Abstract
C36H30La2N6O18, orthorhombic, Pnma (no. 62), a = 14.185(2) A, b = 21.949(2) A, c = 12.135(1) A, V = 3778.1 A, Z = 4, Rgt(F) = 0.032, wRref(F) = 0.088, T = 293 K. Source of material Yellow block-shaped crystals of the title compound were obtained by hydrothermal reaction of LaCl3 · 7H2O (0.0371 g), 2,2'bipyridine-4,4'-dicarboxylic acid (bpdc, 0.0244 g), and deionized water (15 ml) in a 23 ml Teflon-lined reaction vessel at 433 K for five days followed by slow cooling to room temperature. Experimental details The oxygen atom of one of water ligand is distorted over two positions, whereas the O10, O11 and their corresponding H atoms were split during the refinement resulting in a site occupancy factor ratio of 0.5/0.5. The O5, O6, O7, O8, C22, C24 and corresponding H atoms are also split during the refinement resulting in a site occupancy fator ratio of 0.5/0.5. Discussion There is condiserable current interest in the synthesis and characterization of the multi-dimensional coordination polymers because of their potential applications. Multi-dentate ligands were used as building blocks to build supramolecular frameworks, and 2,2'-bipyridine -4,4'-dicarboxylic acid (bpdc) is a potential bridging ligand in various coordination modes as a result of its multifunctional groups. The synthesis, crystal structure and properties on the coordination compounds constructed by bpdc and transition and rare earth metal were investigated [1-7]. The crystal structure of the title compound is built from lanthanum centers and 2,2'-bipyridine-4,4'-dicarboxylic ligands. The coordination polyhedron of the lanthanum is a distorted and defect icosahedron (CN=11),which contains of twonitrogen atoms from a bpdc ligand, seven oxygen atoms from four bpdc ligands and two oxygen atoms from two water molecules. The bond distances La—O range from 2.408 A to 2.763 A, and the bond distances La—N are 2.690 A and 2.740 A, respectively.This is in agreement with distances found in similar rare-earth compound [7]. The bpdc ligands exhibit two different coordinationmodes to link lanthanum. One kind of bpdc acts as five-dentate ligand, in which O2 is coordinated to La(III) center in mono-dentate mode, O3 andO4 are linked to one La(III) ion in chelatingmode, the N1 and N2 are joined to the other La(III) center in chelating mode. The other kind of bpdc acts as tetra-dentate ligand,O5 andO5 are coordinated to one La(III) in chelating mode, while O7 and O8 are linked to another La(III) ion also in chelating mode. The La(III) centers are linked by different bpdc ligands with different coordinationmodes into 3D framework, inwhich the latticewater fill the voids. The crystal structure of the title compound is further stablized by multiple hydrogen-bonding interactions. Z. Kristallogr. NCS 223 (2008) 475-477 / DOI 10.1524/ncrs.2008.0209 475 © by Oldenbourg Wissenschaftsverlag, Munchen Crystal: yellow block, size 0.30 × 0.35 × 0.38 mm Wavelength: Mo Kα radiation (0.71073 A) ': 23.22 cm−1 Diffractometer, scan mode: Bruker SMART CCD, +/3 2#max: 50.02° N(hkl)measured, N(hkl)unique: 28266, 3424 Criterion for Iobs, N(hkl)gt: Iobs > 2 (Iobs), 3242 N(param)refined: 337 Programs: SHELX-90 [8], SHELXS-97 [9], SHELXL-97 [10], SHELXTL [11] Table 1. Data collection and handling. H(9A) 8d 0.2041 0.5168 0.9409 0.040 H(9B) 8d 0.1139 0.5219 0.9820 0.040 H(10A) 8d 0.50 0.2517 0.2719 1.1502 0.049 H(10B) 8d 0.50 0.2770 0.3195 1.2179 0.049 H(11A) 8d 0.50 0.0375 0.2800 1.0998 0.045 H(11B) 8d 0.50 −0.0274 0.3263 1.1100 0.045 H(12A) 8d 0.3065 0.3620 0.3901 0.121 H(12B) 8d 0.3148 0.3016 0.4104 0.121 H(1) 8d 0.3156 0.4387 1.2353 0.056 H(2) 8d 0.4677 0.4449 1.2981 0.044 Table 2. Atomic coordinates and displacement parameters (in A). Atom Site Occ. x y z Uiso
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
