catena-Poly[bis­(μ-4-methyl­benzoato-κ(2) O:O′)hepta­kis(μ-4-methyl­benzoato-κ(3) O,O′:O)tris­amarium(III)]

The title samarium coordination polymer, [Sm(3)(C(8)H(7)O(2))(9)](n), was obtained by the hydro­thermal reaction of Sm(NO(3))(3) with 4-methyl­benzoic acid in alkaline aqueous solution. In the asymmetric unit, there are three crystallographically independent Sm(III) ions, two of which are eight-coordinate in a distorted square-anti­prismatic environment, while the third is nine-coordinate in a distorted tricapped trigonal-prismatic coordination. The metal centres are coordinated and bridged by four tridentate, three bidentate and two monodentate methyl­benzoate anions, forming polymeric chains running parallel to the b axis.