Cation complexing photochromic materials involving bisanthracenes linked by a polyether chain. Preparation of a crown-ether by photocycloisomerization
The first photochemically generated, ‘cation-locked’ crown-ether is reported.
Materials Literature
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Crystal and molecular structure and magnetic properties of tetrakis-[(2-diethylaminoethanolato)isocyanatocopper(II)]
The crystal and molecular structure of the title complex has been determined from single-crystal X-ray diffraction data and refined to R 0.068 for 1 423 independent reflections. Four oxygen-bridged cubane-type molecules with a Cu4O4 core, having crystallographically imposed S4 point symmetry, occupy a tetragonal unit…
Corrosion of base metal alloys in vitro
Corrosion of base metal alloys was studied by placing the alloys in artificial saliva for 2 months and then determining the concentration of metal ions in the saliva. The distribution of the attack on the surface was examined. The results indicated that the amount of metal ions in the artificial saliva could be relate…
Organic builders: A review of worldwide efforts to find organic replacements for detergent phosphates
Abstract Continuing pressures to reduce phosphates in wastewaters have sustained an intensive worldwide search to develop acceptable substitutes. Organic polycarboxylate salts have been most extensively investigated because there are a large number of structural possibilities, and the possibility for biodegradation to…
Glyceraldehyde‐3‐Phosphate Dehydrogenase(NADP) from Sinapis alba L.
Partially purified glyceraldehyde‐3‐phosphate dehydrogenase (NADP) (EC 1.2.1.13) from Sinapis alba seedlings was filtered on Sephadex G‐200 in the presence of NADP(H) and NAD(H). With NADP(H) the enzyme elutes as a dissociated species ( M r ∼ 170 000), whereas with NAD(H) it travels as an aggregate in the void volume…
Absorbent Polymers from Starch and Flour Through Graft Polymerization of Acrylonitrile and Comonomer Mixtures
Abstract Polyacrylonitrile (PAN)‐containing graft copolymers of corn starch were prepared from monomer mixtures and then saponified, and dried. Incorporation of selected comonomers lead to shorter saponification times and higher yields of adsorbent products. Substitution of flour for starch gave products which had a h…
Cyclische Diazastannylene, II1 Intermolekulare Lewis-Säure-Base-Addukte bei 1.3.2.4λ2 -Diazasilastannetidinen / Cyclic Diazastannylenes, II1 Intermolecular Lewis-Acid-Base Adducts of 1, 3,2,4λ 2 -Diazasilastannetidines
Abstract 1,3-Diorganyl-2,2-dimethyl-I,3,2,4λ 2 -diazasilastannetidines can be prepared as monomers (organyl = tert-butyl) or dimers (organyl = isopropyl) in nonpolar solvents, depending on the organic nitrogen substituent. The formation of the dimer, which is due to an intermolecular Lewis-acid-base interaction of Sn(…
Beitrag zur Kenntnis der Verteilung von Amylose und Amylopektin in Stärkekörnern
Abstract Bei der mit Thiosemicarbazid umgesetzten Dialdehydstärke tritt ein gleichzeitiger Fixier‐ und Kontrastiereffekt erst bei der nachträglichen Behandlung mit Silbernitrat auf. Die Fixierung wird auf die durch freiwerdende Protonen begünstigte Bildung interchenarer Acetalbrücken zurückgeführt, die vornehmlich in…
The Influence of the Hydrodynamic Environment on the Growth and the Formation of Liquid Inclusions in Large Potassium Dihydrogen Phosphate (KDP) Crystals
Abstract The influence of the hydrodynamic environment on the growth phenomena of large potassium dihydrogen phosphate (KDP) crystals has been investigated in a three vessel system. Special attention was paid to the onset of inclusion formation. Flow visualization experiments carried out in a wind tunnel showed that t…
Porous Anodic Film Formation on Aluminium Substrates in Phosphoric Acid
SummaryThe initial film growth and pore development sequences during the anodizing of aluminium substrates at constant current density in phosphoric acid have been observed by transmission electron microscopy of stripped anodic films and ultramicrotomed sections. Initial film growth proceeds by immediate film thickeni…
