Crystal structure and magnetic property of spin crossover complex Fe II(3-phenylpyridine) 2[Au I(CN) 2] 2

Abstract

A novel two-dimensional network bimetallic Fe Au spin crossover coordination polymer based on 3-phenylpyridine-coordinated iron centers and linear gold cyanide bridges {Fe(3-phenylpyridine) 2[Au(CN) 2] 2} n ( 1), has been synthesized. The compound is characterized by elemental analysis, IR, single-crystal X-ray analysis at 300 and 90 K and magnetic measurements. The Fe II ions in 1 have octahedral Fe IIN 6 coordination geometries, which are linked by [Au(CN) 2] − units at the equatorial plane to form a polymeric 2D sheet architecture. The two pyridine rings coordinate in axial position. Variable-temperature (2–300 K) magnetic susceptibility measurements of 1 were performed to determine the spin transition behavior. SQUID data show that high and low spin states exist in a 1:1 ratio at 90 K. However, only one kind of Fe II atom is apparent crystallographically at 90 K, indicating that the high and low spin sites are disordered in the polymeric 2D framework.