Three new dinuclear manganese(II) complexes with bis(μ-phosphinato)-bridges

A new series of dinuclear phosphinato-bridged manganese(II) complexes [Mn(μ-bmp)(bpy)(NO3)]2 (1), [Mn(μ-bmp)(phen)(NO3)]2·4CH2Cl2 (2) and [Mn2(μ-bmp)2(5-dmbpy)2(NO3)]2 (3) where Hbmp is bis(4-methoxyphenyl)phosphinic acid, bpy = 2,2′-bipyridyl, phen = 1,10-phenanthroline and 5-dmbpy = 5,5′-dimethyl-2,2′-dipyridyl, have been synthesized and structurally characterized by X-ray crystallography. In this series, the structures consist in bis(4-methoxyphenyl)phosphinato anions (bmp) bridging the two Mn(II) centers in a syn–syn coordination mode. The coordination geometry around the Mn(II) ions in 1–3 is six-coordinate with distorted octahedral environment. The magnetic behavior of these complexes is reported. The complexes show weak antiferromagnetic coupling with |J| in the range 0.1–0.6 cm−1. The magnetic properties are discussed in relation to the structural data.

The reaction of manganese nitrate with chelating blocking ligands (L) as 2,2′-bipyridil and bis(4-methoxyphenyl)phosphinic acid (Hbmp) leads to three dinuclear compounds of general formula [Mn(μ-bmp)(L)(NO3)]2 with μ-O,O′ O–P–O bridges. The compounds show weak antiferromagnetic coupling.Figure optionsDownload as PowerPoint slideHighlights
► The bis(4-methoxyphenyl)phosphinic acid, Hbmp, can be deprotonated.
► The related anion, bmp, can bridge two Mn(II) centers in a syn–syn coordination mode.
► Three new dinuclear [Mn(μ-bmp)(L)(NO3)]2 have been prepared.
► The Mn(II) ions are six-coordinate with distorted octahedral environment.
► The new complexes show weak antiferromagnetic coupling.