Volume 53, Issue 1

Nearly colourless single crystals of the compounds CuDy 2 [B 8 O 16 ] (I) and CuHo 2 [B 8 O 16 ] (II) have been obtained by a B 2 O 3 flux technique. They crystallize in the structure of CuTb 2 [B 8 O 16 ] (I) or in an orthorhombic variant (II). X-ray investigations on single crystals led to the space group C 2h 5 - P2 1 /c (Nr. 14) with lattice parameters a = 1025,5(10); b = 836,99(10); c = 621,2(8) pm, β = 90.47(10)°; Z = 2 (I) and D 2h 9 - Pbam (Nr. 55) with a = 840,7(2), b = 616,6(2), c = 1022,0(2) pm, Z = 2 (II). The structures contain 1 ∞ [B 8 O 16 ] 8- chains isolated from each other, which include tri- and tetracoordinated boron. The chains consist of alternating twelve and eight-membered rings of boron and oxygen atoms connected by BO 4 units. Dy 3+ and Ho 3+ are octacoordinated and Cu 2+ is hexacoordinated in elongated octahedra by oxygen. The relation between these two structures is discussed.

Single crystals of the new compound CuHo 2 [B 2 O 5 ] 2 were obtained by using a B 2 O 3 flux technique with CuO and Ho 2 O 3 at 1050 °C. X-ray investigations on single crystals led to the space group P 2 1 /c (Nr. 14) with lattice parameters a = 454.3(2); b = 726.0(4); c = 936.0(5) pm; β = 90.77(1)°; Z = 2. The compound is isotypic to CuTb 2 [B 2 O 5 ] 2 as well as to the gadolinite structure (FeY 2 [BeSiO 5 ] 2 ). The structure exhibits layer-like ∞ 2 [B 2 O 5 ] 4- , a two-dimensional anion consisting of edge sharing BO 4 -tetrahedra, which form four- and eight-membered rings. The layers are connected by elongated CuO 6 -octahedra and slightly distorted tetragonal LnO 8 -antiprisms.

Bis[bis(trimethylsilyl)amino)]germylene (1) reacts with bromocyanogen to give bis[bis(trimethylsilyl)amino]bromocyanogermane (2). 2 crystallises from petroleum ether as a colourless solid which has been characterised by IR, 1 H, 13 C, 29 Si NMR spectroscopy, ele­mental analysis and X-ray diffractometry.

By treatment of [PtCl 6 ] 2- with an excess of SCN – in aqueous solution [Pt(SCN) 6 ] 2- is formed. The X-ray structure determination on a single crystal of [Py 2 CH 2 ][Pt(SCN) 6 ] (orthor-hombic, space group Pna2 1 , a = 15.5084(9), b = 11.8444(11), c = 13.2830(9)Å, Z = 4) shows, that the thiocyanate groups are exclusively S-coordinated with average Pt-S distances of 2.378 Å and Pt-S-C angles in the range from 103.1° to 108.1°. Based on the molecular parameters of the X-ray determination the low temperature (10 K) IR and Raman spectra have been assigned by normal coordinate analysis. The valence force constant is f d (PtS) = 1.62 mdyn/Å.

The crystal structures of the monoclinic form of Ph 2 P(O)NH 2 and of its cesium salt, [Cs{Ph 2 P(O)NH}] have been determined by X-ray methods. Ph 2 P(O)NH 2 : Space group P2 1 /c, Z = 16, lattice dimensions (-80°C): a = 2530.2(3), b = 858.9(2), c = 2135.5(3) pm, β = 110.78(1)°, R , = 0.055. Diphenylphosphinic acid amide forms dimeric molecules via N-H ··· O hydrogen bonds, the dimeric units again are associated via hydrogen bonds to form infinite double chains along the crystallographic c axis. [Cs{Ph 2 P(O)NH}]: Space group Pccn, Z = 8 , lattice dimensions (-83°C): a = 1262.8(1), b = 2632.3(2), c = 769.1(1) pm , R1 = 0.024. The compound is associated via Cs-O and Cs-N contacts along the crystallographic [001] axis forming a tubular arrangement. There are no hydrogen bonds.

