Lynn K. Kurihara

The formation and crystal and molecular structures of (η5-pentamethylcyclopentadienyl)(η5-cyclopentadienyl)dichloro-titanium, -zirconium and -hafnium

Abstract A reaction between (η5-C5Me5)TiCl3 and C5H5Tl in benzene solution has afforded (η5-C5Me5)(η5-C5H5)TiCl2 (I) in quantitative yield. (η5-C5Me5)(η5-C5H5)HfCl2 (III) has been prepared in 83% yield from a reaction between (η5-C5Me5)HfCl3 and C5H5Na·DME in refluxing toluene solution. The crystal and molecular structures of (η5-C5Me5)(η5-C5H5TiCl2 (I), (η5-C5Me5)(η5-C5H5)ZrCl2 (II) and (η5-C5Me5)(η5-C5H5HfCl2 (III) have been determined from X-ray data measured by counter methods. The three compounds are isostructural, crystallizing in the orthorhombic space group Pnma. The cell constants are: (I): a 9.873(1), b 12.989(3), c 11.376(4) A and Dcalc 1.45 g cm−3 for Z = 4; (II): a 9.930(3), b 13.231(9), c 11.628(3) A and Dcalc 1.58 g cm−3 for Z = 4; (III): a 9.938(1), b 13.156(2), c 11.582(2) A and Dcalc 1.97 g cm−3 for Z = 4. In each case the metal atom resides on a crystallographic mirror plane which bisects both cyclopentadienyl rings and the ClMCl bond angle. The MCl bond lengths are 2.3518(9) for I, 2.4421(9) for II and 2.415(1) A for III. The metal—cyclopentadienyl and metal—pentamethylcyclopentadienyl bond distances average 2.38(5) and 2.42(2) A for I, 2.50(4) and 2.53(2) A for II, and 2.48(4) and 2.50(1) A for III respectively.

f-element/crown ether complexes. 6. Interaction of hydrated lanthanide chlorides with 15-crown-5: Crystallization and structures of [M(OH2)8]Cl3·(15-crown-5) (M = Gd, Lu)

Abstract The interaction of hydrated chloride salts of Gd3+ and Lu3+ with 15-crown-5 in a 1:3 mixture of CH3OH:CH3CN produces crystalline [M(OH2)8]Cl3· (15-crown-5) (M = Gd, Lu). The crystal and molecular structures of both complexes have been determined by single crystal X-ray diffraction. Both are isostructural with previously determined Y analog and crystallize in the monoclinic space group P21/n with Z = 4. Lattice parameters are a = 9.247(4), b = 17.312(5), c = 15.191(6) A, β = 92.19(3)°, Dcalc = 1.72 g cm−3 for M = Gd and a = 9.150(1), b = 17.171(1), c = 15.217(1) A, β = 92.64(1)°, Dcalc = 1.80 g cm−3 for M = Lu. Each complex was refined by least-squares to final conventional R values of 0.052 (M = Gd, 2932 observed [Fo⩾5σ(Fo) reflections) and 0.036 (M = Lu, 3313 observed reflections). The octaaquo M(III) ions exist as a distorted dodecahedron with average MOH2 separations of 2.41(4) A (M = Gd) and 2.35(4) A (M = Lu). The crown ether molecule is hydrogen bonded to metal coordinated water molecules to form polymeric chains along b. The remaining water molecule hydrogen atoms participate in hydrogen bonds with the chloride ions essentially in the ac plane. Two resolvable disordered crown ether conformations are observed with occupancies of 60%/40% (M = Gd) and 75%/25% (M = Lu).

f-Element/crown ether complexes. 1. Synthesis and structure of [Y(OH2)8]Cl3·(15-crown-5)

