Structure and absolute configuration of liquid molecules based on adamantane derivative cocrystallization

Abstract

Liquid molecules are difficult to crystallize, and their structures and absolute configurations cannot be directly determined by X-ray crystallography.

A new versatile crystalline sponge for organic structural analysis without the need for activation

“…Among the 14 guest molecules, (1R)-(−)-menthyl acetate (6) 52 and trans-cinnamaldehyde (10) 53 had been capsulated by (ZnX 2 ) 3 (tris(4-pyridyl)-1,3,5-triazene) 2 , 4R(−)-carvone (8) had been reported to form co-crystals in the hydrogen-bond network, 54 while 1,3-dimethoxybenzene (3), both 4R(−)-carvone (8) and 4S(+)-carvone (9), and 4-allyl-2-methoxyphenyl acetate (14) were caught by a fan-like porous organic cage. 55 The CMOF represents the rst crystal sponge that could absorb different molecules, mixtures, monomers and enantiomers through weak interactions inside the cavity.…”

Benchmarking Guanidinium Organosulfonate Hydrogen-Bonded Frameworks for Structure Determination of Encapsulated Guests

“…This method involved adding one of three different adamantoid chaperones (Figure S33) to a neat guest, in liquid form, at room temperature, heating the mixture to achieve a homogeneous solution, followed by cooling with the aim of producing a cocrystal of the adamantoid chaperone and guest. 17,19,21 Subsequently, other research groups reported the use of GS frameworks for structure determination of target molecules, 23,24 and very recently, a report in this journal described an anthracene-modified adamantoid molecular chaperone for structure determination of guests. 25 Over the past three decades, our laboratory has reported a substantial number of molecular host frameworks, built from two-dimensional hydrogen-bonded networks of guanidinium (G) and organosulfonate (S) ions (Figure 1), capable of encapsulating a wide range of guests and determining their molecular structure.…”

“…Later, substituted tetraaryladamantanes, a.k.a. “molecular chaperones”, − were employed as hosts for the determination of molecular structure, including absolute configuration, for a variety of guest molecules. This method involved adding one of three different adamantoid chaperones (Figure S33) to a neat guest, in liquid form, at room temperature, heating the mixture to achieve a homogeneous solution, followed by cooling with the aim of producing a cocrystal of the adamantoid chaperone and guest. ,, Subsequently, other research groups reported the use of GS frameworks for structure determination of target molecules, , and very recently, a report in this journal described an anthracene-modified adamantoid molecular chaperone for structure determination of guests …”

“…Recognizing that the attributes of the adamantoid chaperones and GS hosts may prove to be complementary with respect to structure determination, we attempted the crystallization of GS host frameworks with 32 guest targets (Figure ). Of these 32 targets, 23 were selected from 53 attempted for the three originally reported adamantoid chaperones , to allow for a head-to-head comparison of the two kinds of hosts. We chose to measure the performance of GS hosts against the adamantoid chaperones, because the latter employed a comprehensive library for guest inclusion and structure refinement, providing a rare opportunity for a comprehensive head-to-head comparison.…”

“…The near-zero value and high precision of the Flack parameters for inclusion compounds provide confidence in the assignment of the absolute configuration. Guests denoted in red correspond to those investigated with “molecular chaperones”. , Compound 5 contains both stereoisomers of cis -rose oxide in equal amounts; the stereochemistry is not denoted here for the sake of clarity. The structure of eugenol in 28a and 28b could not be resolved due to guest disorder.…”