Preparation, infrared spectra, and crystal structure of two modifications of the (thymidinato-N3)methylmercury(II) complex

1985 ◽  
Vol 63 (12) ◽  
pp. 3456-3463 ◽  
Author(s):  
France Guay ◽  
André L. Beauchamp
Keyword(s):  
Infrared Spectra ◽  
Water Molecules ◽  
Monoclinic Space Group ◽  
Hydroxyl Groups ◽  
Carbonyl Groups ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Preparation Conditions

Reaction of CH3HgOH with thymidine (HT) yielded the neutral CH3HgT complex crystallizing as a hydrated or an anhydrous material, depending on preparation conditions. Both forms were examined by X-ray diffraction. The anhydrous variety is monoclinic, space group P21, a = 4.798(6), b = 14.270(8), c = 10.390(4) Å, β = 102.74(9)°, and Z = 2 molecules per cell. The structure was refined on 1552 nonzero MoKα reflections to a conventional R factor of 0.034. The hydrated form belongs to the orthorhombic space group P212121, a = 10.484(3), b = 14.633(3), c = 18.538(5), Z = 8. The structure was refined on 1816 nonzero MoKα reflections to R = 0.036. In both forms, the CH3Hg+ ion is linearly bonded to the deprotonated N(3) site of thymidine. The water molecules and hydroxyl groups in the ribose unit participate in a hydrogen bonding network, in which the carbonyl groups are involved as acceptors. The infrared spectra of the two forms differ significantly only by the absorptions due to the water molecules. By comparing with the spectrum of thymidine, diagnostic regions for complexation with deprotonated thymidine have been proposed

Strukturuntersuchungen an Diaryldichalkogeniden: Die Molekülstrukturen von [2,4,6-(CF3)3C6H2S]2,[2,4,6-Me3C6H2Te]2 und [2-Me2N-4,6-(CF3)2C6H2Te]2 / Structural Investigations of Diaryl Dichalcogenides: The Molecular Structures of [2,4,6-(CF3)3C6H2S]2, [2,4,6-Me3C6H2Te]2 and [2-Me2N-4,6-(CF3)2C6H2Te]2

1992 ◽  
Vol 47 (3) ◽  
pp. 305-309 ◽  
Author(s):  
Anja Edelmann ◽  
Sally Brooker ◽  
Norbert Bertel ◽  
Mathias Noltemeyer ◽  
Herbert W. Roesky ◽  
...  
Keyword(s):  
Molecular Structures ◽  
Monoclinic Space Group ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Structural Investigations ◽  
Space Group ◽  
X Ray

Abstract The Molecular Structures of [2,4,6-(CF3)3C6H2S]2 (1) [2,4,6-Me3C6H2Te]2 and [2-Me2N-4,6-(CF3)2C6H2Te]2 (3) have been determined by X-ray diffraction. Crystal data: 1: orthorhombic, space group P212121, Z = 4, a = 822.3(2), b = 1029.2(2), c = 2526.6(5) pm (2343 observed independent reflexions, R = 0.042); 2: orthorhombic, space group Iba 2, Z = 8, a = 1546.5(2), b = 1578.4(2), c = 1483.9(1) pm (2051 observed independent reflexions, R = 0.030); 3: monoclinic, space group P 21/c, Z = 4, a = 1118.7(1), b = 1536.5(2), c = 1492.6(2) pm, β = 98.97(1)° (3033 observed independent reflexions, R = 0.025).

The Crystal and Molecular Structures of Two Modifications of cis-Dichloro-mer-tris-(dimethylphenylphosphine)hydridoiridium(III)

1988 ◽  
Vol 41 (3) ◽  
pp. 283 ◽  
Author(s):  
GB Robertson ◽  
PA Tucker
Keyword(s):  
Heavy Atom ◽  
Molecular Structures ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
Metal Ligand ◽  
Ligand Bond

