Chiral recognition between host and guest: a binaphthyl-18-crown-6 host with D-phenylglycinium methyl ester perchlorate guest. A difficult structure solved with CRUNCH.
The complex between (R)-4,5,7,8,10,11,13,14,16,17-decahydro-2,19- diphenyldinaphtho[2,1-q:1',2'-s][1,4,7,- 10,13,16]hexaoxa[2,5,8,11,14,17,19]cycloicosaheptene {Chemical Abstracts name: (R)-4,5,7,8,10,11,13,14,16,17-decahydro-2,19- diphenyldinaphtho[2,1-q:1',2'-s][1,4,7,-10,13,16]hexaoxacycloic osin} and D-2-phenylglycinium methyl ester perchlorate, C9H12NO2+.ClO4-.C42H40O6.-H2O, crystallizes in the orthorhombic space group P2(1)2(1)2(1) with two C9H12NO2+.C42H40O6 complexes, two ClO4- ions and two molecules of water in the asymmetric unit. Crystal data: M(r) = 924.44, a = 23.048 (7), b = 34.383 (6), c = 11.992 (6) A, V = 9503 (6) A3, Z = 8, Dx = 1.292 Mg m-3, F(000) = 3904, mu(Cu K alpha) = 1.261 mm-1, T = 175 K, R = 0.0896 for all 7784 reflections, 1208 parameters refined in three blocks with 29 restraints. Nearly twenty years elapsed between the first data collection and the solution of the structure with the direct-methods program CRUNCH. The structural details are of interest because enantiomers of this host show a high degree of discrimination between enantiomers of alpha-amino acids and their esters. The crystal structure demonstrates the influence of C-H...O and C-H...pi interactions on the unexpected orientation of the guest in the host cavity. The same orientation is found in both of the unique complexes, and the geometric details are in agreement with solution studies.
Cram
D J
DJ
Department of Chemistry and Biochemistry, University of California, Los Angeles 90095-1569, USA.
de Graaff
R A
RA
Knobler
C B
CB
Lingenfelter
D S
DS
Maverick
E F
EF
Trueblood
K N
KN
D003198:Computer Simulation; D043844:Crown Ethers; D003460:Crystallization; D018360:Crystallography, X-Ray / Q000379:methods; D004988:Ethers, Cyclic / Q000737:chemistry*; D005998:Glycine / Q000031:analogs & derivatives* / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D012984:Software; D013237:Stereoisomerism; D013816:Thermodynamics
C120465:2-phenylglycinium methyl ester; C120464:4,5,7,8,10,11,13,14,16,17-decahydro-2,19-diphenylnaphtho(2,1-q-1',2'-s)(1,4,7-10,13,16)hexaoxacycloicosin; D043844:Crown Ethers; D004988:Ethers, Cyclic; D005998:Glycine