus, Impatiens necrotic spot tospovirus and Watermelon silver mottle tospovirus

<i>Tomato spotted wilt tospovirus</i>, <i>Impatiens necrotic spot tospovirus</i> and <i>Watermelon silver mottle tospovirus</i>

1H MAS NMR (Magic-Angle Spinning Nuclear Magnetic Resonance) Techniques for the Quantitative Determination of Hydrogen Types in Solid Catalysts and Supports

Distinct hydrogen species are present in important inorganic solids such as zeolites, silicoaluminophosphates (SAPOs), mesoporous materials, amorphous silicas, and aluminas. These H species include hydrogens associated with acidic sites such as Al(OH)Si, non-framework aluminum sites, silanols, and surface functionalities. Direct and quantitative methodology to identify, measure, and monitor these hydrogen species are key to monitoring catalyst activity, optimizing synthesis conditions, tracking post-synthesis structural modifications, and in the preparation of novel catalytic materials. Many workers have developed several techniques to address these issues, including 1H MAS NMR (magic-angle spinning nuclear magnetic resonance). 1H MAS NMR offers many potential advantages over other techniques, but care is needed in recognizing experimental limitations and developing sample handling and NMR methodology to obtain quantitatively reliable data. A simplified approach is described that permits vacuum dehydration of multiple samples simultaneously and directly in the MAS rotor without the need for epoxy, flame sealing, or extensive glovebox use. We have found that careful optimization of important NMR conditions, such as magnetic field homogeneity and magic angle setting are necessary to acquire quantitative, high-resolution spectra that accurately measure the concentrations of the different hydrogen species present. Details of this 1H MAS NMR methodology with representative applications to zeolites, SAPOs, M41S, and silicas as a function of synthesis conditions and post-synthesis treatments (i.e., steaming, thermal dehydroxylation, and functionalization) are presented.

Synthesis of MgAl2O4Spinel Nanometer Powder via Biology Polysaccharide Assisted Sol-Gel Process

A novel and cost-effective sol-gel process for preparation of MgAl2O4 spinel nanometer powders has been developed in this study. A solution of magnesium and aluminum nitrates in stoichiometric proportion was successfully embraced in the biology polysaccharide gel network, formed by the synergistic interaction between xanthan gum (XG) and locust bean gum (LBG) utilizing their broad-spectrum stability of salt tolerance and character of transformation from sol to gel on the condition of proper temperature and relative proportion of polymeric components. Dry gel could be obtained by vacuum dehydration of aqueous gel at low temperatures. Monolithic MgAl2O4 spinel nanometer powders were produced by calcining the dry gel above 800°C, with average crystallite size of 20 nanometers.

Treatment of orange II azo-dye by electrocoagulation (EC) technique in a continuous flow cell using sacrificial iron electrodes

This paper describes the EC treatment of orange II dye solution in a flow cell using sodium chloride as an internal electrolyte. In this technique dye solutions were passed through a flow-through EC apparatus consisting of a flow-through cell, the electrode assembly, the feed pump and the DC power supply unit. The cell contained five parallel iron electrodes, which form four parallel cells. Experiments were run at 25 °C under various electrolyte concentrations, dye concentrations, current density, flow rate of the solution, and pH at dc current range of 2–5 A. Various number of recycles of the treated dye solution were also performed at the same dc current range. Optimum conditions to get high removal efficiency were experimentally determined. It was found that 98.5% of the dye was removed from the solution under the optimum conditions. The residue from a blank run (pH=7.3) and a dye added run (pH=8.5) were collected by vacuum filtration and analyzed by XRD after drying in a vacuum desiccator. The XRD data indicated the presence of mainly maghemite (γ-Fe 2O 3) and magnetite (Fe 3O 4) in the residue. However, there is not much difference between the X-ray diffractograms of the blank sample and the dye-containing residue to warrant any conclusions therefrom with regard to the interactions between the oxides and the dye molecules.

