Crystal structure, quantum mechanical study and spectroscopic studies of nitrate and perchlorate salts of 3-chloroaniline, [C6H7ClN]NO3 (I) and [C6H7ClN]ClO4 (II)

Abstract

Two new organic-inorganic hybrid compounds, 3-chloroanilinium nitrate (I) and 3-chloanilinium perchlorate (II), have been synthesized by an acid/base reaction at room temperature in the presence of 3-chloroaniline as an organic-structure directing agent and their structures were determined by single crystal X-ray diffraction. Compound I, [C6H7ClN]NO3, crystallizes in the orthorhombic space group Pbca with a = 10.4137(16), b = 9.6232(11), c = 16.059(2) Å, V = 1609.3(4) and z = 8. Full-matrix least-squares refinement converged at R = 0.041 and Rw = 0.121. Compound II, [C6H7ClN]ClO4, belongs to the monoclinic system, space group P21/n with the following parameters: a = 10.684(2), b = 7.2667(12), c = 12.229(2) Å, β = 104.27(2)°, V = 920.1(3) and z = 4. The structure was refined to R = 0.054 and Rw = 0.102.Both salts form anionic parallel layers alternating with thick slabs of [C6H7NCl]+ organic molecules. Charge balance is achieved by the protonated amine which interacts with the inorganic framework through hydrogen bonding. Solid-state 13C CP-MAS NMR spectroscopy is in agreement with the X-ray structures. Ab initio calculations allow the partial attribution of carbon signals to the various atoms of the organic groups. Electronic properties such as HOMO and LUMO energies were studied by Quantum mechanical evaluation by using the B3LYP/6-31+G* method.