Crystal and molecular structure of the monoclinic modification of Mn(S2CO-i-C3H7)2(2,2’-bipy)

The crystal and molecular structure of modification II of the Mn(S₂CO-i-C₃H₇)₂(2,2’-Bipy) complex was determined from X-ray diffraction data (“Syntex P2₁” diffractometer, CuK_α radiation, 1603 F(hkl), R = 0.0446). The crystals are monoclinic,a = 23350(3),b = 9.325(1),c = 22.030(2) å, Β = 106.98(1)?,V = 4587.7 å³, Z =8, d _calc = 1.394 g/cm³, space group C2/c. The structure consists of monomeric molecules in which the manganese atom has a distorted octahedral environment (4S + 2N). The orthorhombic and monoclinic modifications of the complex are compared with respect to the molecular geometry and packing.     

Crystal and molecular structure of the mixed-ligand complex Zn[S2CN(CH3)2]2Phen

The crystal and molecular structure of the mixed-ligand complex Zn[S₂CN(CH₃)₂]₂Phen is determined by single crystal X-ray diffractometry (CAD-4 diffractometer, MoK_α radiation, 3347 F(hkl), R = 0.0385). The crystals are monoclinic, a =13.340(3), b =13.827(3), c =24.698(5) å, Β =102.58(3)? V = 4446(2) å ³, Z = 8, d_calc = 1.452 g/cm³ , space group C2/c. The structure consists of monomeric molecules in which the zinc atom has a distorted octahedral environment (4S+2N). The molecular packing in the crystal involves dimers related by the 2 rotation axis and forming continuous chains along the c axis.     

Redetermination of the crystal structure of potassium peroxodisulfate (K2S2O8)

The crystal structure of potassium peroxodisulfate was determined. The crystals are triclinic, a =5.115(1),b =7.034(2), c =5.505(1) å, α =106.32(2),gb =90.18(2), γ =106.12(2)?, V_cell = 181.90(7) å³, space group Pī, Z =1, d_calc =2.468 g/cm ³ [“Syntex P2₁,” λCuK_α, 994 reflections measured in a whole sphere to 2Τ_max =114?, including 496 independent reflections (R_int = 0.0571), R(F) = 0.0391, wR(F²) = 0.0933 for 486 F_hkl > 4Σ(F)]. An absorption correction (Μ = 171.37 cm^?1) was applied taking into account the shape and size of the crystal using data about face indices. The representative of the single crystal was proven by comparing the experimental and calculated diffractograms. The geometrical characteristics of S₂O ₈ ² : S-O 1.645(2), S = 0 1.421(3)-1.429(2), O-O 1.495(5) å, S-O-O 106.2(2)?.     

Solid-state structure determination and solution-state NMR characterization of the (2R,4R)/(2S,4S)- and (2R,4S)/(2S,4R)-diastereomers of the agricultural fungicide propiconazole,the (2R,4S)/(2S,4R)-symmetrical triazole constitutional isomer,and a ditriazole analogue

