The crystal structure of 4,4′-dipyridinium tetracyanooxothiocyanatorhenate(V)

Summary The light purple crystals of (4,4-dipyridinium) [ReO(NCS)(CN)₄] crystallize in the monoclinic space group P2₁/m witha=6.615(1),b=16.043(1),c=8.405(1) Å,=93.20(1)°,z=2. The anisotropic refinement of the 1770 observed reflections converged to R=0.041.The [ReO(NCS)(CN)₄]^2– ion has a distorted octahedral geometry. The rhenium atom is displaced by 0.30 Å out of the plane formed by the four carbon atoms towards the terminal oxo ligand. Bond distances: Re=0 =1.67(1), Re–N=2.12(1) and Re–C_av=2.11(1)Å. The thiocyanate ion is nitrogen bonded to the rhenium atom.     

The crystal structure of tetraphenylphosphonium tetracyanohydroxooxorhenium(V)

Summary The crystal structure of (PPh₄)₂[ReO(OH)(CN)₄]·5H₂O has been determined from three-dimensional x-ray diffraction data. The light brown crystals are monoclinic, space group P2₁/n, with cell dimensionsa=16.753(2),b=19.928(2),c=15.338(2) Å and =101,894(1)°,z=4, D_m=1.45(1) g cm^–3. The anisotropic refinement of the 6088 observed reflections converged to R=0.077.The [ReO(OH)(CN)₄]^2– ion has a distorted octahedral geometry. Bond distances: Re =1.70(1), Re–OH=1.90(1) and ReC_av=2.12(2) Å. The Re atom is displaced by 0.08 Å out of the plane formed by the four carbon atoms towards the terminal oxo ligand.     

The crystal structure of bis(1,4-dithioniumdicyclo-[2,2,2]-octane) μ-oxo-bis[tetracyanooxorhenate(V)]tetrahydrate

Summary The structure of [S(CH₂CH₂)₃S]₂[Re₂O₃(CN)₈]·4H₂O has been determined from three-dimensional x-ray diffraction data. The blue crystals are monoclinic, space group P2₁/c, with cell dimensionsa=9.431(2),b=10.879(2),c=16.217(3)Å, =110.84(2)°,Z=2 andD _m=2.11 gcm^–3. Anisotropic refinement by least-squares methods of 2483 observed reflections converged toR=0.050.The centrosymmetric binuclear anion has a linear O=Re–O–Re=O grouping with an eclipsed configuration for the cyano ligands. Bond distances: Re–O (terminal)=1.69(1), Re–O (bridging)=1.921(1) and Re–C_av=2.12(2)Å. Each Re atom is displaced by 0.11(2)Å towards the terminal oxygen atom giving a slight square-pyramidal distortion of the octahedral environment. The ring-constrained cation has C–S_av=1.82(2)Å with averaged bond angles C–S–C=101(1) and S–C–C=113(1)°.     

Kinetic and equilibrium study of substitution reactions oftrans-tetracyanodioxorhenate(V) ions with monodentate nucleophiles

Summary The kinetics of the substitution reactions of the protonated froms oftrans-tetracyanodioxorthenate(V) with thiourea (TU),N-methylthiourea (NMTU),N, N-dimethylthiourea (NNDMTU) and hydrazoic acid (HN₃) were studied. The results were compared with those obtained for similar reactions of [WO₂(CN)₄]^4–. This study showed that the diprotonated form [ReO(H₂O)(CN)₄]^– is the only species reactive towards substitution reactions (and not the [ReO(OH)(CN)₄]^2– ion) and that only the aqua ligand in [ReO(H₂O)(CN)₄]^– is substituted by the incoming group. A dissociative mechanism is proposed for the substitution reactions between [ReO(H₂O)(CN)₄]^– and the monodentate nucleophiles. The i.r. data for these Re^v complexes are reported and discussed in terms of the relativetrans influence of the various monodentate ligands.     