The structures of two crystalline modifications of mer -(Pme2Ph)3H-cis-Cl2IrIII, (1), have been determined from single-crystal X-ray diffraction data. Modification (A) is monoclinic, space group P21/c with a 12.635(1), b 30.605(3), c 14.992(2)Ǻ, β 110.01(2)° and Z = 8. Modification (B) is orthorhombic, space group Pbca with a 27.646(3), b 11.366(1), c 17.252(2)Ǻ and Z = 8. The structures were solved by conventional heavy atom techniques and refined by full-matrix least- squares analyses to conventional R values of 0.037 [(A), 8845 independent reflections] and 0.028 [(B), 5291 independent reflections]. Important bond lengths [Ǻ] are Ir -P(trans to Cl ) 2.249(1) av. (A) and 2.234(1) (B), Ir -P(trans to PMe2Ph) 2.339(2) av. (A) and 2.344(1), 2.352(1) (B), Ir-Cl (trans to H) 2.492(2), 2.518(2) (A) and 2.503(1) (B) and Ir-Cl (trans to PMe2Ph)2.452(2) av. (A) and 2.449(1)(B). Differences in chemically equivalent metal- ligand bond lengths emphasize the importance of non-bonded contacts in determining those lengths.

The Constituents of Marine Sponges. IX New Norditerpenoids from Aplysilla pallida

1997 ◽  
Vol 50 (9) ◽  
pp. 903 ◽  
Author(s):  
Trevor W. Hambley ◽  
Walter C. Taylor ◽  
Stephen Toth
Keyword(s):  
Crystal Structures ◽  
Spectroscopic Studies ◽  
Marine Sponges ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray

Four novel norditerpenoids were isolated from a new encrusting sponge, conveniently labelled Aplysilla pallida. The structures of aplypallidenone (1), aplypallidoxone (2), aplypallidione (3) and aplypallidioxone (4) were elucidated by spectroscopic studies and the crystal structures of aplypallidenone and aplypallidoxone have been determined by X-ray diffraction methods. The structure of (1) was refined to a residual of 0·040 for 1665 independent observed reflections and the structure of (2) was refined to a residual of 0·031 for 1699 independent observed reflections. The crystals of (1) are orthorhombic, space group P212121, a 7·728(2), b 10·838(4), c 24·880(5) Å, Z 4. Those of (2) are monoclinic, space group C 2, a 23·927(7), b 6·674(2), c 14·033(3) Å, Z 4.

Crystal and molecular structure of Z- and E-1,2-dichloro-1,2-bis(2-chlorophenyl)ethylene. An X-ray and NMR study

1995 ◽  
Vol 73 (9) ◽  
pp. 1520-1525
Author(s):  
Luciano Antolini ◽  
Ugo Folli ◽  
Dario Iarossi ◽  
Adele Mucci ◽  
Silvia Sbardellati ◽  
...  
Keyword(s):  
Chemical Shifts ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Nmr Study ◽  
Phenyl Rings ◽  
A Cell ◽  
C Nmr

The crystal structures of the title compounds were determined by single crystal X-ray diffraction techniques. The molecule of the Z isomer, which crystallizes in the monoclinic space group C2/c with Z = 4 in a cell of dimensions a = 14.891 (2), b = 10.780(2), c = 8.769(1) Å, β = 97.47(2)°, V = 1395.7(7) Å3 has crystallographic twofold symmetry. The E form crystallizes in the orthorhombic space group Pbca with a = 11.730(1), b = 6.932(1), c = 16.841(1) Å, V = 1369.4(2) Å3 and Z = 4. Its molecules have crystallographically dictated [Formula: see text] symmetry. In both isomers the phenyl rings are roughly perpendicular to the average ethylene plane. The atoms characterizing this plane show significant deviations from planarity in the Z isomer. Marked bond-angle distortions at the ethene carbons of both structures are observed. The 1H and 13C NMR spectra of the compounds were measured and, particularly in the case of the 1H chemical shifts, fall into two quite separate spectral regions. At low temperature, two conformational isomers, those with different relative orientation of the C—Cl bonds of the phenyl rings, are observed in the spectrum of each compound. Keywords: chlorostilbenes, overcrowded molecules. X-ray structure, conformations, NMR spectroscopy.