Base pairing structure in the poly d(G-T) double helix: wobble base pairs
High resolution nuclear magnetic resonance (NMR) and ethidium bromide binding studies are used to demonstrate that poly d(G-T) forms an ordered double helical structure at low temperatures (below 24 degrees C in 0.3 M NaCl) in which G and T are hydrogen bonded together in a wobble base pair hydrogen bonding scheme as…
Protonation of the decavanadate(6–) ion: a vanadium-51 nuclear magnetic resonance study
The first protonation site of [V10O28]6– differs both from the second protonation site and from the site of preferential interaction with aqueous manganese(II) ion. It is probably an out-of-plane apex, and not a bridging oxygen as has recently been proposed. The 51V n.m.r. linewidths are almost independent of direct p…
Evidence of two new ordered smectic phases in ferroelectric liquid crystals
From X-ray experiments performed on oriented samples of (R-)-chloro-2-propyl-p-hexyloxybenzylidene-p'-aminocinnamate (HOBACPC) by means of an electric field, we have identified two new ordered smectic phases which appear at lower temperature than the ferroelectric Sm C* phase. These two phases are characterized by a p…
Effect of local environment on formation of local moments in BCC Fe-V alloys: Mossbauer study
The Mossbauer spectra of BCC Fe-V alloys in the concentration range 40-80 at.% V have been obtained for both the ordered and disordered states. No broadening of the absorption line has been detected in an 80 at.% V alloy even at liquid He temperature indicating that the alloy is nonmagnetic. Broadening of absorption l…
Block Copolymer Micelles in Dilute Solution
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBlock Copolymer Micelles in Dilute SolutionTadao Kotaka, Takeshi Tanaka, Mitsuhiro Hattori, and Hiroshi InagakiCite this: Macromolecules 1978, 11, 1, 138–145Publication Date (Print):January 1, 1978Publication History Published online1 May 2002Published inissue 1 January 1978…
Approximations for dynamical calculations of microdiffraction patterns and images of defects
The calculation of dynamical elastic diffuse electron scattering from a crystal containing a point defect or dislocation may require prohibitively large amounts of computing time. Two approximations are described which greatly reduce the computer time required for these calculations, and so allow the simulation of ele…
Calibration constant forFe57Mössbauer isomer shifts derived fromab initioself-consistent-field calculations on octahedral FeF6and Fe(CN)6clusters
Ab initio self-consistent-field molecular-orbital calculations were performed on octahedral Fe${\mathrm{F}}_{6}$ and Fe${(\mathrm{CN})}_{6}$ clusters using extensive basis sets of Gaussian-type functions. Two distances relevant for ferrous and ferric compounds are considered. In this paper, we report the part of our r…
Apparatus for High-Resolution Birefringence Measurement in Liquid Crystals
A rotating-analyzer technique for measuring the optical birefringence in liquid crystals is described. This apparatus is continuously readable and has excellent sensitivity. For a sample 50 μm thick, the apparatus has a resolution in the change of birefringence of 4 × 10−6, corresponding to a temperature change of 1 m…
Effect of shear on the crystallization kinetics of poly(ethylene oxide) and poly(e‐caprolactone) melts
Abstract The effect of shear on polymer crystallization kinetics has been studied for three materials at several shear rates and degrees of supercooling. Two poly(ethylene oxide) samples, with molecular weights of 72, 200 and 12, 600, and a poly(e‐caprolactone) material, with a molecular weight of 9, 400, were investi…
Phase Relations in the System Si 3 N 4 ‐SiO 2 ‐MgO and Their Interrelation with Strength and Oxidation
Phase relation studies of Si 3 N 1 , SiO 2 , and MgO have established three important subsolidus tie lines, viz. Si 3 N 4 ‐MgO, Si 3 N 4 ‐Mg 2 SiO 4 , and Si 2 N 2 O‐Mg 2 SiO 4 for nonoxidizing fabrication conditions. Strength measurements at 1400°C show that optimum strengths are obtained for compositions approaching…