Monosodium phosphoenolpyruvate hydrate: new diffractometer data

Abstract

The fulvalene ligand is essentially planar with only a 6 ° twist about the bond connecting C1 and C6. The metals adopt the trans orientation found in all fulvalene complexes in which there is no M--M bond, to minimize steric interactions between the respective ligand coordination spheres.This crystal structure was solved at the X-ray Crystallographic Facility (CHEXRAY) at the Department of Chemistry, University of California, Berkeley, as part of the requirements of a graduate chemistry course on structure analysis by X-ray diffraction. We thank Mr Tim Karpishin, Dr F. Hollander and Professor K. N. Raymond for their guidance.

Structure of tris(cyclohexylammonium) phosphoenolpyruvate monohydrate and crystal chemistry of phosphoenolpyruvates

“…3. 3 ; (b) Weichsel, ; (c) Lis (1991); (d) Lis (1987); (e) Weichsel & Lis (1989a); (f) ; (g) Lis (1992); (h) Weichsel & Lis (1990a); (i) this work; (j) . 3 are those that minimize the sum of squares of the perpendicular, rather than the vertical, distances of the data points from the lines.…”

“…3(a) Fig. Lis (1991); (d) Lis (1987); (e) Weichsel & Lis (1989a); (f) ; (g) Lis (1992); (h) Weichsel & Lis (1990a); (i) this work; (j) . These behaviors manifest a structural flexibility in the various Pep species that is consistent with the hypothesis (see, e.g., Westheimer, 1987, and references cited therein) that phosphate ester hydrolysis occurs by scission of the P--O(C) bond rather than the (P)O--C bond and passes through a trigonal bipyramidal five-coordinate transition state or a trigonal planar, monomeric metaphosphate PO; intermediate.…”

“…Colorless rectangular parallelepiped shaped crystals of tris(cyclohexylammonium) phosphoenolpyruvate mono- O ,C,H 2 3-( ) o oe II 0 hydrate were obtained by recrystallizing the commercially available material (Sigma Chemical Co.) by vapor diffusion of acetonitrile into a concentrated aqueous solution. Scan widths were Aw = [0(Kt~2) -b 0.325 °] -[0(Kal)-0.325°], which corresponded to ca twice the base width Katti, Hosur & Viswamitra (1981); (d) Lis (1991); (e) Hosur & Viswamitra (1981); (f) Lis (1987); (g) Watson & Kennard (1973); (h) Weichsel & Lis (1989a); (i) ; (j) Lis (1992): (k) Weichsel & Lis (1990a); (l) this work; (m) . A crystal of approximate dimensions 0.5 x 0.2 x 0.2 mm was used for the X-ray analysis.…”

“…(a)Weichsel & Lis (1989b);; (b); (c)Lis (1991); (d)Lis (1987); (e)Weichsel & Lis (1989a); (f); (g)Lis (1992); (h) Weichsel & Lis (1990a); (i) this work; (j) Weichsel & Lis (1990b).MoKct resonant scattering by phosphorus was strong enough to determine the chirality of the hydrogenbonded structure.TheP--O bond lengths provide a particularly clear example of the effects of hydrogen bonding on the bond strengths in P--O acceptor groups. Hydrogen bonding weakens the partial double-bond character and strengthens the charge-separated single-bond character in the acceptor groups + -{P--O--.H--N < >P--O..-H~N} and the acceptor°P--O bond lengths increase from 1.48 to 1.50 to 1.52 A…”