Experimental and computational structural study of two hindered aminoanthraquinones in crystals and solutions

2000 ◽  
Vol 215 (9) ◽  
Author(s):  
A.V. Yatsenko ◽  
K.A. Paseshnichenko ◽  
S.I. Popov
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Electronic Spectra ◽  
Molecular Structures ◽  
Amino Group ◽  
Single Crystal Diffraction ◽  
Molecular Conformations ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Visible Spectra

The crystal and molecular structures of 2-methyl-1-methylamino-anthraquinone (I) and 1-methylphenylamino-anthraquinone (II) were studied by the X-ray single-crystal diffraction and the visible spectra of crystalline specimens and their solutions were recorded. The molecule I is closely planar, whereas in the molecule II the amino group is 58° rotated out of the plane of the anthraquinone skeleton. In both structures the molecules pack in stacks. The comparison of experimental and calculated (on the DFT and AM1 levels) molecular structures, together with the comparison of experimental and INDO/S-calculated electronic spectra, give the evidence that molecular conformations (especially for II) change upon transfer from the solid state to solutions, and the π-delocalisation throughout the whole molecule enhances in the solid state.

Crystal and Molecular Structures of Penta-O-acetyl-aldehydo-D-glucose Dimethyl Acetal and of Hepta-O-acetyl-aldehydo-D-glucose Hydrate

1996 ◽  
Vol 49 (3) ◽  
pp. 391 ◽  
Author(s):  
P Koll ◽  
J Kopf
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Dimethyl Acetal ◽  
Molecular Structures ◽  
Carbon Skeleton ◽  
Parallel Orientation ◽  
X Ray ◽  
X Ray Crystallography ◽  
Crystal And Molecular Structures ◽  
Solid State Structures

The solid-state structures of the title compounds were determined by conventional single-crystal X-ray crystallography. In both cases a planar zigzag conformation of the carbon skeleton is observed with a resulting 1,3-parallel orientation of O(2) and O(4). In the case of the heptaacetate even a second such arrangement is established between O(3) and one of the oxygens at C(1). These findings substantiate the claim that such conformations are not as unfavourable as previously was assumed by many authors.

Lewis-Base Adducts of Group 1B Metal(I) Compounds. XXI The Crystal and Molecular Structures of the Unsolvated Forms of Dibromotris(triphenylphosphine)dicopper(I) and 'step' Tetrabromotetrakis(triphenyl-phosphine)tetracopper(I)

1985 ◽  
Vol 38 (8) ◽  
pp. 1243 ◽  
Author(s):  
JC Dyason ◽  
LM Engelhardt ◽  
C Pakawatchai ◽  
PC Healy ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Molecular Structures ◽  
Lewis Base ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Triphenyl Phosphine ◽  
X Ray ◽  
Crystal And Molecular Structures

The crystal structures of the title compounds have been determined by single-crystal X-ray diffraction methods at 295 K. Crystal data for (PPh3)2CuBr2Cu(PPh3) (1) show that the crystals are iso-morphous with the previously studied chloro analogue, being monoclinic, P21/c, a 19.390(8), b 9.912(5), c 26.979(9) Ǻ, β 112,33(3)°; R 0.043 for No 3444. Cu( trigonal )- P;Br respectively are 2.191(3); 2.409(2), 2.364(2) Ǻ. Cu(tetrahedral)- P;Br respectively are 2.241(3), 2.249(3); 2.550(2), 2.571(2) Ǻ. Crystals of 'step' [PPh3CuBr]4 (2) are isomorphous with the solvated bromo and unsolvated iodo analogues, being monoclinic, C2/c, a 25.687(10), b 16.084(7), c 17.815(9) Ǻ, β 110.92(3)°; R 0.072 for No 3055. Cu( trigonal )- P;Br respectively are 2.206(5); 2.371(3), 2.427(2) Ǻ. Cu(tetrahedral)- P;Br are 2.207(4); 2.446(2), 2.676(3), 2.515(3) Ǻ.

The Crystal and Molecular Structures of Bis(diethyldithiocarbamato)platinum(II) and Bis[di(2-hydroxyethyl)dithiocarbamato]platinum(II)

1992 ◽  
Vol 45 (2) ◽  
pp. 429 ◽  
Author(s):  
AT Baker ◽  
MT Emett
Keyword(s):  
Single Crystal ◽  
Bond Length ◽  
Molecular Structures ◽  
Monoclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
Crystal And Molecular Structures

The structures of [Pt(S2CN(C2H5)2)2] (1) and [Pt(S2CN(C2H4OH)2)2] (2) have been determined by single-crystal X-ray diffractometry. Compound (1) crystallizes in the tetragonal space group P42/n, a 16.4692(10),c 6.2160(6) � (Z = 4); R was 0.029 for 1012 observed reflections. Compound (2) is monoclinic, space group Pc, a 6-0663(11), b 1.1784(15), c 12.5740(21) � ,β92.569(8)� (Z = 2); R was 0.019 for 1573 observed reflections. The presence of electron-withdrawing groups in the ligands of (2) appears to have little effect on the Pt-S distances but causes an increase in the C-N bond length, with the C-N bond lengths being significantly different at the 2 σ level.

