Polysulfonylamine, CLXX [1]. Wasserstoffbrücken in kristallinen Onium-dimesylamiden: Drei Strukturen mit NH2-substituierten 1,3,5-Triazinium-Kationen (einschließlich Melaminium) / Polysulfonylamines, CLXX [1]. Hydrogen Bonding in Crystalline Onium Dimesylamides: Three Structures Involving NH2-Substituted 1,3,5-Triazinium Cations (Including Melaminium)
In order to study hydrogen bonding networks and packing arrangements, preparations and lowtemperature X-ray structures are reported for three ionic solids of general formula BH+(MeSO2)2N−, where BH+ is 2,6-diamino-4-phenyl-1,3,5-triazin-1-ium (compound 1, tetragonal, space group P4̅21c, Z = 8), 2,4,6-triamino-1,3,5-triazinium or melaminium (2, monoclinic, P21/c, Z = 4), and 2,4-diamino-6-methyl-1,3,5-triazin-1-ium (3, triclinic, P1̅, Z = 2). The asymmetric units consist of cation-anion pairs that display in 1 a [DDD:AAA] three-point hydrogen bond pattern formed by two lateral N-H···O bonds and a central N+-H···N interaction, in 2 a related pattern, in which the substantial lateral offset of the ions causes the two-centre H bonds to split up into three-centre bonds, and in 3 a [DD:AA] two-point pattern formed by an N-H···N and an N+-H···O interaction. All NH donors that are not involved in the ion pairs use sulfonyl oxygen atoms and/or non-protonated nitrogen ring-atoms as acceptors to form, in 1 and 3, discrete cation-anion strands, and in 2 similar strands associated into a three-dimensional network via one independent N-H···O bond. The packing topologies of the strands may be viewed as supramolecular analogues to molecular arrangements occurring in crystalline polyaromatic hydrocarbons, viz. the sandwich-herringbone pattern in 1 (sustained by π···π stacking of the triazine rings within the sandwiches and a phenyl-phenyl C-H···π interaction between orthogonal sandwiches), the flattened or γ -type herringbone pattern in 2 (sustained by the unique N-H···O interaction of orthogonal strands), and the pseudo-graphitic β -pattern in 3. In each packing, weak C-H···A hydrogen bonds (A = O, N) originate from the activated methyl groups of the anions and act as structure-supporting links between the cation-anion strands.