scholarly journals Synthesis of photoresponsive cholesterol-based azobenzene organogels: dependence on different spacer lengths

2015 ◽  
Vol 11 ◽  
pp. 1089-1095 ◽  
Author(s):  
Yuchun Ren ◽  
Bin Wang ◽  
Xiuqing Zhang
Keyword(s):  
Nmr Spectroscopy ◽  
Crucial Role ◽  
Molecular Structures ◽  
H Nmr ◽  
Vis Spectroscopy ◽  
Thermal Phase ◽  
Reversible Gel ◽  
Phase Behaviors ◽  
Insight Into ◽  
C Nmr

A series of azobenzene–cholesterol organogel compounds (M 0 –M 12 ) with different spacers were designed and synthesized. The molecular structures were confirmed by 1H NMR and 13C NMR spectroscopy. The rapid and reversible photoresponsive properties of the compounds were investigated by UV–vis spectroscopy. Their thermal phase behaviors were studied by DSC. The length of the spacer plays a crucial role in the gelation. Compound M 6 is the only one that can gelate in ethanol, isopropanol and 1-butanol and the reversible gel–sol transitions are also investigated. To obtain visual insight into the microstructure of the gels, the typical structures of the xerogels were studied by SEM. Morphologies of the aggregates change from flower-like, network and rod with different sizes. By using IR and XRD characterization, it is found that intermolecular H-bonding, the solvents and van der Waals interaction are the main contributions to the specific superstructure.

Zirconocene-mediated selective synthesis of 1,4-bis(alkynyl)benzenes

2020 ◽  
Vol 44 (9-10) ◽  
pp. 571-575
Author(s):  
Bo Zhang ◽  
Hongmei Qu ◽  
Zhongxuan Li ◽  
Yuanyuan Zhai ◽  
Xiaolu Zhou ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Dimethyl Ester ◽  
Acid Ethyl Ester ◽  
Coupling Reactions ◽  
Benzene Derivatives ◽  
Phenylene Ethynylene ◽  
H Nmr ◽  
Vis Spectroscopy ◽  
High Yields ◽  
C Nmr

A series of novel 1,4-bis(alkynyl)benzene derivatives were synthesized from trimethylsilyl-substituted alkynes by the mediation of zirconocene with excellent regioselectivity in high yields. The 3,6-bis(trimethylsilyl)-4,5-dialkylphthalic acid dimethyl esters were prepared by cycloaddition of 2,5-bis(trimethylsilyl)zirconacyclopentadienes to dimethyl acetylenedicarboxylate. After iodination with iodine monochloride, 3,6-diiodo-4,5-dialkylphthalic acid dimethyl esters reacted with terminal alkynes to prepare the corresponding 1,4-bis(alkynyl)benzene derivatives by Sonogashira coupling reactions. After removal of trimethylsilyl, 4,5-dibutyl-3,6-bis(ethynyl)phthalic acid dimethyl ester (compound 3) reacted with 4-iodobenzoic acid ethyl ester and 2-iodothiophene, respectively, to obtain the corresponding products 4a and 4c. Compound 3 can be extended to higher oligomers, which reacted with 1-bromo-4-iodobenzene and phenylacetylene in a stepwise manner under Sonogashira conditions to give the phenylene-ethynylene oligomer 5 in an isolated yield of 85%. The structures of the products were confirmed by 1H NMR spectroscopy, 13C NMR spectroscopy, and MS. The optical properties of the 1,4-bis(alkynyl)benzene derivatives were studied by UV-Vis spectroscopy and fluorescence spectra. The results indicated that some can be developed into potential photovoltaic materials.

Synthesis, Characterization and Complexation Studies with K + and Ca2+ Cations of trans-1.2-Cyclohexanedioxydiacetamides

1988 ◽  
Vol 43 (2) ◽  
pp. 165-170 ◽  
Author(s):  
Whei Oh Lin ◽  
Maria C. B. V. de Souza ◽  
Helmut G. Alt
Keyword(s):  
Nmr Spectroscopy ◽  
Mass Spectroscopy ◽  
H Nmr ◽  
Coordination Sites ◽  
Complexation Studies ◽  
Ir And Nmr Spectroscopy ◽  
Elemental Analyses ◽  
C Nmr

The synthesis of trans-1.2-cyclohexanedioxydiacetamides starting with trans-1.2-cyclohexane-diol is described. Eleven of these compounds are characterized by IR, 1H NMR, 13C NMR and mass spectroscopy as well as elemental analyses. Most of these compounds are suitable ionophors for the cations K+ and Ca2+. The coordination sites of these ligands in the 1:2 complexes were determined by IR and NMR spectroscopy

[Zn(phen)2(CX3COO)]+, X = H orCl; Influence of X on the Coordination Mode of the Carboxylate Group (phen = 1,10-Phenanthroline)

2005 ◽  
Vol 60 (10) ◽  
pp. 1049-1053 ◽  
Author(s):  
Zeanab Talaei ◽  
Ali Morsali ◽  
Ali R. Mahjoub
Keyword(s):  
Nmr Spectroscopy ◽  
Elemental Analysis ◽  
Coordination Mode ◽  
Bidentate Ligand ◽  
Carboxylate Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Coordinate Geometry ◽  
C Nmr

