Reaction of [Mn(2,2′-bpy)2(OAc)](ClO4)(H 2O) with a series of aromatic carboxylic acids yields new Mn(II)carboxylates [Mn(2,2′-bpy)2(L)](ClO4)} 2 (1-3), [Mn(2,2′-bpy)2(L)2] (4-5) and [Mn(2,2′-bpy)2(L)(H2O)](ClO4) (6) (L = 2-aminobenzoate (2-aba) (1), 4-hydroxybenzoate (4-hba) (2), thiophene-2- carboxylate (2-tca) (3), 2-hydroxynapthoate (2-hnapa) (4), 3,5- diisopropylsalicylic acid (dipsa) (5), 2,4,6-triisopropylbenzoate (tipba) (6)). The new compounds have been characterized with the aid of elemental analysis, spectroscopy, and single-crystal X-ray diffraction studies. Compounds 1-3, which have been synthesized from less bulky carboxylic acids, are dimeric in the solid-state. Compounds 4-6, which are derived from more bulkier aromaric carboxylic acids, exist as monomeric complexes. In the case of 6, where very bulky 2,4,6-triisopropyl benzoic acid is used as the starting material, only one carboxylate ligand binds to the metal, resulting in a cationic complex. Interestingly in all the six complexes, the C-H hydrogen atoms of the 2,2′-bpy ligands are involved in extensive hydrogen bonding with the carboxylate oxygen atoms of the adjacent molecules and hence form non-covalent 1-D or 2-D aggregates in the solid state. © 2010 Elsevier B.V. All rights reserved.