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.     

Clusters containing ynamine ligands. 4. The synthesis and characterizations of ReMn(CO)8 [μ-MeC2NMe2] and ReMn(CO)7 [μ-MeCC(NMe2)C(NMe2)CMe] and the development of a bonding model for the coordination of ynamines to M2(CO)8 clusters

The compound ReMn(CO)₈ (-MeC₂NMe₂),2 was obtained in 11% yield by the decarbonylation of ReMn(CO)₁₀ with Me₃NO followed by reaction MeC₂NMe₂. Compound2 will add one equivalent of MeC₂NMe₂ at 25°C to yield the mixed metal complex ReMn(CO)₇ [-C(Me) C(NMe₂) C(NMe₂) C(Me)],3 in 7% yield. Compounds2 and3 were characterized by IR,¹H NMR, and single crystal x-ray diffraction analyses. Compound2 exists as two isomers. Each isomer contains an asymmetric bridging ynamine ligand. The principal isomer has the amine-substituted carbon atom coordinated to the manganese atom. The minor isomer has the amine-substituted carbon atom coordinated to the rhenium atom. In compound3 the two ynamines have been coupled in a head-to-head fashion to produce a ferrole-like structure in which the coupled ligands are -bonded to the manganese atom. Extended Hückel molecular orbital calculations were performed on the parent complex Re₂(CO)₈ (-MeC₂NMe₂),1 to try to understand the reasons for the preferred asymmetric coordination of the ynamine ligand in1 and2. It was found that the asymmetric coordination permits a strong stabilizing interaction between the one of the * orbitals of the ligand and the metallic orbital that is principally responsible for the formation of the metal-metal bond. Crystal Data: for2: space group=P2₁/c,a=9.740(1)Å,b=11.293(2)Å,c=15.483(3)Å, =97.46(1)°,Z=4, 1876 reflections,R=0.026; for3: space group=Pca2₁,a=17.541(2)Å,b=8.441(1)Å,c=14.033(3)Å,Z=4, 1335 reflections,R=0.022.     

The caesium oxygen interactions in the crystalline solids

Through the study of the Cs-O bonds registered in the literature one observes that:

(i)

the bond lengths range from 2.46 to 3.60 Å;

(ii)

the preferential coordination numbers adopted by the caesium ions are 8, 9 and 10 but values from 1 to 12 also exist;

(iii)

the average bond lengths increase with the coordination (CN) of the caesium ions with the following values: 2.714 Å (CN=1), 2.98 Å (CN=2), 3.057 Å (CN=3), 3.104 Å (CN=4), 3.149 Å (CN=5), 3.188 Å (CN=6), 3.224 Å (CN=7), 3.245 Å (CN=8), 3.261 Å (CN=9), 3.269 Å (CN=10), 3.293 Å (CN=11) and 3.323 Å (CN=12).

A new R_ij=2.469 constant is determined with all the caesium coordination polyhedra to compute electrostatic bond valence sums.The U_eq values of caesium in crystal structure are about 0.03 and generally less than 0.06 similar to those of the oxygen atoms and often bigger.     

The reactions of some σ-alkynylnickel complexes with 7,7,8,8-tetracyanoquinodimethane

