Syntheses, crystal structures and magnetic properties of three new molecular metals based on bis(maleonitriledithiolate)copper(II) anion and substituted benzyl isoquinolinium cations

Abstract Syntheses, crystal structures and magnetic properties of three novel molecular metals, [4RBzIQl] 2 [Cu(mnt) 2 ] (mnt 2−  = maleonitriledithiolate; [4RBzIQl] +  = 1-(4′-R-benzyl)isoquinolinium, R = H( 1 ), Cl( 2 ) and NO 2 ( 3 )) are systemically investigated. The crystal structural analysis reveals that three molecular metals crystallize in the triclinic space group P -1, and the [4RBzIQl] + cations stack into a one-dimensional column through C–H⋯π and π⋯π interactions. The anions (A) and cations (C) are arranged alternatively into a column in the sequence of ···A-CC-A-CC··· for 1 and ···AA-CC-AA-CC··· for 2 and 3 though Cu⋯N, C⋯N, C⋯O, C–H⋯π or/and π⋯π interactions. The magnetic susceptibilities measured in the temperature range 2.0–300 K reveals that these molecular show a change of magnetic exchange from weak ferromagnetic to antiferromagnetic around 20 K, 19 K and 47.6 K for 1 , 2 and 3 .