Synthesis and molecular structure of [1, 3-(Me3Si)2C5H3]2Lu(μ-Cl)2

Cp^* ₂Lu(-Cl)₂ (1) was isolated following the reaction of Cp^*Na (Cp^* = 1, 3-(Me₃Si)₂C₅H₃) with LuCl₃ in THF and subsequent treatment with toluene at 80°C. An X-ray structural investigation of1 was performed (MoK radiation, 2933 reflections,R = 0.020). The crystals are triclinic,a = 10.744(3) Å,b=11.821(2) Å, c=12.966(3) Å, a=71.54(1)°, =85.32(2)°, =74.83(1)°,Z = 2, space groupP-1. Two Lu atoms withdistorted tetrahedral coordination are linked by two chloride bridges with a mean Lu-Cl distance equal to 2.62 Å.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 568–570, March, 1993.     

Complexation with diol host compounds. Part 1. Structures of the 1:2 molecular complexes oftrans-9, 10-dihydroxy-9,10-diphenyl-9,10-dihydroanthracene with acetophenone and with 3-methylcyclopentanone

The structures of the 1:2 molecular complexes of trans -9,10-dihydroxy-9,10-diphenyl-9,10-dihydroanthracene with acetophenone (1), (C₂₆H₂₀O₂·2 C₈H₈O) and with 3-methylcyclopentanone (2), (C₂₆H₂₀O₂·2C₆H₁₀O) have been determined by X-ray crystallography. The crystal data are as follows: Compound (1):P ,a =8.979(5) Å,b =9.316(3) Å,c = 11.12(1) Å, =94.40(6)°, = 106.53(6)°, = 109.92(5)°,V = 822.94 ų,Z = 1,R = 0.097 for 2549 unique reflections. Compound (2):P ,a = 8.958(7) Å,b =9.815(4) Å,c = 9.807(4) Å, = 96.88(3)°, = 109.21(8)°, = 103.33(7)°,V = 774.10 ų,Z = 1,R = 0.059 for 2494 unique reflections. The intermolecular arrangements in both structures are characterised by host-to-guest hydrogen bonding interactions. The thermal properties of compound (2) have been characterised by DTA and TGA thermograms.     

Tetracarbonyliron adducts of Cp2Cr2(CO)4(μ-η2-P2). Syntheses and crystal structures of Cp2Cr2(CO)4P2[Fe(CO)4] m (m=1 and 2)

Cp₂Cr₂(CO)₄( - ² - P₂), 1, reacts with one molar equivalent of Fe₂(CO)₉ in THF to yield the mono- and di-iron complexes, Cp₂Cr₂(CO)₄P₂[Fe(CO)₄], 2, (16.5% yield) and Cp₂Cr₂(CO)₄P₂[Fe(CO)₄]₂, 3, (16.9% yield), as dark magenta brown and dark greenish brown crystals, respectively. Both complexes were characterized by single-crystal X-ray diffraction analysis. Crystal data –2: space group =P2₁/c,a=17.024(1) Å,b=8.180(1) Å,c=30.891(2) Å, =100.953(5)°,V=4223.4(7)ų,Z=8, 3743 observed reflections,R _F=0.033; 3: space group P1,a=10.209(2) Å,b=10.212(2) Å,c=15.989(3) Å, =106.93(1)°, =91.87(1)°, =119.50(1)°,V=1356.5(4) ų,Z=2, 3489 observed reflections,R _F=0.029.     

Peri Interactions in Naphthalene Diketones: A Preference for (Z,Z) Conformations

The crystal structures of 1,8-dibenzoylnaphthalene (9), 1,4,5,8-tetrabenzoylnaphthalene (10), and 1,8-diacetylnaphthalene (11) have been determined by X-ray diffraction. Diketone 9 crystallizes in triclinic space group P ^—1 with a = 7.924(2), b = 14.068(3), c = 7.876(1) Å, = 99.47(2), = 90.58(1), = 91.43(2)°. Tetraketone 10 crystallizes in monoclinic space group P2₁/c a = 7.374(4), b = 11.960(5), c = 15.524(5) Å, = 93.15(5)°. Diketone 11 crystallizes in orthorhombic space group Pbca a = 6.986(3), b = 15.946(4), c = 8.257(1) Å. Each of these naphthalene ketones adopt a (Z,Z) conformation, with torsion angles O—C—C¹—C^8a/O—C—C⁸—C^8a of 49.8°/44.5° (9), 52.1°/46.6° (10), and 44.8°/42.4° (11). The structures 9–11 are overcrowded with the distances between two neighboring carbonyl carbon atoms being significantly shorter than the sum of the van der Waals radii of two carbon atoms (342 pm): 293.4 pm (9), 281.6 pm (10), and 293.0 pm (11).     