The σ-alkynyl complexes Ni(η⁵-C₅H₅)(PPh₃)-CC-R (1), Ni(η⁵-C₅H₅)(PPh₃)-CC-X-CCH (2) and Ni(η⁵-C₅H₅)(PPh₃)-CC-X-CC-Ni(η⁵-C₅H₅)(PPh₃) (3), reactwith 7,7,8,8-tetracyanoquinodimethane, TCNQ, at 30 °C by insertion of the alkyne CC into a CC(CN)₂ bond to give Ni(η⁵-C₅H₅)(PPh₃)-C{C₆H₄C(CN)₂}-C{C(CN)₂}-R (4), from 1, Ni(η⁵-C₅H₅)(PPh₃)-C{C₆H₄C(CN)₂}-C{C(CN)₂}-X-CCH (5), from 2, and Ni(η⁵-C₅H₅)(PPh₃)-C{C₆H₄C(CN)₂}-C{C(CN)₂}-X-CC-Ni(η⁵-C₅H₅)(PPh₃) (6),and Ni(η⁵-C₅H₅)(PPh₃)-C{C₆H₄C(CN)₂}- C{C(CN)₂}-X-C{C(CN)₂}-C{C₆H₄C(CN)₂}-Ni(η⁵-C₅H₅)(PPh₃) (7),from 3 {R = (a) C₆H₅, (b) 4-PhC₆H₄, (c) 4-Me₂NC₆H₄, (d) 1-C₁₀H₇ (1-naphthyl), (e) 2-C₁₀H₇ (2-naphthyl), (f) 9-C₁₄H₉ (9-phenanthryl), (g) 9-C₁₄H₉ (9-anthryl), (h) 3-C₁₆H₉ (3-pyrenyl), (i) 1-C₂₀H₁₁ (1-perylenyl), (j) 2-C₄H₃S (2-thienyl), (k) C₁₀H₉Fe (ferrocenyl = Fc) and (l) H; X = (a) nothing, (b) 1,4-C₆H₄, (c) 1,3-C₆H₄ and (d) 4,4′-C₆H₄-C₆H₄}. The reaction is regiospecificand the other possible insertion product, R-C{C₆H₄C(CN)₂}-C{C(CN)₂}-Ni(η⁵-C₅H₅)(PPh₃) etc., is not formed. Under the same conditions, there is no evidencefor the reaction of TCNQ with the -CCH of 2, PhCCH, 1,4-C₆H₄(CCH)₂ or FcCCH, or for the reaction of more than one CC(CN)₂ of TCNQ with a Ni-alkynyl moiety. Complexes 4-7 are all air-stable, purple solids which have been characterised by elemental analysis and spectroscopy (IR, UV-Vis, ¹H NMR and ¹³C NMR),and by X-ray diffraction for 4a, 4b and 4l. The UV-Vis spectra of 4-7 are very similar. This implies that all contain the same active chromophore which, it is suggested, is Ni-C(5)C₆H₄C(CN)₂ and not R-C(4)C(CN)₂. This isconsistent with the molecular structures of 4a, 4b and 4l which show that the first of these potentially chromophoric fragments is planar or close to it with an in-built potential for delocalisation, whilst in the second the aryl group R is almost orthogonal to the CC(CN)₂ plane. The molecular structures of 4a, 4b and 4l also reveal a short Ni?C(4) separation, indicative of a Ni → C(4) donor-acceptor interaction. The electrochemistry of 4a shows aquasi reversible oxidation at ca. 1 V and complicated reduction processes. It is typical of most 4, but 4l is different in that it shows the same quasi reversible oxidation at ca. 1 V but two reversible reductions at −0.26 and −0.47 V (vs. [Fe(η⁵-C₅Me₅)₂]^+/0 0.0 V).     

Equilibrium Structure of Beryllium Dibromide from Combined Gas Electron Diffraction and Vibrational Spectroscopy Analysis

The molecular structure of BeBr₂ has been investigated by gas-phase electron diffraction at the temperature 800(10) K. The conventional analysis yielded the following values: r _g(Be–Br) = 1.944(6)Å, l(Be–Br) = 0.068(4)Å, r _g(Br–Br) = 3.848(8)Å, l(Br–Br) = 0.109(3)Å, k(Be–Br) = 1.1(1.1) × 10^–5 ų, (Br–Br) = 2.1(1.0) × 10^–5 ų. Three models of nuclear dynamics were used to simulate the conventional analysis values—infinitesimal vibrations and two models, which take into account the kinematic and dynamic anharmonicity of the bending vibration. All models give similar values of bond angle, amplitudes, and shrinkage, excluding the harmonic model, which yields too low value l(Br–Br). The equilibrium bond distance r _e(Be–Br) = 1.932(11) Å was estimated, taking into account the anharmonicity corrections for stretching and bending vibrations and centrifugal distortion.     

