Synthesis of Pincer type carbene and their Ag(I)-NHC complexes, and their Antimicrobial activities

In this study, theophylline (1) compounds were synthesized with addition of 2-bromoetha-nol, 2-bromoacetamide and methyl-2-bromoacetate to attain symmetric connections NHCs (2a–c). New complexes containing the N-heterocyclic carbene (NHC) ligands using azolium salts in dimethyl formamide (DMF). After NHC predecessor reacted Ag2O, Ag(I)-NHC following: 7,9-di-(2-hydroxyethyl)-8,9-dihydro-1,3-dimethyl-1H-purine-2,6(3H,7H)-dionedium silver(I)bromide (3a), 7,9-di(acetamide)-8,9-dihydro-1,3-dimethyl-1H-purine-2,6(3H,7H)-di-ondium (3b) 7,9-di(methylacetate)-8,9-dihydro-1,3-dimethyl-1H-pu-rine-2,6(3H,7H)-diondiumsilver(I)bromide (3c). Both predecessors (2a-c) (3a-c) described by FTIR, 1H-NMR, 13C-NMR, liquid solid-state conductivity values, TGA analysis, melting point analysis XRD spectroscopy. In-vitro antibacterial activities NHC-predecessors tested against gram-positive bacteria (Staphylococcus Aureus Bacillus Cereus), gram-negative (Escherichia Coli Listeria Monocytogenes), fungus (Candida Albicans) Tryptic Soy Broth method. showed higher activity than pure predecessors. The lowest microbial inhibition concentration (MIC) value compound 3a was obtained as 11.56 ?g/ml for Escherichia 11.52 Staphylococcus Aureus. All displayed antimicrobial different results.