Volume 50, Issue 8

Single crystals of the new compounds CuLn 2 [B 2 O 5 ] 2 (Ln = Er 3+ (I), Lu 3+ (II)) were obtained by a B 2 O 3 flux-technique. They crystallize in the space group C 52h -P2 1 /c with I: a = 453.14(6); b = 721.94(5); c = 929.5(4) pm; β = 90.01(3)°; Z = 2 und II: a = 451.4(4); b = 718.3(1); c = 928.1(3) pm; β = 90.00(6)°; Z = 2. The compounds are isotypic to CuTm 2 [B 2 O 5 ] 2 as well as to the mineral Gadolinite (FeY 2 [BeSiO 5 ] 2 ) and exhibit layer like 2 ∞ [B 2 O 5 ] 4- -anions consisting of edge sharing BO 4 -tetrahedra, which form four- and eight-membered rings. The borate anions are separated by layers of elongated CuO 6 -octahedra and slightly distorted tetragonal LnO 8 -antiprisms.

Single crystals of the compounds MnFe(BO 3 )O (I) and MnAl 0.5 Y 0.5 (BO 3 )O (II), were obtained by a B 2 O 3 flux technique. I crystallizes with orthorhombic symmetry, space group D 16 2h -Pnma (Nr.62), a = 939.92; b = 319.41; c = 939.11 pm; Z = 4 and II with monoclinic symmetry, space group C 5 2h -P2 1 /n (Nr. 14). a = 325.6; b = 955.1; c = 929.2 pm; β = 90.70° ; Z = 4. I is isotypic to the mineral Warwickite, while II is a distorded variant of this structure. All metal ions are octahedrally coordinated. Both structures contain isolated, trigonal planar BO 3 units and oxygen atoms that are not coordinated to boron.

Single crystals of the new compound Cu 2 Cd(B 2 O 5 )O have been prepared by B 2 O 3 /V 2 O 5 flux technique in a closed silver tube. Their structure is isotypic with Cu 2 Co(B 2 O 5 )O but its preparation is quite different. X-ray investigations on single crystals led to the space group C 5 2h -P2 1 /c (Nr. 14), a = 339.9(2); b = 1509.8(2); c = 927,0(1) pm; β = 93.19(1)°; Z = 4. The structure contains isolated B 2 O 5 groups and oxygen that is not coordinated to boron. Cadmium is octahedrally coordinated by oxygen, while copper exhibits a nearly square planar or a fivefold pyramidal coordination.

The electronic spectrum of [SbS 4 ] 3- in 10 -3 M NaOH displays an absorption band at λ max = 285 nm which is assigned to a ligand-to-metal charge transfer (LMCT) transition. Upon LMCT excitation [SbS 4 ] 3- undergoes an intramolecular redox reaction with the formation of [SbS 3 ] 3- and elemental sulfur (φ = 0.11 at λ irr = 333 nm).

Single crystals of CdCu 1.5 Mg 1.5 Pb 0.5 V 3 O 12 have been prepared in closed steel tubes using V 2 O 5 as a flux. The orange crystals show monoclinic symmetry, space group C 6 2h -C2/c, a = 12.417(5), b = 12.983(6), c = 6.911(3) Å , β = 113.02(1)°, Z = 4. CdCu 1.5 Mg 1.5 Pb 0.5 V 3 O 12 reveals a relationship to the Johillerite type, but it is characterized by an additional point position for cadmium, situated between the square planar CuO 4 polygons of the Johillerite structure.

Single crystals of Bi 1.9 Cu 4 V 4 O 16 have been prepared by quenching of CO 2 -LASER heated samples. They were investigated by X-ray techniques. The compound crystallizes with tetragonal symmetry, space group C 5 4h -I4 /m , a = 9.945(2) Å , c = 2.915(3) Å, Z = 1, and is isotypic to the mineral Hollandite. Bi 1.9 Cu 4 V 4 O 16 is the first Hollandite with a statistical distribution of vanadium and copper in the network of octahedra. Calculations of the Coulomb terms of lattice energy led to a distance of bismuth to the lone pair of 1.07 Å. Considering the lone pair as part of the coordination sphere of Bi 3+ a square pyramidal polyhedron is obtained.

