Magnetic and spectroscopic investigations of tetra-(4-t-butyl)phthalocyano complexes of μ-oxo-bridged iron(II) dimer

✍ Scribed by Reimar Heucher; G. V. R. Chandramouli; Periakaruppan T. Manoharan

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 130 KB
• Volume: 02
• Category: Article
• ISSN: 1088-4246
• DOI: 10.1002/(sici)1099-1409(199807/10)2:4/5<415::aid-jpp115>3.0.co;2-r

✦ Synopsis

The tetra(4-t-butyl)phthalocyanine derivative of the m-oxo dimer of Fe was studied by ESR and Mo ¨ssbauer spectroscopic and magnetic susceptibility methods. The Mo ¨ssbauer spectrum of the iron complex shows DE Q = 1.34 mm s À1 and = 0.14 mm s À1 . The susceptibility data measured as a function of temperature fit the S 1 = S 2 = 1 dimer with J = À5.2 cm À1 and thus the oxidation state of iron is suggested as 2. The weak exchange coupling is attributed to the presence of the bulky t-butyl groups on phthalocyanine. It is proposed that the two phthalocyanine moieties are not superimposable on one another owing to the steric hindrance posed by the t-butyl groups of Pc t . This is likely to lead to a rotation of one of the FePc t moieties about the Fe-O-Fe axis as well as an increase in Fe-O distance.