Tris(2,4,6-trimethylphenyl)antimony dihydroxide; synthesis and reaction with sulfonic acids RSO3H (R = C6H5, CF3). Crystal structure of [2,4,6-(CH3)3C6H2]3SbO · HO3SC6H5

Tris(2,4,6-trimethylphenyl)antimony dihydroxide, Mes₃Sb(OH)₂, which was prepared by oxidation of Mes₃Sb with H₂O₂, has been shown to react with RSO₃H (R = C₆H₅, CF₃) to give the adducts Mes₃SbO · HO₃SR, the first examples of solid hydrogen-bonded adducts of a triorganoantimony oxide and an acid. The crystal structure of Mes₃SbO·HO₃SC₆H₅ has been determined. The three C(mesityl) atoms and the O atom form a distorted tetrahedron around Sb, the distortion by the bulky mesithyl groups being reflected in the CSbC angles (mean: 114.7(3)°) and the CSbO angles: (mean: 103.5(2)°). C₆H₅SO₃H is linked via a short hydrogen bond to O on Sb, with O(1) z^.;O(2) = 256(1) pm. The bond length SbO(1) 189.4(5) pm represents the shortest SbO distance ever reported.     

Microwave spectrum,structure and dipole moment of cyclopentadienylberyllium hydride

Microwave spectra of C₅ H₅ BeH, C₅ H₅ BeD, ¹³CC₄ H₅ BeH, and ¹³CC₄ H₅ BeD are reported. The molecule is a C_5v symmetrical top. The BeH bond length was found to be 1.32 Å with an error limit of 0.01 Å and the CC bond length was determined as 1.423 Å with one standard deviation of 0.001 Å. The distance from the beryllium atom to the centre of the cyclopentadienyl ring, h, and the CH bond length were assumed to be 1.49 Å and 1.09 Å, respectively. The dipole moment was determined through the Stark effect to be 2.08 D with one standard deviation of 0.01 D. Four different vibrationally excited normal modes were identified and their frequencies determined by relative intensity measurements.     

The structure of the metallated iridium complex [(C8H12)Ir{P(OC6H3Me)(OC6H4Me)2} {P(OCH2)3CMe}]

The crystal structure of [(C₈H₁₂)$\text{Ir{P(OC}$₆H₃Me)(OC₆H₄Me)₂} {P(OCH₂)₃CMe}] has been determined. a 18.32, b 18.98, c 9.35 Å, U 3251 ų, Pn2_1^a, Z = 4, R = 0.048, 2541 observed data.The coordination about the iridium atom is distorted trigonal bipyramidal; the two phosphorus atoms are equatorial, the σ-bonded carbon is axial, and the bidentate cyclooctadiene is bonded axialequatorial. The IrC(axial) bonds are longer than the IrC(equatorial) bonds: 2.22, 2.26; 2.17, 2.19 Å. The IrC(σ) bond length is 2.19 Å, not significantly different from the formally π-bonded C to Ir distances. The IrP lengths of 2.201 and 2.240 Å and the PIrP angle of 108.7° are normal. The longer IrP bond is in the five-membered chelate ring. The inertness to substitution is discussed.     

Synthetic and structural studies on some 1,3-diselena- and 1,3-dithia-[3]ferrocenophanes of germanium and tin. crystal and molecular structure of 1,3-diselena-2,2- dichlorogermyl-[3]ferrocenophane

A series of [3]ferrocenophanes of general formula Fe(C₅H₄X)₂YCl₂ and the spiro compounds [Fe(C₅H₄X)₂]₂Ge (X = S, Se; Y = Ge, Sn) have been prepared by the reaction of ferrocene 1,1′-dithiol and ferrocene 1,1′-diselenol with tetrahalides of germanium and tin. Spectroscopic properties of the compounds are reported. In solution, the compounds are fluxional by a bridge reversal process. The crystal structure of 1,3-diselena-2,2-dichlorogermyl-[3]ferrocenophane at 163 K. has been determined by X-ray diffraction methods. At that temperature, crystals have space group P2₁/n with a 6.222(3), b 16.156(13), c 12.968(4) Å, β 97.53(1)° and Z = 4. Least-squares refinement gave R = 0.033 for 2834 unique significant reflections whose intensities were measured by counter diffractometry. The two SeGe bond lengths are 2.323 and 2.325(1) Å, with GeCl 2.148 and 2.161(1) Å. The SeGeSe bond angle is 118.2(1)°, ClGeCl 104.7(1)°, and SeGeCl angles range from 106.2 to 109.8(1)°. The SeC bond lengths are 1.901 and 1.904(5) Å, with CSeGe angles of 95.8 and 96.5(2)°. The cyclopentadienyl rings are in an eclipsed conformation with a mean twist angle of 2.7°, and are inclined to one another at 6.1°. The Se atoms are displaced from the ring planes by 0.17 and 0.20 Å yielding a non-bonded intramolecular Se…Se contact of 3.99 Å.     

