One-, two-, and three-dimensional coordination polymers built from large Mo36-polyoxometalate anionic units and lanthanide cations

The Mo-36-polyoxometalate [Mo36O108(NO)(4)(H2O)(16)](12-) reacts with Ln(3+) to give crystalline solids with 1D, 2D, and 3D polymeric frameworks, depending on the size of Ln(3+) and the reaction conditions. Reaction of LaCl3 with (NH4)(12)-[Mo36O108(NO)(4)(H2O)(16)] gives (H3O)(2)[{La(H2O)(5)}(2){La(H2O)(6)}- {La(H2O)(5)Cl}{Mo-36(NO)(4)O-108(H2O)(16)}]Cl(.)21H(2)O (1), in whose structure the La3+ cations and the polyoxometalate anions are united in a 3D framework, whereas NdCl3 and SMCl3 give [{Ln(H2O)(6)}(4){Ln(H2O)(4)}{Mo-36(NO)(4)O-108(H2O)(16)}]Cl(3)(.)nH(2)O [Ln = Nd, n = 24 (2); Ln = Sm, n = 21 (3)], which have 2D frameworks. Under different conditions, large Ln(3+) ions (La-Nd) give the one-dimensional coordination polymers [{Ln(H2O)(6)}(2){Ln(H2O)(7)}(2){Mo-36(NO)(4)O-108(H2O)(16))}](.)nH(2)O [Ln La, n = 29 (4); Ln = Ce, n = 41 (5), Ln = Pr; n = 40 (6), Ln Nd, n = 36 (7)], whereas reaction with Gd(NO3)(3) gives [{Gd(H2O)(5)}(4){Mo-36(NO)(4)O-108(H2O)(16)}](.)34H(2)O (8), which has a unique 2D layered structure. Smaller Ln(3+) ions (Tb-Lu) give isostructural 1D chain coordination polymers (H3O)(3)-[{Ln(H2O)(6)}(2)[Ln(H2O)(4)}{Mo-36(NO)(4)O-108(H2O)(16)}](.)nH(2)O [Ln = Tb, n = 42 (9); Ln = Dy, n = 43 (10), Ln = Ho, n = 46 (11), Ln = Er, n = 50 (12); Ln = Yb, n = 56 (13); Ln = Lu, n = 31 (14)]. The first coordination polymer based on [Mo36O112-(H2O)(16)](8-), namely (H3O)(2)[{Nd(H2O)(5)}(2){Mo36O112(H2O)(16)}](.) 40H(2)O (15), was prepared from MoO42-, NH2OH, and Nd3+. It has a 2D layered structure. All these compounds are obtained in moderate to high yields (35-93 %), and were characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray structural analysis. Direct coordination of Ln 31 to the oxygen atoms of terminal CiS-MoO22+ groups is responsible for the formation of these polymeric frameworks. The coordination numbers of Ln(3+) change from 9 (La-Sm) to 8 (Gd-Lu).(c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005).