Showing papers on "Derivative (chemistry) published in 2001"
TL;DR: In this article, a carbon nitride compound, structurally related to the proposed graphitic phase of C(3)N(4), has been synthesized in a bulk well-crystallized form.
Abstract: A novel carbon nitride compound, structurally related to the proposed graphitic phase of C(3)N(4), has been synthesized in a bulk well-crystallized form. The new material, with stoichiometry C(6)N(9)H(4)Cl, was prepared through a solid-state reaction of 2,4,6-triamino-1,3,5-triazine with 2,4,6-trichloro-1,3,5-triazine at 1.0-1.5 GPa and 500-550 degrees C and also through a self-reaction of 2-amino-4,6-dichloro-1,3,5-triazine at similar conditions. X-ray and electron diffraction measurements on the yellowish compound indicate a hexagonal space group (P6(3)/m) with cell parameters of a = 8.4379(10) A and c = 6.4296(2) A. This new compound possesses a two-dimensional C(6)N(9)H(3) framework that is structurally related to the hypothetical P6m2 graphitic phase of C(3)N(4), but with an ordered arrangement of C(3)N(3) voids. The large voids in the graphene sheets are occupied by chloride ions with an equivalent number of nitrogen atoms on the framework protonated for charge balance. The composition of the sample was determined by bulk chemical analysis and confirmed by electron energy loss (EELS) spectroscopy. The chemical and structural model is consistent with bulk density measurements and with the infrared and (13)C NMR spectra. This work represents the first bulk synthesis of a well-characterized and highly crystalline material containing a continuous network of alternating carbon and nitrogen atoms.
233 citations
TL;DR: In this paper, a water-soluble chitosan derivative carrying phosphonic groups was synthesized using a one-step reaction that allowed homogeneous modifications without any sharp decrease in its properties, such as filmogenic capacity.
174 citations
TL;DR: A new family of chromogenic ionophores for anion sensing has been developed with 1,3,5-triarylpent-2-en-1-5-diones, which form yellow solutions that undergo a color change to magenta in the presence of certain inorganic ions or nucleotides, depending on the derivative.
Abstract: A new family of chromogenic ionophores for anion sensing has been developed with 1,3,5-triarylpent-2-en-1,5-diones. These species form yellow solutions that undergo a color change to magenta in the presence of certain inorganic ions or nucleotides, depending on the derivative. The reaction with ATP is particulary remarkable and therefore these compounds are chromogenic reagents for "naked-eye" sensing of ATP. The picture shows the color changes induced on one derivative in the presence of GMP, ADP, and ATP (from left to right).
162 citations
DSM1
TL;DR: In this paper, the first time, benzonitriles have been shown to participate in metal-catalyzed cross coupling reactions via activation of the CCN bond.
120 citations
TL;DR: A fluorescent 1,2,4-thiadiazole derivative (oxidized form) and its reduced form, the corresponding iminoyl thiourea, which displays a strong modulation of its fluorescence behavior, selectively upon addition of Cu(II).
Abstract: Here, we report on a fluorescent 1,2,4-thiadiazole derivative (oxidized form) and its reduced form, the corresponding iminoyl thiourea. The thiadiazole displays a strong modulation of its fluorescence behavior, selectively upon addition of Cu(II), while the iminoyl thiourea functions as a chemodosimeter for Hg(II). Additionally, the Cu(II)-thiadiazole complex is characterized by HRMS, and the Hg(II)-induced desulfurization of the iminoyl thiourea is monitored by mass spectrometry.
107 citations
87 citations
TL;DR: A bis(dialkylammonium ion)-substituted stilbene derivative cocrystallizes with bisparaphenylene[34]crown-10 to form, in the solid state, a 2:2 host-guest complex wherein the stilBene double bonds are aligned with a relative geometry suitable for a stereospecific photochemical [2+2] cycloaddition.
Abstract: A bis(dialkylammonium ion)-substituted stilbene derivative cocrystallizes with bisparaphenylene[34]crown-10 to form, in the solid state, a 2:2 host-guest complex wherein the stilbene double bonds are aligned with a relative geometry suitable for a stereospecific photochemical [2+2] cycloaddition. When irradiated with white light, this crystalline complex forms a single diastereoisomer of the corresponding cyclobutane derivative, the stereochemistry of which has been determined unambiguously in the solid state by X-ray crystallography to be syn-anti-syn.
