Novel mixed-ligand Pt(II) complexes: Synthesis, multinuclear magnetic resonance, and crystal structures of cis- and trans-Pt(R2SO)(pyrazine)Cl2

2004 ◽  
Vol 82 (5) ◽  
pp. 649-658 ◽  
Author(s):  
Fernande D Rochon ◽  
Julien RL Priqueler
Keyword(s):  
Crystal Structure ◽  
Magnetic Resonance ◽  
Ir Spectroscopy ◽  
Crystal Structures ◽  
Mixed Ligand ◽  
The Other ◽  
Coupling Constant ◽  
New Type ◽  
Cis And Trans ◽  
Multinuclear Magnetic Resonance

A new type of mixed-ligand Pt(II) complexes, Pt(R2SO)(pyrazine)Cl2, was synthesized from the aqueous reaction of K[Pt(R2SO)Cl3] with pyrazine. The compounds were characterized mainly by IR and multinuclear magnetic resonance spectroscopies (1H, 13C, and 195Pt) and crystallography. Compounds with dimethylsulfoxide, tetramethylenesulfoxide, di-n-propylsulfoxide, di-n-butylsulfoxide, dibenzylsulfoxide, and diphenylsulfoxide were studied. IR spectroscopy suggested a cis geometry for the di-n-propylsulfoxide complex and trans geometry for the other compounds. The 195Pt NMR resonances of the complexes were observed between –3042 and –3121 ppm, with that of the diphenylsulfoxide complex being at higher field than those of the others. The pyrazine 3J(195Pt-1H) coupling constant was observed for the DMSO compound (33 Hz), suggesting a trans geometry. No J(195Pt-13C) coupling could be detected. The crystal structures of trans-Pt(tetramethylenesulfoxide)(pyrazine)Cl2 and of cis-Pt(di-n-propylsulfoxide)(pyrazine)Cl2 were determined and confirmed the geometry suggested by IR and NMR spectroscopies. The compound with di-n-butylsulfoxide could not be isolated, because it rapidly formed the pyrazine-bridged dimer. Key words: platinum, sulfoxide, pyrazine, crystal structure, NMR, IR.

Structural Studies on N-(2,4,6-Trimethylphenyl)-methyl/ chloro-acetamides, 2,4,6-(CH3)3C6H2NH-CO-CH3–yXy (X = CH3 or Cl and y = 0, 1, 2)

2006 ◽  
Vol 61 (10-11) ◽  
pp. 588-594 ◽  
Author(s):  
Basavalinganadoddy Thimme Gowda ◽  
Jozef Kožíšek ◽  
Hartmut Fuess
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Structural Data ◽  
The Other ◽  
Side Chain ◽  
Structural Studies ◽  
Asymmetric Unit ◽  
Lattice Constants ◽  
Peptide Linkage ◽  
The Mean

