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1.
Crystal Structures and Vibrational Spectra of Tetrahalogenoacetylacetonatoosmates(IV), [OsX4(acac)]?, X ? Cl, Br, I By reaction of the hexahalogenoosmates(IV) with acetylacetone the tetrahalogenoacetylacetonatoosmates(IV) [OsX4(acac)]? (X = Cl, Br, I) are formed, which have been purified by chromatography and precipitated from aqueous solution as tetraphenylphosphonium (Ph4P) or cesium salts. X-ray structure determinations on single crystals have been performed of (Ph4P)[OsCl4(acac)] ( 1 ) (triclinic, space group P1 , a = 9.9661(6), b = 11.208(2), c = 13.4943(7) Å, α = 101.130(9), β = 91.948(6), γ = 96.348(8)°, Z = 2), (Ph4P)[OsBr4(acac)] ( 2 ) (monoclinic, space group P21/n, a = 9.0251(8), b = 12.423(2), c = 27.834(2) Å, β = 94.259(7)°, Z = 4) and (Ph4P)[OsI4(acac)] ( 3 ) (monoclinic, space group P21/c, a = 18.294(3), b = 10.664(2), c = 18.333(3) Å, β = 117.68(2)°, Z = 4). Due to the increasing trans influence in the series O < Cl < Br < I the Os? O. distances of O.? Cl? X′ axes are lengthened and the OsO. stretching vibrations are shifted to lower frequencies. The Os? X′ bond lenghts are shorter as compared with symmetrically coordinated X? Os? X axes.  相似文献   

2.
Preparation of Halogeno Pyridine Rhenates(III), [ReX6?n(Py)n](3?n)? (X = Br, Cl; n = 1?3) Crystal Structures of trans-[(C4H9)4N][ReBr4(Py)2], mer-[ReCl3(Py)3], and mer- [ReBr3(Py)3] The mixed halogeno-pyridine-rhenates(III), [ReX6?n(Py)n](3?n)? (X = Br, Cl), n = 1?3, have been prepared for the first time by reaction of the tetrabutylammoniumsalts (TBA)2[ReX6] (X = Br, Cl) in pyridine with (TBA)BH4 and separation by chromatography on Al2O3. Apart from the monopyridine complexes only the trans and mer isomers are formed from the bis-and tris-pyridine compounds. The X-ray structure determinations of the isotypic neutral complexes mer- [ReX3(Py)3] (monoclinic, space group P 21/n, Z = 4; for X = Cl: a = 9,1120(8), b = 12,5156(14), c = 15,6100(13) Å, β = 91,385(7)°; for X = Br: a = 9,152(5), b = 12,852(13), c = 15,669(2) Å, β = 90,43(2)°) reveal, due to the stronger trans influence of pyridine compared with Cl and Br, that the Re? X distances in asymmetric Py? Re? X3 axes with ReCl3 = 2,397 Å and ReBr3 = 2,534 Å are elongated by 1,3 and 1% in comparison with symmetric X1? Re? X2 axes with ReCl1 = ReCl2 = 2,367 Å and ReBr1 = 2,513 and ReBr2 = 2,506 Å, respectively. The Re? N bond lengths are roughly equal with 2,12 Å. Trans-(TBA)[ReBr4(Py)2] crystallizes triclinic, space group P1 , a = 9,2048(12), b = 12,0792(11), c = 15,525(2) Å, α = 95,239(10), β = 94,193(11), γ = 106,153(9)°, Z = 2. The unit cell contains two independent but very similar complex anions with approximate D2h(mmm) point symmetry.  相似文献   

3.
The tripodal ligand N-tris(2-benzimidazolylmethyl)-amine (ntb) was used for the preparation of zinc(II) and iron(III) complexes, [Zn(SCN)(ntb)](SCN) · iPrpOH ( 1 ) and [Fe(acac)(ntb)](ClO4)2 · 2CH2Cl2 · iPrpOH ( 2 ). 1 has a highly distorted trigonal-bipyramidal ZnN5 coordination geometry. The donor atoms are nitrogens of one amine, three benzimidazoles and one SCN?. A striking feature of the complex is the length of the Zn? Namine bond of 2.539(6)Å. The octahedral N4O2 coordination sphere of the iron in 2 is less distorted than that of the zinc in 1 . The metal is surrounded by an amine and three benzimidazole nitrogens of the ligand and two oxygens of the bidentate acetylacetonate co-ligand. The Fe? O bond lengths differ by about 0.1 Å. As for the unusual long Zn? N bond in 1 this is a result of a trans effect. 1 crystallizes in the space group P1 with: a = 9.530(1)Å, b = 13.402(1)Å, c = 13.578(2)Å, α = 98.83(1), β = 95.19(1), γ = 101.21(1)°, Z = 2; 2 is also triclinic, space group P1 , with: a = 9.875(6)Å, b = 12.929(10)Å, c = 18.635(15)Å, α = 94.95(8)°, β = 101.01(6)°, γ = 111.09(4)°, Z = 2.  相似文献   

