Reaction of (dichloro)(1,5-cyclooctadiene)platinum(II) with dimethyl diazomethylphosphonate. Crystal structure analysis of a bis-insertion product, (R,R)-bis[chloro(dimethoxyphosphonyl)methyl]-(1,5-cyclooctadiene)platinum(II)

The reaction of dichloro(1,5-cyclooctadiene)platinum(II), 1 with dimethyl diazomethylphosphonate, 2, results in the formation of products of insertion of the carbene moiety into one or both PtCl bonds. An X-ray diffraction study of a crystal obtained from the major bis-insertion product of this reaction shows it to be (R,R)-bis[chloro(dimethoxyphosphonyl)methylyl](1,5-cyclooetadiene)platinum(II), 5. The space group is polar indicating that spontaneous resolution has occurred upon crystallization.     

Optical resolution of tetra isopropyl-substituted spiro bis(isoxazoline)i-Pr-SPRIX

The optical resolution of racemic tetra isopropyl-substituted spiro bis(isoxazoline) ligand (i-Pr-SPRIX) is achieved by fractional recrystallization of palladium complexes 2a and 2b prepared from (±)-SPRIX 1 and di-μ-chlorobis{(R)-2-[1-(dimethylamino)ethyl]phenyl-C,N}dipalladium(II) (R,R)-3 followed by the decomplexation from palladium by the treatment with 1,2-bis(diphenylphosphino)ethane. The X-ray crystal structure of the complex 2a reveals that (−)-i-Pr-SPRIX has (P,R,R)-configuration.     

Tautomerism of aza cycles: I. Structure of 3(5)-butylsulfanyl-5(3)-methyl(phenyl)-1H-1,2,4-triazole tautomers in crystal. Preference of the 3-RA-5-RD-1H-tautomer of 3(5)-mono-and 3,5-disubstituted 1,2,4-triazoles

The X-ray diffraction study of potentially tautomeric 3(5)-butylsulfanyl-5(3)-methyl-1H-1,2,4-triazole and its 5(3)-phenyl-substituted analog showed that these compounds in crystal have the structure of 3-butylsulfanyl-5-methyl(phenyl)-1H-tautomers. Analysis of our experimental and published data indicated that 3(5)-monosubstituted 1,2,4-triazoles and 3,5-disubstituted derivatives having nonequivalent substituents in crystal as exist as a tautomer in which the electron-acceptor substituent (R_A) occupies the 3 position, while the electron-donor substituent (R_D) resides in the 5 position, i.e., as 3-R_A-5-R_D-1H-1,2,4-triazoles. Symmetric 3,5-disubstituted 1,2,4-triazoles could give rise to tautomeric equilibrium between the 1H-and 2H-structures even in crystal.     

Synthesis and analytical properties of (S)-(+)-2-methoxy-2-(9-phenanthryl)propionic acid

2-Methoxy-2-(9-phenanthryl)propionic acid was synthesized as a novel chiral resolving agent. The absolute configuration of (+)-2-methoxy-2-(9-phenanthryl)propionic acid was determined to be S by using X-ray structural analysis of the (1R,2S,5R)-menthyl ester. In the crystal, the methoxyl and carbonyl groups of the ester are in a syn-periplanar position. The syn-periplanar conformations of (1R,2S,5R)-menthyl esters were also observed by the NMR analyses in CDCl₃. The utility of (S)-(+)-2-methoxy-2-(9-phenanthryl)propionic acid was exemplified by the resolution of (±)-3-octanol.     

Organostibines as ligands. Synthesis of dimethyl(α-picolyl)stibine,dimethyl(8-quinolyl)stibine,and (R;S)-methylphenyl(8-quinolyl)stibine and some transition metal derivatives

The unsymmetrical mono-tertiary stibines dimethyl(α-picolyl)stibine (picstib), dimethyl(8-quinolyl)stibine (quinstib), and (R;S)-methylphenyl(8-quinolyl)stibine (R;S-quinstib) have been synthesised and the square-planar complexes [MX₂(picstib)], [MX₂(quinstib)] (where M = Pd or Pt and X = Cl, Br, I or SCN) and [MCl₂(R;S-quinstib)] (where M = Pd or Pt) isolated. The thiocyanato derivatives display linkage isomerism. The octahedral complexes [M(CO)_4-(picstib)] and [M(CO)₄(quinstib)] have also been prepared from the metal hexacarbonyls and the appropriate ligands by UV irradiation in tetrahydrofuran.     

