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Synthesis of Novel Heteropolycyclic Nitrogen Systems Bearing Fluorine Substituted Pyrazolo[3,4-d] Pyrimidine Derived from Polyfunctional π-Acceptor Compounds and Guanidine as Fungicidal Probes  [PDF]
Dina A. Bakhotmah, Salwa Y. Al-Hazme
International Journal of Organic Chemistry (IJOC) , 2019, DOI: 10.4236/ijoc.2019.91007
Abstract: Novel heteropolycyclic nitrogen systems bearing fluorine substituted pyrazolo[3,4-d] pyrimidine moiety have been synthesis by the interaction between N’-heteroaryl guanidine 4 with polyfunctional π-acceptors in different media and condition. The structures of the synthesis compounds were established by spectroscopic analysis and evaluated as antifungal probes in various concentration.
Synthesis of Novel Fluorine Substituted Isolated and Fused Heterobicyclic Nitrogen Systems Bearing 6-(2’-Phosphorylanilido)-1,2,4-Triazin-5-One Moiety as Potential Inhibitor towards HIV-1 Activity  [PDF]
Reda M. Abdel-Rahman, Mohammed S. T. Makki, Abeer N. Al-Romaizan
International Journal of Organic Chemistry (IJOC) , 2014, DOI: 10.4236/ijoc.2014.44028
Abstract: Novel 6-(5’-fluoro-2’-diphenylphosphorylanilido)-3-hydrazino-1,2,4-trizin-5 (2H) one (3) is achieved from hydrozinolysis of the corresponding 3-thioxo-analoges 2. Compound 2 is also obtained from phosphorylation of 6-(5’-fluoro-2’-aminophenyl)-3-thioxo-1,2,4-triazin-5(2H) one (1). Novel fluorine substituted isolated and/or fused heterobicyclic nitrogen systems bearing and/or containing, 6-phosphoryl anilido-1,2,4-trizin-5 (2H) one moiety (4 - 22) have been synthesized from ring closure reactions of compound 3 with π-acceptors activated carbon compounds in different medium and conditions. Structures of the products are characterized by MS, IR, UV-VIS, CH, N, and 1H/13CNMR spectral data. The new products have been evaluated as potential inhibitors towards HIV-1 activity.
Total synthesis and biological evaluation of fluorinated cryptophycins
Christine Wei?,Tobias Bogner,Benedikt Sammet,Norbert Sewald
Beilstein Journal of Organic Chemistry , 2012, DOI: 10.3762/bjoc.8.231
Abstract: Cryptophycins are cytotoxic natural products that exhibit considerable activities even against multi-drug-resistant tumor cell lines. As fluorinated pharmaceuticals have become more and more important during the past decades, fluorine-functionalized cryptophycins were synthesized and evaluated in cell-based cytotoxicity assays. The unit A trifluoromethyl-modified cryptophycin proved to be highly active against KB-3-1 cells and exhibited an IC50 value in the low picomolar range. However, the replacement of the 3-chloro-4-methoxyphenyl-substituent in unit B by a pentafluorophenyl moiety resulted in a significant loss of activity.
Structures of Fluorinated Graphenes and Their Signatures  [PDF]
Hasan Sahin,Mehmet Topsakal,Salim Ciraci
Physics , 2011, DOI: 10.1103/PhysRevB.83.115432
Abstract: Recent synthesis of fluorinated graphene introduced interesting stable derivatives of graphene. In particular, fluorographene (CF), namely fully fluorinated chair conformation, is found to display crucial features, such as high mechanical strength, charged surfaces, local magnetic moments due to vacancy defects and a wide band gap rapidly reducing with uniform strain. These properties, as well as structural parameters and electronic densities of states are found to scale with fluorine coverage. However, most of the experimental data reported to date neither for CF, nor for other CnF structures complies with the results obtained from first-principles calculations. In this study, we attempt to clarify the sources of disagreements.
Thermal properties of fluorinated graphene  [PDF]
S. K. Singh,S. Goverapet Srinivasan,M. Neek-Amal,S. Costamagna,Adri C. T. van Duin,F. M. Peeters
Physics , 2013, DOI: 10.1103/PhysRevB.87.104114
Abstract: Large scale atomistic simulations using the reactive force field approach (ReaxFF) are implemented to investigate the thermomechanical properties of fluorinated graphene (FG). A new set of parameters for the reactive force field potential (ReaxFF) optimized to reproduce key quantum mechanical properties of relevant carbon-fluor cluster systems are presented. Molecular dynamics (MD) simulations are used to investigate the thermal rippling behavior of FG and its mechanical properties and compare them with graphene (GE), graphane (GA) and a sheet of BN. The mean square value of the height fluctuations $< h^2>$ and the height-height correlation function $H(q)$ for different system sizes and temperatures show that FG is an un-rippled system in contrast to the thermal rippling behavior of graphene (GE). The effective Young's modulus of a flake of fluorinated graphene is obtained to be 273 N/m and 250 N/m for a flake of FG under uniaxial strain along arm-chair and zig-zag direction, respectively.