Two new ZnII(phen)2 complexes with trichloroacetate and acetate anions, [Zn(phen)2(CCl3COO)- (H2O)](ClO4) and [Zn(phen)2(CH3COO)](ClO4), have been synthesized and characterized by elemental analysis, IR, 1H NMR, 13C NMR spectroscopy. The single crystal X-ray data of these compounds show the Zn atoms to have six-coordinate geometry. From IR spectra and X-ray crystallography it is established that the coordination of the COO− group is different for trichloroacetate and acetate. The former acts as a monodentate whereas the latter acts as a bidentate ligand.

scholarly journals Three-Dimensional Supramolecular Network Directed by Intermolecular Interactions in [Pb2(dmp)2(hfacac)4]

2009 ◽  
Vol 6 (4) ◽  
pp. 1085-1090
Author(s):  
Farzin Marandi ◽  
Lotfali Saghatforoush ◽  
Hossein Farzaneh
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Three Dimensional ◽  
Supramolecular Network ◽  
Stacking Interactions ◽  
H Nmr ◽  
Noncovalent Bond ◽  
Donor And Acceptor ◽  
Anionic Ligands ◽  
C Nmr

To investigate the interactions between noncovalent bond donor and acceptor giving rise to three dimensional networks, compound [Pb2(dmp)2(hfacac)2] (1) (dmp = 2,9-dimethyl-1,10-henanthroline and Hhfacac = hexafluoroacetylacetonate) has been prepared and characterized by elemental analysis, IR,1H NMR, and13C NMR spectroscopy and its crystal structures was investigated. The single crystal structure show the coordination number of Pb(II) to be eight with twoN-donor atoms from a “dmp” ligand and sixO-donors from the anionic ligands. The supramolecular structure of 1 is realized by weak directional C–H∙∙∙O–C, C–F∙∙∙F–C andπ–πstacking interactions.

Synthesis and Pharmacological Activities of Some New 2-[1-Heptyl-3-(4- methoxybenzyl)-5-oxo-1,5-dihydro-4H-1,2,4-triazol-4-yl]acetohydrazide Derivatives

2014 ◽  
Vol 69 (9-10) ◽  
pp. 969-981 ◽  
Author(s):  
Olcay Bekircan ◽  
Emre Mentese ◽  
Serdar Ulker
Keyword(s):  
Nmr Spectroscopy ◽  
Elemental Analysis ◽  
Lipase Activity ◽  
Spectral Studies ◽  
Antituberculosis Activity ◽  
Pharmacological Activities ◽  
Mass Spectral ◽  
H Nmr ◽  
Acetohydrazide Derivative ◽  
C Nmr

Abstract In the present investigation, the key intermediate acetohydrazide derivative 5 was synthesized starting from 3-(4-methoxybenzyl)-4-amino-4,5-dihydro-1,2,4-triazol-5-one (1) by a four-step reaction. Thiosemicarbazides 6a-f and arylidenehydrazide derivatives 8a-d were obtained from compound 5. The cyclization of compounds 6a-f in the presence of NaOH resulted in the formation of compounds 7a-f. The compounds were characterized by IR, 1H NMR, 13C NMR spectroscopy, elemental analysis and mass spectral studies. The compounds were tested for their anti-lipase, anti-α-glucosidase and anti-mycobacterial activities. Compounds 6b and 8c exhibited excellent anti-lipase activity, and compound 8d showed excellent anti-a-glucosidase activity. Compounds 3 and 4 exhibited good antituberculosis activity

scholarly journals Synthesis of cis, cis-1,3,5-trisubstituted cyclohexane based chelators with polyfunctional pendant arms

2005 ◽  
Vol 2005 (1) ◽  
pp. 43-45 ◽  
Author(s):  
Minati Baral ◽  
B.K. Kanungo ◽  
Peter Moore
Keyword(s):  
Schiff Base ◽  
Nmr Spectroscopy ◽  
Organic Compounds ◽  
Elemental Analysis ◽  
H Nmr ◽  
Benzenetricarboxylic Acid ◽  
New Compounds ◽  
Pendant Arms ◽  
C Nmr

Some novel organic compounds of the type: cis, cis-1,3,5-tris(X)cyclohexane, where X= –CONH(CH2)2NH2, –CONH(CH2)3NH2, –CONH(CH2)2NCH –C6H4OH, CONH(CH2)3NCHC6H4OH, which are expected to function as potential polydentate chelators have been synthesised from 1,3,5-benzenetricarboxylic acid through multi-steps reactions. 1,3,5-benzenetricarboxylic acid was reduced to cis, cis-1,3,5-tris(ethylcarboxylate)cyclohexane, which on reaction with excess of 1,2-diaminoethane and 1,2-diaminopropane afforded two new compounds. Condensation of the obtained derivatives with three equivalents of salicylaldehyde resulted the formation of two new Schiff base compounds. All the compounds were characterised by a combination of elemental analysis, mass, IR, UV-Vis, 1H NMR and 13C NMR spectroscopy.

scholarly journals Isomeric Di-C-glycosylflavones in Fig (Ficus carica L.)