1,2-Dicyanoferrocene: synthesis and characterization

2016 ◽  
Vol 94 (6) ◽  
pp. 547-551 ◽  
Author(s):  
Mohammad A. Abdulmalic ◽  
Steve W. Lehrich ◽  
Heinrich Lang ◽  
Tobias Rüffer
Keyword(s):  
Cyclic Voltammetry ◽  
Solid State ◽  
Single Crystal ◽  
Square Wave Voltammetry ◽  
Molecular Structures ◽  
Synthesis And Characterization ◽  
X Ray ◽  
Square Wave ◽  
Wave Voltammetry ◽  
Convenient Synthesis

A convenient synthesis of 1,2-dicyanoferrocene (3) was developed by using 2,4-dinitrofluorobenzene as a dehydrating agent for the treatment of 1,2-ferrocenedicarbaldehyde dioxime (2) to give 3 in yields exceeding 80%. Compounds 2 and 3 have been characterized by IR and NMR (1H, 13C{1H}) spectroscopy and by electrochemistry (cyclic voltammetry and square-wave voltammetry). Furthermore, the molecular structures of 2 and 3 in the solid state have been determined by single-crystal X-ray crystallographic studies.

A Speculative Discussion of the Structural Details of 1-Bromo-2-iodo-benzenes

2004 ◽  
Vol 59 (3) ◽  
pp. 264-268 ◽  
Author(s):  
Hubert Schmidbaur ◽  
Oliver Minge ◽  
Stefan Nogai
Keyword(s):  
Single Crystal ◽  
Van Der Waals ◽  
Visible Region ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Structural Details ◽  
Steric Crowding ◽  
Speculative Discussion

The crystal and molecular structures of 2,4-dibromo-1-iodo-benzene (1) and 1,3-dibromo-2-iodobenzene (2) have been determined by single crystal X-ray diffraction. The proximity of two or three large halogen substituents (Br/I) induces only minor distortions of the C-C-Br/I angles (ca. 2°) and the halogen atoms remain in the plane of the molecules. These undistorted structures lead to short intramolecular, sub-van-der-Waals Br-I contacts [in the range 3.465(4) to 3.530(4) Å ]. The results suggest that the peripheral Br-I interactions have an attractive component which alleviates the repulsion out of steric crowding. The influence is associated with an absorption in the visible region and is possibly responsible for the enhanced reactivity of the 1,2-dihalobenzene molecules

scholarly journals Transition metal complexes with pyrazole based ligands, part 27: Structural and thermal characterization of cobalt(II) halide and pseudohalide complexes with 4-acetyl-3-amino-5-methylpyrazole

2007 ◽  
Vol 72 (12) ◽  
pp. 1281-1293 ◽  
Author(s):  
Vukadin Leovac ◽  
Zoran Tomic ◽  
Katalin Mészáros-Szécsényi ◽  
Ljiljana Jovanovic ◽  
Milan Joksovic
Keyword(s):  
Thermal Decomposition ◽  
Solid State ◽  
Transition Metal Complexes ◽  
Thermal Characterization ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Vis Spectroscopy

The crystal and molecular structures of four tetrahedral structurally similar [Co(aamp)2X2] complexes (aamp = 4-acetyl-3-amino-5-methylpyrazole, X = Cl, Br, I and NCS) were determined by X-ray diffraction analysis and are discussed in detail. It was found that the different capacity of the ligand X (NCS vs. Cl, Br, I) for the formation of non-bonding contacts influence the mode of molecular association in the solid state. The complexes were characterized by UV-Vis spectroscopy. The first step of the thermal decomposition of the compounds was checked and is discussed in the view of the IR spectrum of the intermediate isolated from [Co(aamp)2Br2] by the quasi-isothermal technique.

Reactions between ruthenium chlorides and trimethyl phosphite : crystal and molecular structures of RuCI3(NH3)[P(OMe)3]2

1980 ◽  
Vol 33 (1) ◽  
pp. 195 ◽  
Author(s):  
MI Bruce ◽  
DA Kelly ◽  
GM Mclaughlin ◽  
GB Robertson ◽  
IB Tomkins ◽  
...  
Keyword(s):  
Single Crystal ◽  
Diffraction Study ◽  
Molecular Structures ◽  
Trimethyl Phosphite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
A Minor

The reaction between RuCl3,nH2O and P(OMe)3 affords RuCl2[P(OMe)3]4; one batch of RuCl3,-nH2O also gave amminetrichlorobis(trimethyl phosphite)ruthenium(III), RuCl3(NH3)[P(OMe)3]2, as a minor product. The structure of this complex has been determined from a single-crystal X-ray diffraction study (4598 data, R 0.065, Rw 0.090): the ruthenium is approximately octahedrally coordinated by the three mer chloro, two trans P(OMe)3 and one NH3 ligands. Crystals are monoclinic,P21/n, a 8.725(3), b 18.286(7), c 10.936(4)Ǻ, β 94.57(3)°, Z 4.

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