Crystalline complexes of N,N'-ditritylurea (DTU) and N-tritylurea (NTU) hosts with molecular guests

This paper reports crystalline complexes of the new hosts N,N'-ditritylurea (DTU) and N-tritylurea (NTU) with various uncharged molecular guests. The crystal structures of the following complexes were elucidated by single crystal X-ray diffraction analysis at 115^oK: (I) 1:1 DTU-propanamide — space group C2/c, a=15.839Å, b=9.088Å, c=24.584Å, =111.05^o, Z=4; (II) 1:1 DTU-ethyl N-acetylglycinate — space group P1, a=9.010Å, b=10.800Å, c=19.810 Å, =105.29^o =94.33^o, =93.03^o, Z=2; (III) 2:1 NTU-N, N-dimethylformamide — space group Cc, a=29.614Å, b=8.906Å, c=16.127Å, =121.04^o, Z=4. The three crystal structures are stabilized mainly by a cooperative effect of hydrogen bonding between amide fragments displaced along the shortest axis of each crystal. This interaction occurs between host and guest in complexes I and II, and between host and host in complex III. The latter also represents a cage-type clathrate in which the guest molecules are accommodated in voids between the hydrophobic fragments of four neighboring NTU hosts. On the other hand, complexes of DTU are characterized by a more specific interaction between the two components, each guest molecule being inserted between two adjacent hosts (related by translation) and strongly bound to them via hydrogen bridges. These results illustrate a useful concept in the design of molecular species which can be potential hosts upon crystallization with neutral molecular guests. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82022 (7 pages).     

A tetranuclear tungsten carbido alkoxide cluster with a hydride ligand: W4(μ-C)(NMe)(OCH2Bu t )11(H)

A minor product in the reaction between W₂(NMe₂)₆ and neopentanol in hydrocarbon solvents has been isolated and characterized by elemental analysis,¹H and¹³C NMR spectroscopy and a single crystal X-ray study. At –174°C,a=11.669(1) Å,b=25.801(5) Å,c=24.345(4) Å, =100.91(1)°,Z=4,d _calcd=1.60 g cm^–3, and space group P2₁/c. The compound is formulated as W₄(₄-C)(NMe)(OCH₂Bu ^t )₁₁ (H). There is a W₄-butterfly and the carbido group is cradled between the wing-tip and back-bone W atoms with W-C=1.90–1.96 and 2.20–2.26 Å, respectively. The five W-W bonding distances span a narrow range 2.74–2.84 Å. The structure of this molecule resembles that previously reported for W₄(₄-C)(NMe)(OPr ⁱ )₁₂ where one OPr ⁱ ligand bonded to a backbone W atom is replaced by a hydride ligand. The hydride was not located crystallographically but is implicated by (i)a void at one W atom, (ii) itstrans-influence as determined by the W-O bond distance of the group trans to the void, and (iii) electron counting which requires the presence of a W₄(₄-C)¹⁴⁺ rather than a W₄(₄-C)¹³⁺ moiety in order to account for the observed diamagnetism. The present finding is compared with the previous preparations and characterizations of W₄(₄-C)¹⁴⁺ alkoxide supported clusters.     

Synthesis and crystal structure of ammonium (picrate) (dibenzo-18-crown-6)

NH₄(Pic)(DB18C6) (Pic=picrate and DB18C6=dibenzo-18-crown-6), (C₂₆H₃₀N₄O₁₃) FW 606.56, arthorhombic,Pmn2₁,a=26.045(5),b=12.055(3),c=8.982(3) Å,V=2820(1) ų,Z=4,D _c =1.429 g/cm³, CuK, =1.54184 Å, (CuK)=9.5 cm^–1,F(000)=1272,T=298 K. The structure has been refined toR=0.0475 for 2617 unique observed reflections. In the lattice the 1:1 complex exists as a 2:2 dimer in which the crown are coupled through the Pic anions and NH₄ ⁺ cations. The asymmetric unit consists of two independent half crown ethers of which two opposite O atoms are on the mirror plane, two half ammonium cations of which the N and two H atoms are also on the mirror plane while the Pic anion is in a general position. Relative to each other, the corwn ethers are shifted by about 7.3 Å alongb and 1 Å alongc. The 1:1 sandwich of NH₄ with DB18C6 and Pic on dimerisation becomes a club pseudo-sandwich with three phenyl rings on either side of the mirror plane, thus forming a nearly parallel stack with a 3.6 Å inter-ring distance. The NH₄ ions hold the structure; two H atoms on the mirror plane are hydrogen-bonded to the opposite oxygens of the crown located on the purely aliphatic part of the ring (2.10(1), 2.06(3) and 2.26(3), 2.05(1) Å) for the two independent crowns, respectively, while the other two H atoms form mirror-related bifurcated hydrogen bonds with the phenoxide oxygen (1.99(1) and 2.01(1) Å) and theo-nitrogen oxygen (2.44(2) and 2.34(1) Å) of the picrates. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82037 (29 pages)     

