Åke Oskarsson

Metal-metal interactions in chain compounds of gold(I): syntheses and crystal structures of chlorotetrahydrothiophenegold(I), bromotetrahydrothiophenegold(I) and iodotetrahydroselenophenegold(I)

Abstract The crystal structures of the title compounds have been determined from X-ray intensity data collected at 200 K with a CAD 4 diffractometer. Crystal data at 200 K (Mo Kα, \ gl = 0.7107 A) are: [Au(C4H8S)Cl], orthorhombic, Pmc2v, Z = 4, a = 6.540(1), b = 8.192(1), c = 12.794(3) A and V= 685.5(2) A3; [Au(C4H8S)Br], orthorhombic, Pmc2v, Z = 4, a =6.564(1), b = 8.328(2), c = 13.229(4) A and V= 723.1(2) A3; [Au(C4H8Se)I], orthorhombic, Pc21n, Z = 8, a = 8.286(2), b = 11.552(3), c = 16.204(6) A and V= 1551.0(5) A3. Full matrix least-squares refinements using reflections obeying I > 2σ(I) converged to R = 0.053 (652 reflections), R = 0.067 (656 reflections) and R = 0.049 (1453 reflections) for the chloro, bromo and iodo compounds, respectively. [Au(C4H8S)Cl] and [Au(C4H8S)Br] are isostructural and comprise linear, neutral complexes, [Au(C4H8S)X], which are stacked in a staggered conformation forming infinite arrays of gold atoms running along a with gold-gold distances of 3.324(1) and 3.353(1) A and Au-Au-Au angles of 159.30(6)° and 156.29(8)° for the chloro and bromo complexes, respectively. The Au-S distances are in the range 2.26-2.28 A for both compounds, indicating that the difference in trans-influence of Cl and Br on the Au-S distance is negligible. [Au(C4H8Se)I] is composed of linear complexes, [Au(C4H8Se)2]+ and [AuI2]−, which alternate in infinite zigzag chains running along b, with Au-Au distances of 2.987(2) and 3.001(2) A and with Au-Au-Au angles of 160.89(4)° and 156.35(4)°. The Au-I and Au-Se distances are in the ranges 2.569(2)–2.571(2) and 2.430(3)–2.436(3) A, respectively. Since there are no ligand bridges between the gold atoms in any of these compounds, the fairly short gold-gold distances indicate metal-metal bonding. A survey of short Au-Au interactions, not supported by ligand bridges, shows a wide range of distances, 2.97 to 3.78 A, with a frequency maximum at 3.2–3.4 A.

Inorganic ion exchangers—VII: The sorption of first-row transition metal ions on a zirconium phosphate gel of low crystallinity, and a study of the reproducibility of the gel

Abstract Zirconium phosphate gels of low crystallinity have been prepared and characterized by their X-ray diffractograms, and by their dehydration, phosphate release and neutralization curves. At low pH, the phosphate release is not primarily due to any hydrolysis but rather to washing out phosphoric acid which adheres very stubbornly to the gel. It has been confirmed that the affinity for Cs+ increases strongly when the gels are dehydrated to ∼-1 mole H2O/mole Ze, and it has further been found that a similar increase of affinity, though less marked, occurs also for Na+. The sorption of the first-row transition metal ions Cr3+, Fe3+; Co2+, Ni2+, Cu2+, Zn2+ has been investigated. The divalent ions are all sorbed to about the same extent, and their affinity is not very different from that of Sr2+. Of the trivalent ions, Cr3+ is sorbed a little more strongly than the divalent ions, while the affinity for Fe3+ is extremely high. The uptake of this ion is not a simple exchange reaction but rather a process involving the introduction of Fe(III) into the matrix of the exchanger.

Synthesis and crystal structure of tetrakis(dimethylsulfoxide) platinum(II) bis(triflouromethanesulfonate)

Crystals of Pt(DMSO)4(TFMS)2 have been prepared by dissolution of platinum(II) hydroxide in a solution of CF3SO3H in DMSO and subsequent evaporation. The structure was determined by use of a CAD-4 diffractometer with monochromatic Mo Kα radiation. The space group is PFull-size image (<1 K) with Z = 2, a = 8.630(2), b = 9.557(3), c = 16.659(3) A, α = 73.33(2), β = 77.38(2) and γ = 79.19(3)°. The refinement converged to R = 0.056. The coordination around platinum is distorted square-planar with two S- and two O-bonded DMSO ligands in a cis-arrangement. The four donor atoms and the platinum are coplanar within 0.03 A. There is a severe steric crowding between the two S-bonded DMSO molecules, which gives rise to a distortion of the bond angles around the platinum. The crowding is minimized as much as possible by a staggered arrangement of oxygen atoms and methyl groups of adjacent ligands. PtS bond lengths 2.208(3) and 2.205(4) A are significantly shorter that those in the corresponding palladium complex, in accordance with a much stronger bond in the case of platinum. Bond length comparisons also indicate that ground state transinfluence of S-bonded DMSO probably is about the same in platinum and palladium complexes.