Single-crystal X-ray diffraction analysis was used to determine the structure of a racemic diastereomer of the agricultural fungicide propiconazole [1-(2-(2,4-dichlorophenyl)-4-n-propyl-1,3-dioxolane-2-yl-methyl)-1-H-1,2,4-triazole] and of two by-products (a symmetrical 1,3,4-triazole racemic-constitutional isomer and a propiconazole ditriazole analogue). All three crystalline racemic-diastereomers had (2R,4S)/(2S,4R)-stereochemistry in which then-propyl group was observed in atrans-to-phenyl disposition. Propiconazole (2R,4S)/(2S,4R)-diastereomer gives crystals belonging to the monoclinic space group P2₁,/a, and, at 293 K,a=8.1192(3),b=18.9769(6),c=10.7137(4) å,Β=99.765(3)?,V=1626.8(1) å³, Z=4,R(F)=0.060, andR _w(F)=0.058. The constitutional isomer by-product (2R,4S)/(2S,4R)-1-(2-(2,4-dichlorophenyl)-4-n-pro-pyl-1,3-dioxolane-2-yl-methyl)-1-H-1,3,4-triazole gives crystals belonging to the monoclinic space group P2₁/n, and, at 293 K,a=11.1763(6),b=10.7716(4),c=14.5804(8) å,Β=107.445(4)?,V=1674.6(1) å³, Z=4,R(F)=0.043, andR _w(F)=0.043. The ditriazole byproduct (2R,4S)/(2S,4R)-1-(2-(2-chloro-4-(1,2,4-triazole-1-yl)phenyl)-4-n-propyl-1,3-dioxolane-2-yl-methyl)-1-H-1,2,4-triazole gives crystals belonging to the triclinic space groupP¯ 1, and, at 193 K,a=5.3329(8),b=8.3738(7),c=20.240(2) å, α=84.213(6)?,Β=87.20(1)?,γ=86.23(1)?,V=896.5(2) å³, Z=2,R(F)=0.046, andR _w(F)=0.051. The presence of both propiconazole (2R.4S)- and (2S,4R)-enantiomers enables the formation of a crystalline racemic modification, while the diastereomeric propiconazole (2R,4R)- and (2S,4S)-enantiomers are viscous oils. In the absence of its enantiomorphic partner, the propiconazole (2R,4S)- or (2S,4R)-enantiomers remain as viscous oils rather than form chiral crystals.     

Crystal structure of kuznetsovite Hg3(AsO4)Cl

The crystal structure of a rare supergene mineral kuznetsovite Hg₃(As0₄)Cl, previously determined from powder data, is refined (space group P2₁3, a = 8.379(3) å, V = 588.3(4) å⁰³, Z = 4, d_calc = 8.763 glcm³, 3.44 < θ < 24.96?, 563 I_hkl(msd)/211 I_hkl(indep), R₁ = 0.0997, wR₂ = 0.2515). It is formed from the Cl^? and (AsO₄)^3- anions (As-O 1.74(3) and 1.79(1) å) and the trigonal cations Hg ₃ ⁴⁺ (Hg-Hg 2.675(5) å, HgHgHg 60?). The coordination polyhedron around each mercury atom involves two mercury atoms, two oxygen atoms at short Hg-0 distances (2.17(3) and 2.28(3) å, < OHgO 94.3(13)?), and more remote oxygen and chlorine atoms (Hg-0 2.601(6) å, Hg-Cl 2.838(9) å). The polyhedron is irregular and close to a trigonal antiprism. The Hg₃ triangles alternate with AsO₄ tetrahedra along each coordinate axis. Taking into consideration only short Hg-0 bonds (2.17(3) and 2.28(3) å), one can isolate a framework with chlorine ions lying in the cavities.     

Structure of tetrakis-pivaloyltrifluoroacetonates of heavy rare earth elements and sodium. Crystal structure of NaEr(C8H10O2F3)4

The structure of a compound from an isostructural series of pivaloyltrifluoroacetonates of heavy rare- earth elements (REE) (Cd- Lu) and sodium, NaEr(C₈H₁₀O₂F₃)₄, was studied by X- ray diffractometry (“Syntex P2₁,” λMoK_α, 1891 reflections, R =0.0601);a =13.114(4), c =21.004(9) å, V =3128(2) å ³, Z =3,space group P3 ₁. The structures of this series are of ionic type and contain the [Ln(pta) ₄]^? complex anion and the Na⁺ cation. The coordination polyhedron of Ln is a tetragonal antiprism, an ssss stereoisomer. Na is surrounded by 4O +4F in the form of an octahedron with two centered faces. Both polyhedra are distorted (average Er- 0 distances are 2.325 å, Na- O 2.397 å, Na- F 2.682 å) and linked by common faces into polymeric helicoidal ribbons extended along the c axis and arranged according to the closest packing law. It is established that the Na cation affects the stereochemistry of the anion. A relationship between the structure of the compound and its volatility and crystal morphology is discussed.     

