Synthesis, crystal structure, and optical, thermal, and magnetic properties of a new molecular solid based on bis(maleonitriledithiolate)copper(II) anion and 3-bromobenzyl triphenylphosphonium

ABSTRACT

A new molecular solid [3BrBzTPP]₂[Cu(mnt)₂](1) (mnt²⁻ = maleonitriledithiolate; [3BrBzTPP]⁺ = 1-(3′-bromobenzyl)triphenylphosphonium) was synthesized and characterized by elemental analysis, optical spectra, and thermal and X-ray crystallographic analyses. It was crystallized in the monoclinic space group P2₁/n, and the asymmetric unit cell contained half a [Cu(mnt)₂]²⁻ anion and one independent [3BrBzTPP]⁺ cation. The anions and cations in 1 were linked by electrostatic interactions, C–H⋅⋅⋅S hydrogen bonds, and short N⋅⋅⋅Br interactions, and formed an alternating column of anions and cations in a ···AA–CC–AA–CC··· sequence. The thermal analysis revealed that 1 was stable up to 218°C. Magnetic measurements disclosed that 1 was a paramagnetic system with a very weak ferromagnetic coupling interaction in the temperature range of 2.0–300 K.

KEYWORDS:

• 3-Substituted benzyl triphenylphosphonium
• bis(maleonitriledithiolate)copper(II) anion
• weak interactions
• magnetic properties

Funding

The authors thank the Science and Technology Project (No. 2014A010105037) from Guangdong Science and the university students’ innovative experimental project (No.1056411137) from Education Department of Guangdong Province for financial support of this work.