TY - JOUR
T1 - Design and Synthesis of Open-Chain Hosts Having a Partial Structure of p-tert-Butylthiacalixarene
AU - Morohashi, Naoya
AU - Nanbu, Kazuki
AU - Sonehara, Hayato
AU - Ogihara, Jun
AU - Shimazaki, Takanori
AU - Hattori, Tetsutaro
PY - 2018/2/16
Y1 - 2018/2/16
N2 - The development of separation materials for hard-to-separate molecular mixtures is highly desired from environmental and economic perspectives. Although the crystal of p-tert-butylthiacalix[4]arene exhibits high guest selectivity in inclusion from a mixture of molecules with similar sizes and shapes, it cannot include molecules larger than its calix cavity. To extend its guest inclusivity, we designed and synthesized an open-chain host, [3,3′-thiobis(5-tert-butyl-2-hydroxybenzene)-1,1′-diyl]diacetic acid (4). The competitive inclusion among toluidine isomers using compound 4 gave inclusion crystals containing the p-isomer in 1:1 (host/guest) ratio, with lesser amounts of other isomers and/or solvent molecules. The isomer selectivity varied between 66% and 97% depending on the solvent employed. X-ray analysis of inclusion crystals 4·p-toluidine·MeCN and 4·p-toluidine·(o-toluidine)0.5 revealed that compound 4 includes p-toluidine by forming macrocyclic 2:2 inclusion complex(es) and that its higher-order structure has vacant spaces, in which molecules other than p-toluidine are included. Compound 4 was then transformed into monopropyl ester 5 to fill the vacant spaces with propyl moieties. Compound 5 included p-toluidine with high selectivity (∼96%) without the coinclusion of other molecules, regardless of the solvent employed.
AB - The development of separation materials for hard-to-separate molecular mixtures is highly desired from environmental and economic perspectives. Although the crystal of p-tert-butylthiacalix[4]arene exhibits high guest selectivity in inclusion from a mixture of molecules with similar sizes and shapes, it cannot include molecules larger than its calix cavity. To extend its guest inclusivity, we designed and synthesized an open-chain host, [3,3′-thiobis(5-tert-butyl-2-hydroxybenzene)-1,1′-diyl]diacetic acid (4). The competitive inclusion among toluidine isomers using compound 4 gave inclusion crystals containing the p-isomer in 1:1 (host/guest) ratio, with lesser amounts of other isomers and/or solvent molecules. The isomer selectivity varied between 66% and 97% depending on the solvent employed. X-ray analysis of inclusion crystals 4·p-toluidine·MeCN and 4·p-toluidine·(o-toluidine)0.5 revealed that compound 4 includes p-toluidine by forming macrocyclic 2:2 inclusion complex(es) and that its higher-order structure has vacant spaces, in which molecules other than p-toluidine are included. Compound 4 was then transformed into monopropyl ester 5 to fill the vacant spaces with propyl moieties. Compound 5 included p-toluidine with high selectivity (∼96%) without the coinclusion of other molecules, regardless of the solvent employed.
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U2 - 10.1021/acs.joc.7b03137
DO - 10.1021/acs.joc.7b03137
M3 - Article
C2 - 29385344
AN - SCOPUS:85042174863
VL - 83
SP - 2235
EP - 2243
JO - Journal of Organic Chemistry
JF - Journal of Organic Chemistry
SN - 0022-3263
IS - 4
ER -