Picene

Picene [213-14-3] M 278.3, m 364 . Crystd from isopropylbenzene/xylene. Can also be sublimed. 

Benzene rings can also be fused in angular fashion, as in phenanthrene, chrysene, and picene. These compounds, while reactive toward additions in the center ring, retain most of the resonance energy per electron (REPE) stabilization of benzene and naphthalene. ... 

Phenacenes are a family of graphite ribbons , where benzene rings are fused together in an alternating pattern. Phenanthrene is the simplest member of this family and other members include the 22-electron system picene (91), the 26-electron system fulminene (92), and the larger member of this family, the 30-electron [7]phenancene, with seven rings (93). ... 

BCR Analytical Approach for the Certification of PAHs in Natural Matrix CRMs Prior to the certification analyses for the CRM, each participating laboratory has to prepare standard solutions of the analytes to be determined from certified reference compounds (purity >99.0 %) to calibrate their instruments for response and response linearity (multiple point calibration), detection limit, and reproducibility. In the case of PAH measurements, reference compounds of certified purity are used as internal standards, which are not present at a detectable concentration in the matrix to be analyzed (e.g. indeno[i,2,3-cd]fluoranthene (CRM 267), 5-methylchrysene (CRM 081R), benzo[f ]chry-sene (CRM 046), picene (CRM 168), and/or phenanthrene-dio). 

Eisenbrand, J., Baumann, K. (1970) Uber die bestimmung der wasserloslichkeit von coronen, fluoranthen, perylen, picen, tetracen und triphenylen und tiber die bildung wasserloslicher komplexe dieser kohlenwasserstoffe mit coffein. Zeitschrift far Lebensmittel Untersuchung und Forschung 144, 312-317. 

A set of n = 209 polycyclic aromatic compounds (PAC) was used in this example. The chemical structures have been drawn manually by a structure editor software approximate 3D-structures including all H-atoms have been made by software Corina (Corina 2004), and software Dragon, version 5.3 (Dragon 2004), has been applied to compute 1630 molecular descriptors. These descriptors cover a great diversity of chemical structures and therefore many descriptors are irrelevant for a selected class of compounds as the PACs in this example. By a simple variable selection, descriptors which are constant or almost constant (all but a maximum of five values constant), and descriptors with a correlation coefficient >0.95 to another descriptor have been eliminated. The resulting m = 467 descriptors have been used as x-variables. The y-variable to be modeled is the Lee retention index (Lee et al. 1979) which is based on the reference values 200, 300, 400, and 500 for the compounds naphthalene, phenanthrene, chrysene, and picene, respectively. 

FIGURE 5.8 Separation of picene and methyl-substituted picene isomers with (a) a monomeric Cjg column, (b) an intermediate Cjg column, and (c) a polymeric Cjg column L/S values given in parentheses. (Adapted from Wise, S.A. and Sander, L.C., in Jinno, K. (Ed.), Chromatographic Separations Based on Molecular Recognition, Wiley-VCH, Inc., New York, 1997, p. 1. With permission.)... 

Flesher JW, Horn J, Lehner AF Comparative carcinogenicity of picene and dibenz( , )anthracene in the rat. Biochem Biophys Res Commun 190 115-119, 2002... 

There are three kinds of superconductors based on acceptor molecules M(dmit)2 (Scheme 15, M = Ni, Pd) [293], picene [294], and Ceo [141-143], Cgo system has the highest Tc for molecular superconductors (Tc = 38 K) followed by the picene one Tc = 18 K) however, those two systems are very unstable chemically (caused partly by very weak electron accepting ability) and decompose immediately at ambient condition. 

As mentioned, the (superconductors based on Cgo and picene are chemically very unstable, and immediately decompose on exposure to air. Crystal engineering to protect such (super)conductors against air and moisture is essential for further investigation. 

MitsuhashiR, Suzuki Y, Yamanari Y, MitamuraH, KambeT, BcedaN, OkamotoH, Fujiwara A, Yamaji M, Kawasaki N, Maniwa Y, Kubozono Y (2010) Superconductivity in alkali-metal-doped picene. Nature 464 76-79... 

III Benz[a]anthracene, benzolglchrysene, benzo[gW]perylene, dibenzo[a,e]pyrene, picene, pyrene... 

Peri-condensed aromatic compounds compounds based on angular condensed aromatic hydrocarbon systems, e.g., phenanthrene, chrysene, picene, etc. 

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