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

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) Å, 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) Å and average 2.37(4) Å. The average O(water)···Cl and O(water)···O(crown) hydrogen bonded separations are 3.08(4) and 2.76(7) Å, 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)

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) Å, β = 92.19(3)°, D_calc = 1.72 g cm⁻³ for M = Gd and a = 9.150(1), b = 17.171(1), c = 15.217(1) Å, β = 92.64(1)°, D_calc = 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 [F_o⩾5σ(F_o) 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) Å (M = Gd) and 2.35(4) Å (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. 16. Synthesis,crystallization and crystal structure of [Dy(OH2)8]Cl3·18-crown-6·4H2O

When crystals of [Dy(OH₂)₇(OHMe)] [DyCl(OH₂)₂(18- crown-6)]₂Cl₇·2H₂O [1] are allowed to warm from 5 °C to ambient temperature (22 °C) under the original solvent mixture (1:3 CH₃OH: CH₃CN), they redissolve and the title complex can be isolated by slow evaporation of the resulting solution. The crystal structure of this complex, [Dy(OH₂)₈]Cl₃·18-crown-₆·4H₂O, has been determined. It crystallizes in the monoclinic space group, P2₁/c, with a = 10.395(1), b = 18.684(1), c = 16.259- (3) Å, β= 102.56(1)°, and D_calc = 1.61 g cm⁻³ for Z = 4. A final conventional R value of 0.041 was obtained by least-squares refinement using 3453 independent observed [F_o⩾5σ(F_o)] reflections. The [Dy(OH₂)₈]³⁺ cations and crown ether molecules are hydrogen bonded in a polymeric chain with the crown molecules separating the cations and a total of seven DyOH₂···O(crown ether) hydrogen bonds. The chains are connected by a hydrogen bonding network consisting of the cations, chloride ions, and uncoordinated water molecules. The geometry of the cation is best described as a bicapped trigonal prism with distortions on the reaction pathway toward dodecahedral symmetry. The two capping atoms average 2.41(1) Å from Dy, the remaining DyO distances average 2.38(2) Å. The 18-crown-6 molecule has the D_3d conformation normally observed except for a distortion of one OCCO unit containing the oxygen atom accepting two hydrogen bonds.     

Platinum(II) complexes of methyl-substituted xanthines: crystal structures of K[Pt(theobromine)Cl3]·H2O,trans-[ Pt(isocaffeine)2Cl2]·H2O and K(isocaffeinium)[PtCl4]·H2O

The preparations of Pt(theophylline)₂Cl₂, K[Pt- (theophylline)Cl₃], K[Pt(theobromine)Cl₃]·H₂O (1), trans-[Pt(isocaffeine)₂Cl₂]·H₂O (2), and K(isocaffeinium)[PtCl₄]·H₂O (3) are reported.Crystals of 1 are monoclinic P2₁/n with a=7.641- (2), b=11.873(3), c=15.868(4) Å, β=90.80(2)°, Z=4. The structure was refined on 1443 reflections to R=0.028. In the planar [Pt(theobromine)Cl₃]⁻ anion Pt-N(9)=2.016(6) Å, Pt-Cl=2.299(2), 2.289(2), and 2.303(2) Å. The imidazole ring is rotated away from the coordination plane by 79.8°. Symmetry related theobromine units pack parallel to each other with a mean inter-ring separation of 3.27 Å.Crystals of 2 are monoclinic P2₁/a with a=7.345- (2), b=20.021(5), c=8.031(2) Å, β=104.18(2)°, Z=2. The structure was refined on 1132 reflections to R=0.029. The Pt-N(7) distance is 2.003(3) Å and Pt-Cl=2.298(1) Å. The imidazole ring is rotated away from the PtCl₂N₂ plane by 76.8°. In this compound, the isocaffeine units do not stack, but form a staggered arrangement within the unit cell.Crystals of 3 are monoclinic P₁/c with a= 7.382- (1), b=14.014(4), c=15.757(4) », β=92.30(2)°, Z=4. The structure was refined on 2057 reflections to R=0.032. The isocaffeine is protonated at N(7). The Pt-Cl distances in the PtCl₄²⁻ anion range between 2.29–2.31 Å. The protonated isocaffeine cations and the PtCl₄²⁻ anions form a very nearly parallel infinitely stacked arrangement with minimum interlayer atomic separations of 3.37 and 3.44 Å.     