The crystal structure of tetraphenylphosphonium pentacyanonitridorhenate(V), (PPh4)3[ReN(CN)5]·7H2O

Summary The crystal structure of (PPh₄)₃[ReN(CN)₅]·7H₂O has been determined from three dimensional X-ray diffraction data. The orange crystals are triclinic, space group , with cell dimensions a=12.514(3), b=15.8514), c=19.030(3) Å, =77.62(2), =84.61(1) and =74.03(2)^o, z=2, D_obsd=1.40(1) g cm^–3 and D_calc=1.37(1) g cm^–3. The anisotropic refinement of 5861 observed reflections converged to R=0.049.The [ReN(CN)₅]^3– ion has a distorted octahedral geometry. Bond distances: ReN=1.68(1), Re–C_av (planar)=2.12(1), Re–C (axial)=2.39(1) Å. The Re atom is displaced by 0.31 Å out of the plane formed by the four carbon atoms towards the nitrido ligand.     

The crystal structure of caesium tetracyanodioxoosmate(VI) Cs2[OsO2(CN)4]

Summary The crystal structure of the caesium salt of [OsO₂(CN)₄]^2– has been determined from three-dimensional x-ray diffraction data. The orange crystals are monoclinic, space group C2/m with a=12.125(2), b=8.284(1), c=5.457(1) Å, =102.01(1)° with two molecules per unit cell. The final R value using 778 observed reflections and anisotropic thermal parameters for all atoms was 0.028. The [OsO₂(CN)₄]^2– ion has an octahedral geometry. Bond distances: Os=O=1.750(8)Å and Os–C=2.093(9)Å.     

Synthesis,protonation and substitution behaviour of K3[ReO2(CN)4]

Summary The preparation and characterization of salts of the [ReO₂(CN)₄]^3–, [ReO(OH)(CN)₄]^2–, [ReO(H₂O)(CN)₄]^–, [Re₂O₃(CN)₈]^4– and [ReO(NCS)(CN)₄]^2– species are described. The nature of the protonation reactions of [ReO₂(CN)₄]^3– was established by the successful isolation of these salts.     

Synthesis,crystal structures and physical properties of two terephthalate-bridged copper(II) and nickel(II) complexes

Two ₂-terephthalate (tp) bridged complexes, [Cu₂(tp)(pren)₄](ClO₄)₂ (pren = 1,3-diaminopropane) (1) and [Ni₂(tp)(pren)₄(Him)₂](ClO₄)₂ (Him = imidazole) (2), have been synthesized and characterized by X-ray single-crystal structural analysis. In the discrete dinuclear [Cu₂(tp)(pren)₄]²⁺ cation of complex (1), each Cu^II atom has a square-pyramidal geometry, being coordinated by four nitrogen atoms (avg. 2.031 Å) from two pren ligands at the basal plane and one oxygen atom [2.259(3) Å] from a bis-monodentate tp group at the axial position. In the discrete dinuclear [Ni₂(tp)(pren)₄(Him)₂]²⁺ cation of complex (2), each Ni^II center is coordinated by five nitrogen atoms [Ni—N 2.069(3)–2.109(2) Å] from one Him group and two pren groups, and completed by one oxygen atom [Ni—O 2.138(3) Å] from a bis-monodentate tp group to furnish a distorted octahedron. Magnetic susceptibility studies show that the pair of metal atoms, although being separated by >11.5 Å, exhibit weak intramolecular antiferromagnetic interactions in complexes (1) (g = 2.07 and J = –3.4 cm^–1) and (2) (g = 2.10 and J = –0.7 cm^–1). The electrochemical behaviors of the complexes have also been studied by cyclic voltammogram processes.     

