Silver(I) complexes of 2-mercaptopyridine (Mpy), [Ag(Mpy)]NO3and [Ag(Mpy)2]NO3, and the first mixed-ligand complex having a thione and thiolate coordinated to Ag(I), [Mpy–Ag–Tm] (Tm═thiomalate) have been prepared and characterized by IR and NMR spectroscopy. The1H and13C NMR spectra show the presence of both ligands in the mixed-ligand complex, [Mpy–Ag–Tm]. An upfield shift is observed in the >C═S resonance of Mpy and C═O resonances of thiomalate in13C NMR, while the other resonances are shifted downfield. The complexes showed relatively high antibacterial activity (inhibition zone of 6–11 mm) against a gram +ve bacterium,Bacillus subtilis, as compared to that (inhibition zone of 4 mm) against a gram –ve bacterium,Escherichia coli.

The Perkin reaction is an organic reaction which is used for synthesis of α, β-unsaturated aromatic acid by the condensation of an aromatic aldehyde and an acid anhydride, in the presence of an alkali salt of the acid. The alkali salt acts as a base catalyst and other bases can be used instead.

Ten (10) sunflower genotypes were evaluated in a triplicated randomized complete blocked design in field for plant height, stem diameter at base, internodal length, head diameter, number of whorls head . Path analysis showed that direct effects of plant height, head diameter, 100-achene weight and oil contents were positive while direct effects of stem diameter at base, internodal length, number of fertile whorls head -1 and protein contents were negative on achene weight head -1 . This shows that selection based on head diameter, 100-achene weight, plant height, internodal length and stem diameter at base will be more effective in improving yield.

Abstract. Mercury(II) complexes of thiolates having the general formula [Hg(RS)Cl 2 ]− and [Hg(RS) 2 ] have been prepared and characterized by IR and NMR ( 1 H and 13 C) spectroscopy (RSH = 2-aminoethanethiol hydrochloride (Aet), cysteine (Cys), thiosalicylic acid (Ts) and 2-mercaptonicotinic acid (Mnt)). The spectral data suggests that the coordination of thiolates to mercury(II) occurs through the sulfur as indicated by the absence of S-H vibrations in IR and significant downfield shifts in the C-S resonance in 13 C NMR. However, in Mnt complexes, coordination through both sulfur and nitrogen is indicated. Antimicrobial activities of the complexes were evaluated by minimum inhibitory concentration and the results showed that the complexes exhibited a wide range of activities against gram-negative bacteria (E. coli, P. aeruginosa), while moderate activity was observed against a mold, P. citrinum.

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