4.
Chloro- and Polyselenoselenates(II): Synthesis, Structure, and Properties of [Ph3(C2H4OH)P]2[SeCl4] · MeCN, [Ph4P]2[Se2Cl6], and [Ph4P]2[Se(Se5)2] By symproportionation of elemental selenium and SeCl4 in polar protic solvents the novel chloroselenates(+II), [SeCl4]2? and [Se2Cl6]2?, could be stabilized; they were crystallized with voluminous organic cations. They were characterized from complete X-ray structure analysis. Yellow-orange [Ph3(C2H4OH)P]2[SeCl4] · MeCN (space group P1 , a = 10.535(4), b = 12.204(5), c = 16.845(6) Å, α = 77.09(3)°, β = 76.40(3)°, γ = 82.75(3)° at 140 K) contains in its crystal structure monomeric [SeCl4]2? anions with square-planar coordination of Se(+II). The mean Se? Cl bond length is 2.441 Å. In yellow [Ph4P]2[Se2Cl6] (space group P1 , a = 10.269(3), b = 10.836(4), c = 10.872(3) Å, α = 80.26(3)°, β = 79.84(2)°, γ = 72.21(3)° at 140 K) a dinuclear centrosymmetric [Se2Cl6]2? anion, also with square-planar coordinated Se(+II), is observed. The average terminal and bridging Se? Cl bond distances are 2.273 and 2.680 Å, respectively. From redox reactions of elemental Se with boranate/thiolate in ethanol/DMF the bis(pentaselenido)selenate(+II) anion [Se(Se5)2]2? was prepared as a novel type of a mixed-valent chalcogenide. In dark-red-brown [Ph4P]2[Se(Se5)2] (space group P21/n, a = 12.748(4), b = 14.659(5), c = 14.036(5) Å, β = 108.53(3)° at 140 K) centrosymmetric molecular [Se(Se5)2]2? anions with square-planar coordination of the central Se(+II) by two bidentate pentaselenide ligands is observed (mean Se? Se bond lengths: 2.658 Å at Se(+II), 2.322 Å in [Se5]2?). The resulting six-membered chelate rings with chair conformation are spirocyclically linked through the central Se(+II). The vibrational spectra of the new anions are reported.  相似文献   

5.
The Ni complex [C6H5O2P(S)N(C3H72]2Ni is monoclinic, space group P21/n with a = 8.890(3), b = 21.692(5), c = 11.670(4) Å, β = 108.35(5)°, V = 2136(1) Å3, F(000) = 916, Mr = 534.01, Z = 2, Dm = 1.318, Dx = 1.358 Mg m?3, graphite monochromatized MoKα ? radiation, π = 0.7107 Å, μ = 0.76 mm?1, T = 293 K. The structure was solved by a heavy atom method and refined to R = 0.044 for 3095 independent reflexions. The Ni atom lies in the centre of symmetry and is coordinated by four S atoms of the two molecules of the ligand in a planar arrangement. Ni? S bond lengths are 2.205 and 2.226 Å resp., the angles S? Ni? S are 97.65 and 82.35° resp.  相似文献   

