in this research, the tacticity and microstructure of polyvinyl chloride (pvc) were studied through back bone methylene and methine carbons and protons splitting by carbon (13c nmr), proton (1h nmr) and two-dimensional (2dnmr) nulear magnetic resonance spectroscopy in deuterated etrahydrofuran.polyvinyl chloride was synthesized by emulsion polymerization of vinyl chloride (vcm) under pressure t...

The neutral host cucurbit[7]uril forms very stable complexes with a series of cationic cholines (R(3)NCH(2)CH(2)OR'(+)) and their phosphonium analogues (R(3)PCH(2)CH(2)OR'(+)) (R(3) = Me(3), Et(3), or Me(2)Bz, or R(3)N = quinuclidinium, and R' = H, COCH(3), CO(CH(2))(2)CH(3), or PO(3)H), and (+/-)-carnitine, in aqueous solution. The complexation behaviour has been investigated using (1)H and (3...

tacrine (9-amino-1,2,3,4-tetrahydroacridine) as a reversible inhibitor of acetylcholinesterase (ache),was the first drug for the symptomatic treatment of alzheimer’s disease (ad). nmr structuredetermination still presents some considerable challenges: the method is limited to systems ofrelatively small molecular mass, data collection times are long, data analysis remains a lengthyprocedure, and...

the ir and nmr spectra were coupled with quantum chemical calculations in dft approach usingthe hybrid b3lyp exchange-correlation functional to confirm the structure of 2-methoxycarbonyl-7-methyl-1,3-thiazino[3,2-b][1,2,4]triazine-4,8-dione 2d.

in this research, the microstructural of low molecular weight 1,2-polybutadiene (1,2-pbd) was conducted by 1h and 13c nuclear magnetic resonance spectroscopy (nmr) to determine the isomeric contents of 1,4-cis, 1,4-trans and 1,2-vinyl in 1,2-pbd polymer structures. number average molecular weight for low molecular weight 1,2-pbd was measured by nmr techniques and the results were compared with ...

microstructural investigation of low molecular weight 1,4-polybutadiene (1,4-pbd) was studied by 1h and 13c nuclear magnetic resonance spectroscopy (nmr). the isomer contents of 1,4-cis, 1,4-trans and 1,2- vinyl in polybutadiene microstructure were determined. the number average molecular weight for low molecular weight polybutadiene was measured by nmr techniques and comparison was made with g...

influence of aluminum, gallium, indium- doping on the boron-nitride nanotubes (bnnts) investigated with density functional theory (dft) and hartreefock (hf) methods. for this purpose, the chemical shift of difference atomic nucleus was studied using the gauge included atomic orbital (giao) approch. in the following, structural parameter values, electrostatic potential, thermodynamic parameters,...