Unusual manifestation of closed-shell interactions in silver(I) complexes:: Crystal structure of catena-bis(4-aminobenzoato)disilver(I) acetone solvate with ligand unsupported chains of repeated rhombohedral Ag4 units

The crystal structure of catena-bis(2-aminobenzoato)disilver(I) acetone solvate provides an unusual manifestation of closed-shell interactions in silver(I) complexes with ligand unsupported chains, silver(I) ions. The crystals are assembled by rhombohedral Ag-4 units that coordinate eight p-aminobenzoate ligands, four through the carboxylic oxygen and four through the amino nitrogen atoms. The rhombohedral units are not stabilized by bridging or capping ligands but solely linked by Ag-Ag interactions [d(Ag-Ag) = 2.9870(5), 3.0252(4), and 3.2974(4)]. The Ag-4 units are further linked to form infinite chains by Ag-Ag interactions supported by bis(carboxylato-O,O ') bridges [d(Ag-Ag) = 2.9460(6) Angstrom], The carboxylato group exhibits a slightly unsymmetrical syn-syn bridging mode. The Ag-4 units are strictly planar, where successive units are off-set by 0.387(2) Angstrom, giving an angle of 3.3 degrees between the Ag-4 Plane and the plane defined by ail Ag atoms in the chain. The eight bidentate p-aminobenzoate ligands originating from each Ag4 unit link four adjacent chains. The crystal arrangement results in continuous channels parallel to the a axis and to the silver(I) chains, with un opening size of similar to3.6 x 3.9 Angstrom, The solvent accessible volume is 18.5% of the total unit cell volume.