ISSN:
1573-1111
Keywords:
Thiourea
;
tetraalkylammonium salt
;
bicarbonate dimer
;
hydrogen bonding
;
inclusion compound
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract New inclusion complexes R4N+HCO 3 − ·x(NH2)2CS·yH2O (1, R=C2H5,x=1,y=1;2, R=n−C3H7,x=2,y=0;3, R=n−C4H9,x=3,y=0) have been prepared and characterized by X-ray crystallography. Crystal data, MoK α radiation:1, space groupPbca,Z=8,a=8.839(2),b=14.930(3),c=24.852(5) Å, andR F=0.063 for 1419 observed data;2, space groupC2221,Z=8,a=8.521(3),b=16.941(4),c=32.022(7) Å,R F=0.054 for 1689 observed data;3, space group $$P\bar 1$$ ,Z=2,a=9.553(2),b=12.313(3),c=14.228(4) Å, α=90.44(2),β=103.11(2), γ=110.12(2)°,R F=0.044 for 3925 observed data. In the crystal structure of1, the thiourea molecules form hydrogen-bonded zigzag ribbons running parallel to thea axis, and the cyclic dimeric bicarbonate moieties (HCO 3 − )2 together with water molecules behave likewise. A puckered layer is formed by further lateral hydrogen bonding between these two types of ribbons, and the (C2H5)4N+ cations occupy the space between adjacent layers. In the crystal structure of2, the thiourea ribbons are cross-linked orthogonally by (HCO 3 − )2 unitsvia N−H...O hydrogen bonds to form a composite double layer. Half of the cations are enclosed within and the other half sandwiched between these double layers. In the crystal structure of3, the thiourea molecules form puckered double ribbons running in the [110] direction. The host framework is constructed by cross-linking the double ribbons with bridging bicarbonate dimers, yielding two channel systems aligned parallel to [100] and [111] that accommodate the cationic guests. The structural relationship between the present complexes and the classical thiourea channel adducts is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00707613