Compounds with intermediate spin. II. The crystal structure of tris(1,10-phenanthroline)iron(II) iodine dihydrate

The crystal structure of tris(1,10-phenthroline)iron(II) iodide dihydrate, Fe(C 12 N 2 H 8 ) 3 I 2 ·2H 2 O, has been determined from X-ray intensity data collected on a four circle diffractometer. The space group is P2 1 /a with four formula units in the cell. The cell dimensions are a = 10.623(2), b = 16.402(2), c = 20.375(4) A , and β = 104.48(1)°. The structure was refined by least-squares methods to a conventional R factor of 7.2%. Each Fe is pseudo-octahedrally coordinated by three phenanthroline molecules with FeN distances in the range 1.96–1.99 A. The coordination polyhedra are packed in layers parallel to the ab-plane with Fe close to z = 0.25 and 0.75. The water molecules and the iodide ions form hydrogen bond chains between the layers of the metal complexes. The FeO distances are in the range 4.90–5.54 A, and the FeI distances 6.06–6.43 A.

Synthesis and crystal structure of potassium tetranitrato palladate(II)

Abstract K 2 [Pd(NO 3 ) 4 ] has been prepared and its crystal structure determined by use of a CAD-4 diffractometer with monochromatic Mo Kα radiation. The space group is P 2 1 / c with Z = 4; a= 7.940(2); b = 15.469(4); c = 9.453(2) A; β = 91.10(3)°. The refinement converged to R = 0.023. The structure contains discrete complexes of [Pd(NO 3 ) 4 ] 2− with pseudosymmetry C 4. Pd coordinates four oxygens from different unidentate nitrato groups. The average Pd-O distance is 2.000(7) A. The coordination around Pd is distorted square-planar, with Pd situated 0.139 A above the plane through the four coordinated oxygens. Similar to [Pt(NO 3 ) 4 ] 2− , but in contrast with [Au(NO 3 ) 4 ] − , all four nitrato ligands are situated on the same side of the coordination plane forming a basket-like structure. This is probably due to interactions between the non-coordinated oxygens of the nitrato ligands and suitably located potassium ions. Comparison with the structure of cis -[Pd- (NO 3 ) 2 (DMSO) 2 ] indicates strong ground-state trans - influence of dimethyl sulfoxide in palladium complexes.

Trans influence in platinum(II) complexes. Phenylation of Pt(II) dialkylsulfide complexes by BPh4− and SnPh3H. Crystal structures of two polymorphs of trans-chlorobis(dimethylsulfide)(phenyl)platinum(II)

Two methods of phenylation of platinum(II) complexes are described, one by heating [PtCl(dms)3](BPh4) and another starting from triphenyltin hydride and [PtCl2(dms)2], dms = dimethylsulfide. Two different polymorphs of trans-[PtPhCl(dms)2] are obtained, one monoclinic and one triclinic. The monoclinic form contains two crystallographically different complexes. The main difference between the molecular geometries in the polymorphs is the orientation of the dms ligands. Distances found are PtCl, 2.403–2.420; PtS, 2.279–2.298 and PtC, 1.99–2.00 A. A comparison of some PtCl bond distances obtained from the literature reveals that the trans influence increases in the following order: Cl < S ⪕ Sn, P < C, H < Si.