Crystal and molecular structure of 9-methyl-9-phenyl-9,10-dihydro-9-sila-3-azaanthrone

The crystal and molecular structure of 9-methyl-9-phenyl-9,10-dihydro-9-sila-3-azaanthrone has been determined from three-dimensional X-ray diffraction data. The title compound crystals are monoclinic, space group P2₁/b, a = 12.818(2), b = 16.508(2), c = 7.694(1) Å,γ = 105°, 34′(2), Z = 4 and D_cal = 1.278 g cm^?3. The structure was determined by direct methods and refined by full-matrix least-squares calculations in the block-diagonal anisotropic approximation for non-hydrogen atoms to R = 0.043 for 2190 independent reflections, registered at room temperature. This is the first crystal structure determination of a Si-dihydroanthracene derivative with two heterocycles and a planar carbon atom in the C10-position. The tricyclic fragment takes up a planar configuration, the silicon atom having a tetrahedral surrounding, with an endocyclic angle of 103.7(1)° and average bond length SiC, 1.862(1) Å. The CO, 1.220(2) Å, bond length in the carbonylic group exactly corresponds with the double bond length. Average distance NC is 1.335(3) Å, angle CNC, 116.5(2)°.     

Antiferromagnetic complexes involving metalmetal bonds IV. Synthesis,molecular structure and magnetic properties of the heterotrinuclear cluster, (C5H5Cr)2(μ2-SCMe3)(μ3-S)2Fe(CO)3, with direct and indirect exchange between CrIII and FeI centers

The photochemical reaction between the antiferromagnetic complex (C₅H₅-CrSCMe₃)₂S (I) (containing a CrCr bond 2.689 Å long) and Fe(CO)₅ results in the elimination of two carbonyl groups and one tert-butyl radical to give (C₅H₅Cr)₂(μ²-SCMe₃)(μ³-S)₂ · Fe(CO)₃ (III). As determined by X-ray diffraction, III contains a CrCr bond of almost the same length as in I (2.707 Å), together with one thiolate and two sulphide bridges. The latter are also linked with the Fe atom of the Fe(CO)₃ moiety (average FeS bond length 2.300 Å). Fe also forms a direct bond, 2.726 Å long, with one of the Cr atoms, whereas its distance from the other Cr atom (3.110 Å) is characteristic for non-bonded interactions. Complex III is antiferromagnetic, the exchange parameter, ?2J, values for CrCr, Cr(1)Fe and Cr(2)…Fe are 380, 2600 and 170 cm^?1, respectively. The magnetic properties of III are discussed in terms of the “exchange channel model”. The contributions from indirect interactions through bridging ligands are shown to be insignificant compared with direct exchange involving metalmetal bonds. The effects of steric factors and of the nature of the M(CO)_n fragments on the chemical transformations of (C₅H₅CrSCMe₃)₂S · M(CO)_n are discussed.     

A dichromium(II) compound with an elongated metal-metal bond: Cr2(oxindolate)4(oxindole)2

The title compound has been prepared by reaction of (C₅H₅)₂Cr with oxindole (indole with CO in place of CH₂ at the 2-position). Red single crystals belong to space group P2₁/c with a = 10.107(4) Å, b = 22.496(7) Å, c = 9.210(3) Å, β = 93.26(3)°, V = 2091(2), and Z = 2. The centrosymmetric molecule has a CrCr distance of 2.495(4) Å. The mean CrO and CrN distances for the bonds to bridging oxindolate anions are 2.024(7) and 2.065(8) Å, respectively. There is an oxindole molecule bound at each end with a CrO axial bond of length 2.341(8) Å and a hydrogen bond from the oxindole NH group to an equatorial oxygen atom of length 2.83(1) Å. The significance of this compound with respect to CrCr bonding is discussed.     

