Complexation with hydroxy host compounds. Part. 4. Structures and thermal stabilities of inclusion compounds with dioxane as the guest

Abstract

Structures of the inclusion compounds of five hydroxy-containing hosts with dioxane have been solved.Crystal data: 1, monoclinic, C2/c, a = 8.648( 1 ) A, b = 16.551 (1 ) A, c = 17.038(4) A, #I = go", V = 2398.64 A3, Z = 4; 2, triclinic, P i , a = 8.441 ( 8 ) A, b = 10.544(2) A, c = 11.562(2) A, 01 =67.47(1)", /I = 83.96(5)", y = 89.08(5)", V = 944.94 A3, Z = 2; 3, triclinic, P i , a = 9.378(7) A, b = * For details of the deposition scheme see 'Instructions for Authors',

Hydrogen-bonded adducts of triphenylsilanol with diamines: a finite ten-molecule aggregate, and chain, sheet and framework structures built from O—H...O, O—H...N and C—H...π(arene) hydrogen bonds

“…In (I) and (II) the hard hydrogen bonds generate ®vecomponent aggregates in which an inner pair of triphenylsi-lanol molecules are hydrogen bonded to the central double acceptor, with an outer pair of triphenylsilanol molecules linked to the inner pair by means of OÐHÁ Á ÁO hydrogen bonds. Entirely similar aggregates are found in the 4:1 adduct (Ph 3 SiOH) 4 ÁC 4 H 8 O 2 formed with 1,4-dioxan (Bourne et al, 1991;Bowes et al, 2002) and in all three polymorphs of the 4:1 adduct (Ph 3 SiOH) 4 ÁC 10 H 8 N 2 formed with 4,4 H -bipyridyl (Bowes et al, 2003). Moreover, (II) crystallizes in the space group P " 1 with Z H = 0.5, as do the 1,4-dioxan adduct and the simplest of the 4,4 H -bipyridyl adducts.…”

The 1:1 adduct of triphenylsilanol and 4,4′-bipyridyl, and three pairwise-concomitant triclinic polymorphs of the 4:1 adduct having Z′ = 0.5, 1 and 4

“…4) (Figs. 5±7), which is analogous to the aggregate found in the 4:1 adduct (Ph 3 SiOH) 4 ÁC 4 H 8 O 2 , formed with 1,4-dioxan (Bourne, Johnson et al, 1991;Bowes et al, 2002). In such an aggregate, we can conveniently distinguish between an inner pair of triphenylsilanol molecules which provide the donors in the OÐHÁ Á ÁN hydrogen bonds and an outer pair of triphenylsilanol molecules which provide the donors in the OÐHÁ Á ÁO hydrogen bonds (Table 2).…”

“…As noted earlier (x3.2.2), the structure of the hydrogenbonded aggregates in (II)±(IV) closely resembles that of the 1,4-dioxan adduct (Ph 3 SiOH) 4 ÁC 4 H 8 O 2 . However, the structure and composition of this last adduct are entirely different from those of the adduct formed by 1,4-dioxan with triphenylmethanol, Ph 3 COH, where a 1:1 adduct is formed containing a two-component aggregate involving just a single OÐHÁ Á ÁO hydrogen bond (Bourne, Johnson et al, 1991), rather analogous to the structure of (I) (x3.2.1). It is thus pertinent to summarize here the similarities and differences exhibited by the few adducts of Ph 3 COH and Ph 3 SiOH which The independent molecular components of (III), showing the atomlabelling scheme: (a) for the aggregate centred at (0.5, 0.5, 0.5), where the atoms marked`A' are at the symmetry position (1 À xY 1 À yY 1 À z); (b) for the aggregate centred at (0.5, 1.0, 0.5), where the atoms marked`A' are at the symmetry position (1 À xY 2 À yY 1 À z).…”

“…This tetrameric structure, despite the increasing mobility of the phenyl rings with increasing temperature, appears to be extremely robust and the same phase is obtained on crystallization of triphenylsilanol from a wide range of solvents including such potential acceptors of hydrogen bonds as acetone and ethyl acetate (Bowes et al, 2002). Speci®c solvates are, however, obtained from dimethylsulfoxide (DMSO) solution, (Ph 3 SiOH) 2 ÁDMSO (Bowes et al, 2002) and from 1,4-dioxan solution (Ph 3 SiOH) 4 ÁC 4 H 8 O 2 (Bourne, Johnson et al, 1991;Bowes et al, 2002). The dioxan adduct consists of centrosymmetric ®ve-molecule aggregates (B) (see Scheme (I)], in which two molecules of the silanol are linked to the dioxan via OÐHÁ Á ÁO hydrogen bonds, with two further silanol molecules similarly linked to the ®rst pair of silanol molecules.…”

Synthesis of Novel β-Cyclodextrin and Calixarene Derivatives and Their Use in Gas Sensing on the Basis of Molecular Recognition

“…[4Ϫ6] Supramolecular compounds possess inherent advantages for use as coating materials, because their molecular recognition ability and selectivity may be readily adjusted by chemical modification and tailoring. Various macrocyclic receptors, such as crown ethers, [7] cryptands, [8,9] cavitands, [10,11] cyclodextrins [12Ϫ15] and calixarenes, [16,17] have therefore been used as coatings for piezoelectric quartz crystal sensors.…”