Materials Literature
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The oxo-transfer catalyst (nitro)(pyridyl)cobalt(III) tetraphenylporphyrin has been reinvestigated by substitution of the distal pyridine ligand with 4-N,N-dimethylaminopyridine and 3,5-dichloropyridine. Differences in their structures and in the reactivity of the compounds toward catalytic secondary oxo transfer were…
Lanthanide complexes of a tetra-amide derivative of DOTA (structure 4 in text) with four extended carboxymethyl esters have been characterized by X-ray crystallography and multinuclear NMR spectroscopy. [Eu(4)(H(2)O)](triflate)(3) crystallized from water in the monoclinic, P(21/)(c) space group (a = 10.366 A, b = 22.5…
Nature creates selectively refractive materials in butterfly wings and crab shells by alternating layers of chitin with different refractive indices. To mimic this construction, control of both thickness and refractive index of chitosan films is required. Methods were developed for adhering the chitosan layer to glass…
Stable aqueous colloids of 2−3 nm In 2 S 3 nanocrystals have been prepared by using the classical method of nanoparticle stabilization by low molecular weight thiols. TEM crystal lattice spacing, X-ray diffraction, EDAX data, and electron diffraction indicate that the nanoparticles are predominantly in β-In 2 S 3 form…
In this paper we describe model calculations for the self-assembly of N,N-disubstituted melamines 1 and N-substituted cyanuric acid or 5,5-disubstituted barbituric acid derivatives 2 into linear or crinkled tapes and cyclic rosettes via cooperative hydrogen bond formation. The model description considers all possible…
A novel white light-promoted reaction using photoluminescent nanocrystalline silicon enables the hydrosilylation of alkenes and alkynes, providing stabilization of the porous silicon without significant loss of the photoemissive qualities of the material. Photopatterning and lithographic fabrication of isolated porous…
In response to thermodynamic driving forces, the domains in microphase-separated block copolymers have distinct intermaterial dividing surfaces (IMDS). Of particular interest are bicontinuous and tricontinuous, triply periodic morphologies and their mathematical representations. Level surfaces are represented by funct…
Abstract A novel monomer, 2,2‐bis‐(4′‐fluorobenzoylphenoxy)‐4,4,6,6‐bis[spiro‐(2′,2″‐dioxy‐1′, 1′‐biphenylyl)] cyclotriphosphazene, was synthesized and polymerized with 4,4′‐difluorobenzophenone as a comonomer and 4,4′‐isopropylidenediphenol or 4,4′‐(hexafluoroisopropylidene) diphenol in N , N ‐dimethylacetamide at 16…
We have employed the absorption and Raman spectroscopies to study thermostimulated changes in an ensemble of CdS X Se 1-X quantum dots embedded into a borosilicate glass matrix. It is shown that additional annealing of the sample containing CdS X Se 1-X quantum dots leads to growth of the new ones with higher Se conte…
Refinement of the title compound, Li B(OH)4, with CCD data at 120 K has led to a sevenfold increase in precision over the previously reported structure based on film data. The H atoms have been located and refined. Both Li and B are tetrahedrally coordinated. B—O distances are in the range 1.4644 (14)–1.4989 (13) Å, w…
It is demonstrated that a critical Mn-O-Mn angle determines a crossover between ${Q}_{2}$ and ${Q}_{3}$ Jahn-Teller vibrational modes in ${O}^{\ensuremath{'}}$ orthomanganites, which is coincident with a sudden variation of the ferromagnetic moment. The role played by the vibrational anisotropy ${Q}_{3}{/Q}_{2}$ in ch…
Sheet- and column-like cyanide bridged lanthanide-transition metal arrays were synthesized through metathesis reactions between anhydrous LnCl(3) (Ln = Eu, Yb) and A(2)[M(CN)(4)] (A = K(+), NH(4)(+); M = Ni, Pt) in a 1:2 molar ratio in DMF (DMF = N,N-dimethylformamide) solution. Single-crystal X-ray analysis revealed…
The solid-state, gas-phase, and solution characterization of the predesigned cluster Cs[(SnL3)2Ag3] is presented (L = 4-(diphenylphosphino)benzene-1,2-diol). The solid-state structure confirms formation of a C3h mesocate featuring three silver(I) cations linking two enantiomeric {SnL3}2- halves and encapsulating a Cs+…
The organic passivant layer on nanomaterial surfaces has been examined by correlating the phase behavior of the passivant using attenuated total reflection infrared spectroscopy (ATR-IR), coupled with differential scanning calorimetry (DSC). The thermodynamic melting dynamics in the passivant layer supports the descri…
Chemisorption of propionic acid vapors by an iron impregnated MCM-41 porous silica leads to the formation of iron−propionate species that upon pyrolysis can be transformed into γ-Fe 2 O 3 nanoparticles of uniform size (∼150 Å) and homogeneously dispersed on the external surfaces of the porous silica support. The effec…
Four compounds of general formula [M(4,4'bipy)(N(3))2](n) (M = Mn (1), Zn (2), Co (3), Ni (4)) have been synthesized and magnetostructurally characterized by means of X-ray diffraction analysis, IR and ESR spectroscopies, and measurements of the magnetic susceptibility and magnetization. Compound 1 (C(10)H(8)N(8)Mn) c…
Abstract Using the biaxially oriented film process, polypropylene (PP)/ethylene‐vinyl alcohol copolymer (EVOH) blends with an improved barrier property could be obtained by generating a laminar structure of the dispersed phase in the matrix phase. This laminar morphology, induced by biaxial orientation, was found to r…
Abstract New experimental results for the solubility of nitrogen and carbon dioxide in polystyrene are reported, accompanied by data on the change in volume of the polymer caused by the sorption process. The two phenomena were measured simultaneously with a combined technique, in which the quantity of penetrating flui…
Reversible crystallization and melting in isotactic polypropylene are suggested to occur at the lateral crystal surface by correlation of the amount of reversibility to the structure observed by atomic force microscopy. The degree of reversibility is monitored on heating using temperature-modulated differential scanni…
We have prepared a new family of ruthenium complexes containing the bpea ligand (where bpea stands for N,N-bis(2-pyridyl)ethylamine), with general formula [Ru(bpea)(bpy)(X)](n+) (2, X = Cl(-); 3, X = H(2)O; 4, X = OH(-)), and the trisaqua complex [Ru(bpea)(H2O)(3)](2+), 6. The complexes have been characterized through…