Synthese,Struktur und Eigenschaften von [nacnac]MX3‐Verbindungen (M = Ge,Sn; X = Cl,Br, I)

Synthesis, Structure, and Properties of [nacnac]MX₃ Compounds (M = Ge, Sn; X = Cl, Br, I) Reactions of [nacnac]Li [(2,6‐ⁱPr₂C₆H₃)NC(Me)C(H)C(Me)N(2,6‐ⁱPr₂C₆H₃)]Li ( 1 ) with SnX₄ (X = Cl, Br, I) and GeCl₄ in Et₂O resulted in metallacyclic compounds with different structural moieties. In the [nacnac]SnX₃ compounds (X = Cl 2 , Br 3 , I 4 ) the tin atom is five coordinated and part of a six‐membered ring. The Sn–N‐bond length of 3 is 2.163(4) Å and 2.176(5) Å of 4 . The five coordinated germanium of the [nacnac]GeCl₃ compound 5 shows in addition to the three chlorine atoms further bonds to a carbon and to a nitrogen atom. In contrast to the known compounds with the [nacnac] ligand the afore mentioned reaction creates a carbon–metal‐bond (1.971(3) Å) forming a four‐membered ring. The Ge–N bond length (2.419(2) Å) indicates the formation of a weakly coordinating bond.     

Transition-metal complexes of two valence tautomers of a bulky phenoxide, 2,6-Bu-t2-4-MeC6H2O− (ArO−); preparation and crystal and molecular structure of a phenoxytitanium(III) and a cyclohexadienonylrhodium(I) complex, [Ti(η-C5H5)2 OAr] and [Rh(ArO-η5)(PPh3)2]

The 2,6-di-t-butyl-4-methylphenoxo ligand (ArO^?) is ambidentate, giving rise to the O-bonded 15-electron d¹ [Ti(η-C₅H₅)₂OAr] and the η⁵ -[C(2)-C(6)]-bonded 18-electron d⁸ complex [Rh(ArO-η⁵)(PPh₃)₂], obtained from [{Ti(η-C₅H₅)₂Cl}₂]-LiO Ar and [Rh{N(SiMe₃)₂}(PPh₃)₂]-ArOH, respectively; the average TiC(η) distance is 2.362(10) Å, TiO 1.892(2) Å, and O:C(of Ar) 1.352(3) Å, and TiOC 142.3(2)°; in the Rh^I complex, C(2)C(6) are coplanar (with CC(av.) 1.38(2) Å). C(1)O 1.28 Å, and Rh to C(2) C(6) bond lengthsare in the range 2.19–2.65 Å.     

Organometalloidal derivatives of the transition metals: XI. Synthesis and crystal structures of Ph3GeSiMe3 and Ph3GeSiMe2Fe(CO)2(η5-C5H5)

Ph₃GeSiMe₃ and Ph₃GeSiMe₂Fe(CO)₂(η⁵-C₅H₅) have been synthesized and their crystal structures determined. The GeSi bond in iron (2.405(2) Å) is longer by 0.021 Å than in the simple germylsilane (2.384(1) Å). The significant shortening of the SiFe bond (2.328(1) Å) in the iron complex compared to that in the analogous Ph₃SiSiMe₂Fe(CO)₂(η⁵-C₅H₅) (2.346(1) Å) and spectroscopic data indicate an enhanced SiFe interaction.     

Molecular structural of the gauche and trans conformers of ethylamine as studies by gas electron diffraction

The geometrical parameters for the two conformers, gauche (g) and trans (t), of ethylamine have been determined by a joint analysis of the electron diffraction intensity measured in the present study and the rotational constants reported in the literature. The optimized geometries estimated by an SCF MO calculation with a 4-31G(N*) basis set were also used in the analysis to complement the experimental data. The bond lengths (r_g) and the bond angels (r_z) determined are r(CH)_av = 1.107(6) Å r(CN)_t = 1. 470(10)Å, r(CN)_g = 1.475(10) Å r(CC)_t = 1.531(6) Å r (CC)_g = 1.524(6) Å , ∠CCN)_t = 115.0(3)°, and ∠CCCN_g = 109.7(3)°. The uncertainties represent estimated limits of error. The difference between the CCN_g and CCN_g angles predicted by a previous ab initio calculation is confirmed. The enthalpy difference,ΔH(gt), is determined to be 306(200) cal mol⁻¹ using the abundance of the trans conformer, 46(10)%.     

