Synthesis, Structure, Spectroscopy, and Magnetism of Unique Propeller-Type Linear Trinuclear CuII Complexes with In-situ Prepared Formamidine Ligands

✍ Scribed by Gerard A. van Albada; Petra J. van Koningsbruggen; Ilpo Mutikainen; Urho Turpeinen; Jan Reedijk

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 314 KB
• Volume: 1999
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/(sici)1099-0682(199912)1999:12<2269::aid-ejic2269>3.0.co;2-y

✦ Synopsis

Three new copper(II) linear trinuclear compounds are crystallise in the triclinic space group P-1 with a = 8.529( 5), b = 15.760(5), c = 19.639(5) A ˚, α = 101.793(5), β = 101.263(5), reported, all of which were synthesized in-situ, with the general formula [Cu 3 (L) 4 ](CF 3 SO 3 ) 2 (Y) x , where L is the γ = 102.389(5)°, Z = 2. The structure [Cu-Cu-Cu angle 174.96(11)°] consists of four nearly flat molecules of the dehydronated ligand: N,NЈ-bis(pyridine-2-yl)formamidine (abbreviated as Hpdf), N,NЈ-bis(pyrimidine-2-yl)form-ligand, which contribute to the propeller-type structure around the Cu-Cu-Cu axis. A strong antiferromagnetic amidine (abbreviated as Hpmf) and N,NЈ-bis(5methylpyridine-2-yl)formamidine (abbreviated as Hmpdf),

interaction between the Cu II ions is observed with calculated J values, based on the Hamiltonian H = -2J(S 1 •S 2 + S 2 •S 3 ) -Y = EtOH or H 2 O and x = 0.5-1.5. The compounds were characterized by X-ray diffraction, IR, LF, and EPR 2JЈ•S 1 •S 3 , of -174(1) cm -1 , -120(1) cm -1 , and -167(1) cm -1 for the compounds studied with L = pdf, pmf, and mpdf, spectroscopy and by magnetic susceptibility down to 4 K. The structure of the compound [Cu 3 (pmf)

respectively. These values are in agreement with an S = 1/2 ground state below temperatures of 120-160 K. was determined by X-ray crystallography; it was found to per(II) complexes have been fully studied magnetically and [a] Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden pounds in situ is unique.