Structures and conformations of protonated O2N2- and O2N3-macrocyclic ligand salts

Single crystal X-ray structure determinations are described for salts of 5,6,14,15-dibenzo-1,4-dioxa-8,12-diazacyclopentadeca-5,14diene (L-1) (mono-protonated, as its F(3)CSo(3)(-) ('tfs') salt, and diprotonated, as its nitrate salt) and 5,6,17,18-dibenzo-1,4-dioxa8,11,15-triazacyclooetadeca-5,17-diene (L-2) (diprotonated, as its tfs salt), defining their protonic hydrogen atom distributions and conformations. In ((LH)-H-1)(tfs), an NH group is protonated, the associated hydrogen atoms interacting one within the cation to the other NH group, the other with a tfs oxygen atom. In ((LH2)-H-1)(NO3)(2) (two phases), both NH groups are protonated; in each case, although one NH2+ group is oriented so that one of its hydrogen atoms is directed within the ring to the adjacent oxygen atom, there is a competing interaction with a nitrate oxygen atom. All other NH2+ hydrogen atoms interact with nitrate oxygen atoms. In ((LH2)-H-2)(tfS)(2), the peripheral NH groups are protonated, the protonic hydrogen atoms interacting with tfs anions disposed above and below the macrocycle, making a tight [((LH2)-H-2)(tfS)(2)] cluster. (c) 2006 Published by Elsevier Ltd.