Two mixed-ligand lanthanide–hydrazone complexes: [Pr(NCS)(3)(pbh)(2)]·H(2)O and [Nd(NCS)(NO(3))(pbh)(2)(H(2)O)]NO(3)·2.33H(2)O [pbh is N′-(pyridin-2-ylmethylidene)benzo­hydrazide, C(13)H(11)N(3)O]

The gel-mediated syntheses and crystal structures of [N′-(pyridin-2-ylmethylidene-κN)benzohydrazide-κ(2) N′,O]tris(thiocyanato-κN)praseodymium(III) mono­hydrate, [Pr(NCS)(3)(C(13)H(11)N(3)O)(2)]·H(2)O, (I), and aqua(nitrato-κ(2) O,O′)[N′-(pyri­din-2-ylmethylidene-κN)benzohydrazide-κ(2) N′,O](thiocyanato-κN)neo­dym­ium(III) nitrate 2.33-hydrate, [Nd(NCS)(NO(3))(C(13)H(11)N(3)O)(2)(H(2)O)]NO(3)·2.33H(2)O, (II), are reported. The Pr(3+) ion in (I) is coordinated by two N,N,O-tridentate N′-(pyridin-2-ylmethylidene)benzohydrazide (pbh) ligands and three N-bonded thio­cyanate ions to generate an irregular PrN(7)O(2) coordination polyhedron. The Nd(3+) ion in (II) is coordinated by two N,N,O-tridentate pbh ligands, an N-bonded thio­cyanate ion, a bidentate nitrate ion and a water mol­ecule to generate a distorted NdN(5)O(5) bicapped square anti­prism. The crystal structures of (I) and (II) feature numerous hydrogen bonds, which lead to the formation of three-dimensional networks in each case.