TMPAThe effect of substitutions in the ring and in the side chain on the crystal structure of N- (2,4,6-trimethylphenyl)-methyl/chloro-acetamides of the configuration 2,4,6-(CH3)3C6H2NH-COCH3− yXy (X = CH3 or Cl and y = 0,1, 2) has been studied by determining the crystal structures of N-(2,4,6-trimethylphenyl)-acetamide, 2,4,6-(CH3)3C6H2NH-CO-CH3 (); N-(2,4,6- trimethylphenyl)-2-methylacetamide, 2,4,6-(CH3)3C6H2NH-CO-CH2-CH3 (TMPMA); N-(2,4,6- trimethylphenyl)-2,2-dimethylacetamide, 2,4,6-(CH3)3C6H2NH-CO-CH(CH3)2 (TMPDMA) and N-(2,4,6-trimethylphenyl)-2,2-dichloroacetamide, 2,4,6-(CH3)3C6H2NH-CO-CHCl2 (TMPDCA). The crystallographic system, space group, formula units and lattice constants in Å are: TMPA: monoclinic, Pn, Z = 2, a = 8.142(3), b = 8.469(3), c = 8.223(3), β = 113.61(2)◦; TMPMA: monoclinic, P21/n, Z = 8, a = 9.103(1), b = 15.812(2), c = 16.4787(19), α = 89.974(10)◦, β = 96.951(10)◦, γ =89.967(10)◦; TMPDMA: monoclinic, P21/c, Z = 4, a =4.757(1), b= 24.644(4), c =10.785(2), β = 99.647(17)◦; TMPDCA: triclinic, P¯1, Z = 2, a = 4.652(1), b = 11.006(1), c = 12.369(1), α = 82.521(7)◦, β = 83.09(1)◦, γ = 79.84(1)◦. The results are analyzed along with the structural data of N-phenylacetamide, C6H5NH-CO-CH3; N-(2,4,6-trimethylphenyl)-2-chloroacetamide, 2,4,6-(CH3)3C6H2NH-CO-CH2Cl; N-(2,4,6-trichlorophenyl)-acetamide, 2,4,6-Cl3C6H2NH-COCH3; N-(2,4,6-trichlorophenyl)-2-chloroacetamide, 2,4,6-Cl3C6H2NH-CO-CH2Cl; N-(2,4,6-trichlorophenyl)- 2,2-dichloroacetamide, 2,4,6-Cl3C6H2NH-CO-CHCl2 and N-(2,4,6-trichlorophenyl)- 2,2,2-trichloroacetamide, 2,4,6-Cl3C6H2NH-CO-CCl3. TMPA, TMPMA and TMPDCA have one molecule each in their asymmetric units, while TMPDMA has two molecules in its asymmetric unit. Changes in the mean ring distances are smaller on substitution as the effect has to be transmitted through the peptide linkage. The comparison of the other bond parameters reveal that there are significant changes in them on substitution.

Transferable force field for crystal structure predictions, investigation of performance and exploration of different rescoring strategies using DFT-D methods

2016 ◽  
Vol 72 (4) ◽  
pp. 460-476 ◽  
Author(s):  
Anders Broo ◽  
Sten O. Nilsson Lill
Keyword(s):  
Crystal Structure ◽  
Force Field ◽  
Crystal Structures ◽  
Density Functional ◽  
Geometry Optimization ◽  
Field Methods ◽  
Functional Theory ◽  
Ranking List ◽  
Drug Molecules ◽  
New Type

A new force field, here called AZ-FF, aimed at being used for crystal structure predictions, has been developed. The force field is transferable to a new type of chemistry without additional training or modifications. This makes the force field very useful in the prediction of crystal structures of new drug molecules since the time-consuming step of developing a new force field for each new molecule is circumvented. The accuracy of the force field was tested on a set of 40 drug-like molecules and found to be very good where observed crystal structures are found at the top of the ranked list of tentative crystal structures. Re-ranking with dispersion-corrected density functional theory (DFT-D) methods further improves the scoring. After DFT-D geometry optimization the observed crystal structure is found at the leading top of the ranking list. DFT-D methods and force field methods have been evaluated for use in predicting properties such as phase transitions upon heating, mechanical properties or intrinsic crystalline solubility. The utility of using crystal structure predictions and the associated material properties in risk assessment in connection with form selection in the drug development process is discussed.

Organoamido- and Aryloxo-Lanthanoids. XI. Syntheses and Crystal Structures of Nd(Odpp)3, Nd(Odpp)3(thf) and [Nd(Odpp)3(thf)2].2(thf) (Odpp-=2,6-Diphenylphenolate): Variations in Intramolecular π-Ph-Nd Interactions

1995 ◽  
Vol 48 (4) ◽  
pp. 741 ◽  
Author(s):  
GB Deacon ◽  
TC Feng ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Phenyl Group ◽  
Triangular Array ◽  
The Other ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Distorted Trigonal Bipyramidal