Studies on styrene phosphonic acid

Some properties of styrene phosphonic acid (SPA) were studied. The crystals were triclinic, witha=0.6434 nm,b=0.5842 nm,c=2.0338 nm, =96.17°, =97.33°, =79.65° andZ=4. SPA underwent a change in crystal structure at 78.8°C, the hydrocarbon network became disordered (liquid-like) at 138.5°C. Crystals melted at 148.6°C giving a cubic mesophase, then changed to an isotropic liquid at 155.6°C and at 162.13°C SPA underwent decomposition. Values for pK₁=2.15 and pK₂=7.66 were obtained at 25°C. The water solubility of SPA at several temperatures, and its interaction with surfactant micelles were determined.     

Ruthenium complexes with diazadienes,Part V(1).Cis-Dicarbonyl-1,4-diaza-1,3-diene-trans-diiodoruthenium Complexes; synthesis,properties and the crystal structure of [(DAD)Ru(CO)2I2] · DAD (DAD=p-tolyl-N=CMe-CMe=N-p-tolyl)

Summary Diazadienes (DAD) (RN=CRCR=NR with R=H or Me and R=n-,i- ort-alkyl, aryl oro,o-substituted aryl) easily form the thermally inert title compounds [(DAD)-Ru(CO)₂I₂] (2). Their stereochemistry is unambiguously derived from¹H-n.m.r. and i.r. data. One of the complexes (2h) cocrystallizes with the free diazadiene (1h) in a 11 molar ratio. An x-ray diffraction study, which allows a comparison of the free and bound diazadiene. was performed with the monoclinic crystal and gave the following cell parameters: space group C 2/c, a=2237.0(5), b=1017.4(3) and c=1824.9(4) pm, =105.13(2)°, Z=4. From 2781 observed reflections 293 parameters were refined, leading to a final R-value of 0.0346 (R_w=0.0340). The tilting of thep-tolyl group is a consequence of an intra-ligand repulsion R/R, the R-conformation being almost equal in the (E,E,E)-shaped molecule (1h) (68°) and the (E,Z,E)-chelate in (2h) (72°). Complexes (2) are photolabile (with loss of CO), and on reduction they lose iodide, thus offering selective ways for the exchange of -acceptor or -donor ligands for precatalyst formation.For Part IV see Ref. 1, Part III see Ref. 17; Part II and I, seeTransition Met. Chem., 7, 154 (1982) and6, 185 (1982), respectively.     

Physicochemical and Catalytic Properties of La1 – xCaxFeO3 – 0.5x Perovskites Prepared Using Mechanochemical Activation

The phase composition of La_{1 – x} Ca _x FeO_{3 – 0.5x} perovskites synthesized from preactivated oxides was studied by powder X-ray diffraction analysis and differential dissolution. The system does not form a continuous series of homogeneous solid solutions. No intermediate samples from this series are monophasic. It was found that the synthesis under nonequilibrium conditions (mechanical activation + calcination at 900° for 4 h) resulted in nonequilibrium microheterogeneous solid solutions with degrees of calcium substitution for lanthanum of no higher than 0.5. A longer calcination (for 16 h) or an increase in the calcination temperature of solutions up to 1100 ° decreased the calcium content of the samples down to x 0.2 because of the formation of a brownmillerite phase. The catalytic activity of the test samples in the oxidation of CO changed nonmonotonically with x, and it was maximum at x = 0.5–0.6, which correlates with the maximum density of interphase boundaries in these samples.     

