First alkaline earth 2-carbamoyl-4-nitrobenzoate: Synthesis and supramolecular structure

Abstract

2-Carbamoyl-4-nitrobenzoic acid (2-ca-4nbaH) has been prepared by alkaline hydrolysis of 4-nitrophthalimide. Aqueous reaction of MgCO₃ with 2-ca-4nbaH<b style=""> </b>results in the formation of [Mg(H₂O)₆](2-ca-4nba)₂, which crystallizes in the centrosymmetric monoclinic space group <i style="">P2₁/c</i> with Mg(II) situated on an inversion center. The crystal structure consists of a distorted octahedral hexaaquamagnesium(II) cation and a free uncoordinated 2-ca-4nba anion. The cation and anion are involved in three varieties of H-bonding interactions, resulting in a supramolecular bilayer of 2-ca-4nba anions sandwiched between layers of [Mg(H₂O)₆]²⁺ cations.