Chelating modified cellulose bearing pendant heterocyclic moiety for effective removal of heavy metals.

Cellulose bearing pendant Schiff base with heterocyclic chelating groups (CMC-Bz) was synthesized, which were fully characterized using various instrumental techniques such as solid state carbon-13 nuclear magnetic resonance (13C-NMR), Fourier transform infrared (FTIR), scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDX) spectra. The adsorption of toxic metals onto cellulosic material was tested in a batch mode operation. The adsorption functional factors such as pH, adsorbent dose, metal ion concentration, equilibrium time and temperature were experimentally optimized for the maximum removal of Cu(II) and Pb(II) ions. Adsorption isotherms were evaluated with Langmuir, Freundlich, Temkin and Redlich-Peterson isotherms. Kinetic parameters and equilibrium adsorption capacities were investigated for pseudo-first-order, pseudo-second-order and intra-particle diffusion models. Thermodynamic parameters and reusability were also evaluated.

2,3-Dibromo-1-(2,4-dichloro-5-fluoro-phen-yl)-3-phenyl-propan-1-one.

In the title compound, C(15)H(9)Br(2)Cl(2)FO, the dihedral angle between the two aromatic rings is 6.0 (1)°. The dibromo-ethane fragment of the propan-1-one unit is disordered over two positions, with occupancies of ca 0.83 and 0.17. The crystal structure is stabilized by inter-molecular C-H⋯O hydrogen bonds, C-H⋯π inter-actions, and Br⋯Cl [3.505 (2) and 3.576 (6) Å] and Cl⋯F [3.176 (2) Å] short contacts.

(E)-3-(4-Chloro-phen-yl)-1-(2,4-dichloro-5-fluoro-phen-yl)prop-2-en-1-one.

In the title chalcone derivative, C(15)H(8)Cl(3)FO, the dihedral angle between the two benzene rings is 43.35 (8)°. Weak C-H⋯O and C-H⋯Cl intra-molecular inter-actions involving the enone group generate S(5) and S(6) ring motifs, respectively. In the crystal structure, mol-ecules are linked into anti-parallel chains along the a axis. These chains are stacked along the b axis and short Cl⋯F contacts of 3.100 (1) Šlink adjacent mol-ecules of the anti-parallel chains into dimers.

2-Bromo-1-(4-methyl-phen-yl)-3-phenyl-prop-2-en-1-one.

In the crystal structure of the title compound, C(16)H(13)BrO, the two benzene rings are twisted from each other with a dihedral angle of 52.55 (9)°. Both an intra-molecular C-H⋯Br hydrogen bond, which generates an S(6) ring motif, and a short Br⋯O contact [2.9907 (19) Å] may influence the conformation of the mol-ecule. The crystal packing is stabilized by weak inter-molecular C-H⋯O inter-actions.

Erratum: 2-Bromo-1-(4-methyl-phen-yl)-3-phenyl-prop-2-en-1-one. Corrigendum.

The chemical name in the title and the scheme of the paper by Fun, Jebas, Patil, Karthikeyan & Dharmaprakash [Acta Cryst. (2008), E64, o1559] are corrected.[This corrects the article DOI: 10.1107/S1600536808022289.].