Novel butterfly tungsten-osmium carbido cluster Complexes from the reaction of Os3(CO)10(NCME)2 CPW(CO)3(CH2SMe)

Condensation of be triosmium acetonitrile complex Os₃(CO)₁₀(NCMe)₂ with the sulfido complex CpW(CO)₃(CH₂SMe) in refluxing THF solution produced three sulfur-containing compounds Os₃(C0)₁₀)(µ-H)(µ-SMe) (1), Os₃(CO)₁₁ [S(Me)CH₂W(CO)₃Cp] (2) and CpWOs₃(CO)₁₂(µ-CH₂)(µ-SMe) (3). Clusters 2 and 3 were products involving a 1:1 combination of starting materials and were characterized by X-ray diffraction studies. Crystals of 2 belongs to monoclinic space group P 2₁ /c witha=8.418(2),b = 11.912(2),c = 28.288 Å,=97.64(2)°,Z=4;R _F=0.044,R _W,=0.044. Crystal dara far 3: space group P 2₁/e,a 18.156(4).b=9.255(6),c = 15.347(4) Å. = 103.49(2)°,Z = 4;R _F -=0.047,R _W = 0.045. Upon thermolysis in toluene, the methylene cluster 3 released CO and induced C-H bond activation to afford two tetrametallic carbido clusters with formula CPWOS₃(CO)₉(µ₄-C)(µ-H)₂(µ-SMe) (4) and CPWOs₃(CO)₁₁(µ₄-C)(µ-SMe) (5) as the principle products. The first complex possesses a butterfly framework encapsulating a µ₄-C ligmd and a µ-SMe ligand linking a W-Os edge, whereas the second product adopts a puckered, cyclic arrangement of WOs₃ metal atoms with µ-SMe ligand located on a nonbonding Os-Os vector. Complex4 crystallizes in monoclinic space group P 2₁ /c witha=15.633(4) Å,b = 8.699 (3) Å,c=15.422(4) Å,=93.12(2)=°, Z=4,R=0.036,R _W =0.034 for 2780 observed reflections. Crystal data for5: space groupP nma,a=14.542(3),b=13.710(6),c=11.758(3) Å.Z=4,R _F =0.038,R _W = 0.037 for 1826 observed reflections. A variable temperature¹H NMR study was also presented to demonstrate the solution fluxionality of5.     

Hydrogen peroxide oxidation of di(hydroxo)platinum(II) species in carboxylic acids

A facile procedure for synthesizing the mono(hydroxo)tris(carboxylato)platinum(IV) species has been achieved. The reaction of [Pt^II(OH)₂(dmpda)] (dmpda=2,2-dimethyl-1,3-propanediamine) with a 30% aqueous solution of H₂O₂ in the presence of a carboxylic acid produces a stable [Pt^IV(OOCR)₃(OH)(dmpda)] (R=Me, Et) complex in high yield. The crystal structures of [Pt^IV(OOCMe)₃(OH)(dmpda)] . H₂O (triclinic P1 bar, a=8.761(2) Å, b=9.245(3) Å, c=10.659(2) Å, =106.25(2)°, =93.90(2)°, =98.92(2)°, V=813.1(3) ų, Z=2, R= 0.0474) and [Pt^IV(OOCEt)₃(OH)(dmpda)] (monoclinic P2₁/c, a=12.777(4) Å, b=10.514(2) Å, c=14.971(3) Å, =107.40(2)°, V=1919.2(8) ų, Z=4, R=0.0611) show that the hydroxyl group has been selectively positioned at an axial site. The intramolecular hydrogen bond between the OH and C=O moiety exists (O(H)...=C, 2.83 Å for [Pt^IV(OOCMe)₃(OH)(dmpda)] · H₂O; 2.72 Å for [Pt^IV(OOCEt)₃(OH)(dmpda)]. Formation of the axial-mono(hydroxo)tris(carboxylato)platinum(IV) species may be ascribed to a combination of `reactive-equatorial effects' with `cis-addition' in the carboxylic acid.     

