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An analysis of the 1H- and 13C-NMR spectra of a series of 1,2-diaryl-1H-4,5-dihydroimidazoles and comparisons with 4,5-dihydroimidazoles having differentsubstitution patterns are presented. The influence of different 1-aryl and 2-aryl groupsubstituents on spectroscopic parameters of the heterocyclic ring and on the contributionsof possible mesomeric structures in the system was determined. Spectroscopic featuresare coherent with the presence of two conjugated systems (Ar1-N and Ar2-C=N) whichcompete with the delocalization characteristics of the amidine system.

An easy and safe, though only moderately effective method is presented forpreparing (diacetoxyiodo)arenes, ArI(OAc)2, from iodoarenes, ArI, using thecommercially available and easily handled urea-hydrogen peroxide adduct (UHP) as theoxidant. The reactions take place in anhydrous AcOH/Ac2O/AcONa (a catalyst)mixtures, at 40 oC for 3.5 h to afford the purified ArI(OAc)2 in 37-78% yields. The fullyinterpreted 1H- and 13C-NMR spectra of the ArI(OAc)2 products are reported.

Solid chelates derived from some alkaline earth and transition metal complexes with ampicillin (Hamp, a) and amoxicillin (Hamox, b) were synthesized and characterized using elemental analysis, molar conductivity, IR, magnetic susceptibility, and thermogravimetric studies. Both drugs behave as tetradentate ligands coordinating to metal through amino, imino, and carboxylate as well as through β-lactamic carbonyl. All chelates have octahedral geometry except Cu(II) complexes which have square planar structure and uranium has pentagonal bipyramidal coordination. 1H- and 13C-NMR of the Zn(II) and UO2(VI) chelates are compared with the free ligands. The antimicrobial activity of the prepared chelates was determined. [ABSTRACT FROM AUTHOR]

The new acrylic monomer 4‐propanoylphenyl acrylate (PPA) was synthesized and copolymerized with methyl methacrylate (MMA) in methyl ethyl ketone at 70±1°C using benzoyl peroxide as a free radical initiator. The copolymers were characterized by FT‐IR, 1 H‐NMR and 13 C‐NMR spectroscopic techniques. The compositions of the copolymers were determined by 1 H‐NMR analysis. The reactivity ratios of the monomers were determined using Fineman‐Ross (r 1 =0.5535 and r 2 =1.5428), Kelen‐Tüdös (r 1 =0.5307 and r 2 =1.4482), and Ext. Kelen‐Tüdös (r 1 =0.5044 and r 2 =1.4614), as well as by a nonlinear error‐in‐variables model (EVM) method using a computer program, RREVM (r 1 =0.5314 and r 2 =1.4530). The solubility of the polymers was tested in various polar and non‐polar solvents. The elemental analysis was determined by a Perkin‐Elmer C‐H analyzer. The molecular weights (M w and M n ) of the copolymers were determined by gel permeation chromatography. Thermogravimetric analysis of the polymers reveals that the thermal stability of the copolymers increases with an increase in the mole fraction of MMA in the copolymers. Glass transition temperatures of the copolymers were found to increase with an increase in the mole fraction of MMA in the copolymers. [ABSTRACT FROM AUTHOR]