86 citations
TL;DR: A stable organocopper(II) compound of N-confused calix[4]phyrin has been characterized by X-ray crystallography and complete π conjugation was found not to be a prerequisite for the formation of the metal-carbon bond.
Abstract: Rare organometallic complexes can be stabilized by using an N-confused system as a carbon ligand. A stable organocopper(II) compound of N-confused calix[4]phyrin has been characterized by X-ray crystallography. Complete π conjugation was found not to be a prerequisite for the formation of the metal-carbon bond.
81 citations
Patent•
20 Jun 2001TL;DR: Eicosapentaenoic acid or any appropriate derivative (EPA) is disclosed in combination with arachidonic acid (AA) or an AA precursor, selected from DGLA and GLA, to give a pharmaceutical formulation as discussed by the authors.
Abstract: Eicosapentaenoic acid or any appropriate derivative (EPA) is disclosed in combination with arachidonic acid (AA) or an AA precursor, selected from DGLA and GLA, to give a pharmaceutical formulation.
79 citations
TL;DR: A solid-phase-Fmoc-based-synthesis strategy is described for oligourea peptidomimetics as well as a convenient general synthesis approach for the preparation of the required building blocks 5a-j and 5k.
Abstract: A solid-phaseFmoc-basedsynthesis strategy is described for oligourea peptidomimetics as well as a convenient general synthesis approach for the preparation of the required building blocks 5a−j and 5k. These are suitable for use in peptide or robot synthesizers, which is illustrated by the synthesis of oligourea peptidomimetics of part of Leu-enkephalin (10) and a neurotensin derivative (17).
TL;DR: The five-coordinate complex [RuCl(1a)]PF6 (3a; 1a = (S)-N,N-bis[2-(diphenylphosphino)benzylidene]-2,2‘-diamino-6,6'dimethylbiphenylene) catalyzes the cyclopropanation of styrene by decomposition of diazoesters.
TL;DR: In this article, an intramolecular aza-Wittig reaction with trimethylphosphine was used to convert 1-Methyl-3-( o -azidophenyl)quinoline-2.
TL;DR: In this paper, Dimethyl dipropargylmalonate reacted with 1-hexyne in the presence of a catalytic amount of [Ir(cod)Cl]2 combined with dppe at room temperature in 20 min to give an indane derivative in 84% yield.
TL;DR: Derivative spectrophotometry was applied to determination of flavonols and a flavon in two-compound mixtures by means of 'zero-crossing' technique, used as a complementary technique to a HPLC system, which does not separate quercetin and luteolin.
Patent•
18 Dec 2001
TL;DR: In this article, the authors proposed a new indole derivative for light emitting element with a luminous layer or an organic compound layer containing a pair of electrodes provided on a substrate, where the host material has an energy gap of at least 3.6 eV and the ionized potential is 5.4-6.3 eV.
Abstract: PROBLEM TO BE SOLVED: To provide a light emitting element material and a light emitting element capable of conducting high-luminance and high-efficiency light emission, and a new indole derivative. SOLUTION: For the light emitting element with a luminous layer or an organic compound layer containing the luminous layer formed between a pair of electrodes provided on a substrate, a monolayer film of a host material in the organic compound layer has an energy gap of at least 3.6 eV, and the ionized potential of the host material is 5.4-6.3 eV. A new indole derivative is represented by the formula, wherein, L is a divalent to hexavalent bonding group or a divalent to hexavalent bonding group composed of an non-conjugated bonding group containing an arylene group, n is an integer of 2 to 6, R is an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a heteroaryl group having 2 to 20 carbon atoms or a silyl group having 3 to 20 carbon atoms, and m is an integer of 0 to 6.
Patent•
13 Feb 2001
TL;DR: In this article, a cyclic phosphazen derivative and a metal hydroxide are combined in an amount of 10 to 60 wt.% based on the total weight of the resin and flame retardant.
