Crystal Structure of Quinolinium Picrate

A second crystal polymorph of anilinium picrate

“…Crystalline picrates have commonly been used in the preparation of amine derivatives in qualitative organic chemistry (Shriner et al, 1980), and the crystal structures of a large number of such compounds with biological base molecules are known [with serotonin (a monohydrate) (Thewalt & Bugg, 1972), guanine (Bugg & Thewalt, 1975), tryptamine and dl-tryptophane (Gartland et al, 1974), acetylcholine (Frydenvang et al, 1988, imidazole (Soriano-Garcõ Âa et al, 1990), l-proline (Jin et al, 2003), l-valine (Anitha et al, 2004a), and -alanine (Anitha et al, 2004b)]. Neutral adduct compounds having heteromolecular %±% interactions are also common [with naphthalene (1/1) (Banerjee & Brown, 1985), anthranilic acid (2/1) (In et al, 1997), benzene (1/1) (Takayanagi et al, 1991), phenanthrene (1/1) (Goto, Takaya-nagi et al, 1992a), 1,4-naphthoquinone (1/1) (Goto, Toubai et al, 1992) and 4,6,8-trimethylazulene (1/1) (Na È ther et al, 1997)]. Among the proton-transfer examples, %±% interactions have only been found in the picrates of isoquinoline (Goto, Takayanagi et al, 1992b), N-methylaniline and mphenylenediamine (Takayanagi et al, 1996) but not with polymorph 1 or quinoline (Goto, Takayanagi et al, 1992b).…”

“…Neutral adduct compounds having heteromolecular %±% interactions are also common [with naphthalene (1/1) (Banerjee & Brown, 1985), anthranilic acid (2/1) (In et al, 1997), benzene (1/1) (Takayanagi et al, 1991), phenanthrene (1/1) (Goto, Takaya-nagi et al, 1992a), 1,4-naphthoquinone (1/1) (Goto, Toubai et al, 1992) and 4,6,8-trimethylazulene (1/1) (Na È ther et al, 1997)]. Among the proton-transfer examples, %±% interactions have only been found in the picrates of isoquinoline (Goto, Takayanagi et al, 1992b), N-methylaniline and mphenylenediamine (Takayanagi et al, 1996) but not with polymorph 1 or quinoline (Goto, Takayanagi et al, 1992b).…”

“…cation and anion species give partial ring superposition down the b cell direction [the shortest ring centroid separation is 3.73 (1) A Ê , indicative of some %±% interaction]. Although this structural feature is absent in polymorph 1, it is not uncommon among both aromatic neutral and proton-transfer compounds of picric acid (Herbstein & Kaftory, 1975;Banerjee & Brown, 1985;Yamaguchi et al, 1988;Na È ther et al, 1997;Goto, Takayanagi et al, 1992a;Takayanagi et al, 1996), although it has been found only in those DNSA compounds with the polycyclic hetero-aromatic bases quinoline, 2,2 H -bipyridine and 1,10-phenanthroline (Smith, Wermuth, Healy & White, 2004b) and with adenosine (Smith, Wermuth & Healy, 2004). The result in (I) is a three-dimensional hydrogenbonded polymer structure, which is signi®cantly different from that found in the ®rst crystal polymorph of anilinium picrate (Takayanagi et al, 1996).…”