6.
Zinc Coordination Compounds with Imidazoline and Imidazole Donor Ligands . By reaction of the two bidentate bisimidazoline ligands 1,2-bis(2-imidazoline-2-yl)ethan (BIE) and 1,2-bis(2-imidazoline-2-yl)benzene (BIB) with zinc bromide under various reaction conditions the complexes [ZnBr2(BIE)] ( 1 ), [ZnBr2(BIB)] ( 2 ), [Zn(BIE)2]Br2 ( 3 ) and [Zn(BIB)2](BPh4)2 ( 4 ) were synthesized and characterized. In all compounds the zinc atom is tetrahedrally coordinated, either by a bidentate ligand and two bromine ligands, or by two of the chelate ligands. Zn? N? bond distances for 1 – 4 range from 1.966(2) to 2.013(3) Å, and the Zn? Br distances from 2.372(1) to 2.403(1) Å. [3-(imidazole-1-yl)-1-oxopropyl]benzene (IOB) was prepared as a novel imidazole ligand which carries a keto-O atom in 1,5-position to the pyridine-N atom. The zinc in [ZnCl2(IOB)2] ( 5 ) is coordinated by two ligands and two Cl atoms forming a distorted tetrahedral ZnN2Cl2 unit (Zn? N: 2.013(3) and 2.029(2) Å; Zn? Cl: 2.226(1) and 2.242(1) Å). The colourless compounds 1 – 5 were characterized by IR, 1H-NMR, X-ray absorption spectra and single-crystal X-ray structure analysis. Space groups and structural data: 1 : P21/c, a = 7.717(2), b = 22.814(5), c = 8.026(2) Å, β = 117.58(2)° (140 K), R = 0.0283; 2 : Cc, a = 11.831(3), b = 11.677(1), c = 11.846(1) Å, β = 114.55(2)°, R = 0.0237; 3 : P42/n, a = 7.931(1), c = 16.945(1) Å, R = 0.0312; 4 : P21/c, a = 18.666(2), b = 16.615(2), c = 19.786(2) Å, β = 99.17(1)°, R = 0.0472; 5 : P21/c, a = 9.173(2), b = 9.230(1), c = 28.357(3) Å, β = 96.63(1)°, R = 0.0317.  相似文献   

7.
Complexes of trifluoromethanesulfonates (triflates) with alkali metals Na, Rb, Cs have been prepared in the presence of various macrocyclic polyether crowns [(12‐crown‐4), (15‐crown‐5) and (18‐crown‐6)]. Depending on the combination of alkali ion with crown, the complexes include separated ion pairs [Na(12‐crown‐4)2] [SO3CF3] ( 1 ) and contact ion pairs [Na(15‐crown‐5)] [SO3CF3] ( 2 ), [Rb(18‐crown‐6)] [SO3CF3] ( 3 ), and [Cs(18‐crown‐6)] [SO3CF3] ( 4 ), in which the triflate acts as a bidentate ligand. It is shown that the choice of crown ether is of paramount importance in determining the solid‐state structural outcome. The complex resulting from the pairing of crown ether ( 1 ) develops, when the crown ether is too small in relation to the alkali ion radius. When the cavity size of the crown ether is matched with the alkali ion radius, simple monomeric structures are identified in 2 , 3 and 4 . The title compounds crystallize in the monoclinic crystal system: 1 : space group P2/c with a = 9.942(3), b = 11.014(2), c = 10.801(3) Å, β = 97.30(2)°, V = 1173.1(4) Å3, Z = 2, R1 = 0.0812, wR2 = 0.1133: 2 : space group P21/m with a = 7.949(2), b = 12.063(3), c = 9.094(2) Å, β = 105.98(2)°, V = 838.3(4) Å3, Z = 2, R1 = 0.0869, wR2 = 0.1035: 3 : space group P21/c with a = 12.847(5), b = 8.448(2), c = 22.272(6) Å, β = 122.90(3)°, V = 2029.5(1) Å3, Z = 4, R1 = 0.0684, wR2 = 0.1044: 4 : space group P21/n with a = 12.871(3), b = 8.359(1), c = 19.019(4) Å, β = 92.61(2)°, V = 2044.2(6) Å3, Z = 4, R1 = 0.0621, wR2 = 0.0979.  相似文献   

