Phenanthrene crystal structure

Fig. 14. Choleic acid inclusion chemistry (a) crystal structure of DCA inclusion compound with phenanthrene (b) view along a DCA inclusion helix accommodating DMSO and water guest molecules (oxygen and sulfur atoms and methyl groups are represented by open circles and large and small black...

The crystal structure of phenanthrene has been solved by Basak (1950), and his (two-dimensional) data refined by Mason (1961) using least-squares methods. The accuracy of this analysis is not high because of the limited number of data used the standard deviation in bond length is 0-05 A. The results of a three-dimensional analysis at 95°K, which is reported to be in progress (Mason, 1961), are awaited with interest. 

Pure dried tylophorine is a yellow powder, and crystallization from common solvents is difficult. Spectral data, including MS, H-NMR, C-IMMR and chiroptical (ORD and CD), of phenanthroindolizidine alkaloids have been well established [18, 42, 44-45]. The three-dimensional crystal structure of tylophorine (1) was first determined by Wang et al [46]. The structure of tylophorine B, as the benzene solvate, has conjoined phenanthrene and indolizidine moieties. The aromatic rings lie almost in the same plane with dihedral angles of 1.7° (A/B), 2.8° (B/C), 2.2° (A/C), and 7.3° (B/D). The E ring adopts an envelope conformation and makes a dihedral angle of 6.7(3)° with the D ring [46]. 

Trichloro cyclopenta[l]phenanthrene titanium complexes (Scheme 183) have been synthesized. The crystal structure of the 2-methyl-substituted derivative has been determined by X-ray diffraction. In the presence of MAO, these complexes are highly active pre-catalysts for the syndiotactic polymerization of styrene. The 2-phenyl-substituted complex exhibits especially high catalytic activity.416... 

Schneider, N. Prosenc, M.-H. Brintzinger, H.-H. Cyclopenta[l]phenanthrene titanium trichloride derivatives Syntheses, crystal structure and properties as catalysts for styrene polymerization. J. Organomet. Chem. 1997, 545-546, 291-295. 

Figure 13 Clinographic projection of the crystal structure of the complex 2SbCl3,phenanthrene...

The adduct formed by two lithium atoms with polycondensed aromatic hydrocarbons crystallizes with two solvating molecules of TMEDA. The structure of the crystals derived from naphthalene (73) and anthracene (74) was elucidated by XRD. This arrangement of the unsolvated lithium atoms, in 7 -coordination fashion on the opposite sides of two contiguous rings, was found by MNDO calculations to be the most favorable one for naphthalene, anthracene and phenanthrene (75) . 

Photoemission from excited single states produced by photoionization of anthracene crystals occurs after two step laser excitation Biphotonic excitation of phenanthrene under 208 nm irradiation is a complex process involving both ionization andT-T annihilation. Change transfer exciton band structures have been characterized with samples of crystalline tetracene . Measurement of the photoionization efficiency in trans-stilbene crystals as a function of excitation energy shows that ionization occurs after rapid vibronic relaxation o. 

Two different values of REC for particular rings of benzene and phenanthrene result from different measurements of their molecular geometry. The different REC values for symmetrically equivalent rings in other benzenoid hydrocarbons result from the method of X-ray structure determination. If the symmetrical molecule does not lie at the symmetry element in the crystal lattice, each of the rings is measured independently and its geometry (and in turn its REC value) is biased by the another error of measurement. The differences in REC values for symmetrically equivalent... 

New phosphorus containing polysulfones could be obtained by using different phosphorus containing diols in the classical synthesis of PSF (Scheme 6.4). Diols can contain phosphorus in main chain position or incorporate in a phenanthrene-type ring as side chain. These different phosphorus-containing diols form aromatic polyethers by polycondensation with dihalogen-substituted aromatic sulfones [48]. The chain structure of the polymer (aromatic or aliphatic) and the position of phosphorus in the chain influence the polymer properties (electroluminescence [49,50], flame retardancy [51], liquid crystal properties [52]). 

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