Syntheses, crystal structures, magnetic properties and theoretical analysis of two new molecular solids based on Ni(mnt)⁻₂

Abstract

Two new molecular solids, [1-(2′-Cl-4′-Rbenzyl)pyridinium][bis(maleonitriledithiolato)nickel] [abbreviated as ([ClRBzPy][Ni(mnt)₂]), R = Br(1), I(2)], have been prepared and characterized. The Ni(III) ions form a 1-D zigzag alternating chain within a column through Ni ··· S, S … S, or π … π stacking interactions in 1 and a tetramer in 2. The variable temperature magnetic susceptibilities of 1 and 2 in the temperature range 1.8–300 K have been interpreted in terms of a simple dimer model approximation (H = −2JS_AS_B ), revealing strong antiferromagnetic interactions with the fitting value g = 1.98 and J = −231.5 cm⁻¹ for 1, g = 1.96 and J = −245.3 cm⁻¹ for 2.

Keywords:

• Bis(maleonitriledithiolate)nickelate(III)
• Molecular solids
• Pyridinium derivatives
• Crystal structure
• Antiferromagnetic interactions

Acknowledgments

The authors thank financial support from the Science and Technology Project (No. 2008B080703005) from Guangdong Science and Technology Department and the President's Science Foundation of South China Agricultural University (No. 2008 X 015).