Crystal structures of three thiourea (tu) complexes of Pt(II): trans-[(tu)2Pt(NH3)2]Cl2, trans-[(tu)2Pt(CH3NH2)2]Cl2·3H2O and [Pt(tu)4]Cl2

The structures of three Pt(II) thiourea complexes, trans-[(tu)₂Pt(NH₃)₂]Cl₂ (1), trans-[(tu)₂Pt(CH₃NH₂)₂]Cl₂·3H₂O (2) and [Pt(tu)₄]Cl₂ (3), have been determined by X-ray diffraction and refined to R = 0.049 for 1026 reflections (1), R = 0.057 for 2547 reflections (2) and R = 0.046 for 2792 reflections (3). All the compounds crystallize in the space group P2₁/c and have cell dimensions: a = 5.437(1), b = 6.450(1), c = 17.980(3) Å, β = 96.05(2)°, Z = 2 (compound 1); a = 9.225(1), b = 15.404(2), c = 12.601(2) Å, β = 105.39(2)°, Z = 4 (compound 2); and a = 9.051(6), b = 10.203(6), c = 18.263(8) Å, β = 91.12(8)°, Z = 4 (compound 3). The unit cell of 1 and 3 contains only a single type of cation, while that of 2 is formed from two independent cations. In 1 and 2 the coordination spheres of the Pt atoms are rather similar, with angles close to 90° and coplanarity of the metal and respective donor atoms. Instead, in 3 the four sulfur atoms, which surround the Pt, display a slight distortion (0.06 Å from the mean plane) towards tetrahedral.     

Synthesis and structures of porphyrin complexes of scandium: ClSc(TTP)·2(C 10H 7Cl) and O[Sc(TTP)] 2·6THF

A facile, high yield metallation procedure is reported for the insertion of Sc into H ₂(TTP) (TTP= dianion of meso-tetratolylporphyrin) using anhydrous ScCl ₃. Single crystal X-ray structures are reported for ClSc(TPP)·2(C ₁₀H ₇Cl) ( 1) and O[Sc(TTP)] ₂·6THF ( 2). Compound 1: space group P2 ₁/c with a = 19.850(17), b = 28.822(24), c = 9.954(9)Å, β = 95.71(7)°, Z = 4; 2: space group P2/n, a = 16.952(9), b = 16.737(5), c = 19.93(1)Å, β = 112.56(5)°, Z = 4. Compounds 1 and 2 both had large amounts of poorly ordered solvents in the lattice which resulted in rather high R factors in the range of 12–14%. In 1, the Sc is five-coordinate (4N and 1Cl) and is centered 0.68Åabove the plane defined by the four porphyrin nitrogens. For 2, the Sc is 0.82Åfrom the plane and contains a non-linear μ-oxide bridge with a ScO Sc angle of 109(3)°, but with essentially coplanar porphyrin rings.     

Syntheses of new uranium complexes Cl2U(π-S4N4 and (C5H5)3UClAlCl3·THF

The new bridging complexes Cp₃UClClAlCl₂ and Cp₃UClClAlCl₂·THF were synthesized by reaction of triscyclopentadienyl uranium chloride with aluminum trichloride in the presence of different solvents. The Cp₃UClClAlCl₂·THF complex id proposed to have a square bipyramidal structure with THF occupying the sixth position. A new inorganic cyclooctatetraene uranium complex, UCl₂(S₄N₄), was also synthesized by uranium tetrachloride with tetrasulfur tetranitride.     

Rhodium(III) cis-dihydrido complexes with 3,6-bis(2′-pyridyl)pyridazine (dppn) and bidiazines. Crystal and molecular structure of [Rh(H)2(dppn)(PPh3)2]PF6· CH2Cl2

The acetone complex [Rh(H)₂(acetone)₂(PPh₃)₂]- PF₆ reacts with bidiazines and 3,6-bis(2′-pyridyl)- pyridazine (dppn) giving the air stable cis-dihydrido rhodium(III) [Rh(H)₂(L)(PPh₃)₂]PF₆ complexes. The structure of the dichloromethane solvate of [Rh(H)₂(dppn)(PPh₃)₂]PF₆ has been determined by X-ray crystal structure analysis. Crystals are monoclinic, space group P2₁/a, with a = 18.629(6), b = 15.339(5), c = 17.146(5) Å, β = 101.02(3)° and Z = 4. The structure has been solved from diffractometer data by Patterson and Fourier methods and refined by block-matrix least-squares to R = 0.076 for 6225 observed reflections. In the structure discrete [Rh(H)₂(dppn)(PPh₃)₂]⁺ cationic complexes, PF₆⁻ anions and dichloromethane solvent molecules are present. The Rh atom is octahedrally surrounded by two cis hydride ligands and by two cis nitrogen atoms from a dppn molecule acting as a bidentate chelating ligand through two neighbouring pyridyl and pyridazinyl nitrogen atoms. Two P atoms from PPh₃, ligands in trans apical positions complete to octahedral the coordination of Rh.     