Synthesis of (R)- and (S)-4-hydroxyisophorone by ruthenium-catalyzed asymmetric transfer hydrogenation of ketoisophorone

The first synthesis of (R)- and (S)-4-hydroxyisophorone by catalytic transfer hydrogenation of ketoisophorone is reported. Ruthenium catalysts containing commercially available chiral amino alcohols afforded 4-hydroxyisophorone in up to 97% selectivity and 97% ee. (R)- or (S)-4-Hydroxyisophorones with >99% ee were isolated by crystallization. The catalyst precursors [RuCl₂((S,R)-ADPE)(η⁶-p-cymene)] ((S,R)-ADPE=(1S,2R)-amino-1,2-diphenylethanol-N) and (R_Ru)-[RuCl((S,R)-ADPE⁻¹)(η⁶-p-cymene)] (ADPE⁻¹=amino-1,2-diphenylethanolato-N,O) were isolated for the first time and the X-ray crystal structure of the latter determined.     

Carbon-nitrogen bond formation in the reaction of the reaction of diphenyl diazomethane Ph2 CN2 with diiron-carbene complexes (Fe2(CO)7x03BD;-C(R)C(NEt2)x03BD;-C(R)C(NEtx03BC;-C(R)C(NEt2)N(NCPh2)x03BC;-C(R)C(NEtx03BC;-C(R)C(NEt2)NN(CPh2)x03BC;-C(R)C(NEt)]

The diiron ynamine complex [Fe₂(CO)₇{μ-CR)C(NEt₂)}] (1:R=Me,2:R = C₃H₅.3:R=SiMe₃.4:R = Ph) reacts at room temperature with diphenyldiazomethane Ph₂CN₂, in hexane to yield complexes [Fe₂(CO)₆{C(R)C(NEt₂)N (NCPh₂)] (5a:R=Me,6a:R=C₃H₅.7a R=SiMe₃.8a:R=Ph) resulting from the insertion of the terminal nitrogen atom into the Fe=C carbene bond. Insertion the second nitrogen atom and formation of compounds [Fe₂(CO)₆zμ-C(R)C(NEt₂)NN(CPh₂)}] (5b:R=Me,6b:R=C₃H₅,7b:R=SiMe₃,8b:R=Ph) is observed when compounds5a-5a are treated in refluxing hexane. Transformation of compoundsa tob is also obtained at room temperature within a few days. All compounds were identified by their¹H NMR spectra. Compounds6a, 7a, 8a, and8b were characterized by single crystal X-ray diffraction analyses. Crystal data: for6a: space group = P2₁/n,a=12.853(1) A,b=24.800(7) A,c=8.947(6) A,β=99.29(3)°,Z=4, 2227 rellectionsR=0,038; for7a: space group=Pl,a=ll.483(4) A,b=14.975(4) A,c = 17.890(8) A,α = 82.80(3)°,β=94.29(7)°,γ=85.42(2),Z = 4, 5888 reflectionR = 0.035: for8a: space group = Pcab.a = 31.023(8) A.b=20.137(1) A.c=9.686(2) A.Z=8. 1651 reflections,R=0.071; for8b: space group=P2₁/n,a=21.459(4),b=10,100(3) A,c=28,439(8) A,ß=103.86(4)°,Z=8. 2431 reflections.R=0.057.     

Structure elucidation and X-ray crystallographic study of 3-(naphth-1-ylmethyl)indole

Synthesis and structure determination of 3-(naphth-1-ylmethyl)indole are reported. The molecular and crystal structures together with the molecular formula were determined by spectral and single crystal X-ray studies. X-ray crystallography revealed the presence of two conformers arising from the flipping of the naphthalene unit. The crystal of the compound belongs to the triclinic crystal system and space group \(P\bar 1\). Crystal data are as follows: a = 10.302(5) Å, b = 12.522(4) Å, c = 13.383(4) Å, α = 111.9(1)°, β = 116.86(6)°, γ = 71.65(5)°; V = 1726.429 ų; Z = 4. The final R and Rw are R = 0.0744 (on observed F′s); R = 0.0924 (all F data), R _w = 0.1757 (observed F ²) and R _w = 0.1834 (all F ² data).     

