The near equalities of the C1—O1 [1.237 (4) Å] and C1—O2 [1.273 (4) Å] bonds in the carboxyl­ate groups indicate delocalized bonding arrangements, rather than localized single and double bonds. The O2—C1—O1 bond angle [125.2 (3)°] seems to be increased compared to that present in a free acid [122.2°]. The corresponding values for this angle in the closely related structures mentioned above are 123.5 (2) and 120.4 (2)° in (II), 125.2 (5)° in (III), and 124.3 (2)° in (IV); the benzoate ions are coordinated to the metal atoms only monodentately in (III) and (IV), and both monodentately and bidentately in (II). In the SB anion, the carboxyl­ate group is twisted away from the attached C2–C7 benzene ring by 20.92 (17)°, while the benzene and N1/C8–C12 pyridine rings are oriented at a dihedral angle of 81.86 (12)°.