Crystal Structure of Calcium [Aqua(Nitrilotriacetatocobaltate(II)] Tetrahydrate,Ca[Co(Nta)(H2O)]2· 4H2O

Crystals of Ca[Co^II(Nta)]₂· 6H₂O (I), where Nta^3–is a nitrilotriacetate ion, were synthesized and studied using X-ray diffraction analysis. They were found to be monoclinic: a= 6.991(1), b= 10.031(1), c= 16.238(3) Å, = 98.50(1)°, V= 1126.2(3) ų, space group P2₁/n, Z= 2, R ₁= 0.0241, wR ₂= 0.0636, GOOF = 1.050 (for 3132 reflections with I> 2(I)). Structure Iis composed of {[Co(Nta)(H₂O)]^–}₁anion chains united by Ca²⁺cations into a three-dimensional framework. The coordination polyhedra of Co and Ca atoms are distorted octahedra. The Co(II) atom environment includes atoms N(1), O(1), O(3), and O(5) of one Nta^3–ligand, a carbonyl O(2)" atom of the neighboring anion fragment, and an O(w1) atom of the water molecule. The shortest bond is formed by the Co atom with the bridging O(2)" atom in trans-position relative to atom N(1). The Co–O(2)" distance (2.029 Å) is noticeably shorter than the other bond lengths, Co–O(Nta) (2.069–2.103 Å), Co–O(w1), and Co–N(1) (2.155 and 2.177 Å, respectively). Cations Ca²⁺are located in the inversion centers and involve in their coordination atoms O(4), O(6), O(w2), and the oxygen atoms symmetrically bond to them and arranged at 2.271(1), 2.420(1), and 2.351(2) Å, respectively. The structural formula of the title compound is {Ca(H₂O)₂[Co(Nta)(H₂O)]₂}₃· 2H₂O.     

Diaqua[N,N-di(2-carboxyethyl)-o-anisidinato]copper(II) Dihydrate [Cu(o-Andp)(H2O)2] · 2H2O: Synthesis and Crystal Structure

Crystals of [Cu(o-Andp)(H₂O)₂] · 2H₂O (where o-Andp^2–is -anisidine-N,N-di-3-propionate) were synthesized and studied using X-ray diffraction analysis. The crystals are triclinic: a= 12.063(1) Å, b= 12.483(3) Å, c= 13.586(2) Å, = 91.29(1)°, = 111.67(1)°, = 104.00(1)°, V= 1830.5(5) ų, space group P , Z= 2, and R= 0.0528 for 5965 reflections with I2(I). The two crystallographically independent complexes are isostructural. The tetragonal–bipyramidal coordination of copper(III) involves three O atoms, the N atom of the tetradentate ligand o-Andp^2–, and two O atoms from water. The aminodipropionate group of the ligand (average Cu–O 1.939 Å and Cu–N 2.051 Å) and one of the coordinated water molecules (Cu–O(w) 1.991 Å) lie in the equatorial plane. The second water molecule (Cu–O(w) 2.32 Å) and the methoxy O atom of o-Andp^2–(Cu–O 2.37 Å) are in the apical positions of the bipyramid.     

Twinned and Disordered Crystal Structure of Solvated Bis[Aqua(2.2.2-Cryptand)Calcium] Hexa(Isothiocyanato)Calcium

Twinned and disordered crystals of solvated bis[aqua(2.2.2-cryptand)calcium] hexa(isothiocyanato)calcium 2[Ca(2.2.2-Crypt)(H₂O)]²⁺ · [Ca(NCS)₆]^4– · Sol (I), where Sol is acetone and/or ethanol and may be water, were synthesized and studied by X-ray diffraction analysis. Structure I (space group P2₁/n, a = 11.841 Å, b = 21.787 Å, c = 12.377 Å, = 90.90°) was solved by the direct method and refined by the full-matrix least squares method in anisotropic approximation to R = 0.079 from 4168 independent reflections (CAD4 automated diffractometer, MoK ). In crystal form, complex I exists as the two aforesaid complex ions [I¹]²⁺ and [I²]^4– in the molar ratio 2 : 1 united through hydrogen bonds. Complex cation I¹ is of the guest–host type. Its Ca²⁺ cation is coordinated by all eight heteroatoms (6O + 2N) of the cryptand ligand and by the O atom of the water molecule; the coordination polyhedron of this Ca²⁺ cation (CN 9) is irregular. The Ca²⁺ cation of complex anion I² (in the crystallographic center of inversion) is coordinated by six N atoms of six neighboring SCN^– anionic ligands; the coordination polyhedron of this Ca²⁺ cation (CN 6) is a slightly distorted octahedron.     