1985 ◽  
Vol 40 (1-2) ◽  
pp. 8-12 ◽  
Author(s):  
Fred Siewek ◽  
Karl Herrmann ◽  
Lutz Grotjahn ◽  
Victor Wray
Keyword(s):  
Nmr Spectroscopy ◽  
Reversed Phase ◽  
Ficus Carica ◽  
Preparative Hplc ◽  
H Nmr ◽  
Gradient Hplc ◽  
C Nmr

Two isomeric C-glycosides of apigenin (apigenin-6-C-glucosyl-8-C-arabinoside (schaftoside), apigenin-6-C-arabinosyl-8-C-glucoside (isoschaftoside)) were isolated from leaves of Ficus carica with preparative HPLC. 1The glycosides were identified by UV-, 1H-NMR-, 13C-NMR-spectroscopy and FAB-MS. Their concentration in fruits and leaves were determined by gradient HPLC on reversed phase material.

Identification of (R)-Vicianin in Davallia trichomanoides Blume

1986 ◽  
Vol 41 (1-2) ◽  
pp. 5-8 ◽  
Author(s):  
Pauline A. Lizotte ◽  
Jonathan E. Poulton
Keyword(s):  
Nmr Spectroscopy ◽  
Authentic Sample ◽  
Cyanogenic Glycoside ◽  
Enzymic Hydrolysis ◽  
H Nmr ◽  
C Nmr

Abstract The cyanogenic glycoside of young fronds and fiddleheads of the fern Davallia trichomanoides Blume was identified as (R)-vicianin (the β-vicianoside of (R)-mandelonitrile) by acid and enzymic hydrolysis, 1H-NMR and 13C-NMR spectroscopy, and by comparison with an authentic sample isolated from Vicia angustifolia seeds.

β-Hydroxydithiozimtsäurederivate als Liganden. Synthese und Charakterisierung neuartiger 1,1-Ethendithiolato- und O,S-Chelatkomplexe / Derivatives of β -Hydroxydithiocinnamic Acids as Ligands. Syntheses and Characterisation of Novel 1,1-Ethenedithiolato and O,S-Chelate Complexes

2007 ◽  
Vol 62 (3) ◽  
pp. 475-482 ◽  
Author(s):  
Karsten Schubert ◽  
Helmar Görls ◽  
Wolfgang Weigand
Keyword(s):  
Bidentate Ligand ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Chelate Complexes ◽  
X Ray ◽  
H Nmr ◽  
Hexyl Ester ◽  
Elemental Analyses ◽  
Derivatives Of ◽  
C Nmr

Starting from 4-bromoacetophenone 1, the 4-bromo-β -hydroxydithiocinnamic acid 2 and the 4-bromo-β -hydroxydithiocinnamic acid hexyl ester 3 were prepared using carbon disulfide and potassium-tert-butylate as a base. Acting as a ligand, the acid gives 1,1-ethenedithiolato complexes with (Ph3P)2Pt(II) (4a), (Et3P)2Pt(II) (4b), dppePt(II) (4c), (Ph3P)2Pd(II) (4d), dppePd(II) (4e), and dppeNi(II) (4f). In contrast to the acid, the deprotonated ester 3 forms a monoanionic bidentate ligand. [O,S] Complexes of Pt(II) (5a), Pd(II) (5b) and Ni(II) (5c) were obtained. All complexes have been fully characterised using 1H NMR, 13C NMR and 31P NMR spectroscopy, mass spectrometry, infrared spectroscopy and elemental analyses. The molecular structures of the complexes 4b and 5a - 5c were determined by X-ray diffraction analyses.

Ethylene Insertion with Soluble Ziegler Catalysts: Direct Insight into the Reaction Using Enriched 13C2 H4 and 13C NMR Spectroscopy II. The System Cp2TiMeCl/AlMeCl2/13C2H4

1985 ◽  
Vol 40 (2) ◽  
pp. 158-166 ◽  
Author(s):  
Gerhard Fink ◽  
Wolfgang Fenzl ◽  
Richard Mynott
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr ◽  
13C Nmr Spectroscopy ◽  
Elementary Processes ◽  
Carbon Bond ◽  
Spectroscopic Evidence ◽  
Oligomer Distribution ◽  
Insight Into ◽  
C Nmr

Abstract The elementary processes involved in the polymerization of ethylene by soluble Ziegler catalysts of the type Cp2TiMeCl/AlMeCl2 have been studied by 13C NMR spectroscopy. Using 13C-enriched ethylene, detailed information was obtained directly on the system in the course of the polymerization. No spectroscopic evidence was found for precoordination of the monomer. The development of the oligomer distribution, which could be followed spectroscopically, proves that the mechanism proposed by Olivé cannot be correct. These experiments show conclusively that the ethylene is inserted into the titanium-carbon bond.

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