New complexes of 2-hydroxy-1-naphthoic acid and X-ray crystal structure of [Pt(hna)(PPh3)2]

The solid complexes [Zn(Hhna)2(H2O)2], (PPh4)2[MoO2(hna)2], [Pd(Hhna)2], [Pt(PPh3)2(hna)], [Pd(bpy)(hna)], [Pd(phen)(hna)], [Ag(Hhna)(H2O)2] and [Ag(Hhna)(PPh3)(H2O)] (H2hna = 2-hydroxy-1-naphthoic acid) were prepared and characterized by IR, UV–vis, 1H NMR, 13C NMR, 31P NMR and mass spectrometry, and by elemental analysis and thermal measurements. 2-Hydroxy-1-naphthoic acid coordinates the metal ions in either binegative or mononegative bidentate manner through the deprotonated hydroxy and the deprotonated carboxylate oxygen or the carboxylato oxygen atoms. The crystal structure of [Pt(hna)(PPh3)2] has been determined, the Pt(II) center displays a square-planar geometry through the binegative bidentate 2-hydroxy-1-naphthoic acid dianion.

► New complexes of 2-hydroxy-1-naphthoic (H2hna) are reported.
► The X-ray structure of [Pt(hna)(PPh3)2] was determined.
► In Pd(II), Pt(II) and MO22+ complexes, H2hna coordinates via COO– and hydroxo atoms.
► H2hna coordinates Zn(II), Ag(II) and Pd(II) through –COO- oxygen centers.