8.
Chloroselenates(IV): Synthesis, Structure, and Properties of [As(C6H5)4]2Se2Cl10 and [As(C6H5)4]Se2Cl9 The Se2Cl102? and Se2Cl9? anions were prepared, as the first dinuclear haloselenates(IV), from the reaction of (SeCl4)4 with stoichiometric quantities of chloride ions in POCl3 solutions; they were isolated as yellow crystalline As(C6H5)4+ salts. Complete X-ray structural analyses at ?130°C of [As(C6H5)4]2Se2Cl10 ( 1 ) (space group P1 , a = 10.296(7), b = 11.271(6), c = 12.375(8) Å, = 74.17(5)°, α = 81.38(5)°, β = 67.69(4)°, V = 1276 Å3) and of [As(C6H5)4]Se2Cl9 ( 2 ) (space group P21/n, a = 12.397(5), b = 17.492(6), c = 14.235(4) Å, α 93.25(3)°, V = 3082 Å3) show in both cases two distorted octahedral SeCl6 groups connected through a common edge in 1 and a common face in 2 . The terminal Se? Cl bonds (average 2.317 Å in 1 , 2.223 Å in 2 ) are much shorter than the Se? Cl bridges (av. 2.661 Å in 1 , 2.652 Å in 2 ). The stereochemical activity of the SeIV lone electron pair causes severe distortion of the central Se2Cl2 ring in the centrosymmetric Se2Cl102? ion. The vibrational spectra of the anions are reported.  相似文献   

9.
The triligate trimetallic complexes, [{M(CO)5}3(Pf-Pf-Pf)] and tetraligate tetrametallic complexes, [{M(CO)5}4(P-Pf3)] (M = Cr and Mo), were prepared from [M(CO) 6] and the corresponding ligands in MeCN/CH2Cl2 promoted by Me3NO at 0 °C. Crystals of trimer lb are monoclinic, space group P 21/n, with a = 13.407(3), b = 15.002(5), c = 26.52(1) Å, β = 90.65(2)°, Z = 4, and R = 0.060 for 2760 observed reflections. Crystals of tetramer 2a are monoclinic, space group P 21/c, with a – 14.183(8), b = 29.880(4), c = 16.103(2) Å, β = 94.98(3)°, Z = 4, and R = 0.039 for 5014 observed reflections. Crystals of 2b are monoclinic, space group C 2/c, with a = 42.120(8), b = 13.679(1), c = 23.486(2) Å, β = 92.14(1)°, Z = 8, and R = 0.032 for 6897 observed reflections. Each phosphorus atom of the ligands is coordinated to the M(CO)5 moiety in each title compounds. The geometry of the four metals is a distorted tetrahedron for the tetramers.  相似文献   

10.
NaTe3 – a Compound with Cuban-like Clusters Te126? NaTe3 results as a greyish microcrystalline powder if stoichiometric amounts of the pure elements sodium and tellurium (molar ratio 1:3) are allowed to react in liquid ammonia at about ?50°C. After melting the crude product (500°C, 1 h, corundum crucible in sealed glass ampoule), followed by an annealing period (380°C, 5 days) NaTe3 yields as a silvery compound with metallic lustre. NaTe3 is trigonal, space group P3 c1, Z = 12, with a = 9.033(2) Å and c = 21.930(4) Å. It contains Te62?-chains, linked together via their terminal atoms producing infinite strings. These strings may be thought to be built up of cuban-like clusters Te126?.  相似文献   

11.
The phosphorus‐sulfur ligand 1‐(methylthio)‐3‐(diphenylphosphino)‐propane (S‐P3) has been synthesized and characterized by 1H NMR and 13C NMR. Reactions of S‐P3 with [PdCl2(PhCN)2] afforded the complexes [PdCl2(S‐P3)] ( I ) and [PdCl2(S‐P3)2] ( II ), in which S‐P3 acts as a bidentate and monodentate ligand, respectively. Compound I crystallizes in monoclinic space group P21/n (No. 14) with cell dimensions: a = 8.589(3), b = 15.051(3), c = 17.100(3)Å, β = 102.91(2)°, V = 2154.7(9)Å3, Z = 4. Likewise, compound II crystallizes in monoclinic space group P21/n (No. 14) with a = 9.993(5), b = 8.613(4), c = 18.721(5)Å, β = 90.18(3)°, V = 1611.3(12)Å3, Z = 2. Compound II has a trans square planar configuration with only the P‐site of the ligand bonded to the palladium atom.  相似文献   

12.
Preparation and Crystal Structure of Tetraphenylphosphonium Hexathiocyanatorhodate(III), [P(C6H5)4]3[Rh(SCN)6] By treatment of RhCl3 · n H2O with KSCN in water a mixture of the linkage isomers [Rh(NCS)n(SCN)6–n]3?, n = 0–2 is formed which is separated by ion exchange chromatography on diethylaminoethyl cellulose. The X-ray structure determination on a single crystal of [P(C6H5)4]3[Rh(SCN)6] (monoclinic, space group C1c1, a = 13.620(5), b = 22.929(13), c = 22.899(9) Å, β = 98.55(3)°, Z = 4) confirms the coordination of all ligands via S with the middle Rh? S distance of 2.372 Å and Rh? S? C angles of 109°. The SCN groups are nearly linear with 175° and averaged bondlengths S? C 1.63 and C? N 1.14 Å. The crystal lattice is build up by layers of complex anions and voluminous cations with no specific interactions but which are closely connected by thiocyanate ligands and phenyl rings.  相似文献   