Molecular structures of benzoylbenzo-12-crown-4 and diphenylacetylbenzo-12-crown-4 and possible reasons for different conformational states of their macrocycles

The molecular structures of (benzoyl)benzo-12-crown-4 (a=22.387,b=4.503,c=16.167 Å,d _calc=1.34 g cm^–3,Z=4, space groupP2₁ nc, DAR-UM, Cu-K,R=0.056) and (diphenylacetyl)benzo-12-crown-4 (a=8.866,b=23.337,c=10.737 Å;d _calc=1.25 g cm^–3,Z=4, space groupP2₁2₁2₁, DAR-UM, Cu-K, R=0.056) have been investigated. The differences in the conformations of the macrocycles and the degree of conjugation between the benzene ring orbitals and the lone pairs on the adjacent oxygen atoms in the macrocycle are discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1906–1911, November, 1993.     

Reactions of cyano(alkynyl)ethenes with some alkynyl- and diynyl-ruthenium complexes

Reactions of Ru(CCPh)(PPh₃)₂Cp with (NC)₂CCR¹R² (R¹ = H, R² = CCSiPrⁱ₃8; R¹ = R² = CCPh 9) have given η³-butadienyl complexes Ru{η³-C[C(CN)₂]CPhCR¹R²}(PPh₃)Cp (11, 12), respectively, by formal [2 + 2]-cycloaddition of the alkynyl and alkene, followed by ring-opening of the resulting cyclobutenyl (not detected) and displacement of a PPh₃ ligand. Deprotection (tbaf) of 11 and subsequent reactions with RuCl(dppe)Cp and AuCl(PPh₃) afforded binuclear derivatives Ru{η³-C[C(CN)₂]CPhCHCC[ML_n]}(PPh₃)Cp [ML_n = Ru(dppe)Cp 19, Au(PPh₃) 20]. Reactions between 8 and Ru(CCCCR)(PP)Cp [PP = (PPh₃)₂, R = Ph, SiMe₃, SiPrⁱ₃; PP = dppe, R = Ph] gave η¹-dienynyl complexes Ru{CCC[C(CN)₂]CRCH[CC(SiPrⁱ₃)]}(PP)Cp (15-18), respectively, in reactions not involving phosphine ligand displacement. The phthalodinitrile C₆H(CCSiMe₃)(CN)₂(NH₂)(SiMe₃) 10 was obtained serendipitously from (Me₃SiCC)₂CO and CH₂(CN)₂, as shown by an XRD structure determination. The XRD structures of precursor 7 and adducts 11, 12 and 17 are also reported.     

Kristallstruktur von Trimethylisocyanursäure, (CH3NCO)3, und von Trichlorisocyanursäure-1/2-Ethylenchlorid, (ClNCO)3·1/2C2H4Cl2