The compound Li 4 GeS 4 has been prepared as transparent, light yellow moisture-sensitive crystals. Li 4 GeS 4 belongs to the space group Pnma with a = 14.107(6) Å, b = 7.770(3) Å and c = 6.162(2) Å. The crystal structure was solved by direct-methods. The final R and R w -values are 1.85 and 1.65% for 866 observed reflections. The Li 4 GeS 4 structure has three crystallographically independent lithium sites and one germanium site. The lithium atoms adopt two different coordination types. The Li l atom is coordinated to five sulfur atoms in a square pyramidal geometry, while the Li2 and Li3 atoms have distorted tetrahedral coordination. The Ge atom is tetrahedrally coordinated by four sulfur atoms and is found as [GeS 4 ] 4- units. The anisotropic three-dimensional crystal structure of Li 4 GeS 4 is described.

The title compound was prepared in well-crystallized form by thermal decomposition of Ca 5 Re 2 O 12 . Its structure was determined from single-crystal X-ray diffractometer data: I4 1 , a = 1107.0(1), c = 1609.3(1) pm, Z = 4, R = 0.056 for 4565 structure factors and 119 variable parameters. The calcium atoms occupy seven different sites with 8, 9, or 10 oxygen neighbors. The two different rhenium atoms are octahedrally coordinated by oxygen atoms with average Re-O distances of 193.1 and 187.7 pm for the six- and seven-valent rhenium atoms, respectively. The compound shows Curie-Weiss behavior with a magnetic moment of μ exp = 1.15(±0.10) μ B per Re(VI) atom. The structure is closely related to that of Sr 11 Os 4 O 24 which, however, crystallizes in the space group I2/a. The difference between the two structures arises through the higher coordination numbers of the strontium atoms. It is suggested that at high temperature both compounds crystallize in the common higher symmetry space group I4/a. Since Ca 11 Re 4 O 24 crystallizes in the pyroelectric class 4 this compound is expected to be ferroelectric.

Piperidine and perhydroazepine bearing a 1 -(4-nitrophenyl) substituent were inert to mercury-edta, while the a-pipecoline derivative gave an aminoketone with cleavage of the heterocycle. However the corresponding (2-nitrophenyl) compounds reacted to give respectively a piperidin-2-one, an aminopentanal and an aminohexanone. By an additional substituent in 2′-position the p-nitro compounds underwent dehydrogenation too. With a methyl group resulted a pattern analogous to o-nitro products. A neighbouring hydroxymethyl function enhanced the reaction with formation of benzoxazines and if possible their further oxidized derivatives, the hydroxylactams.

Single crystals of (Mn 2.4 Cu 0.6 )TeO 6 (I), Ba 2 MnTeO 6 (II) and Pb(Mn 0.5 Te 0.5 )O 3 (III) have been prepared by crystallization from fluxes. X-ray investigations led to rhombohedric symmetry (I): R3̄, (II): R3̄m with the trigonal lattice constants (I): a = 8.826(1), c = 10.687(2) Å, Z = 2. (II): a = 5.817(8), c = 14.244(3) Å, Z = 3. Compound (III) crystallizes with cubic symmetry P43̄m, a = 4.045(3) Å, Z = 1. (I) is the first example of a manganese(II) tellurate and belongs to the structure type of A 3 XO 6 compounds like (Mn 2 In)SbO 6 , Mn 3 WO 6 and Ca 3 UO 6 . (II) exemplifies an ordered and (III) a disordered variation of the perovskites.

Single crystals of Cu 5 Zn 4 Te 3 O 18 (I), Cu 1.5 Zn 1.5 TeO 6 (II) and Cu 1.5 Co 1.5 TeO 6 (III) have been prepared and investigated by X-ray work. The structure of (I) was solved in the monoclinic space group C 3 2 -C2, a = 14.834(2), b = 8.801(1), c = 10.375(2) Å, β = 93.27(2)°, Z = 4. (II) and (III) crystallize with cubic symmetry, space group T h 7 -Ia3̄, a (II) = 9.557(1), a (III) = 9.570(1) Å, Z = 8. (I) shows a complicated structure formed by TeO 6 octahedra isolated from each other, Zn 2 O 6 double tetrahedra and Zn 2 O 8 double square pyramids. These polyhedra are incorporated into a network of edge and corner connected stretched CuO 6 octahedra. (II) and (III) are isotypic to Cu 3 TeO 6 and have a (Cu/M) 3 O 6 octahedra network, statistically occupied by Cu 2+ and Zn 2+ or Cu 2+ and Co 2+ .

The magnetic properties of the title compound were re-investigated, since a new phase below 240 K has recently been identified. The exchange parameters were evaluated from the temperature dependence of the magnetic susceptibility with a Heisenberg operator taking into account the high pseudo-symmetry of the tetrameric units observed.

