Dear Amirhossein Bayani this is a very interesting technical question. Even with the help of a SciFinder search I have been unable to locate a literature reference in which the crystal structure of 2-(9H-carbazol-9-yl)-ethyl phosphonic acid (2PACz) is reported. This is surprising in view of the fact that the compound is frequently used in materials science. Sorry 😢Perhaps you should ask a crystallographer at your institution to search for the crystals structure in the Cambridge Database CCDC.

Dear Frank T. Edelmann

Thanks a lot for your comment. I did check all available database like CCDC, ICDS, COD and searched on Google and Google scholar but I could not find any information! Only I found the melting point of 2PACz which is around 480 C. So I think there is a crystal structure for 2PACz.

Dear Amirhossein Bayani many thanks for your kind response and explanation. This is your chance! You can prepare (or buy) as sample of 2-(9H-carbazol-9-yl)-ethyl phosphonic acid (2PACz), try to grow nice single-crystals and determine the crystal structure yourself (or have it determined by a crystallographer at your institution).

Good luck and best wishes, Frank Edelmann