X-ray crystal structure analyses of (CH₃NCO)₃ (M) and (ClNCO)₃·1/2C₂H₄Cl₂ (C) were carried out at room temperature (MoK, graphite monochromator, =0.71069 Å): 1.M=171.16, monochlinic, P2₁/c,a=14.848 (1) Å,b=13.400 (2) Å,c=8.149 (1) Å, =100.87 (1)°,V=1 592.3 ų,Z=8,F(000)=720,d _x =1.428 Mgm^–3, =76m^–1,R=6.51%,R _w =7.01% (964 reflections, 218 parameters). 2.M=281.89, monochlinic, P 2₁/c,a=9.416 (3) Å,b=5.728 (1) Å,c=18.199 (8) Å, =98.64 (2)°,V=970.4 Å₃,Z=4,F(000)=556,d _x =1.929 Mgm^–3, =1.11 mm^–1,R=3.96%,R _w =3.44% (605 reflections, 132 parameters). The ring systems together with the C atoms of the methyl groups in (M) and with the Cl atoms in (C) are planar and have D_3h-symmetry. Bond lengths and bond angles are discussed with regard to¹⁴N-NQR,³⁵Cl-NQR and vibrational spectroscopic data.

     

C-C bond formation by cyanide addition to dinuclear vinyliminium complexes

The diiron vinyliminium complexes [Fe₂{μ-η¹:η³-C(R′)C(H)CN(Me)(R)}(μ-CO)(CO)(Cp)₂][SO₃CF₃] (R=Me, R′ = SiMe₃ (1a); R = Me, R′ = CH₂OH (1b); R = CH₂Ph, R′ = Tol (1c), Tol = 4-MeC₆H₄; R = CH₂Ph, R′ = COOMe (1d); R = CH₂Ph, R′ = SiMe₃ (1e)) undergo regio- and stereo-selective addition by cyanide ion (from ), affording the corresponding bridging cyano-functionalized allylidene compounds [Fe₂{μ-η¹:η³-C(R′)C(H)C(CN)N(Me)(R)}(μ-CO)(CO)(Cp)₂] (3a-e), in good yields. Similarly, the diiron vinyliminium complexes [Fe₂{μ-η¹:η³-C(R′)C(R′)CN(Me)(R)}(μ-CO)(CO)(Cp)₂][SO₃CF₃] (R = R′ = Me (2a); R = Me, R′ = Ph (2b); R = CH₂Ph, R′ = Me (2c); R = CH₂Ph, R′ = COOMe (2d)) react with cyanide and yield [Fe₂{μ-η¹:η³-C(R′)C(R′)C(CN)N(Me)(R)}(μ-CO)(CO)(Cp)₂] (9a-d). The reactions of the vinyliminium complex [Fe₂{μ-η¹:η³-C(Tol)CHCN(Me)(4-C₆H₄CF₃)}(μ-CO)(CO)(Cp)₂][SO₃CF₃] (4) with NaBH₄ and afford the allylidene [Fe₂{μ-C(Tol)C(H)C(H)N(Me)(C₆H₄CF₃)}(μ-CO)(CO)(Cp)₂] (5) and the cyanoallylidene [Fe₂{μ-C(Tol)C(H)C(CN)N(Me)(C₆H₄CF₃)}(μ-CO)(CO)(Cp)₂] (6), respectively. Analogously, the diruthenium vinyliminium complex [Ru₂{μ-η¹:η³-C(SiMe₃)CHCN(Me)(CH₂Ph)}(μ-CO)(CO)(Cp)₂][SO₃CF₃] (7) reacts with to give [Ru₂{μ-η¹:η³-C(SiMe₃)CHC(CN)N(Me)(CH₂Ph)}(μ-CO)(CO)(Cp)₂] (8).Finally, cyanide addition to [Fe₂{μ-η¹:η³-C(COOMe)C(COOMe)CN(Me)(Xyl)}(μ-CO)(CO)(Cp)₂][SO₃CF₃] (2e) (Xyl = 2,6-Me₂C₆H₃), yields the cyano-functionalized bis-alkylidene complex [Fe₂{μ-η¹:η²-C(COOMe)C(COOMe)(CN)CN(Me)(Xyl)}(μ-CO)(CO)(Cp)₂] (10). The molecular structures of 3a and 9a have been elucidated by X-ray diffraction.     