Black single crystals of Ti 0.33 Ta 0.67 O 2 have been prepared by CO 2 -LASER techniques heating a mixture of TiO and Ta 2 O 5 to T > 2000 °C. The titanium tantalum oxide crystallizes with tetragonal symmetry, space group D 14 4h -P4 2 /mnm, lattice constants a = 4.7344(6) Å c = 3.0504(2) Å, Z = 2. Ti 0.33 Ta 0.67 O 2 represents the compound TiTa 2 O 6 with rutile structure because of the statistical distribution of Ti 2+ and Ta 5+ . The composition of rutile-type compounds is discussed in more general terms.

Preparation and crystal structure of [P(C 6 H 5 ) 4 ]Cl 3 are reported. [P(C 6 H 5 ) 4 ]Cl 3 crystallizes in the monoclinic space group P2 1/ c with a = 1093.4(4), b = 789.1(1), c = 2682.7(7) pm, β = 90.39(1)°, V = 2200.27·10 6 pm 3 , and Z = 4. The geometry of the trichloride anion in the solid state is almost linear (Cl-Cl-Cl = 178.44(4)°) and unsymmetrical (d(Cl-Cl) = 226.3(1) and 230.7(1) pm).

[{Ru(CO) 3 Cl 2 } 2 ] reacts with the in situ prepared reagent Li 2 [Fe(CO) 3 (PBu t 2 ) 2 ] to give the new heterobinuclear complex [FeRu(CO) 5 (μ-PBu t 2)2 ] (1). Crystals of 1 are isomorphous to those of the known compound [Fe 2 (CO) 5 (μ-PBu t 2 ) 2 ] (2) and crystallize in the triclinic space group P1̄ with a = 867,5(1), b = 1181,0(2), c = 1373,1(2) pm; α = 76,64(1), β = 79,72(1) and γ = 76,48(1)°. A double bond between the two metal atoms concluded for 2 from the results of EHMO calculations is also proposed for 1 (Fe=Ru: 259,8(1) pm).

The title compound was prepared from the elemental components in a tantalum tube at 1070 K and investigated by X-ray diffraction of both powder as well as single crystals. The crystal structure was refined from four-circle diffractometer data: P2 1/ n, a = 618.1(1), b = 613.6(1), c = 743.9(1) pm, β = 109.40(1)°, V = 0.2661(1) nm 3 , Z = 4, wR2 = 0.0536 for 1564 F 2 values and 29 variables. EuPdGe crystallizes with the EuNiGe type structure. Both Pd and Ge atoms in EuPdGe have three germanium or palladium neighbors, respectively. They form two-dimensionally infinite [PdGe] polyanions which consist of corrugated 4.82 nets. These polyanions are separated by the europium atoms.

The new alkalimetal-hydrogenbis(carbonato)-bis(carbonato)complexes with penta-coordinated zinc atoms, NaA 2 {Zn 2 [H(CO 3 ) 2 ](CO 3 ) 2 (H 2 O) 2 } with A = Kor Rb, crystallize in the monoclinic system, P2 1/ n (no. 14), Z = 2 with a = 1057,9(1), b = 1102,2(1), c = 514,9(1) pm, β = 92,94(1)°, V EZ = 599,6(2) · 10 6 pm 3 , R = 0,052, R w = 0,029 for the potassium compound and with a = 1068,2(2), b = 1131,6(4), c = 518,6(1) pm, β = 92,07(1)°, V EZ = 626,4(4)·10 6 pm 3 , R = 0,050, Rw = 0,028 for the rubidium compound. These compounds are the first to be structurally characterized with a simultaneous presence of discrete [H(CO 3 ) 2 ] 3- and CO 3 2- anions. The crystal structure of the isostructural compounds contains two-dimensional infinite {Zn 2 [H(CO 3 ) 2 ](CO 3 ) 2 (H 2 O) 2 } layers parallel [1 0 1] with zinc coordinated in a slightly distorted trigonal-bipyramidal geometry. The layers are held together by hydrogen bonds from water molecules to oxygen atoms of the carbonato groups in adjacent layers. Potassium or rubidium atoms are located between the layers, and sodium atoms in smaller vacancies within the layers. The hydrogen bond of the [H(CO 3 ) 2 ] 3- anion is very short, O···O: 247,4(2) pm (K) and 246,9(5) pm (Rb). The carbonate groups in both compounds exhibit significant deviations from D 3h symmetry in accordance with the vibrational modes observed in the IR spectra. The thermal behaviour of the potassium compound is also reported.