Synthesis and characterization of [Pt(COD)Cl(NO3)] and [Pt(COD)(NO3)2] and the use of [Pt(COD)Clx(NO3)2−x] in the preparation of cis[Pt(PPh3)2Clx(NO3)2−x] (x=0, 1, 2) and [Pt(PPh3)3L](NO3) (L=Cl,NO3)

[Pt(COD)Cl₂] (COD=1,5-cyclooctadiene) is a versatile starting material for the synthesis of Pt(II) compounds. The preparations of the new compounds [Pt(COD)Cl(NO₃)], [Pt(COD)(NO₃)₂] and [Pt(PPh₃)₃(NO₃)](NO₃) and also of the known compounds cis[Pt(PPh₃)₂Cl₂], cis [Pt(PPh₃)₂Cl(NO₃)], cis[Pt(PPh₃)₂(NO₃)₂] and [Pt(PPh₃)₃Cl](NO₃)are reported. The compounds are characterized by elemental analysis, ³¹P{¹H} NMR spectroscopy and IR spectroscopy.     

Further studies on the copper(II) complexes of lysine: [Cu(II)(H3N·C5H10·CH·NH2·COO)2] [HgI3]2

Spontaneous resolution in the formation of the [HgI₃]⁻ salts of the copper complex of racemic lysine was previously reported. X-ray and IR studies were used to support this conclusion. Gas chromatographic studies using a chiral phase on the crystals originally studied, and on newly formed crystals using D,L-lysine, do not substantiate the suggestion that spontaneous resolution occurs.     

Resonance Raman studies of the peroxotitanate(IV) complexes K2(Ti(O2)(SO4)2)·5H2O and K2(Ti(O2)(C2O4)2)·3H2O

The resonance Raman spectra of K₂(Ti(O₂)(SO₄)₂)·5H₂O and K₂(Ti(O₂)(C₂O₄)₂)·3H₂O are recorded. The results are consistent with the triangular structure of the peroxotitanium unit, Ti(O₂), with C_2ν symmetry. The ν(OO), ν_s(TiO) and ν_as(TiO) are observed around 890, 610 and 535 cm⁻¹, respectively. The resonance effects are shown to be associated with the 425 nm absorption band. This band is assigned to the O₂²⁻ → Ti(IV) charge-transfer transition. The calculated force constant values for the O₂²⁻ and TiO bonds are 320 and 275 N m⁻¹, respectively.     

Haloalkyl complexes of the transition metals. Part 5. The synthesis and reactions of some new pentamethylcyclopentadienyl halomethyl and methoxymethyl complexes of molybdenum(II) and tungsten(II) and the X-ray crystal structure of the cationic ylide complex [η-C5Me5W(CO)3CH2PPh3]I

Synthetic routes are described for the new halo- methyl complexes of the type [η-C₅Me₅M(CO)₃- CH₂X]. The complexes where M = Mo, X = Cl or OMe and M = W, X = Cl, I, OMe have been fully characterized. Reaction of [η-C₅Me₅Mo(CO)₃CH₂Cl] with PPh₃ in methanol under reflux or acetonitrile at room temperature gives [η-C₅Me₅Mo(CO)₂(PPh₃)- Cl], whereas reaction of [η-C₅Me₅W(CO)₃CH₂I] with PPh₃ under similar conditions gives the cationic phosphorus ylide complex [η-C₅Me₅W(CO)₃CH₂- PPh₃]I. The structure of this ylide complex has been determined by X-ray crystallography. The complex crystallizes with half a molecule of CH₂Cl₂ in the monoclinic space group P2₁/n with a = 16.616- (8), b = 11.738(6), c = 18.126(9) Å, β = 101.74(2)° and Z = 4. The structure was solved and refined to R = 0.076. It confirms the formulation of the compound and the presence of the ylide ligand, WC_ylide 2.34(2) Å, PC_ylide 1.82(2) Å and the WC_ylideP angle of 119(1)°.     

Crystal structure and properties of [TTF]2.5[V(mnt)3 ]·0.5CH2ClCH2Cl[TTF = tetrathiafulvalene and mnt = 1,2-dicyanoethylene-1,2-dithiolate(2−)]

The title salt was obtained by a reaction of [TTF]₃ [BF₄]₂ (TTF = tetrathiafulvalene) with [NMe₄]₂ [V(mnt)₃] [mnt = 1,2-dicyanoethylene-1,2- dithiolate(2−)] in a mixture of 1,2-dichloroethane and acetonitrile (3:2 ν/ν). A single crystal X-ray analysis of it revealed a TTF columnar structure consisting of both TTF⁰ and the TTF^·+ radical cation and the distorted octahedral geometry of the [V(mnt)₃]²⁻ anion. The salt crystallizes in a monoclinic system, space group C2/c with unit cell constants a = 25.428(3), b = 12.434(2), c = 25.477(3) Å, β = 92.428(3)° and Z = 8. The structure was solved by the direct method and refined, on the basis of 3854 [|F_o| > 3σ(F)] observed data, to an R value of 0.078. The salt e`xhibits electrical conductivity of 1.7 x 10⁻⁴ S cm⁻¹ at 25°C for a compacted pellet.