Synthesis and molecular structure of niobocene trimethylacetate and its π-complex with diphenylacetylene

Niobocene trimethylacetate Cp₂Nb(OOCCMe₃) (I) does not react with usual n-donors (pyridine and triphenylphosphine), but readily adds a π-acceptor molecule of diphenylacetylene (tolane) in benzene to form Cp₂Nb(OOCCMe₃)(π-Ph₂C₂) · 0.5 C₆H₆ (II). The structures of the diamagnetic complexes I and II have been determined by an X-ray diffraction study. These molecules represent wedge-like sandwiches wit dihedral angles between cyclopentadienyl ligands equal to 44.4 and 50.7°, and average NbC distances of 2.39 and 2.44 Å, respectively. The bisector plane of I contains the chelate trimethylacetate group (NbO bond lenghts 2.23 and 2.24 Å) and that of II contains the coordinated tolane molecule and the oxygen atom of the terminal trimethylacetate ligand (NbO 2.16, NbC 2.18 and 2.19, CC 1.29 Å, PhCC angles 141 and 146°). An unusually large splitting of OCO stretching frequencies is observed in the IR spectrum of I (1652?1305 = 347 cm^?1). Structural characteristics of the coordinated CC triple bond in II are similar to those found in Cp(π-Ph₄C₄)Nb(CO)(π-Ph₂C₂) studied earlier. The role played by the Nb^III lone pair in I and II is discussed.     

The molecular structure of a three-coordinate palladium(II)-styrene complex [Pd(η5-C5H5)(PEt3)(styrene)]BF4

The molecular structure of a three-coordinate palladium(II)-styrene complex, [Pd(η⁵-C₅H₅)(PEt₃)(styrene)]BF₄ has been determined by means of X-ray diffraction. The crystal belongs to the monoclinic system, space group P2₁/c, with four formula units in a cell of dimensions: a 10.229(3), b 11.262(3), c 18.760(5) Å and β 103.77(2)°. The structure was solved by the heavy atom method, and refined by the least-squares procedure to R = 0.050 for 3635 observed reflections. The palladium atom is surrounded by the cyclopentadienyl group, the triethylphosphine ligand and the olefinic bond of styrene in the cationic complex. In the palladiumstyrene bonding, the olefinic bond is inclined by 77.3° to the coordination plane defined by the Pd and P atoms and the center of the cyclopentadienyl ring (PdC(1) 2.176(6), PdC(2) 2.234(5) and C(1)C(2) 1.369(8) Å).     

The crystal and molecular structure of tris[(triphenylstannyl)methyl]methane

The title compound, C₅₈H₅₂Sn₃, belongs to the triclinic space group P$\text{1}$, with a 10.165, b 13.365, c 18.670 Å, α 96.28, β 93.88, γ 103.15°, V = 2443.8 ų, f_w = 1105.1, Z = 2, D_calc 1.501 g cm^?3, m.p. 206.5–208°C, λ(Mo-K_$\text{α}$) 0.71069 Å. The structure was refined on 2684 nonzero reflections to an R factor of 0.044. The crystal contains molecules in which the (SnCH₂)₃CH core possesses an approximate C₃ symmetry. The three SnC(H₂) bonds are gauche to the C(4)-H bond. Repulsive interactions involving the bulky Ph₃Sn substituents lead to large SnC(H₂)C(H) angles (av. 117.3°), whereas the C(H₂)C(H)C(H₂) angles at the tertiary carbon average 111.3°. Little distortion of the Ph₃Sn groups themselves is present, since the PhSnPh angles (av. 109.8°) are almost equal to the C(H₂)SnPh angles (av. 109.9°). The molecule as a whole has no symmetry because the aromatic rings in the three Ph₃Sn groups have different orientations. The phenyl groups create a pocket in the middle of the molecule which encloses and shields the tertiary hydrogen atom. The resulting inaccessibility of this hydrogen accounts in part for the low reactivity of the title compound in redox reactions.     

