Bond distances and bond angles of the C10 skeleton in naphthalene derivatives as hard bond parameters:35Cl NQR and structure of 1,8-diaminonaphthalene � Cl2HCCOOH, 1,8-diaminonaphthalene � Cl3CCOOH, 1-aminonaphthalene � Cl3CCOOH, and 1,8-diaminonaphthalene

Hydrogen-bonding one-dimensional chains containing theR42(8) motif in the ammonium salts 1-naphthylammonium iodide and naphthalene-1,8-diyldiammonium diiodide

“…No diprotonated 1,8-diaminonaphthalene salts are reported in the CSD. The 1-naphthylammonium salts have two different counter-ions, namely cyclohexaphosphate (HUNDAV; Nasr et al, 2001), cyclohexaphosphate and hexane-1,6-diammonium together (MAVQEF; Marouani et al, 1998), and trichloroacetate (LECCUR; Basaran et al, 1993). In the current report, we compare the packing arrangements and hydrogen-bonding motifs exhibited by the two title salts, (I) and (II).…”

“…In the latter case, the repulsion is partly countered by an attractive intramolecular hydrogen bond, and the NÁ Á ÁN distances are 2.72 and 2.74 Å for the two molecules in the asymmetric unit. In the monoprotonated salts, the distances are 2.72 Å for both LECCIF and LECCOL (Basaran et al, 1993) and 2.67 Å for YEWRIB (Bartoszak et al, 1995). Compound (II) has no intramolecular hydrogen bond and the N1Á Á ÁN2 distance is thus longer at 2.92 (1) Å .…”

“…The unprotonated cases of the title compounds have been reported previously, viz. 1,8-diaminonaphthalene twice [Cambridge Structural Database (CSD;Version 5.29, November 2007 release;Allen, 2002) refcodes JISVEM (Llamas-Saiz et al, 1991) and JISVEM01 (Basaran et al, 1993)] and 1-naphthylamine once (ZZZOZQ; Kitaigorodskii, 1945). In the diaminonaphthalene case, monoprotonated salts are more common.…”

“…In the diaminonaphthalene case, monoprotonated salts are more common. Counter-ions in these structures include dichloroacetate (LECCIF; Basaran et al, 1993), trichloroacetate (LECCOL; Basaran et al, 1993) and maleate (YEWRIB; Bartoszak et al, 1995). No diprotonated 1,8-diaminonaphthalene salts are reported in the CSD.…”

Arrays with Local Centers of Symmetry in Space Groups Pca21 and Pna21

“…In the case of Pna2 1 , we note one example with a local center very close to the point x = 0, y = 0.25 that could require revision of the space group to Pnab (a nonstandard setting of Pbcn). This entry is JISVEM, 1,8diaminonaphthalene (Llamas-Saiz et al, 1991;Basaran et al, 1993). In this case, the two molecules related by the local center are appreciably non-parallel, due to a pyramidal hydrogen-bond arrangement, and the local center is a relatively poor one; there is no reason to doubt that the space group is indeed Pna2 1 .…”