Synthesis and crystal structure determination of iridium(III) acetylacetonate and its Br-and I-substituted analogs

γ-Halogen-substituted iridium(III) acetylacetonates of general formula Ir(acacX)₃,where acacX = CH₃ -CO-CX-CO- CH₃,X =Br, I, were synthesized. The compounds are characterized by melting points and chemical analysis data for C, H, Br, and I. An X-ray diffraction analysis was performed for iridium(III) acetylacetonate and its y-substituted analogs, crystal data were obtained, and crystal structures were determined. The crystals are monoclinic;the structures are molecular. Crystal data: Ir(acac)3 _- IrO₆C₁₅H₂₁,a = 13.900(2), b = 16.440(3), c = 7.494(2) å, γ =98.63(2)?, V= 1693.2 å³,space group P2₁/b,Z = 4, d_calc =1.92 g/cm³,sin θ/λ_max = 0.703, F_hkl = 2841, R = 0.044. Ir(acacBr)_3- IrBr₃O₆C₁₅H₁₈,a = 12.794(2), b = 15.753(2), c = 9.990(2) å Β = 105.76(2)?, V= 1937.6 å³,space group P2₁/n,Z =4, d_calc =2.49 g/cm³, sinθ/λ_max = 0.702, F_hkl = 1748, R = 0.048. Ir(acacI)3- M₃O₆C₁₅H₁₈,a = 12.855(2), b = 10.136(2), c =16.338(3)å, Β = 104.6(2)?, V=2059.8å³,space group P2₁/n, Z =4, d_calc = 2.79g/cm³, θ_max =25?, F_hkl = 2817, R =0.032. The Ir..Ir distances were estimated to be > 7.49 å for Ir(acac)3 and > 8.10 å for Ir(acacBr)3 and Ir(acacl)₃.If the estimate is limited to 10 å, the intermolecular coordination number (ICN) in the structures is 10.     

Crystal structure of (Et4N) [(µ-H)Fe3(µ3-Se)(CO)9]

The crystal structure of (Et₄N)[(μ-H)Fe₃(μ₃-Se)(CO)₉] is determined;the crystals are monoclinic, a = 11.172(2), b =32.332(5), c =13.552(3) ?, μ =91.86(2)‡, V _cell =4893(2) ? ³, space group P2₁/n, Z =8, d _calc =1.710 g/cm ³, CAD-4 diffractometer, MoK_α radiation;the total number of data collected 4395,including 4086 independent reflections(R_int =0.0701), R(F) =0.0566, wR(F ²) =0.1202 for 1963 F _hkl > 4Σ(F). The data were corrected for the 37.8% linear drop of intensities of the control reflections due to crystal decay. The Fe-H bond lengths are 1.5(1)-1.72(9) ?. As in the case of three-osmium clusters,the presence of the Μ-H ligand leads to a lengthening of the Fe-Fe bond by approximately 0.1 ? and to push-away of the equatorial carbonyl ligands leading to an increase in the FeFeC angle by approximately 5–10‡, whereas the axial CO and (Μ ₃-Se) remain unchanged.     

New structure type in the morphotropic series of A 2 + M 2 2+ (MoO4)3: crystal structure of Rb2Cu2(MoO4)3

Isostructural compounds A₂Cu₂(MoO₄)₃ (A = Rb, Cs) were synthesized. The new structure type of the compounds was established for the rubidium-containing compound as an example (a =27.698,b =5.102,c =19.292 å, Β = 707.26?,Z = 8, space group C2/c, R = 0.016). The structure is characterized by pairs of infinite wolframite-like ribbons of CuO₍₄₊₂₎ octahedra stretching along [010] and additionally bridged by MoO₄ tetrahedra. The tetrahedra located between the ribbons weakly interact with each other at distances Mo-O of 2.545 and 2.853 å. There are four such quasione-dimensional copper-molybdenum-oxygen radicals per unit cell; the radicals are united into a single structure by rubidium ions having coordination numbers (CN) 9 and 10.     