Crystal structure of tetraphenylarsonium aquatetracyanonitridorhenate(V), (AsPh4)2 [ReN(H2O)(CN)4]·5H2O

The crystal structure of (AsPh₄)₂[ReN(H₂O)(CN)₄]·5H₂O has been determined from three-dimensional X-ray diffraction data. The yellow crystals are monoclinic, space group P2₁/n with cell dimensionsa=15.482(1),b=19.950(2),c=16.999(1)? and β=101.69(6)^o,Z=4,D _expt=1.48(1)g cm⁻³ andD _calc=1.52g cm⁻³. The anisotropic refinement of 7858 observed reflections converged toR=0.055. The [ReN(H₂O)(CN)₄]²⁻ ion has a distorted octahedral geometry. Bond distances: Re≡N=1.639(8), Re−OH₂=2.496(7) and Re−C_(av)=2.11(1) ?. The rhenium atom is displaced by 0.35 ? out of the plane formed by the four carbon atoms of the cyano ligands towards the terminal nitrido ligand. TMC 2479     

The crystal structure of tetraphenylarsonium tricyanooxopyridine-2-carboxylatotungstate(IV) dihydrate

Summary The structure of (AsPh₄)₂[WO(CN)₃(Pic)] · 2H₂O has been determined from three dimensional x-ray data. The cell dimensions are:a=17.699(8),b=13.546(6),c= 13.590(6) Å, =117.39(8), = 71.54(7) and = 115.04(8)°, space group P¯1, Z = 2, The structure was solved from 5279 observed reflections. The anisotropic refinement converged to R = 0.060.The [WO(CN)₃(Pic)]^2–-ion is a distorted octahedron. The structure indicates that the aqua group in [WO(CN)₄(H₂O)]^2– was displaced by an oxygen atom of the carboxylate of 2-picolinate, while a cyanide ligand was substituted by the pyridine nitrogen atom. Themer-arrangement of the three cyanide ligands has two normaltrans W-C_av = 2.17(2) Å bond distances and a significant shorter W-C = 2.042(18) Å bond trans to the W-N [2.188(18) Å] bond. The W=O and W-O bond lengths are 1.676(9)Å and 2.171 Å, respectively.     

Preparation and x-ray structure determination of penta-and tetracyano-oxomolybdenum(IV) anions. The influence of water on their reactivity

Summary Several penta-and tetracyanooxomolybdenum(IV) anions have been synthesized containing different numbers of H₂O molecules, either coordinated or present as crystallisation molecules. The influence of these molecules on the reactivity of the complex, especially towards O₂, is discussed. Three compounds were characterized by x-ray structure determination. [Mo(O)(CN)₅(H₂O)₂(MeCN)₂][PPh₄]₄Cl belongs to triclinic space group P-1 witha=13.146(3) Å,b=16.944(5) Å,c=21.761(6) Å, =84.72(2)°, =87.15(2)° and =85.25(2)°. The volume of the unit cell is 4678(6)ų withz=2. The structure was refined to R=6.5%. [Mo(O)(CN)₄(H₂O)·6H₂O][PPh₄]₂ belongs to monoclinic space group P2₁/n witha=15.313(2)Å,b=19.983(3)Å,c=17.006(2)Å, =100.51(2)°. The volume of the unit cell is 5117(3)ų withz=4. The structure was refined to R=8.7%. [Mo(O)(CN)₄(MeCN)](PH₃)₂N]₂ belongs to triclinic space group P-1 witha=13.770(4)Å,b=16.292(5)Å,c=16.889(5)Å, =73.23(2)°, =72.02(2)° and =71.57(2)°. The volume of the unit cell is 3342(3)ų withz=2. The structure was refined to R=7.2%.     

