| Popis: |
Novel substrates for the deposition of thin films of organic molecules suitable for optoelectronic device applications are currently searched for. Recently, we found that single crystals of -alanine, a natural amino acid, can be easily cleaved, providing clean and molecularly flat (010) surfaces. These surfaces allow preparation of high-quality crystalline thin films layers with organic molecular beam epitaxy (OMBE) [1]. In order to find further potential substrates for the heteroepitaxial growth of organic semiconductors thin films, we screened the Cambridge Structural Database (2014) by means of the TOPOS program package [2]. We were looking for crystal structures with the ability to cleave along specific crystallographic planes, possibly with cheap and non-toxic compounds exhibiting high solubility in water or non-toxic solvents. Absence of any solvates and hydrates for the searched structures was mandatory to guarantee stability to ultra-high vacuum conditions needed for OMBE. The search was performed by looking for structures with 2D hydrogen bonded networks: potassium salts of carboxylic and sulfonic acids, derivatives of aminoacids, inorganic salts of organic bases. Additionally, for some key structures we calculated intermolecular interaction energies by means of the PIXEL method [3] trying to establish the structural features that can lead to the ability of molecular crystals to cleave [4]. [1] S. Trabattoni, M. Moret, M. Campione, L. Raimondo, A. Sassella Cryst. Growth Des. 2013, 13, 4268. [2] V.A. Blatov Struct. Chem. 2012, 23, 955. [3] A. Gavezzotti J. Phys. Chem. 2002, 106, 4145; A. Gavezzotti J. Phys. Chem. 2003, 107, 2344. [4] P. Groth, Chemische Kristallographie, Verlag von Wilhelm Engelmann, Leipzig, 1906. |
