- Fourier transforms infrared spectra and structure of triformylmethane. A density functional theoretical study
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Molecular structure and vibrational frequencies of triformylmethane have been investigated by means of density functional theory (DFT) calculations. The geometrical parameters and vibrational frequencies obtained in the B3LYP, B3PW91, BLYP, BPW91, G96LYP and G96PW91 levels of DFT and compared with the corresponding parameters of malonaldehyde (MA). Fourier transform infrared spectra of triformylmethane and its deuterated analogue were clearly assigned. Theoretical calculations show that the hydrogen bond strength of triformylmethane is stronger than that of MA, which is in agreement with spectroscopic results.
- Nowroozi, Alireza,Tayyari, Sayyed Faramarz,Rahemi, Hedayat
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- 2,6-Bis(pyrazolyl)pyridine functionalised with two nitronylnitroxide and iminonitroxide radicals
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During the last two decades, growing interest in the field of material chemistry has been focused on the synthetic design of organic high-spin molecules for use as novel magnetic materials. Conjugated radicals based on the bis(pyrazolyl)-pyridine core are very attractive in principle, since they per se combine optical, chelating and magnetic properties on a single molecular entity. The functionalisation of this core via the bis(4′-formyl) derivatives with Ullman radicals results in novel functional biradicals, which may further be used for supramolecular architectures. In this paper we describe the synthesis, structure and properties of 2,6-bis[4′-(3-oxo-1-oxyl-4,4,5, 5-tetramethylimidazolin-2-yl)pyrazol-1′-yl]pyridine (Pz2PyNN) and 2,6-bis[4-(1-oxyl-4,4,5,5-tetramethylimidazolin-2-yl)pyrazolyl]pyridine (Pz2PyIN). The two biradicals can clearly be differentiated by UV/Vis, IR and EPR spectroscopy. The optical absorptions of the blue Pz 2PyNN appear around λmax= 610 nm (ε ≈ 1700 M-1 cm-1) while for Pz2PyIN the orange-red colour arises from absorptions at λmax= 468 nm (ε ≈ 1400 M-1 cm-1). A triplet ground state for the bis(nitronylnitroxide) Pz2PyNN with ΔES-T5 ≈ 11.8 ± 4.8 cm-1 can be deduced from the EPR studies because of the increase of the double integrated intensity times temperature at very low temperatures, indicating complete population of the triplet state. For the related bis(iminonitroxide) Pz2PyIN a much smaller (at least one order of magnitude lower) singlet-triplet energy gap with an upper limit of 0.7 cm-1 has been derived (0.7 ≥ ΔES-T ≥ -0.07 cm-1). The new multifunctional biradicals represent the first example of high-spin molecules in the bis(pyrazolyl)pyridine family. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).
- Zoppellaro, Giorgio,Geies, Ahmed,Enkelmann, Volker,Baumgarten, Martin
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- A Purely Organic Tricarbanion
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How many carbanions can an organic molecule accommodate? The formation of purely organic carbanions with multiple charges is challenging as charge stabilization cannot be achieved through metal coordination. Previously, only quaternary ammonium dicarbanion salts had been reported. By using highly electron-deficient trifluoromethanesulfonyl (triflyl or Tf) groups, the formation of a purely organic tricarbanion has been realized for the first time.
- H?fler, Denis,Goddard, Richard,Lingnau, Julia B.,N?thling, Nils,List, Benjamin
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- Preparation method of anagliptin intermediate
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The invention provides a preparation method of an anagliptin intermediate. The preparation method comprises the following steps: (1) N,N-dimethylformamide (I) and acyl chloride are subjected to a Vilsmiere reaction to produce a Vilsmiere reagent, bromoacetic acid (II) is dropwise added to the Vilsmiere reagent for a heating reaction, hydrolysis is performed, and dicarbaldehyde acetaldehyde (III) is obtained; (2) dimethyl acetaldehyde (III) and 3-amino-5-methyl pyrazole (IV) are dissolved in an alcohol/sodium alcoholate system, heating and reflux stirring are performed, and 6-carbaldehyde-2-methyl-pyrazo[1,5-a]pyrimidine (V) is produced; (3) 6-carbaldehyde-2-methyl-pyrazo[1,5-a]pyrimidine (V) is oxidized in strong base to produce 2-methyl-pyrazo[1,5-a]pyrimidine-6-carboxylic acid (VI). Thereaction steps are simplified, operation is convenient, few three wastes are produced, and the yield is high.
