9-Cyanoanthracene

Cyanoanthracene (anthracene-9-carbonitrile) [1210-12-4] M 203.2, m 134-137°. Purified by crystn from EtOH or toluene, and vacuum sublimed in the dark and in an inert atmosphere [Ebied et al. 7 Chem Soc, Faraday Trans 7 76 2170 1980 Kikuchi et al. J Phys Chem 91 574 1987. ... 

Cyanoanthracene photodimer [33998-38-8] M 406.4, dec to monomer above 147°. Purified by dissolving in the minimum amount of CHCI3 followed by addition of EtOH at 5° [Ebied et al. J Chem Soc, Faraday Trans 7 75 1111 7979 76 2170 1980]. 

The mechanistic basis of 3 and 4 is a double application of the argument used for the YES operation with 1. Each receptor in 3 is capable of launching a PET process if the lumophore is powered up by ultraviolet excitation. In other words, the fluorescence of the 9-cyanoanthracene unit is efficiently quenched by either the amine or the 1,2-dioxybenzene group within the benzo-15-crown-5 ether unit. These quenching processes are predictable from thermodynamic calculations or from related bimolecular quenching experiments in the literature. The small separation of the amine from the lumophore ensures rapid PET kinetics. On the other hand, the presence of four bonds between the benzo-15-crown-5 ether and the lumophore is probably responsible for the incomplete quenching seen between this pair. No information is yet available regarding possible folded conformations of 3. 

Fig. 3 Electronic absorption spectra of (A) the EDA complex of 9-cyanoanthracene (CNA) and tetracyanoethylene (TCNE) in comparison with the uncomplexed CNA and TCNE (B) the donor cation CNA+- and acceptor anion TCNE -generated spectroelectrochemically and (C) time-resolved picosecond absorption spectra taken at 25, 50, 75 and lOOps following the charge-transfer excitation at 532 nm of [CNA, TCNE] with a 25-ps laser pulse.

Cyanoanthracene, 50,55 p-Cyanobenzenesulfonamide, reduction with Raney nickel alloy to p-for-mylbenzenesulfonamide, 51,20 p-Cyano-N,N-diethylaniline, 50, S4 Cyanohydrins, formation by use of alkyl-aluminum cyanides, 52, 96... 

Cyanoanthracene, 50, 55 p-Cyanobenzenesulfonamide, reduction with Raney nickel alloy to p-formylbenzenesulfonamide, 51, 20... 

For instance, head-head photodimers are predicted from the crystal structures of 9-cyanoanthracene and 9-anthraldehyde, but the head-tail isomer is produced. Craig and Sarti-Fantoni and later others found that photoreactions of 9-cyanoanthracene and 9-anthraldehyde take place at defect sites [96,215], Systematic photochemical and crystallographic studies by Schmidt and co-workers uncovered many cases of substituted anthracenes which behave in an unexpected fashion (Scheme 40) [216,217]. Examples shown in Scheme 40 clearly illustrate that, unlike cinnamic acid derivatives, the stereochemistry of the product dimer from anthracenes cannot be predicted on the basis of crystal packing. An example from the laboratories of Venkatesan is noteworthy in this context [218], Irradiation of crystals of 7-... 

Electron transfer does not follow the simple rule of order of reactivity observed for n-7T, tt-tt and CT states for hydrogen atom transfer. The 77—77 singlet excited state (S of 9-cyanoanthracene for instance also undergoes electron transfer with amines at a diffusion-controlled rate. 

TABLE 11. Results of photooxygenation of substituted stilbenes (PhCH=CHAr) with 9-cyanoanthracene catalyst in the presence of tetraethylammonium acetate (yields given in percent)"... 

Albini et al. reported that the cross-dimerization of 9-cyanoanthracene with substituted naphthalenes and anthracenes takes place through a significantly polar intermediates and is affected by solvents and substituents [156], The combination of 9-cyanoanthracene and unsubstituted anthracene in CH3CN gave the best result (Scheme 31). Photoirradiation of 9-cyanoanthracene with 1-methylnaphthalene,... 

---