The title compounds have been prepared by arc-melting cold-pressed pellets of the elemental components. They crystallize with a new structure type, which was determined from singlecrystal X-ray diffractometer data of Th 2 NiB 10 : Pbam, a = 564.6(2) pm, b = 1120.4(3) pm, c = 417.3(1) pm, Z = 2, R = 0.020 for 748 structure factors and 25 variable parameters. The structures of Th 2 FeB 10 (a = 562.7(1) pm, b = 1126.1(3) pm, c = 418.3(2) pm) and Th 2 CoB 10 (a = 562.4(1) pm, b = 1122.8(2) pm, c = 418.5(1) pm) were refined from single-crystal data to residuals of 0.025 (921 F values) and 0.032 (911 F values). The lattice of these ternary borides may be derived from that of ThB 6 (Th 2 B 12 ) with the cubic CaB 6 type structure by replacing two of the linking boron atoms of adjacent B 6 octahedra by a transition metal atom.

[La(Pc) 2 ] · CH 2 Cl 2 is prepared by anodic oxidation of ( n Bu 4 N)[La(Pc 2- ) 2 ] as slightly soluble black needles crystallizing in the orthorhombic space group Pnma with a = 28.365(5). b = 22.935(3). c = 8.026(3) Å, Z = 4. The La atom is in the center of an antiprismatic coordination polyhedron formed by the eight isoindole N atoms of the two staggered Pc ligands. The mean value of the La -N iso bond distance is 2.51 Å. One Pc ligand is quasi planar, the other is convex. The electronic absorption spectra and IR and resonance Raman spectra of the partially oxidized La III diphthalocyanine are reported and compared with those of the protonated complex H[La(Pc 2- ) 2 ].

The crystal structures of (η 5 -C 5 Me 5 )MoMe 4 1 and (η 5 -C 5 Me 5 )WMe 4 2 are reported. 1 and 2 crystallize in the orthorhombic space group Pbcm with the lattice parameters a = 681.4(2) pm, b = 1538.6(6) pm, c = 1402.4(6) pm with 4 units per cell (1), and a = 684.99(6) pm, b = 1547.3(2) pm, c = 1405.5(2) pm with 4 units per cell (2). Both compounds are monomeric and have a square-pyramidal geometry.

Single crystals of KMnPO 4 grown in a KCl flux show ferroelastic domains. The structure was determined on an optically controlled single domain crystal by X-ray diffraction methods. The cell is triclinic with dimensions a = 5.4813(5), b = 8.627(1), c = 8.887(1), in Å, α = 87.73(1)°, β = 89.10(1)°, γ = 88.01(1)°, Vᴍ = 419.6(1) Å 3 and Z = 4. The structure is closely related to the stuffed β-tridymite type. DTA experiments between room temperature and 1000 °C and polarized light microscopy observations showed four phase transitions: at 165, 330, 353 and 707 °C.