Alkylsulfonato(porphyrinato)gallium(III). Determination de la structure cristalline de la methylsulfonato-(octaethyl-2,3,7,8,12,13,17,18-porphyrinato)-gallium(III)

The insertion of sulfur dioxide into the alkyl-gallium bond of gallium(III) porphyrins [Ga(Por)R] gives rise to sulfinato compounds which can easily be oxidized to the corresponding sulfonato complexes. The latter are also generated by acidic hydrolysis of the GaCl bond of chlorogallium(III) porphyrins [Ga(Por)Cl] by the appropriate sulfonic acid. The obtained derivatives are characterized on the basis of mass spectrometry, ¹H NMR, and UV-visible data. The crystal structure of [Ga(OEP)(SO₃CH₃)] (OEP=2,3,7,8,12,13,17,18-octaethylporphyrinato) has been determined by X-ray diffraction methods. The crystals are monoclinic, space group P2₁/c, with a 14.08(2), b 16.129(9), c 19.274(3) Å, β 126.05(1), and Z = 4. The structure has been solved by the heavy atom method and refined to an R index of R(F) = 0.0635 and R_W(F) = 0.0615 with the SHELX Program. The gallium atom is five-coordinated by the four nitrogen atoms of the porphyrin and one oxygen atom of the sulfonato group (GaO(1) 1.908(6) Å).     

Synthesis and structure of trans-diaquabis(dimethylsulfoxide)bis(3,5-dinitrobenzoato)copper(II)

Single crystal of [Cu(DMSO)₂(3,5-DNB)₂(OH₂)₂], where DMSO-dimethylsulfoxide, 3,5-DNB-3,5-dinitrobenzoate, has been synthesized and its crystal structure is determined. Crystals belong to monoclinic symmetry, space group is P2₁/n, Z = 2, a = 10.911(4) Å, b = 5.362(2) Å, c = 22.673(7) Å, β = 92.06(2)°, V = 1325.8(1) ų, T = 293 K. Final value of R = 0.040 was obtained for 1804 independent reflections with I > 3σ(I). The structure is built from complex molecules.     

Synthesis of chloroantimonates(III) with selected organic cations. X-ray studies of phase transition in ferroelectric tris(trimethylammonium) nonachlorodiantimonate(III) at 125 K

The dependence of molar ratio of reactants on the formula, crystal structure and physicochemical properties of chloroantimonates(III) with different organic cations was studied. It was proved, that the compounds show preferences in crystallization of one product. The changes of the molar ratio of substrates lead to the corresponding changes of these components in crystallized products. The structure of ferroelectric chloroantimonate(III), [(CH₃)₃NH]₃[Sb₂Cl₉], was determined at 165 and 95 K. It crystallizes in monoclinic space group Pc: a=9.9612(11), b=9.0714(8), c=15.1807(14) Å, β=90.086(8)°, R₁=0.0202, wR₂=0.0405 and a=9.9138(10), b=9.0783(7), c=15.1299(14) Å, β=90.026(8)°, R₁=0.0163, wR₂=0.0356 at 165 and 95 K, respectively. At both temperatures the crystal is built of polyanionic layers and trimethylammonium cations. They are bound together by the system of hydrogen bonds. The molecular motions of the organic cations are gradually frozen with decreasing temperature. At 165 K all cations are ordered. The non-structural ferro-ferroelectric phase transition at 125 K is associated with changes in the dynamics of trimethylammonium cations.     

Synthesis of unusual mixed ligand tellurium(IV) dithiocarbamates with perchlorate. Crystal and molecular structure of perchloratotris(diethyldithiocarbamato)tellurium(IV)

Synthetic and structural aspects of perchlorato complexes of tellurium(IV) with different dithiocarbamates (dtc) [(R₁R₂NCS₂) where R₁ = R₂ = methyl, ethyl, n-propyl, i-propyl; R₁R₂ = (CH₂)₅(piperidine), C₂H₄OC₂H₄ (morpholine)] are reported. The crystal structure of TeL₃ClO₄ (where L = diethyl dtc) has been determined. The crystals of the complex are monoclinic, space group P2₁/n, a = 11.379(3), b = 17.745(7), c = 14.016(8) Å, γ = 103.30(2)°, V = 2754.2 ų, F(000) = 1352, D_X = 1.61 mg M−3. The final R and R_w values are 0.047 and 0.058, respectively for 5224 unique reflections. Tellurium displays a distorted dodecahedral stereochemistry formed by two interposing trapezoids, one resulting from the four sulphurs of two L groups and the other from the two sulphurs of the third L and the two oxygens of the perchlorate ion. The average TeS distance 2.648(2) Å is close to that reported in other tris(dithiocarbamato)tellurium(IV) complexes. The perchlorate is weakly coordinated to tellurium(IV), with the average TeO distance being 2.994(8) Å. The unusual coordination of perchlorate (as a bidentate ligand) to tellurium(IV) dithiocarbamate is reported for the first time.     

