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Inclusion Compounds of Diol Hosts Featuring Two 9-Hydroxy-9-fluorenyl or Analogous Groups Attached to Linear Spacer Units

“…below). However, no cis configuration, as exhibited by host 3 in its inclusion crystal with 2,6-lutidine as guest, [51] was observed in the diol molecules in this study. Furthermore, the two fluorenyl groups in host 8 are connected through a linear triphenylene unit, in which each ring may rotate freely around the single bonds linking them together.…”

“…X-ray diffraction analysis of six selected cocrystals indicated extensive involvement of the host alcoholic functions in the enclathration of smaller guest molecules with H-bond capability, in agreement with previous studies of some crystalline inclusion compounds of hosts 1 [40] and 3. [51,52] Accordingly, recognition of guests with OH groups, such as propanols or cyclohexanol, by these diol hosts is characterized by closed H-bonded loops with full H-bond saturation. This interaction pattern is a consequence of the cooperativity of the alcoholic OH groups of both host and guest, simultaneously exhibiting good proton donor and acceptor capacity.…”

“…2·1-PrOH (1:2), 2·cyclohexylOH (1:4), and 3·2-PrOH (1:1)], [52] which may in turn affect the size of the H-bonded loops and/or the organization of the ribbons. Guests with dominating proton acceptor character, such as DMSO, THF, acetone, or lutidines, [51] are usually coordinated by these diol host molecules through single hydrogen bonds. However, DMSO and acetone have also been observed to function as doubleacceptor guest molecules, when enclathrated by host 3, for example, [52] thus giving rise to endless chains of alternating H-bonded host and guest molecules.…”

“…For comparison, a structural study of the unsolvated host compound 8 is also covered here, and reference is made to previously reported structures of crystalline inclusion complexes involving host compounds 1 [40] and 3. [51,52] Crystallographic data and details of structure refinement calculations of the inclusion compounds are given in Table 3. Figures 1Ϫ4, prepared by use of the XP molecular graphics program, [53] show perspective views of the stoichiometric hostϪguest units of the inclusion compounds and of the unsolvated compound 8.…”

Tunable clathrates

“…X B is the mole fraction of guest B in the liquid mixture and Z B that of guest B which has been enclathrated in the host-guest crystal. Curve a results from a host displaying no selectivity, 6 curve b occurs when guest B is strongly selected over A for the whole concentration range 7 and curve c occurs when the selectivity is concentration dependent. 8 In this work, however, we present results of a host-guest system which behaves in a totally different manner.…”