Ce 2 MnN 3 was prepared by reaction of cerium nitride and manganese with nitrogen gas at 900 °C. It crystallizes isotypic to AC 2 MN 3 (Ac = U, Th; M = Cr, Mn) and Ce 2 CrN 3 , space group Immm (No. 71), a = 3.74994(6) Å, b = 3.44450(6) Å and c = 12.4601(2) Å. The manganese atoms are coordinated in a nearly square planar fashion by four nitrogen atoms. These corner-connected MnN 4 units form infinite 1 ∞ [MnN 2 N 2/2 ] chains, which run parallel to each other along the crystallographic a-axis, forming the motif of hexagonal rod packing. Cerium atoms connect the chains into a three-dimensional network. The results of measurements of the magnetic susceptibility, as well as of the electrical resistivity suggest metallic behavior. Electronic effects leading to shorter bonds between manganese and bridging nitrogen atoms than between manganese and terminal nitrogen atoms in the 1 ∞ [MnN 2 N 2/2 ] chains were investigated through extended Hückel and LMTO band structure calculations. Issues pertaining to stability of this and some other nitridometallate structures are discussed.

The title compounds are isostructural to CsSbF 6 and crystallize with the KOsF 6 structure type (space group RS, Z = 3) with the lattice constants a = 749.7(1) pm, c = 758.9(1) pm (RbAsF 6 ), a = 772.3(1) pm, c = 805.0(1) pm (CsAsF 6 ) and a = 767.0(1) pm, c = 786.1(2) pm (RbSbF 6 ). The structures exibit nearly ideal [MF 6 ] – octahedra, the alkaline cations are coordinated by 12 fluorine ions in a distorted cuboctahedral geometry. Cations and complex anions form a slightly distorted CsCl arrangement. On heating, the arsenates transform to a NaCl arrangement with disordered [AsF 6 ] ions, whereas the antimonates of Rb and Cs form the corresponding disordered CsCl type at higher temperatures. The phase transitions and the i. r. and Raman spectra as well as the structural relations to the remaining hexafluoropnictates A I [M V F 6 ] are discussed.

The reaction between lead(II) acetate and 2-acetylpyridine 4 N-methylthiosemicarbazone (H4ML) produced a complex of the formula [Pb(4ML)(OOCMe)] with an unusual polymeric structure in which the lead atom is hepta-coordinate, the deprotonated thiosemicarbazone is a tetradentate bridge, and the acetate group both chelates and bridges. The complex crystallizes in the triclinic space group P1̄ with a = 8.860(2), b = 9.394(2), c = 9.783(3) A, α = 108.93(4), β = 98.67(3), γ = 107.87(5)°, V = 704.1(3) Å 3 , Z = 2.

The compounds [Ni(NH 3 ) 6 ](I 3 ) 2 and [Ni(NH 3 ) 6 ](I 5 ) 2 have been prepared by the reaction of stoichiometric amounts of [Ni(NH 3 ) 6 ]Cl 2 , KI, and I 2 in water. The already known triiodide crystallizes in the monoclinic space group C2/c with a = 1541,0( 10), b = 1521.6(8), c = 876.1 (7) pm, β = 101.44(6)° and Z = 4. The new pentaiodide crystallizes in the monoclinic space group P2 1 /n with a = 899.6(4), b = 1681.6(5), c = 946.8(7) pm, β = 110.90(5)° and Z = 2. Both compounds contain nearly octahedral cations [Ni(NH 3 ) 6 ] 2+ and simultaneously a linear and a bent triiodide ion I 3 - with nearly equal bond lengths or a unsymmetrical V-shaped pentaiodide ion I 5 - which is lined up to a new type of pentaiodide chain.

By reaction of (n-Bu 4 N) 2 [Pt(ox) 2 ] with elemental halogens in dichloromethane the complexes trans-[PtX 2 (ox) 2 ] 2- (X = Cl, Br, I) are formed. The crystal structures of trans-(py 2 CH 2 )[PtCl 2 (ox) 2 ] · C 4 H 6 O 3 (1) (monoclinic, space group P2 1 /n, a = 12.119(3), b = 14.926(2), c = 12.666(4) Å, β = 91.26(3)°, Z = 4), trans-(py 2 CH 2 )[PtBr 2 (ox) 2 ] (2) (monoclinic, space group P2 1 /n, a = 7.402(8), b = 16.997(3), c = 14.898(3) Å, β = 98.15(3)°, Z = 4) and trans-(py 2 CH 2 )[PtI 2 (ox) 2 ] ·C 3 H 7 NO (3) (orthorhombic, space group Pnma, a = 10.380(9), b = 13.973(2), c = 17.440(4) Å, Z = 4) have been determined by single crystal X-ray diffraction analysis. Highly resolution IR and Raman spectra were measured at low temperature (10 K). Using the molecular parameters of the X-ray determinations normal coordinate analyses based on a modified valence force field have been performed and the normal modes of vibration are assigned. The valence force constants are f d (PtCl) = 2.19, f d (PtBr) = 1.68, f d (PtI) = 1.28 mdyn/Å and f d (PtO) ranges from 2.71 to 2.82 mdyn/Å. The observed 195 Pt NMR shifts are δ( 195 Pt) = 6472.4 (X = Cl), 6027.1 (Br) and 5142.7 ppm (I).

