Hydrogenmaleato bridged supramolecular double chains via π–π stacking interactions: syntheses, crystal structures and magnetic properties of ∞1[Cu(phen)X(HL) 2/2] with X=Cl − ( 1), NO 3− ( 2) and H 2L=maleic acid

Abstract

Two novel hydrogen maleato (HL) bridged Cu(II) complexes ∞ 1[Cu(phen)Cl(HL) 2/2] 1 and ∞ 1[Cu(phen)(NO 3)(HL) 2/2] 2 were obtained from reactions of 1,10-phenanthroline, maleic acid with CuCl 2·2H 2O and Cu(NO 3) 2·3H 2O, respectively, in CH 3OH/H 2O (1:1 v/v) at pH=2.0 and the crystal structures were determined by single crystal X-ray diffraction methods. Both complexes crystallize isostructurally in the monoclinic space group P2 1/n with cell dimensions: 1 a=8.639(2) Å, b=15.614(3) Å, c=11.326(2) Å, β=94.67(3)°, Z=4, D calc =1.720 g/cm 3 and 2 a=8.544(1) Å, b=15.517(2) Å, c=12.160(1) Å, β=90.84(8)°, Z=4, D calc =1.734 g/cm 3. In both complexes, the square pyramidally coordinated Cu atoms are bridged by hydrogen maleato ligands into 1D chains with the coordinating phen ligands parallel on one side. Interdigitation of the chelating phen ligands of two neighbouring chains via π–π stacking interactions forms supramolecular double chains, which are then arranged in the crystal structures according to pseudo 1D close packing patterns. Both complexes exhibit similar paramagnetic behavior obeying Curie–Weiss laws χ m (T−θ)=0.414 cm 3 mol −1 K with the Weiss constants θ=−1.45, −1.0 K for 1 and 2, respectively.