Dicyclohexylaminium 4-nitroanthranilate

Graham Smith,Peter C Healy,Urs D Wermuth

doi:10.1107/s1600536804006981

Abstract

The crystal structure of dicyclohexylamnium 4-nitroanthranilate, C12H24N+烷H5N2O4-, shows a three-dimensional hydrogen-bonded network polymer in which the protonated amine groups of both of the independent molecules of dicyclohexylamine give similar hydrogen-bonding interactions with oxygen acceptors of four separate anthranilate carboxylate groups [NO = 2.730 (3)-2.782 (2) ŝ. Secondary centrosymmetric peripheral hydrogen-bonding linkages involve the amine groups of the anthranilate anions with nitro and carboxylate O-atom acceptors, while these groups are also involved in intramolecular N-HO(carboxylate) associations [2.663 (3) and 2.679 (3) ŝ.

Highlights

We report here the crystal structure of the proton-transfer compound of 4-Nitroanthranilic acid (4-NAA) with the secondary amine dicyclohexylamine (DCHA; pKa = 11.4), (I)
Re®nement on F 2 R[F 2 > 2'(F 2)] = 0.042 wR(F 2) = 0.151 S = 0.89 6830 reections 502 parameters H atoms treated by a mixture of independent and constrained re®nement
H atoms involved in hydrogen-bonding interactions [H21 and H22, and H11 and H12] were located by difference methods and their positional and isotropic displacement parameters were re®ned

Summary

Structure Reports Online

We have previously prepared and reported the structure of only one such compound, that of ethylenediaminium 4-nitroanthranilate dihydrate [(EN)2+Á2(4NAA)ÀÁ2H2O] (Smith et al, 2002), in which both amine functional groups of the EN molecule (pKa1 = 6.9 and pKa2 = 9.9) are protonated and are involved in an extensive hydrogen-bonded array, giving a three-dimensional network polymer structure. The protonated amine group in each DCHA molecule gives two direct hydrogen-bonding associations with carboxylate Oatom acceptors of independent 4-NAA anions [N1CÐ H11CÁ Á ÁO72B = 2.744 (3) AÊ , N1CÐH12CÁ Á ÁO71Bi = 2.730 (3) AÊ , N1DÐH12DÁ Á ÁO72Aii = 2.765 (2) AÊ and N1DÐ H11DÁ Á ÁO71Aiii = 2.782 (2) AÊ ; symmetry codes: (i) 1 À x, 1 À y, 1 À z; (ii) x, 1 + y, z; (iii) 2 À x, 1 Ày, Àz]. After concentration to ca 30 ml, partial room-temperature evaporation of the hot-®ltered solution gave orange crystal masses (m.p. 394.2±395.1 K)

Data collection

HÁ Á ÁA