Synthesis and NMR Spectroscopic Characterization of Some Fluoro-2H-1-Benzopyran Derivatives

2005 ◽  
Vol 58 (7) ◽  
pp. 517 ◽  
Author(s):  
Yannick Teral ◽  
Gabriel Roubaud ◽  
Claude Aubert ◽  
Robert Faure ◽  
Mylène Campredon

The synthesis of some new fluoro-2H-1-benzopyran derivatives utilizing a reaction between titanium phenolates and β-phenylcinnamaldehydes in toluene is reported. These compounds were characterized by NMR and UV/visible spectroscopy as well as mass spectrometry. In solution all the compounds are photochromic. Complete assignment of the 1H and 13C resonances was achieved by concerted application of homonuclear (gs-COSY), proton-detected (C, H) one-bond (gs-HMQC), and long-range (gs-HMBC) heteronuclear two-dimensional chemical shift correlation experiments using a 500 MHz NMR spectrometer equipped with a cryoplatform and a 5 mm cryoprobe. The mass spectra of the different compounds were characterized by intense molecular and high fragment ions. The introduction of an atom of fluorine as a molecular probe is of interest in determining the mechanistic aspects of the photochemical process.

2018 ◽  
Vol 34 (4) ◽  
pp. 1787-1794 ◽  
Author(s):  
Saleh A. Ahmed ◽  
Ahmed S. M. Al-Janabi

New Co(II), Ni(II) and Cu(II) complexes with 2-meracapto-5-(2,4-dinitrophenyl)-1,3,4-oxadiazole (IpotH) or 2-meracapto-5-((4-(dimethylamino)benzylidene)amino)-1,3,4-thiadiazole (daptH) ligands, were prepared by treatment two moles of thione ligands with one mole of metal salts in EtOH/Acetone and H2O as a solvents, to afforded octahedral complexes of the types [MX2(k2-IpotH)2] (Where M = Co, Cu, X= Cl and M= Ni , X= NO3 ) or [MX2(k2-daptH)2] (Where M = Co, Cu, X= Cl and M= Ni , X= NO3 ). The thione ligands bonded through the nitrogen atom of heterocylic and sulfur atom of thiol group. The prepared ligands and its complexes were characterization by elemental analysis (CHNM), IR spectroscopy , molar conductivity, magnetic susceptibility, UV-Visible spectroscopy and 1H NMR data.


1986 ◽  
Vol 41 (8) ◽  
pp. 971-973 ◽  
Author(s):  
Hartmut Köpf ◽  
Thomas Klapötke

Abstract Bis(/75-cyclopentadienyl)-chloro-selenophenolatotitanium (IV), Bis(?75-cyclopentadienyl)-chloro-selenophenolatozirconium (IV), Bis(//5-cyclopentadienyl)-chloro-selenophenolatohafnium (IV), Bis(^5-cyclopentadienyl)-chloro-selenophenolatotungsten(IV), Mass Spectra The metallocene chloro selenophenolates C p;M Cl(SeChH 5) (Cp = ^5-C5H 5; M = Ti, Z r, Hf, W) were prepared by reaction of Cp2MCl2 with equivalent am ounts of LiSeC6H 5, obtained from phenylselenol and «-butyllithium, and were characterized by 'H NM R, IR and MS data. The fragmentation behaviour of the Ti and W derivatives is elucidated by observing m etastable transi­ tions in the mass spectra.


2019 ◽  
Vol 824 ◽  
pp. 163-167
Author(s):  
Pema Dechen ◽  
Ekasith Somsook

In this report, synthesis and characterization of gold nanoparticles (AuNPs) from gold leaf by electrolysis in two different media (gel and paper) in presence of sodium chloride (NaCl), glucose (C6H12O6) and polyvinyl pyrrolidone (PVP) at room temperature were investigated. Graphite was used as two electrodes, NaCl was used as an electrolyte, C6H12O6 was used as reducing agent and PVP was used as stabilizer to control the aggregation of the nanoparticles. UV-Visible spectroscopy (UV-Vis) and scanning electron microscopy (SEM) were used to confirm the characteristics and morphologies of the synthesized AuNPs.


2012 ◽  
Vol 557-559 ◽  
pp. 371-374
Author(s):  
Lian Liu ◽  
Teng Yu ◽  
Pei Wang ◽  
Guang Shuo Wang

Nanocomposites of poly(ε-caprolactone) (PCL) and layered double hydroxide (LDH) were prepared by in situ polymerization at low LDHs loadings in this work. The resultants were characterized by FTIR spectroscopy, X-ray diffraction (XRD), differential scanning calorimeter (DSC) and UV-visible spectroscopy (UV-vis). FTIR showed that the PCL/LDHs nanocomposites were prepared successfully by in situ polymerization and XRD spectra showed that the crystal structure did not change greatly in the presence of LDHS. DSC results confirmed that LDHs could act as nucleating agents. UV-vis spectra showed that LDHs had stronger absorbance peak than LDH. Moreover, the PCL/LDHs nanocomposites had strong anti-ultraviolet effect by introduction of LDHs into polymer matrix.


1979 ◽  
Vol 57 (11) ◽  
pp. 1286-1293 ◽  
Author(s):  
T. Chivers ◽  
J. Proctor

Pentasulfur hexanitride, S5N6, has been prepared in good yield by the reaction of [n-Bu4N+][S4N5−] with bromine (or iodine) in methylene chloride at 0 °C. In contrast, the tetrasulfur pentanitride(−1) ion reacts smoothly with chlorine to give S4N5Cl, while the reaction with sulfuryl chloride produces S4N5Cl and S5N6 and the reaction with thionyl chloride produces a mixture of S3N2O, S3N2O2, S4N4, and S5N6. Pentasulfur hexanitride is an air-sensitive, explosive, yellow-orange solid which sublimes at ca. 45 °C/10−2 Torr without significant decomposition. It has been characterised by infrared, Raman, uv–visible, and mass spectra and by a single crystal X-ray structure determination. The crystals are monoclinic and belong to the space group C2/c, a = 8.787(2), b = 11.190(2), c = 7.427(2) Å, β = 106.46(2)°, V = 700.3(5) Å3, Z = 4, Dc = 2.317 g cm−3. The refined structure (Rw = 0.040) has twofold symmetry and resembles a basket in which an —N=S=N— unit (d(S—N) = 1.54 Å) is the handle which bridges an S4N4 cradle via S—N single bonds (d(S—N) = 1.70 Å). The introduction of this bridge widens one of the [Formula: see text] transannular separations in S4N4 to 3.94 Å while the other is shortened to 2.43 Å. Thus, the S4N4 cradle can be viewed as two five-membered rings fused at the S—S bond.


Sign in / Sign up

Export Citation Format

Share Document