2-Aminopyrimidine–terephthalic acid (1:1) complex

Hydrogen-bonding patterns in 2-amino-4,6-dimethylpyrimidine–cinnamic acid (1/2)

“…2 and Table 2. This type of pairing has been observed in the crystal structures of 2-aminopyrimidine-fumaric acid (Goswami, Mahapatra, Ghosh et al, 1999, 2-aminopyrimidine-(+)camphoric acid (Goswami et al, 2000), 2-aminopyrimidine-succinic acid ) and 2-aminopyrimidineterephthalic acid (Goswami, Mahapatra, Ghosh et al, 1999. The two crystallographically independent cinnamic acid molecules are connected via C-HÁ Á ÁO hydrogen bonds, leading to the formation of a hydrogen-bonded supramolecular chain parallel to the b axis ( Fig.…”

Synthesis, crystal structure, spectroscopic characterization and optical properties of bis(4-acetylanilinium) tetrachlorocobalt (II)

“…The protonation on the N site is identified by the bond length of C-N (1.479(7) Å), which is bigger than that in the non-protonated molecule (1.335 (3)) Å [36].…”

Geometry of the 2-aminoheterocyclic–carboxylic acid R 2 2(8) graph set: implications for crystal engineering

“…Etter & Adsmond (1990), in their study of the hydrogen-bonding preferences of 2-aminopyrimidines, were the ®rst to note that the Johnson and Rumon theory for pyridines also did not hold for 2-aminopyridines, but they did not suggest any alternative solution. Our theory can best be demonstrated by the fact that the 2AP, which has a pK a value of 3.45, and fumaric acid (pK a = 3.03) co-crystals are salts , while the terephthalic acid (pK a = 3.51) cocrystal is an adduct (Goswami, Mahapatra, Ghosh et al, 1999). Our theory also explains why all 2APy (pK a = 6.82) and 4APO (pK a = 8.24) co-crystals are salts; because all the acids used had lower pK a values.…”