The phosphaneimine complexes [MnCl 2 (Me 3 SiNPEt 3 )] 2 (1) and [MnI 2 (Me 3 SiNPEt 3 ) 2 ] (2) have been prepared by the reaction of Me 3 SiNPEt 3 with MnCl 2 and Mnl 2 , respectively. Thermal decomposition of 2 leads to the chelate complex [MnI 2 (Me 2 Si(NPEt 3 ) 2 )] (3) by cleaving SiMe 4 . The complexes are characterized by IR spectroscopy and by crystal structure determinations. 1: Space group P2 1 /c, Z = 4, structure solution with 5062 observed unique reflections, R = 0.047. Lattice dimensions at -55 °C: a = 1175.8(5), b = 1634.5(2), c = 1740.2(8), β = 99.58(2)°. 1 forms dimeric molecules via chloro bridges and a cis-arrangement of the Me 3 SiNPEt 3 donor molecules with Mn-N bond lengths of 210.4(5) and 208.2(4) pm. 2: Space group P 4 1 2 1 2, Z = 4, structure refinement with 1633 independent reflections, 1072 observed unique reflections, R = 0.053. Lattice dimensions at -60 °C: a = b = 949.5(1), c = 3345.2(7) pm. 2 forms monomeric molecules with tetrahedrally coordinated Mn atoms and Mn-N bond lengths of 220.7(13) pm. 3: Space group P2 1 /c, Z = 4, structure refinement with 8419 independent reflections, 4584 observed unique reflections, R = 0.047. Lattice dimensions at 20 °C: a = 1343.3(1), b = 2508.2(2), c = 1535.1(1) pm, β = 91.742(5)°. 3 forms monomeric molecules with the [Me 2 Si(NPEt 3 ) 2 ] ligand bound in a chelating fashion with Mn-N bond lengths of 212.9 pm in average.

The adduct formation of iron(III) chlorophyll a with phosphines or phosphites has been studied by spectroscopic methods. The red-shift in the Soret and Q bands caused by the axial coordination of phosphine or phosphite to iron(III) chlorophyll a is an evidence for the autoreduction of the central iron(III) ion. The 31 P{ 1 H} NMR spectrum of bis-adducts measured in the presence of excess phosphine or phosphite ligands gave a single peak in the down field range compared to that of the corresponding free ligand. The ESR and X-ray photoelectron spectra have revealed that the central iron atom of the bis-adduct of iron chlorophyll a with phosphines or phosphites is divalent and in the low-spin state. The axial coordination of phosphine or phosphite influences the electronic configuration of the central iron atom and the macrocyclic chlorine ligand to induce the autoreduction of the central iron(III) ion.

In a search of transition metal complexes with sulfur dominated coordination spheres and free coordination sites for the binding of small molecules, [Ru(L)(' bu S 5 ')] complexes with the sterically demanding pentadentate thioether-thiolate ligand ' bu S 5 ' 2- ( ' bu S 5 ' 2- = 2,2'-Bis(2-mercapto-3,5-di-t-butylphenylthio)diethylsulfide(2-)) have been synthesized. Reaction of [RuCl 3 (NO)(PPh 3 ) 2 ] with 3,5-di(t-butyl)benzene-1,2-dithiolate, ′ bu S 2 ' 2- , yields the 16 electron complex [Ru(NO )(' bu S 2 ') 2 ] - which is isolated as the NBu 4 + -salt, 1. According to the NMR spectra, 1 contains a two-fold axis or a mirror plane. Alkylation of 1 with bis(β-bromethyl)sulfide under reflux leads stereoselectively to meso-[Ru(NO)(' bu S 5 ')]Br, [2]Br. Reaction of [2]Br with LiBEt 3 H yields the barely soluble binuclear complex [Ru(' bu S 5 ')] 2 , 3, with [Ru(' bu S 5 ')Ru(NO)(' bu S 2 ')(' bu S 2 '- C 2 H 4 SH)], 4, as a by-product. 4 ·THF, 4a, has been characterized by X-ray structure analysis. Reactions of 3 with σ-π- and σ-ligands yield mononuclear meso-[Ru(L)(' bu S 5 ')] complexes which have been isolated and characterized with L = CO, PMe 3 , PPh 3 , PCy 3 , pyr, CN - , 5 - 10, NH 2 NHPh, NH 2 NHMe, NH 2 NMe 2 , NH 2 Ph und NHEt 2 , 13-17. Complexes 5 -10 are stable compounds. Complexes 13-17, however, are sensitive towards oxidation and/or substitution. Coordination of L = N 2 H 4 and NH 3 to 3 leads to insoluble [Ru(L)(' bu S 5 ')] x complexes.

