Crystal structure and IR spectrum of 1-O-alpha-D-glucopyranosyl-D-mannitol-ethanol (2/1)

1-O-alpha-D-Glucopyranosyl-n-mannitol-ethanol (2/1), (C12H24O11)(2)-C2H5OH, crystallizes in the monoclinic space group P2(1) with unit cell dimensions a = 11.4230(8) Angstrom, b = 9.525(4) Angstrom, c = 15.854(2) Angstrom, be ta = 102.751(7)degrees and V = 1682.4(7) Angstrom(3), Z = 2, D-x = 1.45 Mg m(-3), lambda (Mo-K-alpha) = 0.71069 Angstrom, mu = 0.128 mm(-1), F(000) = 788 and T = 293(2) K. The structure was solved by direct methods and refine d by least-squares calculations on F-2 to R-1 = 0.0371[I > 2 sigma(T)], and 0.0930 (all data, 3542 independent reflections, R-int = 0.021). There are two molecules of glucopyranosylmannitol (GPM) and one ethanol molecule in t he asymmetric unit, and the glucopyranosyl ring adopts a chair conformation in both GPM molecules. Bond lengths and angles accord well with the mean v alues of related structures. The conformation along the mannitol side chain for one of the GPM molecules was the same as for the known polymorphs of D -mannitol, while the conformation of the other molecule was different, indi cating different conformational arrangements in the terminal carbon atoms o f the mannitol side chains of the two GPM molecules. The structure in 1-O-a lpha-D-glucopyranosyl-D-mannitol-ethanol (2/1) is held together by a very c omplex hydrogen bonding system, which consists of an infinte chain propagat ing along the b-axis and a discontinuous chain, which binds the ethanol mol ecule to the structure. The FTIR spectra for anhydrous GPM, GPM dihydrate a nd GPM-ethanol (2/1) were recorded. Both IR and X-ray results indicate the extensive hydrogen bonding in crystalline state. (C) 1999 Elsevier Science B.V. All rights reserved.