Physical adequacy of parameters in statistical-mechanical calculations of the properties of strong electrolyte solutions

Calculations have been carried out on the distribution functions, free energy F, and heats of dilution H for a 1-1 electrolyte solution with a variety of parameters representative of noncoulombic short-range interionic interaction in water at 15–40°C using a theoretical equation which is strictly valid at c<0.1 moles-liter^–1 and gives a good approximation up to c=0.3. The main result is that agreement with experimental H data could be obtained by very small, physically highly reasonable variations of the interionic specific potentialU _ab(r) of the order of 1% per degree centigrade. Any change in the distance of specific interactionr _c gives an appreciable contribution to H only if it is taken in the form of its temperature derivative. These contributions are large enough to account for the experimental data if one takes simultaneously into account appropriate changes ofU _ab(r) nearr _c to conjugate the former smoothly with the coulomb potential atr=r _c. To fit the calculated H to experimental data for NaCl in H₂O at 25°C it is necessary to allow the solvation of ions to increase with increasing temperature, which is in agreement with experiment.     

Spectra and structure of organophosphorus compounds: XLIX. Microwave,infrared, and Raman spectra,electric dipole moment,molecular structure,and ab initio calculations of dimethylphosphonothioic fluoride

The microwave spectra of (CH₃)₂PSF, (CH₃)(CD₃)PSF, (CD₃)₂PSF, and (CH₃)₂P³⁴SF have been investigated from 20.0 to 40.0 GHz. Botha-type R branch andc-type Q branch transitions have been measured in the ground states of each isotopic species. From a least-square adjustment to fit 12 rotational constants, the following structural parameters were obtained:r(P–F)=1.582 ± 0.003 Å;r(P=S)=1.902 ± 0.001 Å;r(P-C)=1.800 ± 0.001 Å;r(C-H)=1.088 ± 0.002 Å; HCP=109.28 ± 0.12°; SPF=114.50 ± 0.13°; and SPC=116.33 ± 0.06°. From Stark effect measurements, the dipole moment components have been determined to be ¦ _a ¦ =3.556 ± 0.005; ¦ _c ¦=2.026 ± 0.009; and ¦ _t ¦=4.093 ± 0.009 (D). The Raman spectra (3200 to 100 cm^–1) of each isotopic species have been measured for the solid, and liquid and qualitative depolarization values obtained. Additionally, the mid-infrared spectra (3200 to 500 cm^–1) of the solids have been recorded. Proposed assignments of the normal modes have been made on the basis of Raman depolarization values and group frequencies which are supported by normal coordinate analysis utilizing an ab initio force field. Optimized structural parameters have been obtained with both the 3-21G^* and 6-31G^* basis sets. These results are compared to the corresponding quantities for several similar molecules.For part XLVIII, seeJ. Raman Spectrosc.1922,23, 107.     

A Novel Lanthanum(III) Coordination Polymer Constructed by Bridging 3,5-Dinitrobenzoato Anions and π–π Interaction

The title compound, [La₂(H₂O)₄(C₇H₃N₂O₆)₆] _n (I), synthesized by the hydrothermal reaction of 3,5-dinitrobenzoic acid and 1,10-phenanthroline with La(ClO₄)₃ · 6H₂O crystallizes in the triclinic system, space group P with a = 9.566(2) Å, b = 12.126(3) Å, c = 14.214(3) Å, = 114.614(3)°, = 103.246(3)°, = 97.130(3)°, V = 1413.3(6) ų, Z = 2, R(F) = 0.0392 and wR(F ²) = 0.0425. In I, each La³⁺ ion is coordinated by six oxygen atoms of six carboxylate ligands and two oxygen atoms of two coordinated water molecules. The 3,5-dinitrobenzoato anions bridge the La(III) centers to form one-dimensional linear chains, and – interaction between the phenyl rings of 3,5-dinitrobenzoato anions of adjacent linear chains links the chains to engender a two-dimensional network.     