Neodymium(III) triaquatrihydroxo(1,3-diamino-2-propanoltetraacetato)germanium(IV) hydrate [Ge(OH)(μ-HHpdta)(μ-OH)Nd(OH)(H<Subscript>2</Subscript>O)<Subscript>3</Subscript>] · H<Subscript>2</Subscript>O: Synthesis and crystal and molecular structure

The heteronuclear germanium(IV) and neodymium(III) complex with 1,3-diamino-2-propanoltetraacetic acid (H₅Hpdta) [Ge(OH)(μ-HHpdta)(μ-OH)Nd(OH)(H₂O)₃] · H₂O has been synthesized for the first time and characterized by physicochemical methods (elemental analysis, X-ray powder diffraction, thermogravimetry, IR spectroscopy, X-ray crystallography). The crystals are monoclinic: a = 9.331(3) Å, b= 10.279(4) Å, c = 21.474(7) Å, β = 94.59(3)°, V = 2053.0(12) ų, Z = 4, space group P2₁/n, R1 = 0.0245 for 4060 reflections with I > 2σ(I). The compound is built of complex binuclear molecules [Ge(OH)(μ-HHpdta)(μ-OH)Nd(OH)(H₂O)₃] and water molecules of crystallization. The germanium and neodymium atoms are bridged by the oxygen atom of the hydroxo group (Ge-O, 1.798(2) Å; Nd-O, 2.539(2) Å) and the deprotonated oxygen atom of the isopropanol group of the HHpdta^4? ligand (Fe-O, 1.858(2)Å; Nd-O, 2.420(2) Å) to form a dimeric molecule. Each coordination sphere (of the Ge atom and of the Nd atom) contains one nitrogen atom (Ge-N, 2.096(3) Å; Nd-N, 2.807(2) Å) and two carboxylic oxygen atoms from four acetate branches of the octadentate HHpdta^4? ligand (av. Ge-O, 1.928(2) Å; Nd-O, 2.391(2) Å). The coordination polyhedron of the Ge atom is completed to a distorted octahedron by the oxygen atom of the terminal hydroxo group (Ge-O 1.811(2) Å), and the polyhedron of the Nd atom is completed to a nine-vertex polyhedron by the oxygen atoms of the terminal hydroxo group (Nd-O 2.494(3) Å) and three water molecules (Nd-O, 2.512(3), 2.520(3), and 2.723(3) Å). In the crystal structure, the complex molecules and the water molecules of crystallization are joined by a hydrogen bond system.     

The preparation,properties and crystal structure of bis(η5-cyclopentadienyldicarbonyliron)dimethylgermyl]oxide, [(η5-C5H5)(CO)2FeGe(CH3)2]2O

One of the main products of oxidation of (η⁵-C₅-H₅)₂Fe₂(CO)₃Ge(CH₃)₂ by air has been shown to be [(η⁵-C₅H₅)(CO)₂FeGe(CH₃)₂]₂O. The infrared, NMR and mass spectra are consistent with this formula and the detailed structure has been established by X-ray crystallography. In polar solvents the NMR suggests the existence of major and minor conformers interconverting only slowly on the NMR time scale at ≈ 25°. The X-ray diffraction study has shown the compound to consist of two (η⁵-C₅H₅)(CO)₂FeGe(CH₃)₂ moieties joined by a bridging oxygen atom. Two rotational isomers are present in the unit cell in a disordered fashion. Some pertinent average distances and angles are: FeGe, 2.372 Å; GeO, 1.785 Å; GeOGe′, 134°. The compound crystallizes in the monoclinic system, space group P2₁/n, with a 8.056(2), b 12.506(2), c 22.631(3) Å, β 98.01(1)°, d_calc 1.692 g cm^?3. Counter data were collected using Mo-K_α radiation. The 1780 reflections above background were used in least-squares refinement which converged at R₁ = 0.051 and R₂ = 0.068.     

Cyclic polysilanes : VIII. The crystal structure of 1,2,3,4-tetra-tert-butyl-tetramethylcyclotetrasilane

The crystal structure of [Si(CH₃)(t-C₄H₉)]₄ has been determined by single crystal X-ray diffraction. The crystals are tetragonal, P4₂/n; a = b = 13.069(4), c = 7.880(2) Å, Z = 2. The structure was determined using 745 independent data and refined with anisotropic least-squares to a final unweighted R-value of 3.5%. Each tetrameric molecule was found to be arranged about a $\text{4}$ axis, with the independent crystallographic unit comprising one silicon atom, one methyl and one tert-butyl group. The four-membered ring of silicon atoms is nonplanar with an unusually large dihedral angle of 36.8°. The principal mean bond lengths are SiSi 2.377(1), SiC(methyl) 1.893(4), SiC(tert-butyl) 1.918(3) Å, and the SiSiSi bond angle is 86.99°. The SiSi bond length is somewhat longer than in other polysilanes.     