13.
Die Kristallstruktur der Diphenyldithiophosphinsäure (C6H5)2P(S)SH wurde röntgenographisch bei tiefer Temperatur und Normaltemperatur aus Einkristalldiffraktometerdaten bestimmt und bis zu R-Werten von 0,037 (140 K, (sin Θ)/λ < 0,81 Å?1) und 0,035 (293 K, (sin Θ)/λ < 0,64 Å?1) verfeinert. Die Verbindung kristallisiert in der monoklinen Raumgruppe P21/c mit den bei 140 K (in Klammern: 293 K) gemessenen Gitterkonstanten a = 9,824(3) (9,887), b = 10,061(3) (10,175), c = 14,342(4) (14,433) Å, β = 122,08(3) (121,73)° und V = 1201,1 (1234,9) Å3, Z - 4. Im Kristall sind individuelle Moleküle über fast lineare S? H…?S-Wasserstoffbrückenbindungen zu schraubenförmig gewundenen Ketten verknüpft. Bei 140 K beträgt der S…?S-Abstand innerhalb der Brücke 3,790(1) Å; die weiteren geometrischen Daten der Wasserstoffbrücke sind: d(S? H): 1,25(2), d(S…?H): 2,56(2), d(P? S): 2,077(1), d(P?S): 1,954(1) Å, ? (S? H…?S): 169,5(14), ? (P? S…?S): 98,87(2), ? (P?S…?S): 96,65(2)°. Investigations on Compounds Containing S? H…?S Hydrogen Bonds. Crystal Structure of Diphenyldithiophosphinic Acid at 140 and 293 K The crystal structure of diphenyldithiophosphinic acid (C6H5)2P(S)SH was determined from X-ray diffraction data collected at 140 and 293 K and was refined to R factors of 0.037 (140 K, (sin Θ)/λ < 0.81 Å?1) and 0.035 (293 K, (sin Θ)/λ < 0.64 Å?1) respectively. The compound crystallizes in the monoclinic space group P21/c with unit cell parameters at 140 K (in parentheses: at 293 K): a = 9.824(3) (9.887), b = 10.061(3) (10.175), c = 14.342(4) (14.433) Å, β = 122.08(3) (121.73)° and V = 1201.1 (1234.9) Å3, Z = 4. In the crystalline state individual molecules are linked together by nearly linear S? H…?S hydrogen bonds so that endless helical chains are formed. At 140 K the S…?S distance within the hydrogen bond is 3.790(1) Å; the other distances and angles associated with the bridge are: d(S? H): 1,25(2), d(S…?H): 2,56(2), d(P? S): 2,077(1), d(P?S): 1.954(1) Å, ? (S? H…?S): 169.5(14), ? (P? S…?S): 98.87(2), ? (P? S…?S): 96.65(2)°.  相似文献   

14.
Three structures containing the N,N-4-toluenesulfonyl-2-pyridylaminato ligand are presented. The brown crystal of Cu2L4 (L =N,N-4-toluenesulfonyl-2-pyridylaminato) was found to crystallize in the monoclinic space group P2,/c with a = 15.762(12), b = 15.552(5), c = 20.505(11) Å, β = 104.14(7)°; V = 4874(5) Å3;Z = 4; the final RF = 0.050, RWF = 0.049 for 5142 observed reflections and 612 variables. The Cu-Cu distance is small, 2.516(2) Å and the complex is diamagnetic at room temperature. The colorless crystal of Ag2L was found to crystallize in the monoclinic space group P2t/n with a = 9.620(2), b = 5.625(2), c ? 23.250(3) Å, Å = 94.72(1)°; V = 1254.0(5) Å3; Z = 2; the final RF = 0.027; RWF = 0.028 for 1929 observed reflections and 164 variables. The Ag-Ag distance is 2.739(1) Å The green crystal of CuL2 (py)2was found to crystallize in the monoclinic space group P21 with a = 9.366(2), b = 20.615(7), c = 9.862(2) Å,β = 116.73(2)°; V = 1700.5(8) Å3; Z = 2; the final RF = 0.037; RWF = 0.038 for 1636 observed reflections and 423 variables. A reversible transformation between Cu2L4 and CuL2(py)2 is reported.  相似文献   