Synthesis, crystal structure, and vibrational spectra of MVO(SO4)2 (M = Rb, Cs, or Tl)

A series of MVO(SO₄)₂ vanadium complexes, where M = Rb, Cs, or Tl, were prepared, and their crystal structures and physicochemical properties studied. The rubidium and thallium compounds of this series were found to be isostructural to each other and to crystallize, like KVO(SO₄)₂ and NH₄VO(SO₄)₂, in orthorhombic system (space group P2₁2₁2₁, No. 19, Z = 4) with the unit cell parameters a = 4.9735(2) Å, b=8.7894(4) Å, c = 16.6968(8) Å, V = 729.88 ų (Rb); and a = 4.9636(1) Å, b = 8.7399(2) Å, c = 16.8598(4) Å, V = 731.39 ų (Tl). The cesium compound was found to crystallize in monoclinic system (space group P2₁/a, No. 14-2, Z = 4): a = 10.0968(6) Å, b = 8.9131(4) Å, c = 9.8675(5) Å, β = 114.640(2)°, V = 807.16 ų. The MVO(SO₄)₂ crystal structure is built of VO₆ octahedra, which are linked into layers by bridging SO₄ groups. At the apex of each VO₆ octahedron, there is a short V-O terminal bond having a length of 1.54(1) Å (Rb), 1.57(2) Å (Tl), and 1.52(4) Å (Cs).     

Synthesis and x-ray crystal structure of OsBr2(CNBut)4·2CH2Cl2

Reaction of (NH₄)₂OsBr₆ with excess Na/Hg in THF in the presence of excess ^tBuNC yields trans-OsBr₂(CNBu^t)₄ in high yield. The bis-dichloromethane solvate crystallises from CH₂Cl₂ solutions and its X-ray crystal structure has been determined. Crystal data: C₂₂H₄₀Br₂Cl₄N₄Os, M = 852.40, monoclinic, space group P2₁/c, a = 9.702(3) Å, b = 10.143(5) Å, c = 18.497(5) Å, β = 104.28(3)°, U = 1764(1) ų, Z = 2 for D_c = 1.60 gcm^?3. λ(MoK_α) = 0.71069 Å (graphite monochromator), μ(MoK_α) = 65.44 cm^?1, final R = 0.044, R_w = 0.056 from 1105 observed reflections (1777 measured).     

Synthesis and crystal structure of cadmium(II) complex with 2-pyrimidinecarboxamide

The complex [Cd(N₂H₃C₅ONH₂)₂(CH₃COO)₂] (I) was synthesized and its structure was determined. The crystals are monoclinic: space group C2/c, a = 14/416(1), b = 9.410(1), c = 13.708(1) Å, β = 113.82(1)°, V = 1701.0(1) ų, ρ(calcd.) = 1.862 g/cm³, Z = 4. The structure consists of individual complexes I united by the N-H…O hydrogen bonding system into supramolecular framework. The coordination sphere of the cadmium atom (on axis 2) involves two chelate pyrimidinecarboxamide ligands, which form five-membered chelate rings CdOCCN(Cd-N(2) 2.432(4), Cd-O(3) 2.388(4) Å), and two monodentate CH₃COO^? ions (Cd-O(1) 2.280(3) Å). The second O atom of the acetate group is involved in a weak contact with the Cd²⁺ ion (Cd-O 2.670(4) Å). With account for the latter two contacts, the coordination polyhedron of Cd is irregular octahedron.     

Phase equilibria in the Tl2MoO4-Nd2(MoO4)3-Hf(MoO4)2 system and the crystal structure of double molybdate TlNd(MoO4)2

The Tl₂MoO₄-Nd₂(MoO₄)₃-Hf(MoO₄)₂ system was studied in the subsolidus region using X-ray powder diffraction. New triple molybdates were found to exist in this system: Tl₅NdHf(MoO₄)₆ (5: 1: 2), TlNdHf_0.5(MoO₄)₃ (1: 1: 1), and Tl₂NdHf₂(MoO₄)_6.5 (2: 1: 4). The first TlNd(MoO₄)₂ single crystals were grown from melt solutions with spontaneous nucleation. Their crystal structure was refined from X-ray diffraction data (Bruker X8 Apex automated diffractometer, MoK _α radiation, 386 F(hkl), R = 0.0136). The tetragonal unit cell parameters are as follows: a = 6.3000(2) Å, c = 9.5188(5) Å, V = 377.80(3) ų, Z = 2, ρ_calcd = 5.876 g/cm³, space group P4/nnc. The structure is a framework built of NdO₈ and TlO₈ tetragonal antiprisms linked via shared lateral edges and alternating in the checkerboard order. Layers share oxygen vertices with MoO₄ interlayer tetrahedra and are linked into the framework.     