Abstract The crystal and molecular structure of [Y(OH2)8]Cl3·(15-crown-5) has been determined by single- crystal X-ray diffraction. The complex crystallizes in the monoclinic space group P21/n with Z = 4. Lattice parameters are a = 9.202(2), b = 17.247(3), c = 15.208(3) A, and β = 92.39(2)°. The structure was solved by Patterson and Fourier techniques and refined by least-squares to a final conventional R value of 0.081. The Y(III) ion is eight coordinate, bonded to the oxygen atoms of the eight water molecules. Three of the water molecules are hydrogen bonded to crown ether molecules. The three chloride ions participate in hydrogen bonds with the remaining five water molecules. The YO(water) distances range from 2.322(6) to 2.432(7) A and average 2.37(4) A. The average O(water)···Cl and O(water)···O(crown) hydrogen bonded separations are 3.08(4) and 2.76(7) A, respectively.

f-Element/crown ether complexes. 7. Low temperature (−150 °C) structure of [Y(OH2)8]Cl3·(15-crown-5)

Abstract The crystal and molecular structure of [Y(OH2)8]Cl3·(15-crown-5) has been determined by single-crystal X-ray diffraction at −150 °C. At this temperature the lattice constants (monoclinic, P21/n) are a = 9.126(2), b = 17.104(3), c = 15.237(4) A, β = 92.86(2)°, and Dcalc = 1.56 g cm−3 for Z = 4. A final R value of 0.035 was obtained via least-squares refinement using 3399 independent observed [Fo ⩾ 5σ(Fo] reflections. The [Y(OH2)8]3+ cation is a distorted dodecahedron with average YOH2 separations of 2.39(4) A (type A site) and 2.34(2) A (type B site). The crown ether and the chloride ions are hydrogen bonded to metal coordinated water molecules resulting in a polymeric network. The average HOH⋯O(crown) and HOH⋯Cl− separations are 1.80(8) and 2.15(9) A, respectively.

f-Element/crown ether complexes, 11. Preparation and structural characterization of [UO2(OH2)5] [ClO4]2·3(15-crown-5)·CH3CN and [UO2(OH2)5] [ClO4]2·2(18-crown-6)·2 CH3CN·H2O

The reaction of UO2(ClO4)·nH2O with 15-crown-5 and 18-crown-6 in acetonitrile yielded the title complexes. [UO2(OH2)5] [ClO4]2·3(15-crown-5)·CH3CN crystallizes in the triclinic space groupPT with (at−150°C)a=8.288(6),b=12.874(7),c=24.678(7) Å, α=82.62(4), β=76.06(5), γ=81.06(5)°, andDcalc=1.67 g cm−3 forZ=2 formula units. Least-squares refinement using 6248 independent observed reflections [Fo≥5σ(Fo)] led toR=0.111. [UO2(OH2)5] [ClO4]2·2(18-crown-6)·2CH3CN·H2O is orthorhombicP212121 with (at−150 °C)a=12.280(2),b=17.311(7),c=22.056(3) Å,Dcalc=1.68 g cm−3,Z=4, andR=0.032 (3777 observed reflections). In each complex the crown ether molecules are hydrogen bonded to the water molecules of the pentagonal bipyramidal [UO2(OH2)5]2+ ions, each crown ether having exclusive use of two hydrogen atoms from one water molecule and one hydrogen from another water molecule. In the 15-crown-5 complex the remaining hydrogen bonding interaction is between one of the water molecules and one of the perchlorate anions. The solvent molecule has a close contact between the methyl group and a perchlorate anion suggesting a weak interaction. There are a total of three U-OH...OClO3 hydrogen bonds to the two perchlorate anions in [UO2(OH2)5] [ClO4]2·(18-crown-6)·2CH3CN ·H2O. The remaining coordinated water hydrogen bond is to the uncoordinated 2H2O molecule, which in turn is hydrogen bonded to a perchlorate oxygen atom and an acetonitrile nitrogen atom. One solvent methyl group interacts with an anion, the other with one of the 18-crown-6 molecules. Unlike the 15-crown-5 structure, the hydrogen bonding in this complex results in a polymeric network with formula units joined by hydrogen bonds from one of the solvent molecules and the uncoordinated water molecule.

f-Element/crown ether complexes III: Synthesis and structural characterization of [Y(NO3)2(OH2)5][NO3]·2(15-crown-5)☆

