5879-67-4Relevant academic research and scientific papers
Synthesis, structure and catalytic activity of bis(phenoxyiminato)iron(III) complexes in coupling reaction of CO2 and epoxides
Al-Qaisi, Feda'a,Genjang, Nevil,Nieger, Martin,Repo, Timo
, p. 81 - 85 (2015/12/30)
Here we described the synthesis and characterization of a series of new bis(phenoxyiminato)Fe(III)-chloro complexes using a variety of techniques, including: elemental analysis, IR-, MS(EI), UV-Vis-spectroscopy, and X-ray diffraction. A solid-state structure of bis(N-salicylidene-3-phenylpropylamine)iron(III)chloride reveals a distorted square-pyramid coordination with crystallographic C2-symmetry wherein chloride occupies the axial position. Isolated complexes were also evaluated as catalysts for a coupling reaction of CO2 and various epoxides, including propylene, 1-hexene, cyclohexene and styrene oxides to form corresponding cyclic carbonates. Accordingly, the ligand structure and the solvent used influenced the catalytic activity and marked enhancement in the activity was observed using DMF as a solvent. Under optimized reaction conditions (145 °C and 10 bar of CO2) bis(N-salicylidene-2-phenylethylamine)iron(III)chloride gave cyclopropylene carbonate with considerable high TON value (1029) within 3 h.
Ruthenium-(II)/-(III) terpyridine complexes incorporating imine functionalities. Synthesis, structure, spectroscopic and electrochemical properties
Mondal, Biplab,Chakraborty, Soma,Munshi, Pradip,Walawalkar, Mrinalini G.,Lahiri, Goutam Kumar
, p. 2327 - 2336 (2007/10/03)
A new class of ruthenium terpyridine complexes of the type [RuII(trpy)(L1-6)Cl] 1-6 (trpy=2,2':6',2''-terpyridine; L1-3=o--OC6H3(R)C(R')=NCH2C6H5 and L4-6=o--OC6H3(R)CH(R')N=NC6H5; where R=H or p-NO2 and R'=H or CH3) have been synthesized. The "free" ligands incorporating a NH spacer o--OC6H3(R)C(R')=NNHC6H5 (HL4-6) have undergone imine to azo tautomerism on co-ordination to the ruthenium terpyridine moiety in the complexes 4-6, whereas those having a CH2 spacer (HL1-3) remain unaltered on co-ordination. The diamagnetic, neutral complexes 1-6 exhibit strong MLCT transitions in the visible region and intraligand transitions in the UV region. A significant shift in MLCT band energy has been observed depending on the ligand field strength of the co-ordinated L. The complexes display a reversible ruthenium(III)-ruthenium (II) couple in the potential range of 0.12-0.63 V and a quasi-reversible ruthenium(IV)-ruthenium(III) couple in the range of 1.21-1.85 V versus SCE. The higher ligand field strength of the co-ordinated L4-6 compared to the co-ordinated L3- is reflected in the observed metal redox processes. The reduction of the co-ordinated terpyridine has been observed near -1.3 V. The complexes exhibit moderately strong emissions from the lowest energy MLCT bands in the range 661-690 nm in EtOH-MeOH (4:1 v/v) at 77 K. The quantum yields of the complexes (Φ=0.006-0.09) are found to be reasonably sensitive to the nature of the co-ordinated L. The oxidised complexes 3+ and 6+ have been isolated in the solid state as their perchlorate salts. The crystal structure of 3+ exhibits pseudo-octahedral trans geometry with regard to the relative disposition of the imine nitrogen (N4) of L3 and the central pyridyl group of the trpy ligand. The one-electron paramagnetic complexes show 1:1 conductivity and display ligand-to-metal charge transfer bands near 600 and 400 nm and intraligand transitions in the UV region. The observed rhombic EPR spectra at 77 K corresponding to the distorted octahedral geometry have been analysed to furnish values of axial (Δ) and rhombic (V) distortion parameters as well as the energies of the two expected ligand field transitions (ν1 and ν2) within the t2 shell.
Synthesis and Antifungal Activity of Coumarinimides
Manrao, M. R.,Kohli, Sunita,Kalsi, P. S.,Sharma, R. C.,Jhooty, J. S.
, p. 1130 - 1132 (2007/10/02)
Condensation of 2-hydroxyphenylethylidenebenzylamines (I) with cyanoacetic acid, cyanoacetamide, malononitrile and ethyl cyanoacetate gives coumarinimides, viz. 4-methyl-4-(N-benzylamino)-3,4-dihydrocoumarinimide-3-carboxylic acids (IV), 4-methyl-4-(N-benzylamino)-3,4-dihydrocoumarinimide-3-carboxamides (V), 4-methyl-3-cyanocoumarinimides (VIII) and 4-methylcoumarinimide-3-carboxylic acid ethyl esters (IX), respectively as a result of cyclization due to interaction between 2-hydroxy and nitrile groups of the adducts (II, III) or of addition-elimination products (VI, VII).All the above coumarinimides except VIII show promising antifungal activity in vitro.
Study of Photochromism in the Anils of o-Hydroxyacetophenone, o-Hydroxybenzophenone and 2'-Hydroxydeoxybenzoin
Mal, S.,Norula, J. L.,Rawat, M. S. M.
, p. 120 - 123 (2007/10/02)
The photochromic activity of anils (VI) of o-hydroxyacetophenone, o-hydroxybenzophenone and 2'-hydroxydeoxybenzoin has been investigated in methylcyclohexane-pet. ether (40 - 60 deg C) at -180 deg C and in liquid paraffin at -75 deg C.No photocoloured species has been observed in any of these anils after irradiation with 365 nm wavelength in rigid glassy solutions.This is most likely due to the increased height of potential energy barrier which in turn is caused by the increased basicity of the imine nitrogen because of positive inductive effect of methyl, benzyl and phenyl groups substituted in place of aldehydic proton.
