Methanol guest molecules

The Raman spectra of quinol clathrates unlike the infrared spectra [4], are not dominated in the 2700-3700 cm" region by the OH band of the host lattice. It is consequently quite easy to observe the methanol guest molecule bands in the Raman spectrum of the clathrate (Fig. 2a), and the difference spectrum (Fig 2c) merely highlights the intensity of the guest molecule bands. 

The example specified as II a in Fig. 19 reveals the pattern found invariably in the methanol, ethanol, and 2-propanol inclusions of /. It is characterized by a loop of H-bonds which always involves two guest molecules opposing each other through a center of symmetry and two carboxyl groups of two symmetry-related molecules of 1 thus having adverse chirality (Fig. 17 a). The loop of H-bonds seems to be formed with... 

Pedersen (1971) reported on a number of crystalline complexes with thiourea and similar molecules and found that the solubility of dibenzo-18-crown-6 [11] in methanol is enhanced by urea and thiourea. The latter observation precludes the possibility of the solid complexes being urea or thiourea inclusion compounds. Factors that are of importance in the complex formation are ring size (dibenzo-12-crown-4 did not form complexes), and steric hindrance in the complex caused by the guest molecule. Thiourea, N-phenylthiourea, and 2-thiazolidinethione form complexes but N,N,N -trimethylurea, thiocarbanilide and N-methylthiazolidinethione do not. 

Figure 5 Antiparallel fi-sheet-like structure of 2 including methallyl alcohol and methanol. (a) ab plane. To improve clarity, guest molecules are omitted, and the naphthyl and phenyl groups are unshaded, (b) Guests (dark gray) in the pocket-type void surrounded by naphthyl and phenyl groups (unshaded).

Ten kinds of PEG DM (n = 1-7, 9, 12 and 20) were selected as guest molecules. Fortunately, the inclusion compound was obtained from 2 and all of the selected PEG DM( ) by co-crystallization from methanol. As summarized... 

When allylic alcohols were used as a guest molecule instead of the ethers (THF and diethyl ether), the arrangement of the dipeptide molecules was changed to an antiparallel / -sheet-like structure. By crystallization from methanol-methallyl alcohol, we obtained the single crystal of an inclusion compound, which consisted of 2, methanol, and methallyl alcohol. The X-ray structure shows an antiparallel mode... 

It is well known that deoxycholic acid 1 forms inclusion complexes with a number of guest molecules. The crystalline inclusion complexes 87a-c l were obtained from solutions of deoxycholic acid 1 with acetophenone 87a, ra-chloro-acetophenone 87b, or / -fluoroacetophenone 87c in methanol. The host guest molar ratios are 5 2, 3 1, and 8 3, respectively. The guest molecules are... 

Conditions for the formation of potato starch-alcohol complexes do not follow predictable trends. For example, all complexes are formed more readily from air-dried starch rather than from oven-dried starch. Only the starch-methanol complex favors room temperature for its formation the other alcohols require elevated temperatures for effective complexations (see Table XXXI).659,681 682 In contrast, moisture inhibits the formation of the starch-(-)-menthol complex, which is characterized as an interchain complex.710 The Scatchard binding parameters show that (-)-menthol and 1-hexanol adsorb on starch by only one mode, whereas 1-octanol and 1-decanol adsorb in two modes.656 The results for the latter two alcohols indicate that the helices are not fully filled before the second mode of complexation starts. Temperatures of the formation of starch-alcohol complexes likewise do not follow any clear relationship.673,680 Bushuk and Winkler687 reported that the amount of guest molecules (HzO, MeOH,... 

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