A series of new charge-transfer cocrystals of F2TCNQ with anthracene, tetracene, and chrysene was prepared and characterized. The donor and acceptor molecules are arranged in alternating D–A–D–A stacks. The linear acenes in combination with F2TCNQ form layered structures due to in-plane lateral donor–acceptor and acceptor–acceptor interactions via multiple C–H···N and C–H···F hydrogen bonds, which govern the crystal structure and significantly alter face-to-face π–π interactions. In the cocrystal of F2TCNQ with chrysene no interactions between acceptor molecules are observed, and the π–π interactions prevail. Thus, the donor–acceptor interplanar distance is the smallest in the chrysene complex despite its lower energy level of the HOMO and weaker donor ability, as determined through electrochemical oxidation potentials in this series of PAHs. The charge-transfer values estimated through empirical correlations and QTAIM analysis also do not manifest a direct dependence on the donor ability of PAHs. Thus, though face-to-face π–π interactions dictate the formation of cocrystals, the lateral noncovalent interactions are as important for the supramolecular arrangement and charge transfer. UV/vis spectroscopy and electronic structure quantum chemical calculations show that these cocrystals may be classified as small-gap semiconductors with energy gaps of 0.7–1.3 eV.

A new diastereoselective synthesis of alpha-aminophosphonates has been developed, based on the reaction, in the presence of trifluoroacetic acid, of trialkyl phosphites with chiral imines derived from (R)- or (S)-1-(alpha-aminobenzyl)-2-naphthol. The reaction proceeds at room temperature in toluene with high diastereoselectivity. The major diastereomer can be separated by crystallization from an appropriate solvent. The relative configuration of both chiral centers of the major diastereomer was determined by single-crystal X-ray structure analysis. The desired alpha-aminophosphonic acids can be obtained in enantiopure form by treatment of the corresponding diastereomers with HCl.

An improved method for enantioseparation of racemic 1-(a-aminobenzyl)-2-naphthols has been developed by the reaction in situ of Betti base product mixtures with L-(+)-tartaric acid taken in a 1:1 ratio. The products of this reaction are (-)-1-(a-aminobenzyl)-2-naphthol tartrate, the acetal of benzaldehyde and tartaric acid as well as (+)-1,3-diaryl-2,3-dihydro-1H-naphth[1,2-e][1,3]oxazine, which can be easily separated by crystallization.

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