Two-dimensional molecular magnets based on [Pt(mnt)₂] ^- ions: Structures and magnetic properties

Two compounds of composition [FBzPy][Pt(mnt)₂] (1) and [FBzPy][Pt(mnt)₂]·0.25-MeCN (2) ([FBzPy]⁺ = 1-(4′-fluorobenzyl)pyridinium and mnt^2- = maleonitriledithiolate) were prepared and their crystal structures were determined. The solvent molecule, MeCN, incorporated into lattice leads the anionic stacking pattern to be distinct between 1 and 2. The regular anionic stacking columns are connected by the anionic dimers to construct into 2D anionic networks in 1, while the anionic fourfold subunit develop into anionic layers though lateral S⋯S interactions in 2. As for two compounds, the magnetic susceptibilities in 2-350 K were measured, and the magnetic exchange schemes were built based on the analyses both crystal structures and extended Hückel molecular orbital calculations. The magnetic coupling model of an alternating AFM Heisenberg chain with an isolated AFM coupling dimer was dealt with 1, while a spin dimer with s = 1/2 with 2, and the magnetic coupling parameters were further gained via simulating the temperature dependent magnetic susceptibility data of two compounds.