The relation between the molecular weight and intrinsic viscosity of polyvinyl alcohol

Summary A series of unfractionated and fractionated samples of polyvinyl acetate were prepared by homogeneous solution polymerization of vinyl acetate in N,N-dimethylformamide at 90 °C. in presence of , -azo-(-cyano-n-valeric acid) as initiator under a variety of conditions. A portion of each sample was hydrolysed to polyvinyl alcohol. The number average molecular weights have been determined by end-group titrations. The following molecular weight-intrinsic viscosity relationships for polyvinyl alcohol have been obtained. [] = 33.88 X 10^–5 M ^0.716 — for unfractionated samples in water at 30 °C. [] = 29.51 X 10^–5 M ^0.716 — for fractionated samples in water at 30 °C.With 1 figure and 2 tables     

Acid association quotients of bis-tris in aqueous sodium chloride media to 125°C

The ionic strength and temperature dependencies of the molal acid association quotients of 2,2-Bis(hydroxymethyl)-2,2,2-nitrilotriethanol (also abbreviated as bis-tris) were determined potentiometrically in a concentration cell fitted with hydrogen electrodes. The emf was recorded for equimolal bis-tris/bis- trisHCl buffer solutions from 5 to 125°C at approximately 25°C intervals, and at nine ionic strengths from 0.05 to 5.0m (NaCl). The molal association quotients, combined with infinite dilution values from the literature, are described precisely by a seven parameter equation which yielded the following thermodynamic quantities at infinite dilution and 25°C: logK=6.481±0.003, H ^o =–28.5±0.2 kJ-mol ^–1 , S ^o =28.5±0.8 J-K ^–1 -mol ^–1 , and C _P ^o =–22±5 J-K ^–1 -mol ^–1 . The equation incorporates a simple three term expression for logK, but requires four terms to describe the rather complex ionic strength dependence despite the reaction being isocoulombic. The molal association quotients from this study and the literature were also subjected to the Pitzer ion interaction treatment.     

Structure of Complexes Formed in the CuX2–Cu–N-Allylisoquinolinium Chloride System (X = Cl,Br)

The crystals of N-allylisoquinolinium chlorides of the compositions [C₉H₇N(C₃H₅)]₂Cu^IICl₄ (I), [C₉H₇N(C₃H₅)]Cu^ICl₂ · H₂O (II), and [C₉H₇N(C₃H₅)]Cu^ICl_1.43Br_0.57 · H₂O (III) were prepared by alternating-current electrosynthesis. X-ray diffraction analysis (using diffractometer models DARCH1 for I, STOE for II, and KUMA/CCD for III, MoK radiation) showed that the crystals of I are monoclinic, space group P2₁/n, a = 14.91(1) Å, b = 10.41(1) Å, c = 16.90(1) Å, = 109.73(8)°, V = 2470(8) ų, Z = 4. The crystals of isostructural compounds II and III are triclinic, space group P, Z = 2; crystals II: a = 7.2446(6) Å, b = 7.4379(6) Å, c = 12.110(1) Å, = 80.95(1)°, = 85.55(1)°, = 86.60(1)°, V = 641.8(2) ų; crystals III: a = 7.253(2) Å, b = 7.459(4) Å, c = 12.151(5) Å, = 80.82(4)°, = 83.73(3)°, = 86.81(4)°, V = 644.6(9) ų. The structure of I is composed of Cu^IICl₄ ^2– tetrahedra and N-allylisoquinolinium cations united by C–H···Cl hydrogen bonds in corrugated layers. The crystal structures of -complexesII and III are built of [C₉H₇(C₃H₅)]₂Cu₂ ^IX₄ dimers, which form layers along the c axis due to the C–H···X hydrogen bonds. An important role in the structure formation is played by water molecules, which crosslink the organometallic layers to form a three-dimensional framework through the O–H···X contacts.     

Spectra and structure of small ring compounds. Part L VIII: Structural parameters for chlorocyclobutane from combined microwave data and ab initio calculations

The structural parameters of chlorocyclobutane,c-C₄H₇Cl, have been obtained fromab initio Hartree-Fock calculations employing the 6–31G^* basis set for both the more stable equatorial and the high energy axial conformers. The determined carbonhydrogen distances were adjusted by 0.010 Å and held fixed while a weighted least-squares adjust was used to obtain all of the heavy atom parameters for the equatorial conformer by fitting the rotational constants of nine isotopic species. The determinedr ₀ parameters are:r(C - C) = 1.535(8) År(C - C) = 1.548(3) År(C - Cl) = 1.788(9) Å CCC, - CL = 132.0(2)°; CCC, = 89.7(6)°; CCC, = 87.1(2)°, and CCC, = 88.7(2)°. These results are compared to the calculated values as well as those obtained earlier from electron diffraction and microwave studies.For Part LVII, seeJ. Raman Spectrosc.,1990,21, 591.Taken in part from the thesis of M. J. Lee which will be submitted to the Department of Chemistry in partial fulfillment of the Ph.D. degree.     

