NMR Spectral Studies (nmr + spectral_studies)

Distribution by Scientific Domains


Selected Abstracts


Functional modification of poly(vinyl alcohol) through phosphorus containing nitrogen heterocyclic moieties

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008
S. Karpagam
Abstract Functional modification of poly(vinyl alcohol) (PVA) with phosphorus containing nitrogen heterocyclic has been believed to have extensive thermal and biological applications in the area of polymers. Efforts have been taken for the synthesis of phosphorus-containing N -heterocyclic (5,6 member and fused ring) based PVA. The synthesized compounds were characterized using UV, FTIR, and NMR spectral studies. Thermal studies (DSC-TGA) scans display phosphorus-containing five membered and fused heterocyclic-based PVA has less thermal stability than six-membered compounds. Modified polymers infer to have excellent bacterial response against micro-organisms. 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]


Synthesis, characterization, and antimicrobial properties of novel quaternary amine methacrylate copolymers

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008
Supriya Punyani
Abstract A novel amine methacrylate monomer trimethylolpropane trimethacrylate,piperazine,ethyleneglycol dimethacrylate (TMPTMA-PPZ-EGDMA) was synthesized by amination of trimethylolpropane trimethacrylate (TMPTMA) with excess of piperazine (PPZ) followed by reaction with ethyleneglycol dimethacrylate (EGDMA). Copolymerization of TMPTMA-PPZ-EGDMA with 2-hydroxyethyl methacrylate (HEMA) was carried out by free radical polymerization using ammonium persulfate (APS) and N,N,N,,N,-tetramethyl ethylenediamine (TEMED) as a redox initiator. The copolymers obtained were then quaternized with 1-iodooctane. The monomers were characterized by FTIR and 1H NMR spectral studies. The molecular weights and polydispersity values of the monomers were determined with gel permeation chromatography. Quaternized copolymers containing more than 20% amine methacrylate monomer showed microporosity in the range of 9.9,10.4 ,m. The antibacterial activity of the quaternized copolymers against Escherichia coli and Staphylococcus aureus was studied using UV,vis spectrophotometer and scanning electron microscopy. Quaternized copolymers showed broad-spectrum contact-killing antibacterial properties without releasing any active agent as checked by iodide selective ion meter. 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]


Piperidone derivative from Dalbergia sympathetica

MAGNETIC RESONANCE IN CHEMISTRY, Issue 3 2005
N. Shanmugam Nagarajan
Abstract An alcoholic extract of Dalbergia sympathetica, on column chromatography, yielded a compound which analyzed for C6H11NO3 (M+ 145). The IR spectrum of the compound showed the presence of carbonyl and hydroxyl groups. PMR, 13C and DEPT NMR spectral studies of the compound showed the presence of one N -methyl, two methine and two methylene groups. A quaternary carbon signal at , 172.88 ppm was assigned to C-2 carbonyl of the compound. From all the above observations and also from the HMQC 2D NMR spectrum, the compound was identified as 3, 6-dihydroxy- N -methyl-2-piperidone. This is the first report of the natural occurrence of this compound from plant sources. Copyright 2004 John Wiley & Sons, Ltd. [source]


Behavioural dynamics in the biological control of pests: role of silicon complexes

APPLIED ORGANOMETALLIC CHEMISTRY, Issue 11 2008
Savita Belwal
Abstract The complexes of silicon (IV) with Schiff base ligands (L1H and L2H of isatin derivatives) having a sulfur and oxygen donor system were prepared by the reactions in methanol environment. These were isolated and characterized by elemental analysis, molecular weight determinations and conductance measurements. On the basis of electronic, infrared, 1H, 13C and 29Si NMR spectral studies, trigonal bipyramidal geometry was suggested for the resulting complexes. These data support preferential binding of sulfur and oxygen atom to the silicon atom. The disease resistance activities of the ligands and their corresponding complexes were examined successfully in in vitro and in vivo experiments, against pathogenic fungi and bacteria. Results were quite encouraging and these were compared with the standard pesticides Bavistin and Streptomycin. Copyright 2008 John Wiley & Sons, Ltd. [source]