The X-ray crystal structure of Nd (Odpp)3 ( Odpp- = 2,6-diphenylphenolate), obtained by sublimation of Nd ( Odpp )3( thf )2 ( thf = tetrahydrofuran ) [triclinic, Pī , a 15.835(5), b 13.499(10), c 10.955(11) Ǻ, α 116.25(7), β 92.87(7), γ 101.66(6)°, V 2031 Ǻ3, Z2, No 5726 'observed' data (I > 3σ(I)) refined to conventional R 0.047 shows a near triangular array of oxygens surrounding neodymium { Nd -O} 2.169 Ǻ, ∑ O- Nd -O 353.2° with additional, intramolecular Nd-η6-Ph chelate interactions { Nd -C} 3.046 Ǻ and Nd-η1-Ph ( Nd -C 2.964(7)Ǻ). There is a pseudotrigonal bipyramidal arrangement of the oxygens, the centroid of the η6-Ph, and the η1-carbon. The complex Nd ( Odpp )3( thf ), obtained by crystallization of Nd ( Odpp )3( thf )2 from toluene (monoclinic, P21/c, a 12.213(4), b 21.447(4), c 17.744Ǻ, β 104.25(2)°, V 4505 Ǻ3, Z 4, R 0.042 for No 8014) also has pseudotrigonal bipyramidal stereochemistry, with a triangular equatorial array of aryl oxide oxygens { Nd -O} 2.193 Ǻ; ∑ O- Nd -O 358.7°, an apical thf oxygen (Nd -O 2.446(3)Ǻ), and an apical intramolecular chelating phenyl group. As the last has three Nd -C contacts (3.094(5), 3.144(5), 3.010(5)Ǻ) significantly shorter than the other three (3.300(5), 3.427(5), 3.377(5)Ǻ), an η3-Ph-Nd interaction seems likely. For [ Nd ( Odpp )3( thf )2].2( thf ), obtained by crystallization from tetrahydrofuran without drying of the crystals, the X-ray structure (monoclinic, P21, a 10.230(2), b 21.919(5), c 13.411(4) Ǻ, β 101.15(2)°, V 2950 A3, Z2, R 0.058 for No 3237) reveals a distorted trigonal bipyramidal arrangement of three aryl oxide oxygens (two equatorial 2.208(9), 2.16(1) Ǻ; one axial 2.203(9) Ǻ) and two thf oxygens (one equatorial 2.44(1) Ǻ; one axial (significantly distant) 2.62(1) Ǻ). The X-ray structure of [La( Odpp )3( thf )2].2( thf ) shows it to be isostructural with the neodymium analogue.

Structures and photochemistry of 1,5-disubstituted dibenzobarrelenes

1996 ◽  
Vol 52 (1) ◽  
pp. 151-158
Author(s):  
R. Jones ◽  
S. J. Rettig ◽  
J. R. Scheffer ◽  
J. Trotter ◽  
J. Yang
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Crystal Structures ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
The Other ◽  
Steric Effects ◽  
Molecular And Crystal Structures ◽  
Electronic And Steric Effects

The effect of 1,5-disubstitution on the photochemistry of 9,10-ethenoanthracene-11,12-diesters has been studied and correlated with the crystal structures determined for several derivatives; photoproduct structures have been established from a crystal structure analysis of one of the products and from NMR correlations. The crystals studied are: (1)-Cl, dimethyl 1,5-dichloro-9,10-dihydro-9,10-ethenoanthracene-11,12-dicarboxylate, C20H14Cl2O4, P21/n; (1)-CN, 1,5-dicyano derivative, C22H14N2O4, P21/n; (1)-CN.0.5p-xylene, C22H14N2O4.0.5C8H10, P21/c; (1)-CN.xxylene, C22H14N2O4.xC8H10, P21/n; (1)-OMe, 1,5-dimethoxy derivative, C22H20O6, P{\bar 1}; (2b)-Cl, C20H14C12O4, dimethyl 1,5-dichloro-4b,8b,8c,8d-tetrahydrodibenzo[a, f]cyclopropa[c,d]pentalene-8c,8d-dicarboxylate, Pna21. The dibenzobarrelene molecules all have geometries and dimensions similar to those of related materials. In particular, the orientations of the two ester groups in each molecule differ, one being in general almost fully conjugated with the C(11)=C(12) double bond and the other almost non-conjugated. Relationships are sought between the ratios of the two regioisomeric photoproducts and molecular and crystal structures; both electronic and steric effects are considered, but no one effect seems to dominate.