Molecular Recognition Based on Roof-shaped Diol Hosts. X-Ray Crystal Structures of Inclusion Compounds with Methanol, Pyridine and Toluene

Three crystalline inclusion compounds of roof-shapedtrans-11,12-bis(diaryl-hydroxymethyl)-9,10-dihydro-9,10-ethanoanthracene host molecules [where aryl is 4-methyl-phenyl (3) or4-t-butylphenyl (4)] have been studied by X-ray diffraction.The crystals of both the 3methanol (2 : 1) [a = 10.755(1),b = 11.571(1), c = 14.697(2) Å, = 75.12(1), = 89.67(1), = 87.13(1) °] and the 4-pyridine (2 : 3) compounds[a = 14.045(3), b = 14.366(3), c = 15.607(3) Å, = 91.62(1), = 103.65(1) and =116.05(1)°] are triclinic (P–1),while the 3toluene (1 : 1) complex has orthorhombic (Fddd) symmetry [a = 16.041(1), b = 25.008(1), c = 40.440(4) Å]. The host–guest interactions in both triclinic crystals are characterised by hydrogen bonds, with different patterns however. The determined crystal structures indicate a compromise between the requirement of hydrogen bonding on the one hand and close packing on the other. The highly symmetrical host framework in the toluene (1 : 1) complex of 3 seems to be the result of shape recognition, although atendency towards weak (C_methyl)H _arylinteractions [C_methyl = 3.533(7) and 3.674(6) Å] between the hosts was observed. The present roof-shaped diol hosts give excellent examples of molecular recognition by exhibiting two significantly different conformations, mostly depending on the proton donor/acceptor ability of the guest component. (O)H O intramolecular bonding between the two alcoholic groups characterises the so-called active form, whereas weaker (O)H and interactions stabilise the `inactive'conformation.     

Structure of 2,4-diamino-6-(2,4-diphenyl-1-cyano-1,3-butadien-1-yl)-5-cyano-nicotinonitrile

An x-ray diffraction structural analysis was carried out to determine the structure of the 12 solvate of 2,4-diamino-6-(2,4-diphenyl-1-cyano-1,3-butadien-1-yl)-5-cyano-nicotinonitrile with acetonitrile (I) using Mo radiation to R=0.043. The unit cell parameters of the monoclinic crystals of I are as follows: a=11.019, b=23.541, c=9.861 Å, =105.45°, d _calc =1.27, Z=4, space group P2₁/c. The nonplanar, sterically strained molecule has trans configuration with E arrangement of the substituents in the butadiene fragment. The molecular packing in the crystal solvate is determined by the hydrogen bonding between the amino and cyano groups and coulombic interactions due to the polar nature of the acetonitrile molecules. The effect of the substituents on the pyridine ring geometry, analogous to that reported for benzene derivatives, is discussed.Research Institute for Organic Intermediates and Dyes and A. N. Nesmeyanov Institute of Heteroorganic Compounds, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 30, No. 5, pp. 114–122, September–October, 1989.     

Molecular and crystal structure of 2-phenoxy-2λ5-2,2′(3H,3′H)-spirobi[1,3,2-benzoxazaphosphole]

The crystal and molecular structure of 2-phenoxy-2⁵-2,2(3H,3H)-spirobi[1,3,2-benzoxazaphosphole] has been determined using X-ray diffraction structure analysis. The P atom in the molecule in question has a distorted trigonal bipyramidal coordination, with the bond lengths P-O_ax=1.701(1) and 1.700(1) Å, P-O_eq (Ph)=1.625 Å, P-N_eq=1.654(2) and 1.645(1) Å, and bond angles (O-P-O)_ax=175.69(7)° and (N-P-N)_eq = 132.38(7)°.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 876–879, May, 1993.     