Specific nonbonding interactions in the structure of (N2H5)2[Mo3S7I6]·1.5H2O

The crystal structure of (N₂H₅)₂[Mo₃S₇I₆]· 1.5H₂O is investigated;triclinic crystals, a-10.029(2), b = 10.258(3), c =14.152(2) å, a =109.21(2), Β =106.14(1), γ =98.97(2)?, V _cell =1270.6(5) å ³, space group P1, Z =2, d _calc =3.572 g/cm ³, CAD-4 diffractometer, λMoK_α, 2θ_max =50?, N _tot =4118, R(F) = 0.0554, wR(F²) = 0.1365 for 3057 F_hkl 4Σ(F). The cluster onions are united into centrosymmetric dimers with distances 3S_ax...I 3.324(5)-3.473(4) å. The dimers, in turn, form a three-dimensional framework with cations and solvate water molecules in the cavities due to additional contacts S_eq...I and S_ax...I 3.624(4)-3.785(4) å. The hydrogen bonds formed in the structure are N(N₂H₅)...O(H₂O) and N(N₂H₅)...I 2.78(4)-2.96(8), 3.64(3)-3.75(3) å. The nonbonding interactions completely determine the crystal structure.     

Synthesis and structure of complex compound Rh(III) of (NH4)2[Rh(NO2)3(NH3)(µ-OH)]2 composition

The crystalline structure of a new compound Rh(III) of (NH₄)₂[Rh(NO₂)₃(NH₃)(μ-OH)]₂ composition has been determined. The crystallographic characteristics are H₁₆N₁₀O₁₄Rh₂: a = 6.3963(2) Å, b = 9.3701(4) Å, c = 13.6646(5) Å, β = 102.266(1)°, V = 800.28(5) ų, Z = 2, d _calc = 2.432 g/cm³. The distance Rh...Rh in the dimer is 3.200 Å. Original Russian Text Copyright ? 2006 by S. P. Khranenko, I. A. Baidina, and S. A. Gromilov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 47, No. 2, pp. 380–384, March–April, 2006.     

Coordination compounds of cobalt(II) and cadmium(II) with 2-amino-4-methylpyrimidine: Synthesis, crystal structure, and luminescent properties

The coordination compounds [CoL₂Cl₂] (I) and [CdL₂(H₂O)₂(NO₃)₂] (II) have been synthesized by the reaction of CoCl₂ · 6H₂O and Cd(NO₃)₂ · 4H₂O with L = 2-amino-4-methylpyrimidine (Ampym, C₅H₇N₃), and their structures have been solved. The crystals of complex I are triclinic, space group $P\bar 1$ , a = 5.627(1) Å, b = 11.191(1) Å, c = 12.445(1) Å, α = 81.00(1)°, β = 77.21(1)°, γ = 76.18(1)°, V = 737.7(2) ų, ρ_calcd = 1.567 g/cm³, Z = 2. The crystals of complex II are monoclinic, space group P2₁/c, a = 10.390(1) Å, b = 11.982(1) Å, c = 7.624(1) Å, β = 102.61(1)°, V = 926.1(2) ų, ρ_calcd = 1.760 g/cm³, Z = 2. Discrete [CoL₂Cl₂] moieties are realized in the structure of complex I. The cobalt atom is tetrahedrally coordinated to the two nitrogen atoms of crystallographically nonequivalent ligands L and two chlorine atoms (Co(1)-N_avg, 2.051(4)Å; Co(1)-Cl(1), 2.241(1) Å; Co(1)-Cl(2), 2.263 Å; bond angles at the cobalt atom lie within a range of 102.1°–118.6°). The complexes are linked into supramolecular zigzag chains by N-H...N(Cl) hydrogen bonds. In the structure of complex II, the Cd²⁺ ion (at the inversion center) is coordinated in pairs to the nitrogen atoms of ligand L and the O(NO₃) and O(H₂O) oxygen atoms. The coordination of the Cd²⁺ ion is distorted octahedral (Cd(1)-N(1), 2.341Å; Cd(1)-O(1), 2.340(4) Å; Cd(1)-O(4), 2.327(3) Å; bond angles at the cadmium atom lie within a range of 79.1°–100.9°). N-H...N hydrogen bonds link the complexes into supramolecular chains. These chains are linked into a supramolecular framework by the O-H...O hydrogen bonds between water molecules and NO₃ groups.     

