Phenanthrene absorption spectrum

Hexahydrobenzoyloxodedelphonine acetate (VI) was dehydrogenated by selenium at 330° and gave as chief product a hydrocarbon, b.p. 90°/0-02 mm., whose composition, ultra-violet absorption spectrum and chemical properties, so far as examined, indicate that it may be a bicyclopentenobenzene and therefore in a different category from the phenanthrene hydrocarbons yielded by the atisine group of bases. 

D + 3A —> D + 3A (higher triplet). This type of transfer requires overlap of the fluorescence spectrum of D and the T-T absorption spectrum of A (e.g. quenching of perylene by phenanthrene in its lowest triplet state). 

The occurrence of processes 1) and 2) is at once evident from the observation of the sensitized hole current in an organic crystal with an excitation spectrum closely resembling the absorption spectrum of the dye and with a linear dependence on the light intensity. Fig. 25 shows the identity (except for a slight red shift) of the absorption spectrum e of the rhodamine monomer with the excitation spectrum of the corresponding sensitized current j of a 10-eM solution at phenanthrene. 

Using ps-spectroscopy, Rentzepis and co-workers detected the ground state ion pair (SSIP). However, a red shift in the absorption spectrum of chloranil/dihydro-phenanthrene (12) mixtures occuring between 75 ps and 600 ps after excitation could be interpreted as the ion pair expanding its diameter. Consequently, the CIP is formed before it diffuses to give an ion pair with less contact (SSIP). 

Figure 1.3. The absorption spectrum of phenanthrene in various presentations a) absorbance A versus A, b) c versus A, and c) log c versus i> (by permission from Jaffd and Orchin, l%2).

In Figure 5.18 the absorption and emission spectra of azulene are shown. The anomalous fluorescence of azulene from the S, state is easy to recognize. The AP(F) spectrum exhibits a deep minimum at 33,900 cm. The small peak in the absorption spectrum at the same wave number is therefore not due to vibrational structure but rather to another electronic transition, the polarization of which had been predicted by PPP calculations. Figure 5.19 shows all four types of polarization spectra of phenanthrene. FP becomes negative at the vibrational maxima of the fluorescence the most intense vibration is not totally symmetric, in contrast to the one which shows up weakly. For all absorption bands, AP(P) = -0.3. The polarization direction of phosphorescence is perpendicular to the transition moments of all transitions lying in the mo-... 

Monoclinic plates from ale. Sublimes. When pure, colorless with violet fluoresence when impure (due to tetracene, naphthacene), yellow with green fluorescence. Strongly triboluminescent and triboelectric. dj 1.25. mp 218. bp,M 342. Absorption spectrum Clar, Ber. 65, 506(1932). Less soluble than the isomeric phenanthrene. Insol in water one gram dissolves in 67 ml abs alcohol, 70 ml methanol, 62 ml benzene, 85 ml chloroform, 200 ml ether, 31 ml carbon disulfide, 86 ml carbon tetrachloride, 125 ml toluene. Anthracene darkens in sunlight. According to Downs, U.S. pat. 1,303.639 (1919), when solns of crude anthracene in coal tar naphtha are exposed to ultraviolet irradiation, the anthracene is precipitated as dianthracene (para-anthracene) which is reconverted to anthracene by sublimation. 

Benzanthracene, Benzlajanthracene 2,3-benzphenanthrene tetraphene benzanthrene naphthanthra-cene. C,HI2 mol wt 228.28. C 94.70%, H 5.30%. Occurs in coal tan Cook el at. J. Chcm. Soc. 1933, 395. Synthesis from naphthalene and phthalic anhydride Elbs, Her. 19, 2209 (1886). From o-to uy] naphthalene Fieser, Dietz, Ber. 62, 1827 (1929). From phenanthrene and succinic anhydride Haworth, Mavin, J. Chcm. Soc. 1933, 1012. Absorption spectrum Capper, Marsh, J. Chem. Soc. 1926, 726 Clar. Ber. 65, 507 (1932) Mayneord, Roe, Proc. Roy. Soc. London A152, 299 (1935). Review E. Clar. Polycyclic Hydrocarbons (Academic Press, New York, 1964) 2 vols. 

The most important experimental fact, however, reported for any of the miscellaneous bases concerns the unnamed base recently (90) isolated, which accompanies delphinine and staphisine in D. staphisagria. This base, which may not be correctly formulated, on dehydrogenation over selenium jdelds a crystalline hydrocarbon (CisHie), the ultraviolet absorption spectrum of which indicates the presence of a phenanthrene structure. The fact that the presence of a phenanthrene system can be established both in this new base and in staphisine, i.e., in both minor alkaloids accompanying delphinine, whilst delphinine itself does not readily yield a phenanthrene derivative on dehydrogenation (70), should stimulate further research in this field. If the reason for this difference in behavior can be ascertained, it should permit a better imderstanding of the nature of the polycyclic skeleton present in the atisines and in the aconitines and result in a great advance towards the complete elucidation of the structures of the Aconitum and Delphinium alkaloids. 

Robin57 59 studied this system up to 1000 atm. He measured the concentration of phenanthrene from its light absorption—a method that can only be used where a careful study has been made of the direct effect of pressure on the spectrum. He studied the direct effect in separate experiments with unsaturated solutions. 

Fig. 25. Comparison between the excitation spectrum of the rhodamine sensitized current Jyi in phenanthrene (dye coverage 0 = 0.4 for 10-e M rhodamine in aqueous solution at pH = 7) with the absorption coefficient Cmonomer of the rhodamine monomer in aqueous solution at pH = 7...

For cyclic jr-electron hydrocarbons two more schemes, introduced by Clar (1952) and Platt (1949), are widely used. Clar s empirical scheme is based on the appearance of the absorption bands and designates the first three bands in the spectrum of phenanthrene as the a, p, and j3 bands, re-... 

R. D. Gordon (later Professor of Chemistry at Queens s University, Ontario) had at this time joined me as an NRC Research Fellow. He measured the first absorption system at 340 nm in the vapour, pure crystal and in mixed crystals in a variety of hosts, for phenanthrene-hio and -dm. Even at high resolution the vapour spectrum yielded little, but at 4 K in the pure crystal there was a splitting of the origin... 

The similarity between the absorption spectra of decamethylbiphenyl and hexamethylbenzene7 (Figure 83) may be taken as experimental evidence for very large twists (Type 3). Similarly, the absorption spectra of bimesityl and 2,2, 4,4, 6,6 -hexachlorobiphenyl may be compared with the spectra of mesitylene and m-trichlorobenzene respectively20. The spectra of the two non-planar phenanthmie derivatives, IV and V, are similar to the spectrum of phenanthrene itself21. The naphthalene derivative, VI, exhibits the same... 

Studies on benzo-fused analogs of 78 have also been reported. Solutions of unstable dibenzo[b,e]phosphabenzene (phosphaanthracene) (80, R = H)286 and dibenzo[6,d]phosphabenzene (phosphaphenanthrene) (81)287 have been prepared and examined by UV spectroscopy. The overall shape of the spectrum due to 80 (R = H) resembles that of anthracene rather than acridine, whereas that of 81 resembles the phenanthridine more closely than the phenanthrene spectrum. The absorptions of both 80 (R = H) and 81 show the typical strong bathochromic shifts relative to their nitrogen and carbocyclic analogs. 10-Phenyldibenzo[6, e]phospha-benzene (80, R = Ph)288 is more stable than its parent and shows similar UV absorption. 

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