Synthesis and Crystal Structure Determination of 6-(N-Isopropyl)Amidino-2-Methylbenzothiazole Hydrochloride Monohydrate and 2-Amino-6-(N-Isopropyl)Amidinobenzothiazole Hydrochloride

Two novel substituted amidino-benzothiazoles 6-(N-isopropyl)amidino-2-methylbenzothiazole 4 and 2-amino-6-(N-isopropyl)amidinobenzothiazole 6 were prepared in multistep synthesis in form of hydrochloride salts. They were characterized by means of IR, ¹H, and ¹³C-NMR spectroscopy and elemental analysis. The crystal structures have been also determined by X-ray analysis. Both compounds crystallize as colorless prisms in the triclinic crystal system, space group P . Crystal data: (4) a = 8.741(4) Å, b = 9.602(7) Å, c = 9.946(2) Å, = 63.94(3)°, = 79.18(2)°, = 79.68(3)°, V = 732.1(6) ų, Z = R = 0.0396; a = 8.106(1) Å, b = 9.148(2) Å, c = 9.291(2) Å, = 104.83(1)°, = 103.36(2)°, = 90.62(1)°, V = 646.2(2) ų , Z = 2, R = 0.0376. The bond distances and angles in both structures are almost similar. Between these two structures was found the difference in the orientation of the 6-(N-isopropyl)amidino moiety with respect to the benzothiazole ring. In the crystal structures of the both compounds the intermolecular hydrogen bonds form three-dimensional networks.     

Small-ring inclusion hosts. 4. X-ray crystal structures oftrans-3,3-Bis(4-methylphenyl)cyclopropane-1,2-dicarboxylic acid and of its inclusion complex with Dimethyl Sulphoxide (1:2)

The crystal structures of the unsolvatedtrans-3,3-bis(4-methylphenyl)cyclopropane-1,2-dicarboxylic acid (1) and of its inclusion compound with dimethyl sulphoxide,1·DMSO (1:2), have been studied by X-ray diffraction. Crystals of1 show triclinic symmetry (P ) withZ = 4 and the unit cell dimensionsa = 7.617(2),b = 15.321(4),c = 15.297(3) Å, = 109.76(2), = 103.47(1), = 89.87(2)°. FinalR = 0.037 for 3601 reflections collected atT = 153(1) K. Crystals of1·DMSO (1: 2) are monoclinic (P2₁/n) withZ = 4 and cell dimensionsa = 10.744(1),b = 10.806(1),c = 21.302(2) Å, = 101.68(1)°. The clathrate structure was refined toR = 0.034 for 1671 reflections obtained atT = 173(1) K. In the unsolvated host compound cyclic pairs of O-H ... bonds, commonly observed in carboxylic acids, couple the carboxylic functions two by two, thus giving rise to endless chains due to the bifunctionality and thetrans position of the acid groups of1. The complex with DMSO as guest, however, consists of distinct hydrogen-bonded 1:2 host-guest associates, held together by weak intermolecular interactions.Supplementary Data relating to this article have been deposited with the British Library at Boston Spa, Wetherby, West Yorkshire, U.K., as Supplementary Publication No. SUP 82139 (32 pages).For Part 3, see Reference [1].     

Preparation, characterization and crystal structure of Na4[Mn(NCS)6]·13H2O

Na₄[Mn(NCS)₆] · 13H₂O was prepared and characterized by chemical analysis, magnetic susceptibility, thermal dehydration reactions, and single crystal X-ray structure analysis. The crystals are triclinic with a=9.310(1)Å, b=9.367(1)Å, c=9.730(2)Å, = 89.89(1)°,=75.33(1)°, =70.72(1)°, space group P¯I.Z=1. The structure is built up from Na(H₂O)₅ S, Na(H₂O)₆, and Mn(NCS)₆, octahedra. All water molecules are coordinated to Na⁺ -ions in terminal as well as bridging fashion. They form O-H···O as well as O-H···S hydrogen bonds.Dedicated to Professor Dr. rer. nat. Dr. h.c. Hubertus Nickel on the occasion of his 65th birthday