Comparison of the structures of 1,5-dichloro- and 1,5-dibromonaphthalene-2,6-diol and their co-crystalline compounds with dioxane

Balance of forces between various contacts in crystal structures of two isomeric benzo-condensed dibromodihydroxy-containing compounds

“…Unlike hydrogen bonds, knowledge of the influence of halogen atoms on crystal packing and their interactions with other halogen atoms, nucleophilic and electrophilic groups and aromatic p-systems is still at an early stage 6,7 and the nature of these contacts is under current discussion. 8 For the analysis of halogen contacts, early work was done with simple halogen compounds including Cl 2 , Br 2 and I 2 and comparative studies between halogensubstituted benzene derivatives, 9 showing that halogen atoms are able to form various important interactions with preferential ranges of contact distances and angles, relatively easy to describe between pairs of identical halogens (Cl … Cl, Br … Br, I … I) and mixed pairs (Br … Cl, Cl … I, Br … I).…”

2,3-Dichlorobenzene-1,4-diol

“…Crystal structures of related dichloronaphthalenediols have been previously reported by us (Ahn et al, 1995(Ahn et al, , 1996. In the title compound (Fig 1), each molecule participates in four hydrogen bonds, two as donor and two as acceptor, creating a layer structure in the ac plane with O1-H1O1···O2-H1O2···O1-H1O1··· chains parallel to a (Fig 2, Table 1).…”

“…For the structures of related dichloronaphthalenediols, see: Ahn et al (1995Ahn et al ( , 1996. For the preparation of the title compound, see: Beddoes et al (1981).…”

4-Chloro-1-naphthol

“…Halo-substituted hydroxyaromatic compounds (among them the title compound) are a class of starting materials for the preparation of bis(hydroxyaromatic) compounds, which find many uses in chemical applications such as dyes, plastics, pharmaceuticals and agrochemicals, and in forming polymers such as polycarbonates, polyestercarbonates, polyesters, polyethers, polyetherimides and polyether ketones (Patel et al, 2005). A search of the Cambridge Structural Database (CSD, Version 5.30 of November 2008;Allen, 2002) for chloro-substituted hydroxy-derivatives of naphthalene revealed only five reports of four chloro-substituted naphthalenediols, namely 1,5-dichloro-2,6-dihydroxynaphthalene [CSD refcodes JIMFAM (Nakasuji et al, 1991) and JIMFAM01 (Ahn et al, 1995)], 1,5-dichloro-2,6-naphthoquinone 1,5-dichloro-2,6-dihydroxynaphthalene (JIMDUE; Nakasuji et al, 1991), 1,5-dichloronaphthalene-2,6-diol dioxane solvate (RAYPOW; Ahn et al, 1995) and bis(1,4-dichloronaphthalene-2,3-diol) dioxane (ZIPYEC; Ahn et al, 1994), and no prior reports of the structures of chlorosubstituted naphthols. Thus, this paper concerning the results of structural studies of the title compound, (I), would appear to be the first example involving a chloronaphthol.…”