A new type of mixed framework in the crystal structure of binary molybdate Nd2Zr3(MoO4)9

Single crystals of binary molybdate Nd₂ZrMoO₄)₉ were grown. The crystal structure of this compound was investigated by X-ray diffraction analysis (CAD-4 diffractometer, MoKα radiation, 2844 reflections. R = 0.0230), and a new type of structure was found. The crystals are trigonal with cell dimensions a = 9.804(1), c = 58.467(12) å, V= 4867(1) å³, Z = 6, d_calc = 4.098 g/cm₃, space group R ₃ ^? c. The structure involves polyhedra of three types: MoO₄ tetrahedra, ZrO₆ octahedra, and NdO₉ tricapped trigonal prisms linked by their common vertices into an original three-dimensional framework.     

Copper(II) Halide Complexes of 2-Aminopyrimidines: Crystal Structures of [(2-aminopyrimidine) n CuCl2] (n=1,2) and (2-amino-5-bromopyrimidine)2CuBr2

The reaction of CuX₂(X=Cl, Br) with 2-aminopyrimidine in aqueous solution, or 2-amino-5-bromopyrimidine in aqueous acid yields compounds of the forms [LCuCl₂] _n (1), [L₂CuCl₂] (2) and [L'₂CuBr₂] (3) [L=2-aminopyrimidine; L'=2-amino-5-bromo-pyrimidine]. The three compounds all form layered structures in which each copper ion is coordinated to two 2-aminopyrimidine molecules and two halide ions. Common structural threads involve bridging ligation [either by monomeric (1) or hydrogen bonded ligand dimers (2 and 3)], N-H···X and N-H···N hydrogen bonding and π-π stacking interactions as well as semi-coordinate Cu···X bond formation (1 and 2) or Br···Br interactions (3). Compounds 1 and 2 crystallize as two-dimensional coordination polymers with asymmetrically bihalide bridged (CuX₂) _n chains cross-linked into sheets by the 2-aminopyrimidine molecules (1) or by hydrogen bonded L₂ dimers (2). The halide bibridged chains expand their primary copper coordination spheres to give 4 + 2 coordination spheres in 1 and 2. In 3, the layer structure involves coordination of the hydrogen bonded L'₂ dimers and C-Br···Br- interactions. Crystal data: (1): monoclinic, P2₁/m, a=3.929(1), b=12.373(2), c=7.050(1)å, β=91.206(4)°, V=342.7(1)&Aringsup3;, Z=2, D _calc= 2.225Mg/m³, μ=3.878 mm^-1, R=0.0269 for [|I|≥3σ(I)]. For (2): triclinic, P-1, a=4.095(4), b=7.309(5), c=10.123(6) å, α=86.28(6), β=78.44(6), γ=74.55(8)°, V=286.1(4) ų, Z=1, D _calc=1.884 Mg/m³, μ=2.360 mm^-1, R=0.0506 for [|I|≥2σ(I)]. For (3): triclinic, P-1, a=6.074(4), b=7.673(3), c=8.887(3) å, α=108.43(3) β=100.86(5), γ=106.96(4)°, V=357.0(3) ų, Z=1, D _calc=2.657 Mg/m³, μ=12.714mm^-1, R=0.0409 for [|I|≥2σ(I)].     