2,5-Dihydroimidazoline-l-oxyl radicals I, II with imino substituents coordinate to Pd(II) and Pt(II) complexes with formation of the N,N chelate complexes 1-6. With oxygen containing substituents either monodentate N-coordination to give 8 or N ,O chelate formation to give 9 takes place, depending on the position of the oxygen atom relative to the ring nitrogen atom. With radicals III that also have the second ring nitrogen atom oxidized and the Rh(III) or Ir(III) complexes [Cp*MCl 2 ] 2 the O , O chelates 11 -13 could be obtained, while with Na 2 PdCl 4 the heterocycle was destroyed with formation of a N,N chelate complex 10 of an α-nitrosooxime ligand. The orthopalladated 2,2,5,5 tetramethyl-4-phenyl-2,5-dihydroimidazoline-l-oxyl complex 7a reacts with several a-amino acidates under splitting of the dichloro bridge with formation of the C,N/N,O-bis-chelate complexes 7b-f. The molecular structures of 2 and 10 were determined by X-ray diffraction.

The phase diagram of the ternary system Sr/Mo/O has been determined at a temperature of 1000°C. Powder samples of the ternary compounds SrMoO 4 , Sr 3 MoO 6 , SrMoO 3 , Sr 2 MoO 4 and SrMo 5 O 8 were prepared by solid state reactions. The thermochemical data of all ternary compounds were determined. A new compound, Sr 3 Mo 2 O 7 , with a layered perovskite structure (a = 3.967(1), c = 20.588(5) Å, I4/mmm) was found. Rietveld analysis based on powder X-ray diffraction data confirms that the compound Sr 2 MoO 4 has the K 2 NiF 4 structure (I4/mmm) with a = 3.9176(1), c = 12.8545(4) Å.

The transmetalation of bis[bis(trimethyIsilyl)amino]stannylene in tetrahydrofuran with the alkaline earth metals yields the bis(tetrahydrofuran) adducts of calcium (1a), strontium (1b) and barium bis[bis(trimethylsilyl)amide] (1c). The metalation of 6-methyl-6-phenylfulvene with 1a, 1b and 1c gives 1,1′-bis(l-phenyl-ethen-l-yl)calcocene 2a, -strontocene 2b and -barocene 2c, respectively. The reaction of 1b with equimolar amounts of 6-methyl-6-phenylfulvene and acetophenone leads to the formation of bis[μ-[η 5 -1-(3-hydroxy-1-methyl-1,3-diphenyl-2- propen-1-yl )-2,4-cyclo -pentadien-l-yl](2-)-C,O:O]tetrakis(tetrahydrofuran-O)distrontium 3. The metathesis reaction of 2a with YCl 3 and SnCl 2 yields the corresponding yttrocenechloride 4 and stannocene 5. Crystallographic data of 1a: monoclinic, P2 1 /c, a = 841.6(4), b = 1936.9(6), c = 1938.0(10) pm, β = 100.84(4)°, Z = 4, wR 2 =0,1199); 1b: orthorhombic, Pbca, a = 1924.8(4), b = 1747.8(3), c = 1930.1(4) pm, Z = 8, wR 2 = 0.1248; 3: monoclinic, P2 1 /c, a = 1230.42(11), b = 1343.08(11), c = 1597.34(14) pm, β = 104.610(7)°, Z = 4, wR 2 = 0.0980.

New optically active 3,5-dinitrosalicyloxazolines, derived from 3,5-dinitrosalicylonitrile and the chiral aminodiols (1S,2S)-(+)-2-amino-1-phenyl- 1,3-propanediol, (2S)-(-)-2-amino-1,1,4,4-tetraphenyl- 1,4-butanediol and (2S)-(-)-2-aminol, 1-diphenyl-1,3-butanediol, were prepared and used as in situ catalysts for enantioselective cyclopropanation reactions.