Effect of storage in aqueous environments on polymer–metal interfacial fracture

The effect of environmental exposure on the fracture characteristics of two polymer–metal interfaces was measured using a four-point bend delamination test. Films of high-molecular-weight polymethylmethacrylate (PMMA) resin were spin-cast on metal-coated silicon wafer substrates, for which the metal was either titanium or aluminum. Sandwich beam specimens were fabricated and stored in one of the following conditions prior to the bending tests: vacuum desiccator at 25 °C, vacuum desiccator at 65 °C, distilled water at 25 °C, or distilled water at 65 °C. Load–displacement behavior measured during bending revealed significant differences between the delamination characteristics of the two PMMA–metal interfaces after vacuum exposure which were eliminated after the degrading effects of water exposure. Three distinctive load–displacement behaviors were observed: plateau, fracture at a single load; R-curve, fracture at increasing load with crack extension; and stick-slip, cycles of gradual load increase and sudden load drop with crack extension. PMMA–Al samples stored in vacuum desiccator at 25 °C exhibited R-curve fracture and the largest average crack driving force, GC, 12.2 (±0.5) J/m2, of all samples tested. After storage in 25 °C water, these PMMA–Al samples exhibited stick-slip fracture and GC decreased to 7.1 (±2.6) J/m2; storage in 65 °C water further decreased GC to 2.1 (±0.7) J/m2. PMMA–Ti samples exhibited stick-slip fracture after storage in vacuum desiccator at 25 °C, with an average GC of 8.0 (±2.6) J/m2; storage in 65 °C water resulted in a transition to plateau fracture and a decrease in GC to 1.6 (±0.3) J/m2. The initial difference and subsequent similarity are interpreted in terms of surface roughness and hydrolysis, respectively.

Study on ESR and inter-related properties of vacuum-dehydrated nanotubed titanic acid

Nanotubed titanic acid (H 2Ti 2O 4(OH) 2) is a novel kind of material. The electron spin resonance (ESR) and inter-related properties of its vacuum-dehydrated product were investigated by means of transmission electron microscopic, X-ray diffraction, ESR, diffuse reflectance spectra. The results showed that after treatment under vacuum (−0.1 MPa) at 100°C, single-electron-trapped oxygen vacancies (SETOV), characterized by a symmetrical ESR signal ( g=2.003), were generated in nanotubed H 2Ti 2O 4(OH) 2 crystal lattice. The g=2.003 ESR signal intensity ( I ESR) increased with treatment time. SETOV played the role of F centers, the visible-light absorption power of vacuum-dehydrated H 2Ti 2O 4(OH) 2 was proportional to I ESR. During vacuum dehydration at 100°C, the H 2Ti 2O 4(OH) 2 nanotubes shortened but its crystalline form kept unchanged. The formation mechanism of SETOV was discussed.

From a smokehouse to a vacuum dehydrator

The tradition of fruit dehydration in Serbia has been long and anviable. It seems that Serbian machine-building in the area of fruit processing technology has given its greatest contribution in this field. It has been one 100 years since the smoking house of Mr Stokovic, PhD was announced to be the best and the most promising plum dehydrator at the open competition organized in Topcider by the Ministry of Agriculture. It was the first real almost continual fruit dehydrator where plums were moved at certain intervals closer and closer to the source of heat. Such a concept of plum dehydration from lower to higher temperatures was held on even later in perhaps our most famous dehydrator CER. Even the smoky smell was retained but liquid fuel was used for technical purposes. For a long time, it has been a well- known fact that vacuum dehydration has many advantages. In our country there have been many attempts to make fruit dehydrator of greater capacities in which vacuum would be used. Of course, there have been many problems, both technical and technological, but today a hundred years after accepting Stojkovic?s smokehouse, it is our great honor to present to you the results of plum dehydration in a home-made vacuum condensation dehydrator. We hope that now path is widely open to high quality dehydration, and not only for that plum, but for fruit susceptible to oxidation which is the reason our food industry has not produced it so far. This is probably a farewell to the most dangerous, but for the product quality, the most necessary operation - sulphuration.

