A New Approach to Prepare 2-Acetyl-Mono(5,6,7,8)-Nitro-l,2,3,4-Tetrahydroisoquinolincs

2-Acetyl-nitro-1,2,3,4-tetrahydr are very important intermediates fororganic synthesis'. McCoubrey reported 2-acetyl-7-nitro-l,2,3,4-tetrahydro-isoqunolineand 2-acetyl-5,7-dinitro-l,2,3,4-tet could be prepared by nitration of2-acetyl-l,2,3,4-tetrahydroisoqu low yield and tiresome purification procedurewere disadvantages of this method, and 2-acetyl-5, 6 or 8-nitro-1,2,3,4-tetrahydroisoquinolines could not be obtained according to this approach (Scheme I ) 2'3'4.The method of preparation of 2-…     

Functional Characterizations of Basic Properties of Utility Representations

 Consider uncertain alternatives for which an event has two consequences (binary gambles, “gambles” for short) and over them an operation of joint receipt which need not be closed and may be non-commutative. The two structures are linked by a distributivity property called segregation and a preference order. Utility functions order nonnegative numbers to consequences and gambles. Utility representations describe how the utility of a gamble depends on the utilities of consequences and on the “weight” of the event (a number in [0,1], depending on the event). Functional characterizations give necessary and sufficient conditions, often in form of functional equations, for certain properties of representations. We first give a functional characterization of the often postulated event commutativity stating that two events can be interchanged in special composite gambles where one outcome is a consequence but the other is itself a gamble. A utility representation is separable if it is multiplicative for gambles with one consequence having 0 utility. We give three more specific characterizations of separable representations by segregation, by homogeneity and event commutativity, and by homogeneity and segregation, and show that in the last case event commutativity follows.     

Synthesis of Long-Chain SpirobenzopyransBearing a Monoazacrown ether

Thephotochromicpigmentsinthechloroplastandinthephotoreceptorcellofthevisionsystemhaveamonolayerorganization'.Itisknownthatthemonolayerassembliesfavourtheenergetictransformations.Forthevisionprocess,light-inducedisomerizationofretinallinkedtoopsintrig...     

Determination of paralytic shellfish toxins in dinoflagellate Alexandrium tamarense by using isotachophoresis/capillary electrophoresis

Baseline separation of seven paralytic shellfish toxins (PSTs), namely decarbamoylsaxitoxin (dcSTX), saxitoxin (STX), neosaxitoxin (NEO), gonyautoxin-2 (GTX-2), gonyautoxin-3 (GTX-3), gonyautoxin-1 (GTX-1), and gonyautoxin-4 (GTX-4), was achieved by using capillary ITP (CITP)/CE with UV detection. Separation parameters including duration time and voltage in CITP process, separation voltage, and pH and concentration of buffer were optimized. The developed method provided linear responses from 1.3 to 200 microM for the PSTs. The LOD ranged from 0.1 to 0.3 microM. PST extracts from two algal strains of Alexandrium tamarense were analyzed and the toxin concentrations in the samples were quantified with an internal standard method by using NEO as the internal standard. The algal extract of A. tamarense HK9301 contained 332 microM GTX-2 and 224 microM GTX-3, while the PSTs were not detected in the extract of A. tamarense CI01.     

A new fullerene complexation ligand: N-pyridylfulleropyrrolidine

The subject of this paper is a new fullerene building block design with the potential for defined geometry and good electronic communication. The synthesis and characterization of a new pyridinofullerene ligand capable of forming axially symmetric complexes with metalloporphyrins is reported. X-ray structural and molecular modeling studies, (1)H NMR, UV-vis spectroscopy, electrochemistry studies, and fluorescence quenching data support the formation of a strong complex between the new ligand and the metal center of ZnTPP. On the basis of computational studies, the highest occupied molecular orbital (HOMO) of this ligand is significantly different from a model compound with insulating carbons between the pyridine and the fullerene. The N-pyridinium fulleropyrrolidine salts of the new ligand and model compound were also prepared and their spectral and electrochemical properties are reported.     

Hydrogen adsorption in the series of carbon nanostructures: Graphenes–graphene nanotubes–nanocrystallites

A comparative analysis of hydrogen absorption capability is performed for the first time for three types of carbon nanostructures: graphenes, oriented carbon nanotubes with graphene walls (OCNTGs), and pyrocarbon nanocrystallites (PCNs) synthesized in the pores of TRUMEM ultrafiltration membranes with mean diameters (D_m) of 50 and 90 nm, using methane as the pyrolized gas. The morphology of the carbon nanostructures is studied by means of powder X-ray diffraction, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and transmission electron microscopy (TEM). Hydrogen adsorption is investigated via thermogravimetric analysis (TGA) in combination with mass-spectrometry. It is shown that only OCNTGs can adsorb and store hydrogen, the desorption of which under atmospheric pressure occurs at a temperature of around 175°C. Hydrogen adsorption by OCNTGs is quantitatively determined and found to be about 1.5% of their mass. Applying certain assumptions, the relationship between the mass of carbon required for the formation of single-wall OCNTGs in membrane pores and the surface area of pores is established. Numerical factor Ψ = m_dep/m_calc, where m_dep is the actual mass of carbon deposited upon the formation of OCNTGs and mcalc is the calculated mass of carbon necessary for the formation of OCNTGs is introduced. It is found that the dependence of specific hydrogen adsorption on the magnitude of the factor has a maximum at Ψ = 1.2, and OCNTGs can adsorb and store hydrogen in the interval 0.4 to 0.6 < Ψ < 1.5 to 1.7. Possible mechanisms of hydrogen adsorption and its relationship to the structure of carbon nanoformations are examined.     

Structures and Bonding Situation of Iron Complexes of Group‐13 Half‐Sandwich ECp* (E = B to Tl) Based on DFT Calculations

Quantum chemical calculations at the BP86 level with various basis sets (SVP, TZVPP, and TZ2P+) were carried out for the Fe(CO)₄ of group‐13 half‐sandwich ECp* [Fe(CO)₄‐ECp*] ( Fe4‐E ) (E = B to Tl). The chemical bonding of the Fe(CO)₄‐ECp* bond was analyzed with charge‐ and energy decomposition methods. The calculated equilibrium structures of complexes Fe4‐E show that the ligands ECp* are bonded in an end‐on way to the fragment Fe(CO)₄ in Fe4‐E with E = B to Ga. The compound Fe4‐In has a distorted end‐on ligand InCp*. In contrast, Fe4‐Tl has a side‐on bonded ligand TlCp*. The calculated bond dissociation energies (BDEs) suggest that the bond in the iron group‐13 half‐sandwich complexes Fe4‐E decreases from Fe4‐B to Fe4‐Tl . Natural bond orbital (NBO) analysis of the bonding situation reveals that the Fe(CO)₄←ECp* donation in Fe4‐E comes from the σ lone‐pair orbital of ECp*. Bonding analysis indicates that the ligand ECp* in complexes are strong σ donors and the NOCV pairs of the bonding show small π‐back donation from the Fe(CO)₄ to the ECp* ligands.