Abstract: PROBLEM TO BE SOLVED: To provide a flame-retardant resin composition, which exhibits excellent flame retardancy when used in small amounts and does not generate any halogen gas when heated or burnt, by compounding a phosphazen derivative and a metal hydroxide as a flame retardant in a polyolefin resin. SOLUTION: A cyclic phosphazen derivative (A) represented by formula I [wherein, (m) is 3 to 10; Q represents an aryloxy group of OAr or an alkoxy group of OR in which the numbers of OAr and OR in the molecule satisfy all the following relations: 1<=(the number of OAr groups)<=2m-1, 1<=(the number of OR groups)<=2m-2n=, and (the number of OAr groups)+(the number of OR groups = 2m)], and a metal hydroxide (B) represented by formula II (wherein Z represents 2 or 3; and M is a metal selected from metals of groups IIa and IIb and groups IIIa and IIIb of the periodic table) are compounded as a flame retardant in a polyolefin resin. The flame retardant is compounded in an amount of 10 to 60 wt.% based on the total weight of the resin and flame retardant provided that the components (A) and (B) are used at rates of 1 to 40 wt.% of the component (A) and 99 to 60 wt.% of the component (B), thereby obtaining a flame-retardant polyolefin resin composition having an oxygen uindex of 27 or over.
TL;DR: In this paper, a microwave-enhanced synthesis of 3-Aryl-4-hydroxyquinolin-2(1 H )-ones has been developed, which are potent and selective NMDA receptor antagonists of pharmaceutical interest.
TL;DR: In this article, a new polydentate N -heterocyclic biscarbene, stable at −20°C in THF solution, was obtained by deprotonation of the corresponding bisimidazolium salt.
TL;DR: The results show that the peripheral substituents not only control the electronic structure, but also influence its mode of coordination.
Abstract: The construction of nanostructured polynuclear metal complexes with cyclic topologies, particularly those containing multifunctional ligands containing π-electronic structures, is of great interest since they can potentially lead to compounds with unusual electrochemical properties. A novel cyclic module with a hexacarboxylate derivative is described. The results show that the peripheral substituents not only control the electronic structure, but also influence its mode of coordination.
TL;DR: The key step is a palladium-catalyzed N-arylation of a suitably protected 8-bromo-2'-deoxyguanosine derivative of the food mutagen 2-amino-3-methylimadazo[4,5-f]-quinoline.
TL;DR: The tris(3,5-dimethylpyrazolyl)methane complex with MeLi or LiNPri2 in tetrahydrofuran (THF) gave the zwitterionic titanium imido derivative.
TL;DR: A thermal reaction of fullerene C(60) with 4,6-dimethyl-1,2,3-triazine (4) in o-dichlorobenzene gave azacyclohexadiene-fused fulleene derivative 5, by the reaction with intermediate azete 11, and then, after flash chromatography over SiO(2), open-cage fulleren derivative 6 having an eight-membered ring orifice on the C
Abstract: A thermal reaction of fullerene C60 with 4,6-dimethyl-1,2,3-triazine (4) in o-dichlorobenzene gave azacyclohexadiene-fused fullerene derivative 5, by the reaction with intermediate azete 11, and then, after flash chromatography over SiO2, open-cage fullerene derivative 6 having an eight-membered ring orifice on the C60 cage. Compound 6 is assumed to be formed via addition of diradical intermediate 13 to C60. Compound 6 underwent a further photochemical reaction with singlet oxygen with the cleavage of one of the double bonds at the rim of the orifice to afford triketone derivative 8 having a 12-membered ring orifice.
TL;DR: A chiral continuous bed was easily prepared by in situ polymerization of monomers, including an L‐4‐hydroxyproline derivative, which showed chiral recognition for several hydroxy acids, in addition to amino acids.
Abstract: This paper deals with the enantioseparation of hydroxy acids by ligand-exchange capillary electrochromatography. A chiral continuous bed was easily prepared by in situ polymerization of monomers, including an L-4-hydroxyproline derivative. This phase showed chiral recognition for several hydroxy acids, in addition to amino acids.
