Eric J. Voss

Neutral solvent/crown ether interactions, 4. Crystallization and low temperature (?150C) structural characterization of 18-crown-6 2(CH3CN)

The crystal structure of 18-crown-6 · 2(CH3CN) has been determined via data collection at −150°C. The structure consists of two crown molecules each hydrogen bonded to two acetonitrile moieties in the asymmetric unit, each residing around a center of inversion. The crown ethers display their fullD3d symmetry; methyl ... O contacts range from 3.189(8) to 3.598(8) Å. There are no close contacts indicative of any interaction between the crown/2(CH3CN) units.

f-element/crown ether complexes. 14. Synthesis and crystal structure of [Lu(OH2)8] [Na(12-crown-4)2]Cl4·2H2O

Abstract [Lu(OH 2 ) 8 ] [Na(12-crown-4) 2 ]Cl 4 ·2H 2 0 crystallizes at 5 °C from a reaction mixture of LuCl 3 ·6H 2 O and 12-crown-4 (in a 1:3 solution of CH 3 OH: CH 3 CN) following the addition of NaCl. The crystal structure of this complex has been determined by single crystal X-ray diffraction techniques. The title complex is monoclinic, P 2 1 /c , with a =15.265(2), b =14.203(2), c =16.030(1) A, β=94.570(9)°, and D c =1.67 g cm −3 for Z =4 formula units. Primarily organic and inorganic zones exist essentially in layers parallel to bc . The organic layers consist of [Na(12- crown-4) 2 ] + cations with the oxygen atoms forming a square antiprism around Na + (NaO=2.49(3) A average). The [Lu(OH 2 ) 8 ] 3+ cations (also essentially square antiprismatic, LuO=2.34(2) A), the chloride ions, and the two uncoordinated water molecules are hydrogen bonded forming a network in the b and c directions. The two unique cations are packed linearly along a in a staggered square face to square face arrangement.

f-element (crown ether complexes 12. Synthesis and crystal structure of [Y(NO3)3(OH2)2(NCMe)][Y(NO3)3(OH2)2 (OHME)]. 2(benzo-15-crown-5)-OHMe

Abstract The title complex has been synthesized via reaction of hydrated yttrium(III) nitrate with benzo-15-crown-5 in a 3:1 solvent mixture of acetonitrile and methanol. Its crystal and molecular structure have been determined by single crystal X-ray diffraction. This complex is monoclinic, P21/c, with a=16.180(3), b=18.955(3), c=16.660(3)A, β=91.01(2)° and Dcalc =1.64 g cm−3 for Z=4 formula units. Least-squares refinement utilizing 5234 independent observed [F0 ≥ 3σ(F0 )] reflections led to the final R value of 0.055. There are two independent yttrium(III) cations in the asymmetric unit. Each is nine-coordinate with three bidentate nitrate groups, two water molecules, and a coordinated solvent molecule. The geometry approximates a tricapped trigonal prism, with the nitrate chelate bites occupying ‘c’ edges. The Y[sbnd]O(nitrate) and Y[sbnd]O(water) separations average 2.42(3) and 2.33(3)A, respectively. Each water molecule is hydrogen bonded to two oxygens of a benzo-15-crown-5 molecule resulting in pol...