Molecular Motions in (CH3)3XCl, X = Sn and Pb. NMR Investigations and Crystal Structure Study of (CH3)3PbCl and CH3SnBr3

1991 ◽  
Vol 46 (4) ◽  
pp. 337-343 ◽  
Author(s):  
Da Zhang ◽  
Shi-Qi Dou ◽  
Alarich Weiss
Keyword(s):  
Molecular Motion ◽  
Structure Study ◽  
Methyl Groups ◽  
Monoclinic Space Group ◽  
Molecular Motions ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Group D

Abstract The molecular motion in (CH3)3XCl, X = Sn and Pb has been investigated by measurement of the second moment M2(1H) as function of temperature in the range 95 < T,/K<345. The methyl groups in both compounds rotate freely over the whole temperature range studied. In (CH3)3SnCl the C'3-rotation of (CH3)3Sn-group about the Sn CI axis sets in above 273 K. To explain the NMR and INS results, the crystal structures of (CH3)3PbCl and CH3SnBr3 were determined by single X-ray diffraction. (CH3)3PbCl crystallizes in a monoclinic space group C32-C2, a = 1276.7(3) pm, b = 982.3(3) pm, c = 547.0(2) pm, ß = 91.12(1)°; Z = 4, R = 0.035. CH3SnBr3 crystallizes in an orthorhombic space group D162h-Pnma, a = 643.0(3) pm, b= 1005.3(4) pm, c= 1148.0(4) pm; Z = 4, R =0.057

Structural Systematics of Metal Acetylide Complexes. II. X-Ray Studies of Some Nickel σ-Acetylide Complexes

1998 ◽  
Vol 51 (3) ◽  
pp. 219 ◽  
Author(s):  
Ian R. Whittall ◽  
Mark G. Humphrey ◽  
David C. R. Hockless
Keyword(s):  
Single Crystal ◽  
Least Squares ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Triclinic Space Group ◽  
Full Matrix ◽  
Space Group ◽  
X Ray ◽  
Trans Influence

The structures of Ni(C≡CR)(PPh3)(η-C5H5) (R = Ph (1), C6H4-4-NO2 (2), 4-C6H4C6H4-4′-NO2 (3), (E)-4-C6H4CH=CHC6H4-4′-NO2 (4), 4-C6H4C≡CC6H4-4′-NO2 (5), 4-C6H4N=CHC6H4-4′-NO2 (6)) have been determined by single-crystal X-ray diffraction studies, refining by full-matrix least-squares analysis. For (1), crystals are triclinic, space group P-1, with a 10·094(2), b13·429(3), c 18·835(5) Å,α 103·24(2), β 91·50(2), γ 90·10(2)°, Z 4, 5844 unique reflections (595 parameters), converging at R 0·033 and Rw 0·024. For (2), crystals are orthorhombic, space group Pna21, with a 16·799(2), b 8·681(2), c 17·485(2) Å, Z 4, 1774 unique reflections (325 parameters), converging at R 0·031 and Rw 0·029. For (3), crystals are monoclinic, space group P 21/c, with a 11·140(3), b 18·282(4), c 15·296(2) Å, β 105·18(2)°, Z 4, 3132 unique reflections (397 parameters), converging at R 0·039 and Rw 0·024. For (4), crystals are monoclinic, space group P 21/n, with a 12·929(7), b 16·953(8), c 15·601(7) Å, β 112·55(3), Z 4, 3023 unique reflections (397 parameters), converging at R 0·039 and Rw 0·025. For (5), crystals are monoclinic, space group P 21/n, with a 12·710(5), b 16·882(3), c 15·693(4) Å, β 111·37(3)°, Z 4, 3216 unique reflections (397 parameters), converging at R 0·035 and Rw 0·030. For (6), crystals are monoclinic, space group P 21/n, with a 12·594(1), b 16·936(2), c 15·611(1) Å, β 112·476(5)°, Z 4, 3564 unique reflections (397 parameters), converging at R 0·038 and Rw 0·041. For structurally characterized 18-electron (cyclopentadienyl)nickel(II) acetylide complexes, statistically insignificant decreases in the average Ni-C(1) distance and trans influence and an increase in the average C(1)-C(2) parameter are observed on introduction of an acceptor substituent at the alkynyl ligand.