TL;DR: The synthesis of a new sandwich lutetium(III) bisphthalocyanine substituted with hexylthio groups (1), [(C6H1)S)8-Pc]2Lu, is described, which is very soluble in most common organic solvents and has been fully characterized.
Abstract: The synthesis of a new sandwich lutetium(III) bisphthalocyanine substituted with hexylthio groups (1), [(C6H1)S)8-Pc]2Lu, is described. The compound is very soluble in most common organic solvents and has been fully characterized (elemental analysis, IR, 1H and 13C NMR, UV-vis spectroscopy, mass spectrometry). The chemically oxidized and reduced forms have been formed and characterized. The crystal structure of the compound (1) has been determined by X-ray diffraction on a single crystal. It crystallizes in the monoclinic space group C2/c with a = 31.558(2) A, b = 32.755(2) A, c = 20.489(1) A, beta = 127.119(1) degrees, and Z = 4. The temperature dependence of the magnetic susceptibility, measured on polycrystalline samples and in the range 6-300 K, is in agreement with one unpaired electron per molecular unit as found for the unsubstituted derivative. The magnetic results can be modeled assuming one-dimensional chain of spin S = 1/2 with g = 2.04 and an antiferromagnetic coupling (J = -11.83 cm(-1), H = -2JSigmaSiSj).
Patent•
27 Apr 2001TL;DR: In this paper, a method of preparing polycarbonate by the melt process is described, which consists of melting a dihydric phenol and a diester of carbonic acid for a time and at a temperature sufficient to form a melt, and thereafter introducing a catalyst composition comprising a tetraorganophosphonium salt or a derivative thereof and an alkali and/or alkali earth metal compound or derivative thereof.
Abstract: A method of preparing polycarbonate by the melt process comprising the steps of: a) melting a dihydric phenol and a diester of carbonic acid for a time and at a temperature sufficient to form a melt: and thereafter introducing a catalyst composition comprising a tetraorganophosphonium salt or a derivative thereof and 1) an alkali and/or alkali earth metal compound or derivative thereof or 2) a less active alkali and/or alkali earth metal derivative thereof into the melt; and b) oligomerizing the product from step a) to a number average molecular weight of from about 3000 to about 7500; and c) polymerizing the product from step b) to a number average molecular weight of from about 16,000 to about 35,000.
TL;DR: In this paper, the crystal structure determinations of two niobium dichalcogenides (3R- Nb1.09S2 and 2H-NbSe2) are reported.
TL;DR: The lithium compound (S)-7, formed by deprotonation of the (S)"S"-S-1-phenylethyl thiocarbamate" derivative, represents the first essentially enantiopure alpha-thiocarbanion derivative and can be utilized in asymmetric synthesis.
Abstract: The lithium compound (S)-7, formed by deprotonation of the (S)-S-1-phenylethyl thiocarbamate (S)-10, is configurationally stable at -70 degrees C. Even at elevated temperatures it racemizes only very slowly. It represents the first essentially enantiopure alpha-thiocarbanion derivative and can be utilized in asymmetric synthesis. Most electrophiles (except proton acids) add to (S)-7 with complete stereoinversion. Cleavage of the substitution products leads to practically enantiopure, tertiary 1-phenylalkanethiols.
TL;DR: The novel silver(I) coordination polymer with 2,5-bis(4’,5’-bis (methylthio)-1‘,3‘-dithiol-2‘ylidene)-1,3,4,6-tetrathiapentalene (TTM-TTP), [Ag(TTM)-TTP)(CF3SO3)]n (1), which consists of 1-D waving chains, was synthesized
Abstract: The novel silver(I) coordination polymer with 2,5-bis(4‘,5‘-bis(methylthio)-1‘,3‘-dithiol-2‘ylidene)-1,3,4,6-tetrathiapentalene (TTM-TTP), [Ag(TTM-TTP)(CF3SO3)]n (1), which consists of 1-D waving chains, was synthesized and characterized. Polymer 1 can be also regarded as a 3-D supramolecular network formed via many shorter side-by-side and face-to-face S···S contacts. This polymer and its iodine-doped compound 2 behave as semiconductors with σ25°C values of 7.1 × 10-6 and 0.85 S cm-1, respectively.