15.
Molecular and crystal structures of 1-amino-3,5-diphenyl-2,4,4,6,6-pentacyano-cyclohex-1-ene (I) and 1-amino-3,5-diphenyl-2,4,4,6-tetracyanocyclohex-1-ene (II) are studied to examine intermolecular interactions. Crystal data for (I): space group P21, a=11.172(3), b=6.561(2), c=16.390(4) Å, β=100.25(2)0, V=1182.1 Å3, Z=2, R=0.046; for (II): space group P1, a=10.756(3), b=10.890(3), c=12.999(3) Å, α=62.20(2), β=70.73(2), γ=65.42(2)0, V=1207.2 Å3, Z=2, R=0.074. Intermolecular bonds via the aminonitrile fragment in (I) lead to formation of chains along they axis: N1…N6′ (1?x, ?1/2+y, 1?z) of 3.465(8) Å, N6…N1″ (1?x, 1/2+y, 1?z), and the contact with the solvent (acetone) O1…N1 of 2.984(7) Å. In compound (II), the intermolecular contacts N1…N5′ (?x+1, ?y, ?z+1) of 3.064(7) Å link the molecules into dimeric associates.  相似文献   

16.
The red complex trans-Mo2(O2CCH3)2(μ-dppa)2(BF4)2, 1 , was prepared by reaction of [Mo2(O2CCH3)2(CH3CN)6][BF4]2 with dppa (dppa = Ph2PN(H)PPh2) in THF. The reactions of Mo2(O2C(CH2)nCH3)4 with dppa and (CH3)3SiX (X = Cl or Br) afforded the complexes trans-Mo2X2(O2C(CH2)nCH3)2(μ-dppa)2 (X = Cl, n = 2, 2; X = Br, n = 2, 3; X = Cl, n = 10, 4 ; X = Cl, n = 12, 5 ). Their UV-vis, IR and 31P{1H}-NMR spectra have been recorded and the structures of 1, 2 and 3 have been determined. Crystal data for 1 : space group P21/n, a = 12.243(1) Å, b = 17.222(1) Å, c = 13.266(1) Å, β = 95.529(1)°, V = 2784.1(6) Å3, Z = 2, with final residuals R = 0.0509 and Rw = 0.0582. Crystal data for 24CH3Cl2: space group P21/n, a = 13.438(1) Å, b = 19.276(1) Å, c = 14.182(1) Å, β = 111.464(1)°, V = 3418.9(6) Å3, Z = 2, with final residuals R = 0.0492 and Rw = 0.0695. Crystal data for 3·4CH2Cl2: space group P21/n, a= 13.579(1) Å, b = 19.425(1) Å, c = 14.199(1) Å, β = 111.881(2)°, V = 3475.6(7) Å3, Z = 2, with final residuals R = 0.0703 and Rw = 0.0851. Comparison of the structural data shows that the effect of the axial ligand on weakening the Mo-Mo bond strength is X? > CH3CN > BF4?. The Tm values are 121.7 °C for 2 , 111.1 °C for 3 and 91.5 °C for 5 , respectively.  相似文献   

17.
Cu3SbS3: Crystal Structure and Polymorphism The hitherto unknown crystal structure of β-Cu3SbS3 at room temperature could be determined from a twinned crystal. The compound crystallizes in the monoclinic system, space group P21/c (No. 14), with a = 7.808(1), b = 10.233(2) and c = 13.268(2) Å, β = 90.31(1)°, V = 1 060.1(2) Å3, Z = 8. An Extended-Hückel-Calculation shows weak bonding interactions between copper atoms which are coordinated trigonal planar. At ?9°C a first order phase transition occurs and the crystals disintegrate. The low-temperature modification (γ) crystallizes in the orthorhombic system with a = 7.884(2), b = 10.219(2) and c = 6.623(2) Å, V = 533.6(2) Å3 (?100°C). At 121°C a phase transition of higher order is observed. The high-temperature polymorph (α) of Cu3SbS3 is orthorhombic again. From high-temperature precession photographs the space groups Pnma (No. 62) or Pna21 (No. 33) can be derived. The lattice constants at 200°C are a = 7.828(3), b = 10.276(4) and c = 6.604(3) Å, V = 531.2(2) Å3.  相似文献   