Steric Modification of Metal-Phosphorus Bond Lengths: the Preparation, Characterization and CrystalStructures of mer-trans-(PPri3)2(Pme2Ph)-Cl-cis-H2IrIII(1) and mer-trans-(PPri3)2(PMe2Ph)H3IrIII

1995 ◽  
Vol 48 (6) ◽  
pp. 1183 ◽  
Author(s):  
EJ Ditzel ◽  
GB Robertson
Keyword(s):  
Chloride Content ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
Steric Crowding ◽  
Unit Increase

The syntheses and subsequent characterization of the complexes mer -trans-(PPri3)2(Pme2Ph)-Cl-cis-H2IrIII(1) and mer-trans-(PPri3)2(PMe2Ph)H3IrIII (2) by n.m.r. and by low temperature (153�5 K) X-ray diffraction analyses are reported. Crystals of (1) are monoclinic, space group P21/c with a 19.277(2), b 9.020(1), c 17.657(2) Ǻ, β 101.40(1)° and Z 4. Crystals of (2) are orthorhombic, space group P212121, with a 19.373(3), b 18.724(2), c 8.113(1) Ǻ and Z 4. Full-matrix least-squares analyses converged with R = 0.027 and wR = 0.031 for (1) (3243 reflections), and R = 0.030 and wR = 0.038 for (2) (2892 reflections). Consistent with previous observation, the unit increase in chloride content (in place of hydride) in (1) is accompanied by a global lengthening of 0.036 Ǻ (av.) in the Ir -P bond lengths cf. those in (2). Also, because of increased steric crowding (two PPri3 ligands in place of two Pme2Ph), the Ir-PMe2Ph bond in (1) is 0.019(2) Ǻ longer than the chemically equivalent bond in mer-(PMe2Ph)3Cl-cis-H2IrIII. In previously reported complexes in this series metrically similar increases in Ir-PMe2Ph distances result from the replacement of just one Pme2Ph ligand by PPri3.

Die Kristallstruktur von [Ca(N3)2(H2O)2] · C6H14N4 bei 100 K /The Crystal Structure of [Ca(N3)2(H2O)2] · C6H14N4 at 100 K

1989 ◽  
Vol 44 (2) ◽  
pp. 135-138 ◽  
Author(s):  
Franz A. Mautner ◽  
Harald Krischner ◽  
Christoph Kratky
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray

Abstract The crystal structure of calcium azide dihydrate trans-bicyclo-[4.4.0]-1,4,6.9-tetraazadecane has been determined by single crystal X-ray diffraction at 100 K. [Ca(N3)2(H2O)2 (C6H14N4 crystallizes in the orthorhombic space group Pnma, Z = 4. with a - 1396.6(5), b = 1407.1(5), c = 712.2(2) pm. Calcium is hexacoordinated to four azide groups and two water molecules. The elongated octahedra are linked via μ(1,3)-bridging azide ions to form monolayers parallel to the ac-plane. The C6H14N4 molecules are arranged between these layers.

scholarly journals Indole alkaloids from Vinca erecta type of sarpagine and ajmaline

2019 ◽  
Vol 10 (4) ◽  
pp. 409-416 ◽  
Author(s):  
Shahobiddin Adizov ◽  
Bakhodir Tashkhodjaev
Keyword(s):  
Conformational Changes ◽  
Absolute Configuration ◽  
Indole Alkaloids ◽  
Diffraction Method ◽  
Monoclinic Space Group ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray

The single crystal X-ray diffraction method established the absolute configuration of the Vinca erecta indole alkaloids of the akuammidine sarpagine type (3S, 5S, 15R, 16R) and its o-acyl derivative, as well as the type of ajmaline, quebrachidine (2S, 3S, 5S, 7R, 15S, 16R, 17S) and majoridine (2R, 3S, 5S, 7R, 15R, 16S, 17R). Crystal data for C21H24N2O3 (1): orthorhombic, space group P212121 (no. 19), a = 6.3949(5) Å, b = 13.5009(10) Å, c = 22.461(3) Å, Z = 4, 7694 reflections measured (7.64° ≤ 2Θ ≤ 152.294°), 3813 unique (Rint = 0.0798) which were used in all calculations. The final R1 was 0.0680 (I > 2σ(I)) and wR2 was 0.1650 (all data). Crystal data for C23H26N2O4 (2): orthorhombic, space group P212121 (no. 19), a = 9.9730(13) Å, b = 10.2090(10) Å, c = 20.409(3) Å, Z = 4, 7959 reflections measured (8.666° ≤ 2Θ ≤ 151.998°), 4212 unique (Rint = 0.0386) which were used in all calculations. The final R1 was 0.0477 (I > 2σ(I)) and wR2 was 0.1171 (all data). Crystal data for C42H48N4O6 (3): monoclinic, space group P21 (no. 4), a = 8.9320(10) Å, b = 21.515(5) Å, c = 9.5420(10) Å, β = 97.103(10)°, Z = 2, 16677 reflections measured (9.34° ≤ 2Θ ≤ 151.836°), 7393 unique (Rint = 0.0278) which were used in all calculations. The final R1 was 0.0366 (I > 2σ(I)) and wR2 was 0.1037 (all data). Crystal data for C23H28N2O3 (4): orthorhombic, space group P212121 (no. 19), a = 10.636(2) Å, b = 11.208(12) Å, c = 16.725(13) Å, Z = 4, 1650 reflections measured (9.498° ≤ 2Θ ≤ 119.97°), 1650 unique (Rint = 0.0436) which were used in all calculations. The final R1 was 0.0608 (I > 2σ(I)) and wR2 was 0.1720 (all data). In alkaloids such as sarpagine and ajmaline exo, the substituents of alkaloids do not lead to conformational changes of a stable polycyclic framework. In the series of sarpagine, alkaloids form mono-salts in the tetrahedral nitrogen N4, and in indolines of the ajmaline type, the tetrahedral hybridization of the N1 and N4 atoms favors the formation of disols. In V. erecta alkaloids, the exomethylene fragment (C18-C19=C20-C21) of the polycyclic backbone always takes on the E-state.

The crystal structures of two isomers of a macrocyclic binuclear compound each containing both divalent and trivalent cobalt

1975 ◽  
Vol 28 (12) ◽  
pp. 2593 ◽  
Author(s):  
BF Hoskins ◽  
GA Williams
Keyword(s):  
Bromine Atom ◽  
Fourier Method ◽  
Water Molecules ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
R Factor ◽  
A Cell ◽  
Coordinated Water

The compound Lco2Br3,2H2O (where L is a binucleating ligand derived from the macrocycle LH2 formed by condensation of two molecules each of propane-1,3-diamine and 2-hydroxy-5- methylisophthalaldehyde) was found to occur in two crystalline forms. The structures of both have been determined by single-crystal X-ray diffraction techniques, revealing that each corresponds to a different geometrical isomer of composition Lco2Br3,2H2O. Each structure was determined by the conventional Patterson-Fourier method and refined by a least-squares procedure, with only the Co, Br, N and O atoms being refined anisotropically. The first form, designated the A-isomer, crystallizes in the orthorhombic space group Pn21a with four formula units in a cell of dimensions a 15.173(1), b 17.370(2) and c 10.493(1) Ǻ. The structure refined to a conventional R-factor of 0.074 by means of 1883 unique reflections collected by counter methods. The second form, or B-isomer, crystallizes in the monoclinic space group P21 with two formula units in a cell of dimen- sions a 10.676(1), b 15.235(2), c 9.304(1) Ǻ and β 111.83(2)°. The structure refined to a conventional R-factor of 0.101 by means of 2006 independent reflections collected by counter methods. Both isomers are composed of discrete bromide anions together with discrete binuclear cations of com- position [Lco2Br2,2H2O]+, each containing one cobalt(II) and one cobalt(III) atom with a Co...Co distance of 3.13 Ǻ. In both isomers the cobalt atoms are in octahedral environments. In the A-isomer two bromine atoms are bonded to the cobalt(III) atom in positions perpendicular to the ligand N2O2 donor plane, with the two water molecules occupying similar positions about the cobalt((II). But in the B-isomer, one water molecule and one bromine atom are bonded to each of the cobalt(III) and the cobalt((II) atoms in the comparable positions. In both structures the ionic bromide is involved in a hydrogen-bonding scheme with the coordinated water molecules.

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