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Paragraph 0017; 0033-0048
(2019/07/29)
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- Visual organic molecular fluorescence probe on basis of cyanine and method for preparing visual organic molecular fluorescence probe
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The invention belongs to the technical field of fluorescence spectrum detection and analysis, and particularly relates to a visual organic molecular fluorescence probe on the basis of cyanine and a method for preparing the visual organic molecular fluorescence probe. The visual organic molecular fluorescence probe comprises a cyanine fluorophore and benzothiazole groups. The method includes stepsof (1), dropwise adding phosphoryl chloride into N, N'-dimethylformamide to obtain mixtures, then adding the mixtures into bromoacetic acid and carrying out reaction to obtain products II; (2), carrying out reaction on 2, 3, 3'-trimethyl indole and ethyl iodide to obtain products III; (3), dropwise adding piperidine into the products II and the products III and carrying out reaction to obtain products IV; (4), carrying out reaction on the products IV and aminothiophenol at the room temperature to obtain the visual organic molecular fluorescence probe. The visual organic molecular fluorescenceprobe and the method have the advantages that obvious color change of the visual organic molecular fluorescence probe can be seen in natural light or ultraviolet lamps, linear relations between the fluorescence intensity and peroxynitrite negative ions are established, and accordingly the peroxynitrite negative ions can be qualitatively and quantitatively detected; the visual organic molecular fluorescence probe is good in selectivity and high in sensitivity, detection methods are easy to implement, and obvious effects can be realized.
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Paragraph 0048
(2018/05/01)
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- NOVEL HETEROCYCLIC COMPOUNDS AS INHIBITORS OF VANIN-1 ENZYME
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Compounds, pharmaceutically acceptable salts thereof, are disclosed wherein the compounds have the structure of Formula (I) as defined in the specification. Corresponding pharmaceutical compositions, methods of treatment, methods of synthesis, and intermediates are also disclosed.
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Page/Page column 103
(2016/12/22)
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- Pentamethine cyanine fluorescent dyes, preparation methods and uses thereof
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A pentamethine cyanine fluorescent dye having the general formula I, a synthetic method and a use thereof are disclosed. In the general formula, X is CHO or CHCR3R4; R1 and R2 are independently selected from the group consisting of (CH2)nR7 and et al.; R3 and R4 are independently selected from the group consisting of CN, COOH and COOR16; R5, R6 and R7 are independently selected from the group consisting of H, SO3R10 and COOR11; R8 is H or C1-18 alkyl; R9 is H or CH3; R10 is N(R12R13R14R15); R11 is C1-18 alkyl; R12, R13, R14, R15 and R16 are independently selected from the group consisting of H, C1-18 alkyl, (CH2)mOR8 and (CHR9CH2O)pR8; Y? is halogen anion or OTs?; and n, m and p are integers of 0-18. The dye can be utilized to sensitively detect viscosity of micro-environment such as tissues and cells.
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Page/Page column 8
(2015/01/16)
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- Fluorescence ratiometry and fluorescence lifetime imaging: Using a single molecular sensor for dual mode imaging of cellular viscosity
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Intracellular viscosity strongly influences transportation of mass and signal, interactions between the biomacromolecules, and diffusion of reactive metabolites in live cells. Fluorescent molecular rotors are recently developed reagents used to determine the viscosity in solutions or biological fluid. Due to the complexity of live cells, it is important to carry out the viscosity determinations in multimode for high reliability and accuracy. The first molecular rotor (RY3) capable of dual mode fluorescence imaging (ratiometry imaging and fluorescence lifetime imaging) of intracellular viscosity is reported. RY3 is a pentamethine cyanine dye substituted at the central (meso-) position with an aldehyde group (CHO). In nonviscous media, rotation of the CHO group gives rise to internal conversion by a nonradiative process. The restraining of rotation in viscous or low-temperature media results in strong fluorescence (6-fold increase) and lengthens the fluorescence lifetime (from 200 to 1450 ps). The specially designed molecular sensor has two absorption maxima (λabs 400 and 613 nm in ethanol) and two emission maxima (in blue, λem 456 nm and red, 650 nm in ethanol). However it is only the red emission which is markedly sensitive to viscosity or temperature changes, providing a ratiometric response (12-fold) as well as a large pseudo-Stokes shift (250 nm). A mechanism is proposed, based on quantum chemical calculations and 1H NMR spectra at low-temperature. Inside cells the viscosity changes, showing some regional differences, can be clearly observed by both ratiometry imaging and fluorescence lifetime imaging (FLIM). Although living cells are complex the correlation observed between the two imaging procedures offers the possibility of previously unavailable reliability and accuracy when determining intracellular viscosity.
- Peng, Xiaojun,Yang, Zhigang,Wang, Jingyun,Fan, Jiangli,He, Yanxia,Song, Fengling,Wang, Bingshuai,Sun, Shiguo,Qu, Junle,Qi, Jing,Yan, Meng
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supporting information; experimental part
p. 6626 - 6635
(2011/06/27)
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- Contrast Agents
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The present invention relates to a class of compounds and to diagnostic compositions containing such compounds where the compounds are iodine containing compounds. More specifically the iodine containing compounds are chemical compounds containing an aliphatic central moiety containing hydroxyl groups allowing for the arrangement of three iodinated phenyl groups bound thereto. The invention also relates to methods employing such diagnostic compositions as contrast agents in diagnostic imaging and in particular in X-ray imaging and to contrast media containing such compounds.
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Page/Page column 6-7
(2010/11/28)
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