Single crystals of In 2.24 (NCN) 3 and NaIn(N CN) 2 can be synthesized from a reaction between InBr and NaCN at 400 °C, followed by chemical transport at 400-500 °C. The X-ray crystal structure determinations of In 2.24 (NCN) 3 (rhombohedral R3̄c, a = 606.09(4), c = 2884.4(2) pm, Z = 6) and NaIn(NCN) 2 (orthorhombic Cmcm, a = 961.30(6), b = 716.84(5), c = 603.65(4) pm, Z = 4) reveal ionic layer structures built from sheets of cationic and anionic (cyanamide) motifs. While NaIn(NCN) 2 contains In 3+ and Na + ions, In 2.24 (NCN) 3 is a mixedvalence compound, incorporating a monovalent In + ion besides trivalent indium. The NCN 2- units of both In 2.24 (NCN) 3 and NaIn(NCN) 2 reflect perfect D ∞h point group symmetry within the limits of experimental accuracy. Furthermore, an evaluation of all presently available crystallographic data on metal cyanamide crystal structures manifests that there is no evidence for a non-centrosymmetric description of any of these. Likewise, we propose an alternative centrosymmetric structural model for lead cyanamide, PbNCN, and question the evidence of the unsymmetrical, non-D ∞h shaped cyanamide anion in the latter structure.

Hexacarbonyl diiron complexes of N-substituted sulfimides (SNR) have been obtained from the parent tetrahedrane, Fe2(CO) 6 (μ-SNH) (1), by deprotonation to give the anion Fe 2 (CO) 6 (μ-SN - ) (2) and subsequent reaction with either trialkyloxonium or carbenium tetrafluoroborates. The new aza-diferra-thia-tetrahedranes, Fe 2 (CO) 6 (μ-SNR) (R = CH 3 (3a), C 2 H 5 (3b), CPh 3 (3c), cyclo-C 3 Ph 3 (3d), cyclo-C 7 H 7 (3e), and cyclo-(C 7 H 7 )M (CO) 3 with M = Cr (3f), Mo (3g), W (3h)) were characterized by their 1 H and 13 C NMR as well as their IR and MS spectra. The molecular structure of Fe 2 (CO) 6 [SN-cyclo-C 7 H 7 Mo(CO) 3 ] (3g) has been determined by X-ray diffraction.

A new tetracyclic derivative, difurocoumarin, was synthesized and studied in order to ascertain its possible use as a photochemotherapeutic agent alternative to psoralens. The compound proved able to photobind monofunctionally to DNA on irradiation with UV-A. A photocycloadduct with thymine was isolated and characterized spectroscopically.

The new series of ten 4,4'-bis(5-alkyl-2-thienylcarbonyloxy)azobenzenes (2a -2j) and ten 2,5-bis(5-alkyl-2-thienylcarbonyloxy)toluenes (3a -3j) were prepared. These, as yet unknown esters were characterized in relation to their structures by elemental analyses, IR, UV, 1 H NMR spectra and MS. The azobenzene-esters 2a -2j which form liquid crystalline phases were studied by microscopy under polarized light and DSC (differential scanning calorimetry). Through the observation of the optical textures nematic phases were monitored. Only 2j has an additional smectic phase; 2h and 2i form monotropic smectic phases during cooling. The toluene-esters 3a -3j do not form liquid crystalline phases.

Mg 6 Ni 16 As 7 (F m 3m ; a = 11.479(1) Å; Z = 4) was prepared by heating a mixture of the elements and investigated by means of single crystal X-ray methods. The arsenide crystallizes in a modified Th 6 Mn 23 type structure, similar to many ternary compounds of the composition A 6 M 16 X 7 , called G phases.

The reactions of CF 3 OCl with SbX 5 (X = F, Cl) and AsF 5 at 195 K yield the adducts CF 3 OCl · SbX 5 and CF 3 OCl · AsF 5 respectively. At 213 K CF 3 OCI · SbCl 5 forms SbCl 4 F, Cl 2 and OCF 2 , while compounds CF 3 OCl · MF 5 (M = As, Sb) slowly decompose giving ClF, OCF 2 and mixed M(V) halides. The formation of IF 5 , OCF 2 and Cl 2 in the oxidative fluorination of I 2 with CF 3 OCl at 293 K is described. Br 2 reacts with CF 3 OCl to give BrF 3 under similar conditions.