Hydrogen bonding in triamine copper(II) P,P′-Diphenylmethylenediphosphinate (pcp²⁻) hybrids. Syntheses and crystal structures of [Cu(pcp) (2,2′-dipyridylamine)(H₂O)] · 2H₂O and [Cu(pcp)(2,2′ : 6′,2′′terpyridine)] · 4H₂O

Abstract

Two hybrid materials [Cu(pcp)(dipyam)(H₂O)] · 2H₂O (1) and [Cu(pcp)(terpy)] · 4H₂O (2), have been prepared by reaction of copper(II) acetate monohydrate with P,P′ diphenylmethylenephosphinic acid (H₂pcp) and 2,2′ dipyridylamine (dipyam) or 2,2′ : 6′,2′′ terpyridine (terpy), and have been structurally characterized by X-ray analyses. Both structures have a three-dimensional architecture, created by a close network of hydrogen bonding interactions. The copper centers present approximate square-pyramidal coordination, surrounded by pcp, dipyam and one water molecule in 1, and by pcp and terpyridine in 2. In both complexes the pcp ligand chelates only one metal, so that the free phenylphosphinate oxygens remain available for hydrogen-bonding interactions with water molecules, present in coordinated and solvated forms in 1 and solely as the solvated form in 2.

Keywords:

• Copper(II)
• Diphosphinate
• Hydrogen bond
• Hybrid materials
• X-ray structure