Ferrocene Compounds. XXXI. Structure of 3-Ferrocenylpropanoic Acid

The title compound was prepared by modified procedure and characterized by means of IR, [¹H] and [¹³C] NMR spectroscopy. The structure was also determined by a single-crystal X-ray diffraction (XRD). 3-Ferrocenylpropanoic acid crystallizes as orange prisms in the triclinic space group P with a = 7.645(1) Å, b = 7.953(1) Å, c = 9.961(1) Å, = 81.67(1), = 68.43(1), = 83.76(1), V = 556.3(1) ų, Z = 2, R = 0.0435. In the ferrocene skeleton, Fe-C distances are in the range 2.033(2)–2.052(2) Å and C C distances in the range 1.412(5)–1.431(3) Å. The angle defined by ring centers and Fe atom is 177.7(1). The cyclopentadienyl rings are twisted from the eclipsed conformation by 8.3(2) (average value). In the structure was observed strong intermolecular hydrogen bond of 2.670(3) Å forming cyclic dimers of the R₂ ² (8) type.     

Synthesis,structural characterization and bonding properties of heterometallic-heterobridging cubane-type tetranuclear cluster compounds [CuMo3OS3]·I·(μ-OAc)[S2P(OC2H5)2]3·L (L=py,DMF)

By the reaction of cluster [Mo₃OS₃](dtp)₄(H₂O) used as starting material with CuI using [3+1] mode, two novel heterometallic-heterobridging cubane-type tetranuclear cluster compounds [CuMo₃OS₃]·I·(-OAc)[S₂P(OC₂H₅)₂]₃·L [(I)L=py, (II)L=DMF] [dtp=S₂P(OC₂H₅)₂; OAc=OOCCH₃] containing [CuMo₃OS₃] core have been obtained. Compounds (I) and (II) have been characterized by IR, EPR, UV-VIS, electrochemistry and X-ray crystallography. By comparison of these two compounds with the analogous [CuMo₃S₄] series in the structure and molecular orbital calculation, the influence of mixed S/O bridging on the structure is discussed. It is demonstrated that the {Mo₃S₃} cluster ring in [Mo₃OS₃]⁴⁺ possesses a similar quasi-aromaticity to [Mo₃S₄]⁴⁺. Crystal data: for (I), space group= ,a=13.781(8)Å,b=14.523(6)Å,c=12.098(6)Å, =98.37(4)°, =109.41(5)°, =105.00(5)°,V=2133(2)ų,Z=2,R=0.058; for (II), space group= ,a=13.215(4)Å,b=17.818(8)Å,c=9.873(4)Å, =106.06(4)°, =109.78(3)°, =82.00(3)°,V=2100(2)ų,Z=2,R=0.045.Invited Professor at Fuzhou University.     

Synthesis and crystal structure of monoclinic Fe2(SeO4)3

Summary Crystals of monoclinic Fe₂(SeO₄)₃ were synthesized under hydrothermal conditions. The structure was determined by single crystal X-ray methods and refined in space group P2₁/n with 2 646 independent reflections (sin /<0.7 Å^–1) toR=0.033,R _w=0.037:a=8.530 (2) Å,b=8.888 (2) Å,c=11.952 (2) Å, =91.13 (1)°,V=906.0 ų,Z=4. The crystal structure is isotypic with the monoclinic modification of Fe₂(SO₄)₃, containing two different Fe(III) and three Se(VI) atomic positions. The FeO₆ and SeO₄ polyhedra are only slightly distorted, the mean Fe-O bond lengths are 1.986 Å and 2.004 Å, the average distances within the SeO₄ tetrahedra are each 1.628 Å. The isolated FeO₆ octahedra only share corners with SeO₄ tetrahedra to build a framework structure.

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Synthese und Kristallstruktur von monoklinem Fe₂(SeO₄)₃

Zusammenfassung Kristalle von monoklinem Fe₂(SeO₄)₃ wurden unter Hydrothermalbedingungen gezüchtet. Die Struktur wurde mit Einkristall-Röntgenmethoden bestimmt und in der Raumgruppe P2₁/n mit 2 646 unabhängigen Reflexen (sin /<0.7Å^–1) aufR=0.033,R _w=0.037 verfeinert:a=8.530(2) Å,b=8.888(2) Å,c=11.952(2) Å, =91.13(1)°,V=906.0 ų,Z=4. Die Kristallstruktur ist isotyp mit der monoklinen Modifikation von Fe₂(SO₄)₃, sie enthält zwei unterschiedliche Fe(III) und drei Se(VI) Atompositionen. Die FeO₆-Polyeder sind nur gering verzerrt, die mittleren Fe-O Bindungslängen sind 1.986 Å und 2.004 Å, die mittleren Abstände in den SeO₄-Tetraedern sind jeweils 1.628 Å. Die isolierten FeO₆-Oktaeder sind nur über gemeinsame Ecken mit SeO₄-Tetraedern verbunden, wobei eine Gerüststruktur entsteht.