Contribution to the crystal chemistry of tetrametaphosphates(II)

Chemical preparations and crystal structures of two hydrated forms of CsNa₃P₄O₁₂ are described. CsNa₃P₄O₁₂ · 4H₂O with a = 14.50(2), b = 7.804(3), c = 7.006(3)Å crystallizes in space group Imm2, Z = 2. The crystal structure has been determined using 745 independent reflexions with a final R value of 0.028 (R = 0.040 with the 934 collected reflexions), CsNa₃P₄O₁₂ · 3H₂O with a = 11.39(1), b = 10.92(1), c = 11.81(1)Å, β = 95.24(5)° in $\text{P2}{}_1\text{c}\text{, Z = 4}$. The crystal structure has been solved with 2975 independent reflexions with a final R-value of 0.018 (R = 0.057 with all the 6531 collected reflexions). In both structures there are four-membered rings built up with corner-sharing phosphate tetrahedron. For the tetrahydrate, the ring symmetry is mm whereas in the trihydrate, one observes two independent ring anions of symmetry $\text{1}$. In both cases hydrogen atoms have been located and refined.     

Monomeric and polymeric structures of oxovanadium(IV) complexes with Schiff base ligands derived from (R,R)-2,4-pentanediamine: Synthesis and crystal structure

New tetradentate Schiff base–oxovanadium(IV) complexes which have electron donating or withdrawing groups at the 5-position of the salicylaldehyde moieties, [VO{Xsal-(R,R)-2,4-ptn}] (H₂{Xsal-(R,R)-2,4-ptn}: N,N′-di-Xsalicylidene-(R,R)-2,4-pentanediamine; X=5-MeO (methoxy), 5-Br, and 5-NO₂) were prepared. The structures and redox potentials for the V(V)/V(IV) couple of the complexes were compared with those of other [VO{Xsal-(R,R)-2,4-ptn}] (X=3-EtO (ethoxy), 3-MeO, and H). The 5-MeO substituted complex which has electron donating groups at the 5-position of the salicylaldehyde moieties forms a monomeric structure in the solid state. The 3-EtO substituted complex has both monomeric and polymeric structures. On the other hand, the other [VO{Xsal-(R,R)-2,4-ptn}] (X=H, 3-MeO, 5-Br, 5-NO₂) complexes have only polymeric structures. X-ray crystal structure analysis of [VO{5-MeOsal-(R,R)-2,4-ptn}]⋅CH₃OH (1) was carried out. Complex 1 has a monomeric five-coordinate square–pyramidal structure. The six-membered N–N chelate ring forms a distorted flattened boat form with two methyl groups in the axial positions.     

Durene-rhodium(I) complexes. Crystal structures of the complexes [Rh(durene)(diolefin)]ClO4 (diolefin  tetrafluorobenzobarrelene or trimethyltetrafluorobenzobarrelene)

The crystal structures of [Rh(durene)(diolefin)ClO₄ (diolefin  tetrafluorobenzobarrelene (TFB) and trimethyltetrafluorobenzobarrelene (Me₃TFB)) have been solved by standard X-ray single crystal methods. The compounds crystallize in the space groups R₃c for the unmethylated TFB compound and P2₁/n for the methylated one. The cell dimensions are 25.7586(5), 17.0059(4) Å and 12.6686(6), 11.5565(3), 16.7269(8) Å, β  104.023(5)°, respectively. The refinement was taken to R values of 0.04 and 0.06, respectively. The arene in the TFB derivative has a distorted inverted boat conformation which becomes a skew one in the Me₃TFB compound. These puckering seems to be related to the tendency of rhodium(I) to achieve square-planar coordination.     

Synthesis and structural characterization of Al4Si2C5-homeotypic aluminum silicon oxycarbide, (Al6−xSix)(OyC5−y) (x∼0.8 and y∼1.6)

We have prepared a new layered oxycarbide, [Al_5.25(5)Si_0.75(5)][O_1.60(7)C_3.40(7)], by isothermal heating of (Al_4.4Si_0.6)(O_1.0C_3.0) at 2273 K near the carbon-carbon monoxide buffer. The crystal structure was characterized using X-ray powder diffraction, transmission electron microscopy and energy dispersive X-ray spectroscopy (EDX). The title compound is trigonal with space group R3?m (centrosymmetric), Z=3, and hexagonal cell dimensions a=0.32464(2) nm, c=4.00527(14) nm and V=0.36556(3) nm³. The atom ratios Al:Si were determined by EDX, and the initial structural model was derived by the direct methods. The final structural model showed the positional disordering of one of the three types of Al/Si sites. The reliability indices were R_wp=4.45% (S=1.30), R_p=3.48%, R_B=2.27% and R_F=1.25%. The crystal is composed of three types of domains with nearly the same fraction, one of which has the crystal structure of space group R3¯m. The crystal structure of the remaining two domains, which are related by pseudo-symmetry inversion, is noncentrosymmetric with space group R3m.     

