Synthesis and Characterization of Some Novel Homo- and Hetero-Diradicals of Hydrazyl and Nitroxide Type

2007 ◽  
Vol 60 (3) ◽  
pp. 173 ◽  
Author(s):  
Petre Ionita ◽  
Floriana Tuna ◽  
Marius Andruh ◽  
Titus Constantinescu ◽  
Alexandru T. Balaban

Starting from the well known stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH; 2a) and its congener 2,2-diphenyl-1-(4-cyano-2,6-dinitrophenyl)hydrazyl 2b, or from their reduced hydrazine counterparts 1a,b, it was possible to obtain the p-quinonoid compounds 4a,b by oxidation with ceric (Ce4+) sulfate, which by reduction gave the corresponding hydroxyl derivatives 2-phenyl-2-(4-hydroxyphenyl)-1-picrylhydrazine 5a or 2-phenyl-2-(4-hydroxyphenyl)-1-(4-cyano-2,6-dinitrophenyl)hydrazine 5b. These hydroxyl derivatives (5a,b) react with 4-carboxy-TEMPO or 2,2-diphenyl-1-(4-carboxy-2,6-dinitrophenyl)hydrazine to form the corresponding esters 6a,b or 8a,b. These esters (6a,b and 8a,b) lead to the hybrid hetero diradicals (nitroxide–hydrazyl type) 7a,b or homo biradicals (hydrazyl–hydrazyl type) 9a,b by oxidation with lead dioxide or potassium permanganate. The new compounds were characterized by UV-vis, NMR, EPR, and MS analysis, and their magnetic behaviour was investigated.

Author(s):  
Petre Ionita ◽  
Marcela Rovinaru ◽  
Ovidiu Maior

The new persistent 2,2-diphenyl-1-(3,6-dinitro-4-coumarinyl)hydrazyl free radical 4 was obtained by potassium permanganate or lead dioxide oxidation of the corresponding 2,2-diphenyl-1-(3,6-dinitro-4-coumarinyl)hydrazine 3; hydrazine 3 reacts with nitrous acid to give successively the 2-(p-nitrophenyl)-2-phenyl-1-(3,6-dinitro-4-coumarinyl) hydrazine 6 and 2,2-(p-nitrophenyl)-1-(3,6-dinitro-4-coumarinyl) hydrazine 7. Compound 6 results also from free radical 4 and sodium nitrite in the presence of 15-C-5 crown ether. The structure of new compounds was confirmed by means of TLC, UV-Vis, 1H-NMR, IR, and for the free radicals by the EPR spectra.


Author(s):  
Parameshwar Achugatla ◽  
Majid Ghashang ◽  
S. Guhanathan

We report here the synthesis and characterization of new N-(3-(8-bromoimidazo[1, 2-a]pyridin-2-yl)-4-fluorophenyl)benzamide derivatives. This collection was obtained from 3-(8-bromoimidazo [1,2-a]pyridin-2-yl)-4-fluoroaniline(5). The family of new compounds was characterized by 1H-NMR, 13C-NMR, FT-IR and LC-MS analysis.


2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Madalina Angelusiu ◽  
Maria Negoiu ◽  
Stefania-Felicia Barbuceanu ◽  
Tudor Rosu

The paper presents the synthesis and characterization of Cu(II), Co(II), Ni(II), Cd(II), Zn(II) and Hg(II) complexes with N1-[4-(4-bromo-phenylsulfonyl)-benzoyl]-N4-(4-methoxyphenyl)-thiosemicarbazide. The new compounds were characterized by IR, EPR, electronic spectroscopy, magnetic moments, thermo-gravimetric analysis and elemental analysis.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
G. Kiran ◽  
T. Maneshwar ◽  
Y. Rajeshwar ◽  
M. Sarangapani

A series of β-Isatin aldehyde-N,N′-thiocarbohydrazone derivatives were synthesized and assayed for theirin vitroantimicrobial and antioxidant activity. The new compounds were characterized based on spectral (FT-IR, NMR, MS) analyses. All the test compounds possessed a broad spectrum of activity having MIC values rangeing from 12.5 to 400 μg/ml against the tested microorganisms. Among the compounds3e,3jand3nshow highest significant antimicrobial activity. The free radical scavenging effects of the test compounds against stable free radical DPPH (α,α-diphenyl-β-picryl hydrazyl) and H2O2were measured spectrophotometrically. Compounds3j,3n,3l, and3e, respectively, had the most effective antioxidant activity against DPPH and H2O2scavenging activity.


RSC Advances ◽  
2016 ◽  
Vol 6 (45) ◽  
pp. 39522-39529 ◽  
Author(s):  
Wanfen Pu ◽  
Daijun Du ◽  
Rui Liu ◽  
Jiongyi Gu ◽  
Kewei Li ◽  
...  

HDPAM was synthesized by water free-radical copolymerization based on functional hyperbranched polyamide-modified ultrafine silica as functional monomer.


2007 ◽  
Vol 40 (22) ◽  
pp. 7819-7826 ◽  
Author(s):  
Tor Kit Goh ◽  
Adrian P. Sulistio ◽  
Anton Blencowe ◽  
Jeffery W. Johnson ◽  
Greg G. Qiao

1987 ◽  
Vol 42 (11) ◽  
pp. 1411-1418 ◽  
Author(s):  
Manfred L. Ziegler ◽  
Hannelore Weber ◽  
Bernhard Nuber ◽  
Orhan Serhadle

A transition metal induced C-C coupling by the reaction of W2(N(CH3)2)6, (4) and CS2 yielded the zwitter ion S2C-C(N(CH3)2)2 (1d) besides W2(N(CH3)2)2(CS2)2S4 (5). The com- plex chemistry of the zwitter ions 1d and S2CC(N(CH2)4X)2 (X = CH2, O) has been investigated by their reaction with (η5-C5H5)2Mo2(CO)4 (2) and (η5-C5H5)Mo(CO)3Cl (3). Reaction of the former led to complexes (η5-C5H5)Mo(CO)2(S2CR) (R = N(CH3)2, N(CH2)4X) and the new compounds [(η5-C5H5)Mo(CO)2(S2C-CR2)]+. X-ray structure analyses of 1d and ((η5-C5H5)Mo(CO)2(S2C-C(N(CH2)5)2)]⊕PF6⊖ (10b) are described.


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