     

Synthesis and Structure of Acetonitrile Solvates of Copper(II) Monofluoroacetate and Silver(I) Trifluoroacetate, [Cu2(CH2FCOO)4· 2CH3CN](CH3CN) and Ag3(CF3COO)3(CH3CN)2

Compounds [Cu₂(CH₂FCOO)₄· 2CH₃CN](CH₃CN) (I) and Ag₃(CF₃COO)₃(CH₃CN)₂(II) were synthesized and studied by X-ray structural analysis. Crystals Iare monoclinic, space group C2/c, a= 27.854(6), b= 8.286(2), c= 19.428(4) Å, = 106.82(3)°, V= 4292(2) ų, Z= 8, R ₁= 0.0426; crystals IIare triclinic, space group , a= 8.676(2), b= 9.819(2), c= 11.961(2) Å, = 95.27(3), = 109.59(3)°, = 104.60(3)°, V= 911.4(3) ų, Z= 2, R ₁= 0.0252. Structure Iis composed of the structural units (lanterns) typical of copper(II) carboxylates. The presence of an additional acetonitrile molecule noncoordinated by the copper atoms makes it possible to consider compound Ias a lattice clathrate. Structure IIhas no analogs among the silver carboxylates. It simultaneously contains silver atoms with coordination numbers varying from 2 to 4.     

Inclusion complexes of the natural product gossypol. Strong influence of the guest on the host structure in channel-type isostructural inclusion complexes of gossypol

The crystal structures of 1 : 1 inclusion complexes of gossypol with tetrahydrofuran (GPTHF), cyclohexanone (GPCHN) and butanal (GPBTA) have been determined by X-ray structure analysis. The crystals of GPTHF are triclinic, space group P,a = 10.788(2),b = 10.979(3),c = 13,880(2) Å, = 80. 11(2), = 103.87(1), = 77.96(2)°,V = 1517.8(6) ų,Z = 2,R = 0.052 for 2701 observed reflections. The crystals of GPCHN are triclinic, space groups P,a = 10.803(4),b = 11.157(5),c = 15.428(6) Å, = 108.75(3), = 106.93(3), = 103.34(3)°,V = 1573(1) ų,Z = 2,R = 0.071 for 1879 observed reflections. The crystals of GPBTA are triclinic, space group P,a = 10.190(2),b = 11.335(1),c = 14.665(2) Å, = 73.04(1), = 103.74(1), = 81.07(1)°,V = 1529.9(5) ų,Z = 2,R = 0.068 for 2964 observed reflections. Crystal data for another 13 isostructural inclusion complexes are given.[/p]In this isostructural group of complexes guest molecules are accommodated in channels and are hydrogen bonded to the host molecules via an 0(1)-H....O(1) hydrogen bond. The molecular association changes significantly with the shape and size of the guest component. In GPTHF centrosymmetric dimers of gossypol formedvia O(5)-H...O(3) hydrogen bonds are associated in columns via a weak O(4)-H...O(8) hydrogen bond. In GPCHN the latter bond disappears as the distance O(4)-O(8) is increased to 3.73 Å. In GPBTA the O(5)-H...O(3) bond is replaced by three centre hydrogen bonds O(5)-H...O(2) and O(3)-H...O(5), and a centrosymmetric dimer of a new type is formed. These dimers are further connected by two weak hydrogen bonds to form columns. The butanal molecule interacts with the host structure via two hydrogen bonds. This indicates that a guest component can activate or deactivate different functional groups of the host in channel inclusion complexes of gossypol for hydrogen bond formation.