μ2-Halogenokomplexe von N-Bromsuccinimid und N-Bromphthalimid. Die Kristallstrukturen von PPh4[X(N-Bromsuccinimid)2] und von PPh4[X(N-Bromphthalimid)2] mit X = CI und Br / μ2-Halogeno Complexes of N-Bromosuccinimide and N-Bromophthalimide. The Crystal Structures of PPh4 [X(N-Bromosuccinimide)2] and PPh4 [X(N-Brom ophthalimide)2] with X = Cl and Br

1994 ◽  
Vol 49 (5) ◽  
pp. 593-601 ◽  
Author(s):  
Mitra Ghassemzadeh ◽  
Klaus Harms ◽  
Kurt Dehnicke ◽  
Dieter Fenske
Keyword(s):  
Crystal Structure ◽  
Ir Spectroscopy ◽  
Crystal Structures ◽  
Yellow Crystal ◽  
Halide Ions ◽  
Space Group ◽  
Bond Angles ◽  
Structure Solution ◽  
Structure Determinations ◽  
Acetonitrile Solutions

The μ2-halogeno complexes PPh4[X(N-bromosuccinimide)2] and PPh4[X(N-bromophthali- mide)2] with X = Cl and Br have been prepared by reactions of N-bromosuccinimide and N-bromophthalimide, respectively, with the corresponding tetraphenylphosphonium halides PPh4X in acetonitrile solutions. The compounds form pale yellow crystal needles, which were characterized by IR spectroscopy and by crystal structure determinations. PPh4[Cl(N-Bromosuccinimide)2] (1): Space group P21/n, Z = 4, structure solution with 2516 observed unique reflections, R = 0.040. Lattice dimensions at -25 °C: a = 1775.9(1), b = 764.3(1), c = 2341.7(2) pm, β = 101.84(1)°. PPh4[Br(N-Bromosuccinimide)2] (2): Space group P21/n, Z = 4, structure solution with 5620 observed unique reflections, R = 0.061. Lattice dimensions at 20 °C: a = 1776.9(9), b = 762.2(3), c = 2331(1) pm, β = 103.02(3)°. PPh4[Cl(N-Bromophthalimide)2] (3): Space group P1̅, Z = 4, structure solution with 3812 observed unique reflections, R = 0.039. Lattice dimensions at -50 °C: a = 918.5(2), b = 1115.0(3), c = 2584.4(5) pm, α = 88.22(3)°, β = 83.20(3)°, γ = 85.10(3)°. PPh4[Br(N-Bromophthalimide)2] (4): Space group P1̅, Z = 2, structure solution with 3413 observed unique reflections, R = 0.044. Lattice dimensions at -50 °C: a = 1120.2(2), b = 1308.6(3), c = 1343.2(3) pm, α = 105.10(3)°, β = 104.16(3)°, γ = 92.99(3)°. The structures of 1-4 consist of PPh4+ ions, anions [X(N-bromosuccinimide)2]- and [X(N-bromophthalimide)2]-, respectively, in which the halide ions X- are coordinated by the bromine atoms of N-bromosuccinimide and N-bromophthalimide molecules, respectively. The bond angles Br···X···Br are 86.48(5)° for 1, 85.1(1)° for 2, 102.31(6)° and 93.61(6)° for 3, and 91.86(4)° for 4. The bond angles N-Br···X are nearly linear.

scholarly journals Azo-linked corner porphyrin systems: synthesis, crystal structures and spectroscopic investigation

2010 ◽  
Vol 14 (06) ◽  
pp. 481-493 ◽  
Author(s):  
Bruno Bašić ◽  
John C. McMurtrie ◽  
Dennis P. Arnold
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Spectroscopic Investigation ◽  
The Other ◽  
X Ray ◽  
Tert Butyl ◽  
Dinitro Derivative

1,2-bis[10,15-di(3,5-di-tert-butyl)phenylporphyrinatonickel(II)-5-yl]diazene was synthesised via copper-catalyzed coupling of aminated nickel(II) 5,10-diarylporphyrin ("corner porphyrin") and its X-ray crystal structure was determined. Two different crystals yielded different structures, one with the free meso-positions in a trans-like orientation, and the other with a cis-like disposition. The free meso-positions of the obtained dimer have been further functionalized while the synthesis of a zinc analog has so far been unsuccessful. The X-ray crystal structure of the dinitro derivative of the dinickel(II) azoporphyrin was determined, and the structure showed a cis-like disposition of the nitro groups.

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