Crystal structure of bis(diaqua-dicinnamatocopper(II)), C36H36CU2O12

C36H36Cu2O12, orthorhombic, Pbca (No. 61), a = 10.992(1) A, b = 7.706(1) A, c = 41.770(5) A, V = 3538.0 A, Z = 4, Rgt(F) = 0.109, wRref(F) = 0.269, T = 293 K. Source of material All reagents and solvents were used as obtained without further purification. An aqua-ammonium solution (10 ml) of Cu2O (71 mg, 0.5 mmol) and cinnamatic acid (147 mg, 1.0 mmol) were stood still for 1 week to vapor most of the ammonium gas, large blue slab crystals of the title complex were deposited and collected by filtration, washed with water and dried in a vacuum desiccator over silica gel (yield 67%). Elemental analysis: found – C, 54.66%; H, 4.66%; calc. for C36H36Cu2O12 – C, 54.89%; H, 4.61%. Experimental details All the hydrogen atoms are geometrically fixed excepting those attached to the water molecules which are located using the program HYDROGEN [1] and freely refined. We refined these hydrogen atoms to confirm that these are really water molecules and not OH or O atoms. Discussion Metal complexes with carboxylates are among the most investigated compounds in the field of coordination chemistry. Nevertheless, the crystal structures of metal complexes with cinnamate ligands have rarely been reported. Previously, we reported the structure and properties of a silver(I) comples [Ag( -hmt)(cin)] · 2H2O (hmt = hexamethylenetetramine, cin = cinnamate) [2], with this organic carboxylic acid. The title complex is a discrete electronically neutral dinuclear copper(II) unit, [Cu(cinH)2(H2O)2]2, where cinH is cinnamatic acid. The two copper(II) atoms in each dinuclear unit are equivalent, each of which is ligated by four oxygen atoms from two cinnamate anions and two coordinated water molecules, respectively. The four coordination atoms around the central metal are coplanar, constituting a square-planar geometry around the copper(II) atom with plane deviation of 0.0384(4) A, and the copper atom is deviated from the square-plane by 0.0123(4) A. All the cinnamate anions are unidentate ligands, and the average Cu-O(cinnamate) bond length (2.001(6) A) is in the normal range for the complexes with aromatic carboxylates. The two diagonal angles in the CuO4 square plane are respectively 175.8(3)° and 178.0(2)°, indicating a slightly distorted square-planar geometry of Cu(1). The Cu square plane is at the angles of 73.7(2)° and 123.4(2)° with the two kinds of aromatic rings. All the CuO4 planes in the complex are parallel one another. Weak interactions play an important role in the crystal structure of the title complex. The shortest distance between the CuO4 planes is 3.528(6) A, and a great deal of hydrogen bonds between the adjacent O atoms join the two monomers to form a dinuclear copper(II) unit. Z. Kristallogr. NCS 218 (2003) 261–262 261 © by Oldenbourg Wissenschaftsverlag, Munchen Crystal: blue slab, size 0.06 × 0.24 × 0.38 mm Wavelength: Mo K radiation (0.71073 A) : 12.65 cm Diffractometer, scan mode: Siemens SMART CCD, 2 max: 56.6° N(hkl)measured, N(hkl)unique: 20956, 4397 Criterion for Iobs, N(hkl)gt: Iobs > 2 (Iobs), 2212 N(param)refined: 242 Programs: SHELXTL [3], SHELXTL-plus [4] Table 1. Data collection and handling. H(1) 8c –0.0137 0.9659 0.1160 0.057 H(2) 8c –0.0383 0.8838 0.1683 0.078 H(3) 8c 0.1206 0.7573 0.1960 0.065 H(4) 8c 0.3001 0.7099 0.1705 0.060 H(5) 8c 0.3330 0.8065 0.1194 0.047 H(7) 8c 0.1043 0.9792 0.0674 0.034 H(8) 8c 0.3519 0.9345 0.0716 0.033 H(10) 8c 0.4710 0.8780 0.1946 0.068 H(11) 8c 0.4746 0.9165 0.2493 0.073 H(12) 8c 0.6345 1.0631 0.2727 0.072 H(13) 8c 0.7882 1.1667 0.2419 0.084 H(14) 8c 0.7803 1.1317 0.1865 0.070 H(16) 8c 0.5333 0.9393 0.1426 0.066 H(17) 8c 0.7683 1.0099 0.1368 0.078 H(1W1) 8c 0.50(2) 1.21(2) 0.048(4) 0.13(6) H(1W2) 8c 0.509(8) 0.67(1) 0.027(2) 0.02(2) H(2W1) 8c 0.628(9) 1.31(1) 0.016(2) 0.05(3) H(2W2) 8c 0.619(8) 0.67(1) 0.056(2) 0.05(3) Table 2. Atomic coordinates and displacement parameters (in A). Atom Site x y z Uiso