18.
Preparation, Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of trans-(PNP)[TcCl4(Py)2] and trans-(PNP)[TcBr4(Py)2] By reaction of (PNP)2[TcX6] with pyridine in the presence of [BH4]? (PNP)[TcX4(Py)2], X = Cl, Br, are formed. X-ray structure determinations on single crystals of these isotypic TcIII complexes (monoclinic, space group P21/n, Z = 2, for X = Cl: a = 13.676(4), b = 9.102(3), c = 17.144(2) Å, β = 91.159(1)°; for X = Br: a = 13.972(2), b = 9.146(3), c = 17.285(4) Å, β = 90.789(2)°) result in the averaged bond distances Tc? Cl: 2.386, Tc? Br: 2.519, Tc? N: 2.132(3) (X = Cl) and 2.143(4) Å (X = Br). The two pyridine rings are coplanar and vertical to the X? Tc? X-axes, forming angles of 42.28° (X = Cl) and 43.11° (X = Br). Using the molecular parameters of the X-ray structure determination and assuming D2h point symmetry, the IR and Raman spectra are assigned by normal coordinate analysis based on a modified valence force field. Good agreement between observed and calculated frequencies is obtained with the valence force constants fd(TcCl) = 1.45, fd(TcBr) = 1.035, fd(TcN) = 1.37 (X = Cl) and 1.45 mdyn/ Å (X = Br), respectively.  相似文献   

19.
The new compounds K2Au2Ge2S6 ( 1 ), K2Au2Sn2Se6 ( 2 ), and Cs2Au2SnS4 ( 3 ) have been synthesized through direct reaction of the elements with a molten polyalkalithiogermanate(stannate) flux at 650, 550, and 400 °C, respectively. Their crystal structures have been determined by single crystal X-ray diffraction techniques. 1 crystallizes in the monoclinic space group P21/n with a = 10.633(2) Å, b = 11.127(2) Å, c = 11.303(2) Å, β = 115,37(3)°, V = 1208,2(3) Å3 and Z = 4, final R(Rw) = 0.045(0.106). 2 crystallizes in the tetragonal space group P4/mcc with a = 8.251(1) Å, c = 19.961(4) Å, V = 1358,9(4) Å3 and Z = 4, final R(Rw) = 0.040(0.076). 3 crystallizes in the orthorhombic space group Fddd with a = 6.143(1) Å, b = 14.296(3) Å, c = 24.578(5) Å, V = 2158.4(7) Å3 and Z = 4, final R(Rw) = 0.039(0.095). The structures of 1 , 2 , and 3 consist of infinite, one-dimensional anionic chains containing X2Q64– units linked by Au+ ions and charge balancing K+/Cs+ ions situated between the chains. All compounds were investigated with differential thermal analysis, FT-IR, and solid state UV/VIS diffuse reflectance spectroscopy.  相似文献   

20.
On the Low Temperature Modifications of Ag6Si2O7 and Ag6Ge2O7 – Synthesis, Crystal Structure, and Comparison of Ag? Ag Distances For the first time, single crystals of Ag6Si2O7 and Ag6Ge2O7 have been obtained by solid state reactions of the binary oxides at temperatures of 350°C while applying oxygen pressures of 700 bar. According to the results of X-ray crystal structure determinations both compounds crystallize isostructural in P21 (Ag6Si2O7: a = 5.3043(5) Å, b = 9.7533(7) Å, c = 15.9283(13) Å, β = 91.165(8)°, 3881 independent reflections, R1 = 3.3%, wR2 = 7.2%; Ag6Ge2O7: a = 5.3713(4) Å, b = 9.9835(8) Å, c = 16.2249(14) Å, β = 90.904(8)°, 2111 independent reflections, R1 = 4.3%, wR2 = 6.0%, Z = 4). The crystal structures contain two independent M2O76? anions, one in a staggered, and the other in an ecliptic conformation. The cationic partial structure may be described as a distorted bcc arrangement of Ag+ and M4+. Comparison of the structures with respect to the Ag? Ag separations reveals the latter to be probably due to intrinsic d10–d10 bonding interactions as far as the range of 2.89 Å to 3.25 Å is considered.  相似文献   

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