Insights into supramolecular design 2: Analysis of anion coordination geometry of oxoanions in a protonated polyamine matrix

Single-crystal X-ray diffraction analysis of 16 hydrogen bonded structures formed from reaction of 8 aliphatic polyamines with nitric (1), phosphoric (2) and sulfuric acid (3) is reported. The polyamines included are diethylenetriamine, H2N(CH2)(2)NH(CH2)(2)NH2 (a), N-2-aminoethyl)-1-3-propanediamine, H2N(CH2)(3)NH(CH2)(2)NH2 (b), spermidine, H2N(CH2)(4)NH(CH2)(3)NH2 (c), bis(hexamethylene)triamine, H2N(CH2)(6)NH(CH2)(6)NH2 (d), triethylenetetramine, H2N(CH2)(2)NH(CH2)(2)NH(CH2NH2 (e), N,N-bis(3-aminopropyl)ethylenediamine, H2N(CH2)(3)NH(CH2)(2)NH(CH2)(3)NH2 (f), spermine, H2N(CH2)(3)NH(CH2)(4)NH(CH2)(3)NH2 (g) and 2,2$,2$$-triaminotriethylamine, N[(CH2)(2)NH2](3) (h). The complexes are formed in amine:anion ratios of 1:1 to 1:4. The oxoanions are connected by hydrogen bonds to the protonated amines following specific patterns. These patterns depend on the mode of covalent connectivity of the oxygen within the anion as well as on the distance between the oxygen of interest and the central atom of the anionic species.