Crystal structure of 4-aminobenzenesulfonosilver(I), C6H6AgNO3S

C6H6AgN03S, monoclinic, P12i /c l (No. 14), a = 9.109(5) Â, b = 8.910(5) Â, c = 9.546(6) Â, β = 100.076(7)°, V = 762.8 Â , Z = 4, Rgt(F) = 0.030, wRKi(F) = 0.078, T= 293 K. Source of material All reagents and solvents were used as obtained without further purification. An ammonium solution (10 ml) of Ag20 (116 mg, 0.5 mmol) and 4-aminobenzenesolfonic acid (159 mg, 1.0 mmol) were stood still for 1 week to evaporate most of the ammonium gas. Large colorless rod-like crystals of the title complex were deposited and collected by filtration, washed with acetonitrile and diethyl ether and dried in a vacuum desiccator over silica gel (yield 43%). Elemental analysis: found C, 25.49%; H, 2.17%; N, 4.86%; calc. for C 6 H 6 AgN0 3 S C, 25.73%; H, 2.16%; N, 5.00%. Discussion Preparation of noble metal complexes is very important in the development of optical materials, polymer conductors, catalyst carriers, and other applications [1]. The isolation of s i lve r® complexes is complicated by the fact that they often form polynuclear complexes and are generally light sensitive. Additionally, nearly all polymeric si lver® complexes are water insoluble and most of them are light unstable [2,3]. In this work, -1-aminophenylsulfonate was utilized as ligand to ligate silver !ons and subsequently keep them soluble in water and stable to light. The title complex is an electronically neutral mono-nuclear compound. In the title compound, the Ag( l ) atom is four-coordinated by three oxygen atoms and one nitrogen atom from each of the four aminophenylsulfonate ligands. The AgOiN coordination is a severely distorted tetrahedron (the angles around the silver(I) atom are from 77.68(8)° to 132.35(9)°). The Ag—O (average 2.444(4) A) and Ag—Ν (2.250(3) A) bond lengths in the title complex are slightly longer than the similar bond contacts. To decrease steric effects, the four aromatic rings are located far away from each other. The S atom in the ligand is in the slightly distorted tetrahedral geometry. Table 1. Data collection and handling. Crystal: Wavelength: μ· Diffractometer, scan mode: 2$max: W(/iW)mCasured, N(hkl)unique: Cr i te r ion f o r 70bs, N(hkl)gt: N(param) refined: Programs: colorless, size 0.13 χ 0.41 χ 0.56 mm Mo Ka radiation (0.71073 Â) 28.74 cm Bruker SMART CCD, φ/ω 52.88° 4126, 1507 /obs > 2 a(Iobs), 1286 133 SHELXTL [3], SHELXTL-plus [4] Table 2. Atomic coordinates and displacement parameters (in A). Atom Site X y ζ U so H(l) 4e 0.561(4) 0.482(4) 0.405(4) 0.035(9) H(2) 4e 0.320(4) 0.511(5) 0.313(4) 0.04(1) H(3) \e 0.390(5) 0.295(4) -0.045(5) 0.05(1) H(4) 4e 0.633(5) 0.278(4) 0.049(4) 0.04(1) H(5) \e 0.158(4) 0.410(4) -0.028(4) 0.033(9) H(6) 4e 0.134(4) 0.490(5) 0.119(4) 0.04(1) * Correspondence author (e-mail: hlzhu@wist.edu.cn) Unauthenticated Download Date | 6/27/16 7:16 AM

Crystal structure of triaquasulfato-2,3-diaza-1,6-di(4-fluorobenzyl)-hexanecopper(II) dihydrate, Cu(C16H18N2F2)(H2O)3(SO4) · 2H2O

Abstract C16H28CuF2N2O9S, monoclinic, P121/c1 (No. 14), a = 15.169(8) Å, b = 12.614(6) Å, c = 11.387(6) Å, β = 94.651(7)°, V = 2171.6 Å3, Z = 4, Rgt(F) = 0.046, wRref(F2) = 0.138, T = 298 K.