Synthesis and Characterization of Molecule-Based Magnets Containing Methyl-Substituted Phenyltricyanoethylene Acceptors

A new family of molecule-based magnets related to the V[PTCE]x · yCH2Cl2 magnet (PTCE = phenyltricyanoethylene, x = ~2, y = ~0.2) was synthesized utilizing new reversible one-electron acceptors with the general form MexPTCE (PTCE = phenyltricyanoethylene, x is the number of methyl groups on the phenyl ring, Me = -CH3). These new acceptors were synthesized for the purpose of studying electronic and steric effects of the substitution of the phenyl ring with electron donating groups on the overall magnetic properties of the solid, specifically to contrast their behavior with materials that contain similar trifluoromethyl (-CF3) substituted acceptors. These electron-poor olefins react with V(CO)6 in dichloromethane (CH2Cl2) under N2 to yield air-sensitive, amorphous magnetic coordination polymers that exhibit ordering temperatures ranging from 160 K to 250 K and display anhysteretic behavior at all temperatures. The magnets synthesized in this project were all characterized and studied using magnetic measurements, infrared spectroscopy, and elemental analysis. The neutral acceptors used were characterized using NMR spectroscopy, infrared spectroscopy, mass spectrometry, cyclic voltammetry, and modeled using density functional theory (DFT) calculations.