Structure of tris(cyclohexylammonium) phosphoenolpyruvate monohydrate and crystal chemistry of phosphoenolpyruvates
Abstract
The crystal structure of (C 6 H 11 NH 3 + ) 3 .Pep 3− .H 2 O, where Pep 3− = (O − ) 2 P(O)—O—C(CH 2 )—CO − 2 , is reported and the systematic structural variations among 19 crystallographic occurrences of H 3 Pep, H 2 Pep − , HPep 2− and Pep 3− species, which are important phosphate donors in the ATP cycle of bioenergetics, are reviewed. Tris(cyclohexylammonium) phosphoenolpyruvate monohydrate, (C 6 H 11 NH 3 + ) 3 .[O 3 POC(CH 2 )CO 2 ] 3− .H 2 O, M r = 483.6, m.p. 418–420 K; T = 296 (1) K; orthorhombic, P 2 1 2 1 2 1 ; a = 16.7042 (5), b = 24.4881 (6), c = 6.38910 (10) Å; V = 2613.49 (11) Å 3 , Z = 4, D x = 1.23, D m = 1.22 mg mm −3 , μ = 0.14 mm −1 for λ (Mo K α) = 0.7107 Å; F = 1056 e; R (| F |) = 0.0608 for 6056 hkl and hk \bar l data with (sin θ )/ λ ≤ 0.65 Å −1 .