Assembly of Silver–Organic Frameworks Containing Trifluoroacetate, Embedded 1,5-Hexadiyne-1,6-diide, and Ancillary Nitrogen-Donor Ligands



Ten new silver(I) trifluoroacetate complexes containing the 1,5-hexadiyne-1,6-diide dianion and various types of ancillary heteroaromatic N-donor ligands, namely, Ag2C6H4·5AgCF3CO2·4H2O (1), Ag2C6H4·5AgCF3CO2·3L1 (L1 = imidazole) (2), 3Ag2C6H4·10AgCF3CO2·4L2 (L2 = pyrazole, 3), Ag2C6H4·AgCF3CO2·5L3·H2O (L3 = 3,5-dimethylpyrazole, 4), Ag2C6H4·5AgCF3CO2·2L4 (L4 = 2,2′-bipyridine, 5), Ag2C6H4·3AgCF3CO2·L5 [L5 = trans-1,2-di(4-pyridyl)ethylene, 6], Ag2C6H4·4AgCF3CO2·L6 (L6 = 1,4-dicyanobenzene, 7), Ag2C6H4·6AgCF3CO2·2AgL7·H2O (HL7 = 4-pyridinecarboxylic acid, 8), Ag2C6H4·3AgCF3CO2·2AgL8 (HL8 = pyrazine-2-carboxylic acid, 9), and Ag2C6H4·3AgCF3CO2·2AgL9·H2O (HL9 = 4-cyanobenzencarboxylic acid, 10) have been synthesized and characterized by single-crystal X-ray analysis. All complexes are based on assemblies with the multinuclear metal–ligand supramolecular synthon C6H4⊂Agn (n = 7, 8, 9), in which the C6H42– ligand has a gauche configuration. Complexes 2, 4, and 5 each possess an infinite argentophilic silver(I) chain coordinated by N-donor ligands, and such coordination chains are further interlinked into a three-dimensional supramolecular architecture through hydrogen bonding. Complexes 1, 3, and 7 exhibit coordination layers, which are further connected into three-dimensional supramolecular frameworks through hydrogen bonding (1 and 3) or π···π stacking interactions (7). Complexes 6, 8, 9, and 10 all have a three-dimensional coordination network with ancillary N-donor ligands as bridge linkers.