Versatility of the 1,1′-binaphthyl-2,2′-dicarboxylic acid host in solid-state inclusion: crystal and molecular structures of the dimethylformamide (1 : 2), dimethyl sulphoxide (1 : 1), and bromobenzene (1 : 1) clathrates

Abstract

The clathrate structures of the host 1,l '-binaphthyl-2,2'-dicarboxylic acid (1 ) with dimethylformamide, (2), dimethyl sulphoxide, (3), and bromobenzene, (4) as guest molecules have been studied. X-Ray structure analyses show that the capacity for inclusion is primarily dependent on the proton donoracceptor (co-ordinating) ability of the host. Nevertheless, the structures are very different. In (2) [crystal data: a = 14.91 6(13), b = 9.882(10), c = 17.1 28(13) A, p = 90.45(7)", space group P2,/c, Z = 4, R, = 0.066 for 2 550 observations] the guest molecules can act both as proton donor and acceptor in hydrogen bonding with the host, in ( 3 ) [a = 12.912(5), b = 17.979(15), c = 9.702(7) A, p = 1 1 0.79(7)", P2,/n, Z = 4, R, = 0.080 for 1 932 reflexions] the guest molecule acts as proton acceptor only, and in (4) [a = 9.955(2), b = 10.426(3), c = 12.005(3) A, cc = 77.34(2), p = 93.02(2), y = 104.59(2)", P i , 2 = 2, R, = 0.074 for 1 555 observations] a 'true' clathrate structure is established, with bromobenzene being incorporated in a hydrogen-bonded host matrix of (1). The decrease in coordinating bond strength between host and guest is also manifested in the gradual increase of disorder observed for these guest species. Conclusions concerning the clathrate formation selectivity of (1 ) are derived from the structural observations. Clathrate compounds and related lattice-controlled host-guest systems t are becoming objects of considerable a t t e n t i ~n . ~. ~

X-ray crystal structures of halogen containing nucleobase derivatives in unsolvated and DMSO solvated forms

“…These strands are surrounded by purine bases in direction of the c-axis and of O15 i-butyryl groups in direction of the b-axis. Contacts between the DMSO molecules are in the form of C-HÁÁÁO [35] interactions yielding an inverse bifurcated hydrogen bonding pattern (Fig. 7b).…”

“…From among the rather rare cases of organic solvents that dissolve nucleobases and nucleosides to a sufficient extent, DMSO was selected which is a highly polar solvent and strong acceptor in hydrogen bonding but only a weak F. Eißmann Á D. Schindler Á E. Weber (&) Institut für Organische Chemie, Technische Universität Bergakademie Freiberg, Leipziger Str. 29, 09596 Freiberg, Sachsen, Germany e-mail: edwin.weber@chemie.tu-freiberg.de hydrogen bonding donor [35]. Nevertheless, solvated aggregate structures could be formed that might exhibit interesting modes of interaction between particular nucleobase derivatives and DMSO.…”

Disorder as adaptation of the crystal structure to increase the crystallization temperature. X-ray crystal structure of the host-guest complexes between 1,1′-binaphthyl-2,2′-dicarboxylic acid and dimethyl sulphoxide obtained at 50 and 60 °C

“…It should be noted that the intrinsic symmetry C 2 of the host molecule is lost in both the previous BNDAÁDMF 14 and the b-form BNDAÁDMSO complex. In these conformations two carboxyl groups of BNDA are differently oriented to the respective naphthyl fragment in order to form a relatively strong intermolecular Hbond between the carboxyl hydroxy group and the oxygen atom of the solvent molecule [ Fig.…”

“…In the crystal of the 1:1 BNDAÁDMSO complex, 14 solvent molecules show double-acceptor abilities, incorporating host molecules in the infinite chains by H-…”

Solvent manipulation of N-methylacetamide inclusion compounds with a xanthenol host

“…Ibragimov studied the effect of crystallisation temperature on the topology and the stoichiometry of host-guest compounds and has listed 18 such systems [8,9]. Examples of these studies include that of the racemic scissor-shaped host 1,1′-binaphthyl-2,2′-dicarboxylic acid (BNDA) which formed four crystal structures differing in their host:guest ratios with the guests 1,4-dioxane [10] and dimethylformamide [11,12], respectively. Variation of the solvent composition can also result in compounds with different stoichiometries.…”