Abstract [Y(NO 3 ) 2 (OH 2 ) 5 ][NO 3 ]·2(15- crown -5) was prepared by the addition of 15- crown -5, dissolved in a 1:3 solution of CH 3 OH:CH 3 CN, to a solution of Y(NO 3 ) 3 ·nH 2 O in the same solvent mixture. The crystal and molecular structures of the title compound were determined by single-crystal X-ray diffraction using counter methods with crystals obtained by slowly cooling the reaction mixture. The complex is monoclinic, P2 1 c , with unit cell data a = 12.399(8) A , b = 10.488(4) A , c = 27.248(9) A , β = 91.47(5)° and D calc = 1.51g cm −3 for Z = 4 formula units. The structure was refined to a conventional R value of 0.107 using 2930 observed reflections [ I ⩾ 3 σ (I)]. High thermal motion and disorder were encountered when refining the two crownether molecules and the uncoordinated nitrate group. The yttrium atom is ninecoordinate with two bidentate nitrate groups (Y-O average length, 2.44(6) A) and five-coordinated water molecules (Y-O average length, 2.36(3) A).

f-Element–crown ether complexes. Part 9. The role of solvent hydrogen bonding: synthesis and crystal structure of aquatetrachlorotris(ethanol)thorium(IV)–1,4,7,10,13,16-hexaoxacyclo-octadecane–water (1/1/1)

The interaction of ThCl4·nH2O with 1,4,7,10,13,16-hexaoxacyclo-octadecane (18-crown-6) in ethanol yields crystalline [ThCl4(OHEt)3(OH2)]·(18-crown-6)·H2O. The crystal structure of this complex has been determined from three-dimensional X-ray diffraction data collected by counter methods. It crystallizes in the triclinic space group P, with (at –150 °C)a= 10.486(3), b= 10.859(5), c= 16.092(6)A, α= 75.45(4), β= 72.41(4), γ= 60.58(4)°, and Dc= 1.79 g cm–3 for Z= 2. The final R value was 0.059 for 4 759 independent observed [Fo 5σ(Fo)] reflections. The thorium atom is eitht-co-ordinate with square antiprismatic geometry. The four chlorines occupy trans positions in opposite square planes, with co-ordination completed by one water molecule and three ethanol groups. Two ethanolic hydrogen atoms participate in inter- and intra-molecular bifurcated hydrogen bonds to two of the chlorine atoms. The co-ordinated water molecule is hydrogen-bonded to the crown ether and the second water molecule. The third ethanol group is hydrogen-bonded to the other side of a symmetry related crown ether. The resulting ‘supermolecule’ consists of infinite zigzag chains (crown–metal–crown–metal) with the chains linked via the intermolecular ethanolic hydrogen to chlorine hydrogen bonds. The crown ether has the symmetric D3d conformation. The Th–Cl separations average 2.790(4)A(hydrogen-bonded chlorines) and 2.694(3)A.

f-Element/crown ether complexes 2. The synthesis and crystal structure of Y(NO3)3(12-crown-4)

Y(NO3)3(12-crown-4) was prepared via reaction of the crown ether and Y(NO3)3·nH2O in acetonitrile. Y(NO3)3(12-crown-4) crystallizes in the monoclinic space groupP21/c witha=12.084(5),b=8.524(4),c=15.150(6) Å, β=91.62(3)0 andDcalc=1.92 g cm−3 forZ=4. The structure was refined by least-squares to a final conventionalR value of 0.105 using 1249 independent observed reflections [I≥3σ(I)]. The title compound is isostructural with its Eu(III) analog. The yttrium ion is ten-coordinate, bonded to three bidentate nitrate groups and to the four oxygens of the crown ether. The coordination polyhedron is best described as a 4A, 6B-extended dodecahedron. The Y-O(nitrate) and Y-O(ether) separations average 2.44(5) and 2.46(4) Å, respectively.

Crystallization and structural characterization of dibenzo-18-crown-6·2(MeCN) and dibenzo-18-crown-6·2(MeNO2); assignment of specific C–H ⋯ O interactions

Stoicheiometric 2 : 1 complexes of acetonitrile and nitromethane with dibenzo-18-crown-6 have been crystallized from the corresponding solvent and their structures established by single crystal X-ray diffraction techniques at –150 °C.