ISSN:
0941-1216
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Interaction in Crystals. 98. Protonated Hexamethylmelamin Salts with Different Anions: Monomeric Tetraphenylborate, Dimeric Trifluoracetate and Polymeric Chloride-DihydrateHexamethylmelamin (2,4,6-tris(dimethylamino)-1,3,5-triazine), on monoprotonation at one of the triazine nitrogens keeps its close to planar skeleton. Its salts with different anions reflect biochemically interesting hydrogen-bridge networks: Crystallization of the hydrochloride from isopropanol solution containing Li⊕ [B⊖(C6H5)4], yields “naked” molecular cations, packed in herringbone fashion in between the lattice-dominating bulky, phenyl-shielded and non-protonable tetraphenylborate anions. From trifluoroacetic acid, crystals with sandwich-like subunits connected by hydrogen-bridged anions [F3CCOO⊖…HOOCCF3] are obtained. The hydrochloride salt, prepared by adding aqueous HCl to a diethylether solution, crystallizes in stacks of triazinium cation dimers with an intermolecular bridge N⊕-H…Cl⊖…H⊕N in between chloride-bydrate strands (…Cl⊖…HOH…O(H)H…Cl⊖…). Together, the structures of the three different hexamethyl-melaminium salts further illustrate the influence of anions on the crystallization of protonated nitrogen heterocycles and complement that of counter cation cation solvation in molecular anion salts.
Additional Material:
3 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/prac.19973390195
