Concomitant Crystallization of Copper(II) Sachharinato Complexes with 2-Methylpyrazine as a Monomer and an One-Dimensional Polymer: Syntheses, Crystal Structures, Spectroscopic and Thermal Properties

Abstract

The reaction of [Cu(sac) <inf>2</inf>(H <inf>2</inf>O) <inf>4</inf>] ·2H <inf>2</inf>O with 2-methylpyrazine (mpyz) leads two complexes, concomitant crystallization of a mononuclear complex [Cu(sac) <inf>2</inf>(mpyz)(H <inf>2</inf>O) <inf>2</inf>] (1) and a polymeric complex [Cu(sac) <inf>2</inf>(μ-mpyz)] <inf>n</inf> (2). Both complexes have been characterized by elemental analyses, magnetic measurements, FT-IR and ESR, TG-DTA and single-crystal X-ray diffraction analyses. Single-crystal X-ray analyses show that complex 1 consists of discrete molecules in which the copper(II) ions exhibits a square-pyramidal coordination geometry. The individual molecules of 1 are connected into a hydrogen-bonded chain structure, which is further assembled to form a three-dimensional network by π-π stacking interactions. Complex 2 is an 1D coordination polymer in which copper(II) centers are bridged by the mpyz ligand. The chains are further assembled to form two-dimensional frameworks by π-π and C-H⋯π stacking interactions. © 2008 Springer Science+Business Media, LLC.