Highly Fluorinated Graphene  [PDF]
Chad E. Junkermeier,Stefan C. Badescu,Thomas L. Reinecke
Physics , 2013,
Abstract: We give the results of density functional calculations for graphene with a widely varying fluorine adsorptions. We give a systematic analysis of the adsorption energies, lattice constants, bulk modulus, bandgap openings, and magnetic properties. We find that a number of different adsorption geometries and a range of physical properties can occur for each adsorbate coverage. The systems are found to range from metallic to semiconducting with widely vary band gaps, and a number of interesting magnetic phases are found. We expect that many of these structures may occur in real materials systems. Further that a listing of the properties found here may help in determining what fluorinated graphenes are produced experimentally.
Regiospecific synthesis of new non-condensed heteropolycyclic systems from beta-heteroaryl-beta-methoxyvinyl trihalomethyl ketones
Bonacorso, Helio G.;Oliveira, Marlí R.;Costa, Michelle B.;Silva, Letícia B. da;Zanatta, Nilo;Martins, Marcos A. P.;Flores, Alex F. C.;
Journal of the Brazilian Chemical Society , 2005, DOI: 10.1590/S0103-50532005000500029
Abstract: a novel series of twelve heteroaroyl-2-pyrazolines trihalomethyl and substituted heteroaryl, as non-condensed heteropolycyclic systems, have been synthesized in one-step in 50-78% yield from the regiospecific cyclocondensation reaction of 1,1,1-trifluoro(chloro)-4-methoxy-4-(2-furyl)- and 4-(2-thienyl)-3-buten-2-ones (b-alkoxyvinyl trihalometil ketones) with furoic hydrazide, 2-thiophenecarboxylic hydrazide and isonicotinic acid hydrazide (heteroaroylhydrazines) under mild conditions in methanol as solvent.
Synthesis and Structural Characterization of Fluorinated Thiosemicarbazones  [PDF]
Juan L. Bautista,Marcos Flores-Alamo,Jorge Tiburcio,Rebeca Vieto,Hugo Torrens
Molecules , 2013, DOI: 10.3390/molecules181013111
Abstract: Six new fluorinated thiosemicarbazones R?C(R′)=N-NH-C(S)NH 2 (R = 2,4-C 6H 3F 2, R′ = H ( 1); R = 2,5-C 6H 3F 2, R′ = H ( 2); R = 2,6-C 6H 3F 2, R′ = H ( 3); R = 3,4-C 6H 3F 2, R′ = H ( 4); R = 3,5-C 6H 3F 2, R′ = H ( 5) and R = 4-C 6H 4F, R′ = C 6H 5, ( 6)) have been prepared. The molecular structures of compounds 1 to 6 have been determined.
Properties and refinements of the fused lasso  [PDF]
Alessandro Rinaldo
Mathematics , 2008, DOI: 10.1214/08-AOS665
Abstract: We consider estimating an unknown signal, both blocky and sparse, which is corrupted by additive noise. We study three interrelated least squares procedures and their asymptotic properties. The first procedure is the fused lasso, put forward by Friedman et al. [Ann. Appl. Statist. 1 (2007) 302--332], which we modify into a different estimator, called the fused adaptive lasso, with better properties. The other two estimators we discuss solve least squares problems on sieves; one constrains the maximal $\ell_1$ norm and the maximal total variation seminorm, and the other restricts the number of blocks and the number of nonzero coordinates of the signal. We derive conditions for the recovery of the true block partition and the true sparsity patterns by the fused lasso and the fused adaptive lasso, and we derive convergence rates for the sieve estimators, explicitly in terms of the constraining parameters.
The Classification of fused links  [PDF]
Timur Nasybullov
Mathematics , 2015,
Abstract: We construct the complete invariant for fused links. It is proved that the set of equivalence classes of $n$-component fused links is in one-to-one correspondence with the set of elements of the abelization $UVP_n/UVP_n^{\prime}$ up to conjugation by the elements from the symmetric group $S_n
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