The crystal and molecular structure of DI-trans-β-styrylmercury

The structure of di-trans-β-styrylmercury has been determined by single crystal X-ray methods from counter data. The compound crystallizes in the orthorhombic space group Pbcn with unit cell dimensions a 15.413(6), b 11.161(9), c 7.668(5) Å, V 1319(1) ų, D_calc 2.049 g/cm³, and Z = 4. The crystal was solved by conventional heavy atom techniques. The crystal consists of individual molecular units with the mercury atom located on a two fold axis of symmetry. The CHgC fragment is nearly linear with an angle of 178°. The β-styryl groups are oriented so that a dihedral angle of 66.8° is formed between the planes defined by HgC(1)C(2) and HgC(1)′C(2)′ fragments. The HgC bond distance is 2.07(4) Å.     

Fulvene—platinum complexes: x-ray crystal structure of [Pt(η2-C5H4CPh2)(PPh3)2]

Bis(cycloocta-1,5-diene)platinum reacts with 2,3,4,5-tetraphenylfulvene to afford the complex [Pt(η²-CH₂C₅Ph₄)(cod)] (cod  C₈H₁₂) in which the metal atom is coordinated to the exo-cyclic double bond of the fulvene. Related compounds [Pt(η²-CH₂C₅Ph₄L₂] (L  PPh₃, PMePh₂, PMe₂Ph, AsPh₃ or CNBu^t have also been prepared and characterised. Reaction of the complexes [Pt(C₂H₄)₂(L)] (L  P(cyclo-C₆H₁₁)₃, PPh₃ or AsPh₃) with 2,3,4,5-tetraphenylfulvene yields the compounds [Pt(C₂H₄)(η²-CH₂C₅PH₄)(L)]. NMR data for the new species are reported and discussed. 6,6-Diphenylfulvene reacts with [Pt(cod)₂] and PPh₃ ($\text{1}\text{2}$ mol ratio) to give the complex [Pt(η²-C₅H₄CPh₂)-(PPh₃)₂] in which the metal atom is bonded to carbon atoms C(2) and C(3) of the fulvene ring. This was established by an X-ray diffraction study. Crystals are monoclinic, space group P2₁/n, with Z  4 in a unit cell of dimensions a  13.761(4), b  21.653(13), c  17.395(6) Å, β,  104.46(2)°. The structure has been solved and refined to R  0.064 (R′  0.064) for 3139 independent diffracted intensifies measured at room temperature. The platinum atom is in a trigonal environment formed by the two ligated phosphorus atoms and the CC bond of the fulvene which is elongated to 1.52(3) Å. The c₅ fulvene ring is planar, and makes an angle of 108° with the coordination plane around the platinum. In this plane the metal atom is slightly asymmetrically bonded with PtC 2.15(2) and 2.24(2) Å, and PtP 2.280(6) and 2.301(6) Å.     

The chemistry and the stereochemistry of poly(N-alkyliminoalanes) : V. The preparation and crystal structure of the pentamer [(HalN-i-Pr)2(H2AlNH-i-Pr)3]

The compound [(HAlN-i-Pr)₂(H₂AlNH-i-Pr)₃] has been prepared and the crystal and molecular structure determined by an X-ray analysis, carried out with three-dimensional data collected on a diffractometer. The molecule is made up of a cyclohexane-type ring, [(HAlN-i-Pr)₂(H₂AlNH-i-Pr)], in skewboat conformation, on each side of which is bonded an -H₂AlNH-i-Pr- bridging unit between a nitrogen atom and an aluminum atom of the ring. The molecule lies on a binary axis of the crystal, but this symmetry is fulfilled only by a statistical orientation of the asymmetric molecular units (the statistical model is not however completely defined). The AlN bond lengths range from 1.901 to 1.985 Å; the average NC bond length is 1.527(9) Å. Main crystal data are: monoclinic space group C2/c; a = 10.15(2), b = 21.64(3), c = 12.84(2) Å, β = 111.9(5)°; Z = 4; calculated density 1.095 g/cm³. The structure was solved by direct methods and block-matrix least-squares converged to an R value of 5.6%.