A new vanadium(III) fluorophosphate with ferromagnetic interactions, (NH4)[V(PO4)F]

A new vanadium(III) phosphate, (NH₄)[V(PO₄)F], has been synthesized by using mild hydrothermal conditions under autogeneous pressure. The crystal structure has been solved from X-ray single crystal data. The compound crystallizes in the Pnna orthorhombic space group, with the unit-cell parameters a=12.982(2), b=10.608(1), c=6.4789(6)Å and Z=8. The final R factors were R₁=0.077 [all data] and wR₂=0.068. The crystal structure consists of a three-dimensional framework formed by VO₄F₂ octahedra and tetrahedral (PO₄)³⁻ phosphate anions. The vanadium(III) cations from the VO₄F₂ octahedra are linked through the fluorine atoms giving rise to zig-zag chains. The ammonium cations are located in the cavities of the structure compensating the anionic charge of the [V(PO₄)F]⁻ inorganic skeleton. The IR spectrum shows the characteristic bands of the phosphate anion. The diffuse reflectance spectroscopy allowed us to calculate the Dq and Racah parameters. The values are Dq=1540, B=505 and C=2460 cm⁻¹. Magnetic measurements indicate the existence of weak ferromagnetic interactions.     

Regioselectivity in nickel(0) catalyzed cycloadditions of carbon dioxide with diynes

The regioselectivity of Ni(0)-catalyzed cycloadditions of CO₂ (1 atm) with various asymmetrical diynes to afford pyrones was explored. The use of 1,3-bis-(2,6-diisopropylphenyl)-imidazol-2-ylidene (IPr) provided high regioselectivity when one terminal substituent on the diyne was a methyl group and the other was medium or large in size (R_L=i-Pr, t-Bu, or TMS). In contrast, the use of a relatively small N-heterocyclic carbene, 1,3-dimesitylimidazol-2-ylidene (IMes), afforded high selectivity only when R_L was large (TMS). X-ray crystal analysis of the major isomer indicated that the relatively large R_L group was in the 3-position of the pyrone.     

Synthesis and X-ray diffraction studies of chiral nickel(II), zinc(II), manganese(II), and cobalt(II) complexes with C 2-symmetric 2,6-bis[4′-(R)-ethoxyoxazolin-2′-yl]pyridine

Chiral nickel(II), zinc(II), manganese(II), and cobalt(II) complexes with C ₂-symmetric 2,6-bis[4′-(R)-ethoxyoxazolin-2′-yl]pyridine were prepared, the single crystal of nickel(II) complex, [Ni((R,R)-Et-Py-box)(H₂O)₂Cl]Cl ((R,R)-Et-Pybox is 2,6-bis[4′-(R)-ethoxyoxazolin-2′-yl]pyridine), was obtained and indicated by X-ray diffraction analysis. The nickel(II) complex crystallizes in the orthorhombic system, space group P2₁2₁2₁ with a = 7.7346(4) Å, b = 19.7133(13) Å, c = 25.8014(14) Å, V = 3934.1(4) ų, Z = 8, and R = 0.0526 against 7010 reflections with I > 2σ (I). A feature of interest was noted in the unit cell of the compound, where two types of molecules exist, which similarly have a distorted octahedral geometry but only slightly differ in the orientation of the coordinated atoms to the central Ni atom. These two types of molecules interact with each other by O-H…Cl hydrogen bonds, giving rise to one dimensional ribbon structure.     

New pathway to triammine complexes of chromium(III): Crystal structure of 1-chloro-2,3-diaquo-4,5,6-triamminechromium(III) chloride

A new synthetic method to triammine complexes of Cr(III) is reported, via a hydrolytic process from tetrammine complexes. The crystal and molecular structure of 1 -chloro - 2,3 - diaquo - 4,5,6 - triamminchromium(III) chloride are described. The crystals are orthorombic, space group Pnma, with a = 13.230(2), b = 10.545(1), c = 6.754(1) Å, V = 942.3(3), Z = 4. Least-squares refinement of the structure based on 529 observations led to final discrepancy indices of R = 0.047 and R_w = 0.056. The Cr atom is bonded to two water molecules, three ammonia molecules and one chlorine atom in a distorted octahedral coordination showing a trans chloro-aquo configuration.