Monomeric five-coordinate rhenium diazenido and hydrazido complexes with aromatic thiolate ligands: X-ray structures of [Re(NNC6H4-Br)2(SC6H3-2,5-Me2)(PPh3)2] and [ReO(NNMePh)(SPh)3], and of the synthetic precursor [Re(NNC6H4-4-Br)2Cl(PPh3)2]

Reaction of [ReOCl₃(PPh₃)₂] with bromophenylhydrazine in methanol yields [ReCl(N₂C₆H₄Br)₂(PPh₃)₂] (1). Complex 1 reacts with arylthiolates to give mixtures of [Re(SAr)(N₂C₆H₄Br)₂(PPh₃)₂] (2) and [Re₂(SAr)₇(NNR)₂]⁻. Complexes 1 and 2 display trigonal bipyramidal geometries with the phosphine ligands occupying the axial sites. A significant feature of the structures is the nonequivalence of the rhenium-diazenido moieties, such that for 1 the ReN(1) and N(1)N(2) distances are 1.80(2) and 1.24(3) Å, while ReN(3) and N(3)N(4) are 1.73(2) and 1.32(3) Å, and for 2 the ReN distances are 1.73(1) and 1.80(2)° with corresponding NN distances of 1.32(2) and 1.25(2) Å. Reaction of (PPh₄)[ReO(SPh)₄] (3) with unsymmetrically disubstituted hydrazines affords complexes of the type [ReO(SPh)₃(NMRR′)] (R = Me, R′ = Ph for 4). Complexes 3 and 4 display distorted square pyramidal geometries with the oxo groups apical. The significant feature of the structure of 4 is the nonlinear ReN(1)N(2) linkage, exhibiting an angle of 145.6(10)°. The angle does not appear to correlate with a significant contribution from a valence form with sp² hybridization at the α-nitrogen. Crystal data: 1: monoclinic space group, P2₁/n, a = 12.216(2) Å, b = 19.098(2) Å, c = 20.257(4) Å, β = 106.20(1)°, V = 4538.3(8) ų to give Z = 4; structure solution and refinement based on 1905 reflections converged at R = 0.070. 2: monoclinic space group P2₁/n, a = 14.393(2) Å, b = 18.842(3) Å, c = 20.717(4)Å, β = 110.26(1)°, V = 5270.5(8) ų to give Z = 4 for D = 1.53 g cm⁻¹; structure solution and refinement based on 4249 reflections to give R = 0.070. 3: monoclinic space group P2₁/n, a = 12.531(2) Å, b = 24.577(4) Å, c = 16.922(3) Å, β = 99.06(1)°, V = 5146.2(9) ų, D = 1.36 g cm⁻³ for Z = 4, 2912 reflections, R = 0.050. 4: monoclinic space group p2₁/n, a = 16.137(2) Å, b = 9.863(2) Å, c = 16.668(2) Å, β = 111.12(1)°, V = 2474.7(6) ų, D = 1.74 g cm⁻³ for Z = 4, 2940 reflections, R = 0.066.     

Structural chemistry of bimetallic hydride complexes of titanium and aluminium: I. Crystal and molecular structure of [(η5-C5H5)2,Ti(μ-H)2AlH2]2(CH3)2NCH2CH2N(CH3)2C6H6

The structure of a titanium aluminium hydride complex of composition [(C₅H₅)₂TiAlH₄]₂(CH₃)₂NC₂H₄N(CH₃)₂C₆H₆ has been determined by X-ray diffraction. The complex forms triclinic crystals with unit cell dimensions a = 8.406(2), b = 10.117(2), c = 11.269(3) Å; α = 112.01(2)°, β = 109.25(2)°, γ = 87.04(2)°, space group P$\text{1}$, Z = 2 and density d = 1.21 g/cm³. The structure was refined to give a discrepancy index R = 0.056. The crystals are composed of centrosymmetric molecules of (Cp₂TiAlH₄)₂TMEDA (Cp = η⁵-cyclopentadienyl) and molecules of crystal benzene. Two moieties of Cp₂TiH₂AlH₂ are linked by a tetramethylethylenediamine molecule (r_AlN 2.11 Å). The aluminium atom is bonded to a titanium atom by a double hydride bridge (r_AlH b = 1.8, 1.6 Å, r_TiH b = 1.6 Å), and has trigonal bipyramidal stereochemistry, [H₄N] (r_AlH t = 1.6 Å).