Synthesis and Structure of Catena-[Bis(2-Methylimidazole)(μ-Phthalato)cobaltate(II)]

A new coordination compound [Co(Pht)(2-MeIm)₂] (I), where Pht^2–is the deprotonated radical of o-phthalic acid (H₂Pht) and 2-MeIm is 2-methylimidazole, was synthesized. Its structure was established using X-ray diffraction analysis. The crystal is orthorhombic: space group Pca2₁, a= 15.350(3), b= 7.957(2), c= 13.997(3) Å, (calcd.) = 1.505 g/cm³, and Z= 4. The tetrahedral coordination of the Co(II) atom includes two N atoms of two 2-methylimidazole molecules and two oxygen atoms of two carboxyl groups from different acid radicals. The Co–N distances are equal to 2.022(2) and 2.031(2) Å, while the Co–O distances are 1.972(2) and 2.000(2) Å. The carboxyl groups of the Pht^2–radical and the aromatic nucleus form angles of 47.2° and 35.9°, whereas the angle formed by the carboxyl groups themselves is 50.3°. Compound Iis a polymer, which is confirmed by the 1,6-bridging function of the o-phthalic acid radical. The Co···Co distance in a chain is equal to 7.367 Å. Separate chains are united in the crystal into a framework via N–H···O hydrogen bonds.     

Crystal structure determination and properties of hydrogen hexacyanododeca-μ-chloro-octahedro-hexatantalate(4−)-Dodecahydrate

Summary The cluster compound H₄[Ta₆Cl₁₂(CN)₆] · 12H₂O was prepared and identified by potentiometric titrations, i.r. and visible spectra and by three-dimensional single-crystal x-ray diffraction methods. Discrete [Ta₆Cl₁₂(CN)₆]^4– ions contain a linear Ta–CN unit with Ta–C=2.21(4) and C–N=1.16(5) Å, respectively. Each nitrogen atom is hydrogen bonded [2.63(12)Å] to two oxygen atoms.     

Ethylenediamine-N,N"-Diacetate Ion (Edda2–) as a Tridentate Ligand: Synthesis and Structure of the [Co(Edda)(Dien)]ClO4 · H2O and [Co(Edda)(En)(CN)] · 2H2O Complexes

The cobalt(III) complexes with tridentate ethylenediamine-N,N"-diacetate ions (Edda^2–) and additional ligands, namely, diethylenetriamine (Dien) or ethylenediamine (En) and cyanide ions, were synthesized. As follows from X-ray diffraction analysis of [Co(Edda)(Dien)]ClO₄· H₂O (monoclinic crystals with a = 9.243 (2) Å, b = 14.167 (4) Å, c = 13.046 (3) Å, = 91.19 (2)°, Z = 4, space group P2₁/c), the secondary N atom of the Dien ligand occupies the trans-position relative to the N atom of the Edda^2– ligand, which contains a free acetate group. Two fac-isomers of [Co(Edda)(En)(CN)] with the CN^– ion in the cis- and trans-positions relative to the oxygen atom of the carboxyl group were isolated, and the structure of the trans-(O,CN)-[Co(Edda)(En)(CN)]· 2H₂O was determined: monoclinic crystals with a = 9.136 (3) Å, b = 15.484 (3) Å, c = 10.564 (3) Å, = 110.67 (5)°, Z = 4, space group P2₁/c.     

Synthesis,spectroscopic and structural studies of tris(3-methyl-pyridinium)(3-ethylpyridinium)β-octamolybdate monohydrate

Summary Three isostructural compounds of general formula (3-MepyH) _x (3-EtpyH)_4–x [Mo₈O₂₆] (x=0, 2, 4) crystallize in the monoclinic system, space group P2₁/n, Z=2. Previously determined parameters for the compoundx=4 area=13.652(2),b=10.887(1),c=13.759(1) Å, =90.87(1)°,V=2044.8(4) ų,Dx=2.53,Do=2.54(1) mg m^–3,F(000)=1496. Slight differences in cell dimensions have been observed whenx=0 or 2. A nonisomorphous compound of formula (3-MepyH)₃(3-EtpyH)[Mo₈O₂₆]·H₂O crystallizes in the triclinic system, space group P2₁/n,Z=2,a=10.918(1),b=10.985(3),c=18.991(2) Å, =97.19(2), =91.45(2), =107.30(2)⁰,V=2152.8(7) ų,Dx=2.456,Do=2.456(5) mg m^–3,F(000)=1532. The distinguishing features of tris(3-methylpyridinium)(3-ethylpyridinium) -octamolybdate monohydrate are its non-centrosymmetric polyanion and its extensive hydrogen bonding. The asymmetric unit contains three independent 3-methylpyridinium and one 3-ethylpyridinium cations, one water molecule and the -octamolybdate anion. The planar cations are oriented to permit hydrogen bonds with either molybdate oxygen atoms or water oxygen atoms. Four different types of hydrogen bonds have been found: N–H...O (mono- and bifurcated); N–H...Ow (monofurcated); Ow–Hw...O (monofurcated); and C–H...O (monofurcated). The proposed hydrogen bonding interactions appear to stabilize the structure.     

