Three-Dimensional Open-Framework Neodymium Oxalates with Organic Functional Groups Protruding in 12-Member Channels

Two open-framework neodymium oxalates, [NH(3)CH(2)CH(NH(3))CH(3)][Nd(C(2)O(4))(2)(HCOO)].H(2)O (I) and [OC(CH(3))NCH(2)CH(CH(3))NH(3)][Nd(C(2)O(4))(2)].H(2)O (II), have been synthesized hydrothermally in the presence of 1,2-diaminopropane (1,2-DAP) and formic (I) and acetic (II) acids. The Nd atoms in both these oxalates have 9-fold coordination with respect to the oxygens, with the Nd atom in a distorted monocapped square antiprism coordination in I and in an idealized D(3)(h) triply capped trigonal prism coordination in II. The three-dimensional framework structures of I and II are built up by in-plane linkages between the Nd and the oxalate moieties, forming layers with 12-membered honeycomb-like apertures, pillared by an out-of-plane oxalate unit. The 12-memberd channel in I contains a dangling formate group in addition to the disordered amine molecule, while in II, the channel has N-(2-aminopropyl acetimide) molecules formed by the in situ reaction of 1,2-DAP and acetic acid. The accessibility of the formate and N-(2-aminopropyl acetimide) functional groups in I and II, respectively, uniformly distributed within the channels enables chemical manipulation. Crystal data: I, monoclinic, space group P2(1)/c (no. 14), M = 459.5, a = 9.0279(4) A, b = 18.1362(8) A, c = 8.5631(4) A, beta = 102.735(10) degrees, V = 1367.56(11) A(3), Z = 4, R(1) = 0.0229, wR(2) = 0.0599 [1782 observed reflections with I > 2sigma(I)]; II, triclinic, space group P(-)1 (no. 2), M = 454.5, a = 8.6222(9) A, b = 9.5683(10) A, c = 9.5712(10) A, alpha = 109.388(2) degrees, beta = 98.508(10) degrees, gamma = 102.361(12) degrees, V = 706.73(13) A(3), Z = 2, R(1) = 0.0446, wR(2) = 0.115 [1730 observed reflections with I > 2sigma(I)].