A Tetra-Nitrato Complex of Platinum(II), Synthesis and Crystal Structure of K2[Pt(NO3)4].1/2H2O

K2[Pt(NO3)4]·Full-size image (<1 K)H2O was prepared from ca 0.4 M solutions of platinum(II) perchlorate in perchloric acid by addition of KHCO3 and KNO3. Its crystal structure was determined from X-ray intensity data collected with a CAD-4 diffractometer. Monochromatic MoKα-radiation was used. The space group is I4/m with Z = 4; a = 7.5277(4) and c = 20.470(3) A. The refinement converged to R = 0.036. The structure contains discrete complexes, [Pt(NO3)4]2−, with symmetry C4. Pt coordinates four O from different unidentate nitrato groups. The PtO distance is 2.010(5) A. The coordination around Pt is distorted square-planar, with Pt situated 0.14 A above the plane formed by four O, so that a very flat, square pyramid is formed. Two such pyramids on each side of the mirror plane are packed together with their bases facing each other. The closest OO distance between them is 3.29(1) A and the PtPt distance is 3.590(1) A. The potassium ions are located between the pairs of complexes so that a three-dimensional packing of K+ and 2×[Pt(NO3)4]2− is formed.

PHENYLATION OF PLATINUM(II) THIOETHER COMPLEXES BY TETRAPHENYLBORATE(III) IN SOLID STATE AND NITROMETHANE SOLUTION

Abstract Platinum(II) complexes of the type [Pt(thioether)3Cl]+ (thioether = dimethyl sulfide, thioxane) are capable of abstracting a phenyl group from the BPh− 4 counterion with formation of trans-[Pt(thioether)2ClPh] compounds. Thermal reactions proceed both in the solid phase and in nitromethane solution at elevated temperature and have preparative importance. Phenylation of the Pt(II) centre also occurs in reaction between [Pt(Me2S)2Cl2] and AgBPh4 in CH2Cl2 suspension. Brief X-ray crystallographic structural data for trans-[Pt(Me2S)2ClPh] and [Pt(thioether)3Cl]X (thioether = Me2S, tx, X = SO3CF3; thioether = Me2S, X = PF6) are reported.

Structures of trans-[PtCl2(PBz3)2], trans-[PtI2(PBz3)2], trans-[Pt(NCS)2(PBz3)2].0.5C6H6 and trans-[PdI2(PBz3)2]

A series of structures of trans-[MX2(PBz3)2] [M = Pt, X = Cl−; PBz3 = tribenzylphosphine (1), I−, trans-diiodobis(tribenzylphosphine)platinum(II) (2), and NCS−, trans-di(thiocyanate)bis(tribenzylphosphine)platinum(II) (3); M = Pd, X = I−, trans-diiodobis(tribenzylphosphine)palladium(II) (4)] have been characterized by X-ray crystallography. In all compounds each tribenzylphosphine has one benzylcarbon close to the coordination plane. In (1), (2) and (4) those (in-plane) C atoms, from the two different PBz3, exhibit an anti conformation along the P—P axis, while (3) has the gauche conformation. Root mean square (RMS) calculations and half-normal probability plots show that the complexes in (2) and (4) are very similar and the only significant differences between them are the M—P bonds, 2.354 (4) and 2.330 (5) A, and the M—I bond distances, 2.604 (1) and 2.611 (2) A, for Pd and Pt, respectively. Calculations of the steric demand of the PBz3 ligands based on the Tolman model gave values ranging from 155 to 178° for the effective and 156 to 179° for the Tolman angles, respectively.

Compounds with intermediate spin. 5. X-ray study of tris(N,N-dimethyldithiocarbamato)iron(III) at the two extreme temperatures 25 and 400 K

Fe[S2CN(CHa)2] 3 has a temperature-dependent magnetic moment. Its crystal structure has been determined at 25 and 400 K from X-ray intensities collected with a diffractometer equipped with a Be-walled liquid He cryostat and a microfurnace. The space group is Pbca with Z = 8 at both temperatures: a = 17.288 (50), b -19.947 (26), c = 9.998 (13) A at 25 K (fleff ----2.0) and a = 17.6961 (8), b = 20.7906 (10), c = 10.1630 (6)A at 400 K (//eft ---4.83). The refinements converged to R = 0.046 (25 K) and 0.058 (400 K). At both temperatures the mononuclear tris(dithiocarbamato) complexes with pseudosymmetry D 3 are van der Waals packed. The main structural difference between the lowand high-spin complexes is the Fe -S distances: the average length is 2.302 (3) at 25 and 2.415 (4) A at 400 K. The 25 K low-spin complex is the least distorted. The average apparent decrease in bond lengths between non-H atoms in the planar ligands is only 0.011 (3) A when the temperature rises from 25 to 400 K. Preliminary ESCA studies indicate a charge redistribution in the complex: the low-spin Fe -S bond is more covalent than the high-spin bond.