Crystal and molecular structures of heteroligand bis(hexafluoroacetylacetonato)copper(II) complexes with 3-imidazoline nitroxyl radicals,Cu(C5HF6O2)2:L=1:1 (L1=C13H18N3O,L2=C8H15N2O)

Crystal structures were determined for two new derivatives of heteroligand complexes of Cu(C₅HF₆O₂)₂ with nitroxyl radicals derived from 3-imidazoline: Cu(C₅HF₆O₂)₂(C₁₃H₁₈N₃O) (I) and Cu(C₅HF₆O₂)₂(C₈H₁₅N₂O) (II). The unit cell parameters for I are as follows: a=10.555(3), b=15.505(5), c=18.509(6) Å, V = 3029(1) ų, Z=4, d_calc=1.57 g/cm³, space group P2₁2₁2₁. The unit cell parameters for II are as follows: a=16.018(3), b=15.886(3), c=19.665(4) Å, V = 5004(1)ų, Z=8, d_calc=1.68 g/cm³, d_exp=1.68 g/cm³, space group P2₁2₁2₁. The structure of I is molecular. The coordination of the copper ion is a trigonal bipyramid formed by two oxygen atoms of the (hfac) ions and the nitrogen atom of the imidazoline heterocycle in the equatorial plane [Cu–O, 1.91(7), 2.242(7) Å, Cu–N, 2.010(7) Å] and the other oxygen atoms of the (hfac) anion in the axial positions [Cu–O, 1.940(6), 1.963(6) Å]. Complex II is polymeric. The two crystallographically independent Cu(hfac)₂ fragments are linked in a chain by means of two L² ligands. The coordination of the copper ions is a square bipyramid, whose equatorial plane is formed by the oxygen atoms of the (hfac) anion [Cu–O, 1.89(1)–2.03(1) Å]. The axial positions are occupied by nitrogen atoms [Cu–N, 2.52(1), 2.40(1) Å] and an oxygen atom of the NO fragment [Cu–O, 2.96(1), 2.67(1) Å] of different L² ligands. The ...Cu(hfac)₂–L²–Cu(hfac)₂–L₂... chains in the unit cell are located at two levels (x1/4 and 3/4).Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated from Zhurnal Strukturnoi Khimii, Vol. 34, No. 2, pp. 126–133, March–April, 1993.     

Synthesis,crystal structure and magnetic properties of triaquahexakis(μ2-betaine)(μ3-oxo)triiron(III) perchlorate heptahydrate

The synthesis and characterization of the oxo-centered carboxylato-bridged trinuclear iron(III) complex, triaquahexakis(₂-betaine)(₃-oxo)triiron(III) perchlorate heptahydrate are described. X-ray crystallography shows that the Fe^III atom in the complex has a slightly distorted octahedral geometry, coordinated by four oxygen atoms from different betaine ligands [Fe—;O = 2.009(3) 2.034(3) Å], one aqua ligand [Fe—O = 2.028(4) and 2.031(3) Å] and the central ₃-oxo atom [Fe—O = 1.917(2) and 1.917(3) Å]. The central oxygen is ideally coplanar with the plane of the three metal atoms. Magnetic susceptibility data (4–320 K) show the presence of an antiferromagnetic exchange interaction with a coupling constant of J = –20.2 cm^–1.