Crystal and molecular structure of two calix[6]arenes:p-Isopropylcalix[6]arene andp-tert-butylcalix[6]arene?benzene(1?3) complex

Halit, M.; Oehler, D.; Perrin, Monique; Thozet, A.; Perrin, R.; Vicens, Jacques; Bourakhouadar, Mohamed

doi:10.1007/bf00656343

Cited by 40 publications

(15 citation statements)

References 17 publications

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“…Hydrogen-bonding solvents (DMSO, acetone, dioxane/water, DMF) have induced 1,2,3-alternate conformation, 8 whereas the pinched cone conformation is related to the crystallization of nonhydrogen-bonding solvents (benzene, chloroform, acetonitrile, carbon disulfide, tetrachloroethylene, toluene, dichloromethane, bromobenzene, and chlorobenzene). 11 Therefore, our structure is an exception to this series. At last, the overall packing of the multiple solvate is featured by the formation of layers of host–guest complexes, which are face-to-face packed on top of each other (Figure 2a).…”

Section: Resultsmentioning

confidence: 93%

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Winged-Cone Conformation in Hexa-p-tert-butylcalix[6]arene Driven by the Unusually Strong Guest Encapsulation

et al. 2017

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Hexa- p - tert -butylcalix[6]arene (1) is believed to adopt a winged conformation in a solution, featured by four phenyl rings perpendicular to the calix basis and two others at 1,4-positions lying down. However, there is some controversy on the occurrence of this conformation because it has never been found in the solid state of calix[6]arenes, regardless of the substitution pattern at lower and upper rims. Here, we have observed the winged-cone conformation for the first time in a solvate form of 1 with dimethyl sulfoxide (DMSO), dimethylformamide, and pyridine. The DMSO molecule is strongly encapsulated into 1 through two OH···O hydrogen bonds with both flattened phenolic moieties, one lp (S) ···π and four CH···π interactions with the four perpendicular phenyl rings. This host–guest complex has energy lower by 23.4 kcal mol –1 than the isolated species. In addition, another DMSO solvate form with 1,2,3-alternate conformation was also obtained in this study, and its structure is compared with that of the precedent one. A detailed density functional theory study has also been carried out to understand the energetic relationships among cone conformers, intramolecular hydrogen-bonding patterns, and DMSO encapsulation.

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Section: Resultsmentioning

confidence: 93%

“…This conclusion was based on two main factors: the lower energy of the pinched cone and its occurrence in several crystal structures. In the course of the next two decades, other structures with pinched cone conformation have been reported for 1 in the solid state, 11 but winged cone has not reported for any calix[6]arene thus far.…”

Section: Introductionmentioning

confidence: 99%

Winged-Cone Conformation in Hexa-p-tert-butylcalix[6]arene Driven by the Unusually Strong Guest Encapsulation

et al. 2017

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“…In contrast with the calix[4]arenes, which form a variety of well characterized host-guest and solvent-free structures, only a few structure analyses of inclusion compounds of calix[6]arenes are reported in the literature (Mandolini et al, 2000). Apart from a poor characterization of the title compound, (I), in its solvent-free form (Andreetti et al, 1987), inclusion compounds with benzene (Halit et al, 1988), tetrachloroethylene (Andreetti et al, 1989), carbon disulfide (Schatz et al, 2000), dimethyl sulfoxide (DMSO; Wolfgong et al, 1996), acetonitrile (Dale et al, 2003;Thuery et al, 1995) and toluene (Lu et al, 1999) are known. With the exception of the DMSO clathrate, in which the calix [6]arene adopts a double partial cone conformation, in all other structures the calixarene is found in a pinched cone conformation, in which two of the methylene groups point to the centre of the bowl.…”

Section: Commentmentioning

confidence: 99%

5,11,17,23,29,35-Hexa-tert-butyl-37,38,39,40,41,42-hexahydroxycalix[6]arene dichloromethane disolvate

2006

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“…3 The conformational characteristics of calix [6]arene were studied by using the molecular mechanical method. 4 The most stable conformation of calix [6]arenes (1 5 and 2 6,7 ) (Chart 1) in the solid state is called a pinched cone because two methylene bridges are pointing into the cavity (Figures 1(a) and 2(a)). The skeleton of calix [6]arene is pinched to allow for a circular array of six hydrogen bonds.…”

Section: Introductionmentioning

confidence: 99%

DFT Conformational Study of Calix[6]arene: Hydrogen Bond

Kim

Choe²

2009

Bulletin of the Korean Chemical Society

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We have performed DFT calculations to investigate the conformational characteristics and hydrogen bonds of the calix[6]arene (1) and p-tert-butylcalix [6]arene (2). The structures of various conformers of 1 were optimized by using the B3LYP/6-31G(d,p) and /6-31+G(d,p) methods followed by single point calculation of MPW1PW91/ 6-31G(d,p). The relative stability of the conformers of 1 is in the following order: cone (pinched: most stable) > partial-cone > cone (winged) ~ 1,2-alternate ~ 1,2,3-alternate > 1,4-alternate > 1,3-alternate > 1,3,5-alternate. The structures of different conformers of 2 were optimized by using the B3LYP/6-31G(d,p) method followed by single point calculation of MPW1PW91/6-31G(d,p). The relative stability of the conformers of 2 is in the following order: cone (pinched) > 1,2-alternate > cone (winged) > 1,4-alternate ~ partial-cone > 1,2,3-alternate > 1,3,5alternate > 1,3-alternate. One of the important factors affecting the relative stabilities of the various conformers of the 1 and 2 is the number and strength of the intramolecular hydrogen bonds.

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Crystal and molecular structure of two calix[6]arenes:p-Isopropylcalix[6]arene andp-tert-butylcalix[6]arene?benzene(1?3) complex

Cited by 40 publications

References 17 publications

Winged-Cone Conformation in Hexa-p-tert-butylcalix[6]arene Driven by the Unusually Strong Guest Encapsulation

Winged-Cone Conformation in Hexa-p-tert-butylcalix[6]arene Driven by the Unusually Strong Guest Encapsulation

5,11,17,23,29,35-Hexa-tert-butyl-37,38,39,40,41,42-hexahydroxycalix[6]arene dichloromethane disolvate

DFT Conformational Study of Calix[6]arene: Hydrogen Bond

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