Synthesis, X-ray structural and magnetic characterizations, and epoxidation activity of a new bis(l-acetato)(l-alkoxo)dinuclear iron(III) complex Bhaskar Biswas a , Merry Mitra a , Jaydeep Adhikary b , G. Rama Krishna c , Partha Pratim Bag c , C. Malla Reddy c , Nuria Aliaga-Alcalde d , Tanmay Chattopadhyay e , Debasis Das b,⇑ , Rajarshi Ghosh a,⇑ a Department of Chemistry, The University of Burdwan, Burdwan 713 104, India b Department of Chemistry, University College of Science & Technology, Calcutta University, 92 A.P.C. Road, Kolkata 700 009, India c Department of Chemical Sciences, Indian Institute of Science Education & Research, Kolkata 741 252, India d ICREA & Departament de Química Inorgànica, Universitat de Barcelona, Diagonal 647, 08028 Barcelona, Spain e Department of Chemistry, Panchakot Mahavidyalaya, Purulia 723 121, India article info Article history: Received 3 November 2012 Accepted 31 December 2012 Available online 9 February 2013 Keywords: Iron(III) Schiff base Crystal structure Magnetism Epoxidation abstract The synthesis, crystal structure and variable temperature magnetic measurements of a new dinuclear Fe(III) complex, [Fe 2 (l 1,3 -O 2 Cfn)(OH 2 )(MeOH)Cl 2 L] (1) [fn = furan, L = N,N 0 -bis(salicyaldehydene)-1,3-dia- minopropan-2-ol], is reported. From X-ray diffractometry, it is shown that each Fe(III) centre in 1 is in a distorted octahedral environment. A variable temperature magnetic study reveals strong antiferromag- netic behaviour of 1 with J = 22.2 ± 0.1 cm 1 . Use of 1 as an alkene epoxidation catalyst towards (E)-stil- bene and styrene with tert-butyl hydrogen peroxide (TBHP) and iodosylbenzene (PhIO) reveals that TBHP is the better oxidant in terms of the yield of the reaction. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction Molecular oxide bridged iron(III) coordination clusters with structural and other relevance to minerals such as hematite or fer- rihydrite [1], the iron oxo-hydroxo core of the iron storage protein ferritin [2], and biomineralization in general [3] are some of the areas of interest in high nuclearity iron chemistry. Smaller nuclear- ity molecules are also of biological interest, such as those contain- ing the [Fe 2 (l-O)(O 2 CR) 2 ] 2+ core of the oxygen carrier protein hemerythrin and the related core in other dinuclear iron proteins. Cyt-P-450 is also an iron containing mono oxygenase [4,5]. Fe(III) (salen)/porphyrins have already acquired special attention as syn- thetic analogues of Cyt-P-450 [6–12] and the possibility of Fe(III) (salen)/porphyrins catalyzed [13–16] epoxidation of olefins. Tran- sition metal catalyzed epoxidation of olefins has widespread appli- cation in the production of epoxides [17], an interesting class of compounds [18] which may be transformed into a large variety of compounds. However, several problems are still unresolved, in particular the nature of the oxidant, catalyst and the product selec- tivity. So the search for new epoxidation catalysts is one of the most important topics connected with both industrial and aca- demic research. However, very little attention has been paid to investigate the role of binuclear [Fe(III)(salen)] compounds as epoxidation catalysts [19]. Here in this contribution, we report the synthesis, single crystal X-ray structure, magnetostructural correlations and catalytic activity of a l-alkoxo-l 1,3 -carboxylato mixed bridged dinuclear iron(III) compound, [Fe 2 (l 1,3 -O 2- Cfn)(OH 2 )(MeOH)Cl 2 L] (1) [fn = furan, L = N,N 0 -bis(salicyaldehyd- ene)-1,3-diaminopropan-2-ol]. 2. Experimental 2.1. Materials High purity salicyaldehyde (Sisco Research Laboratories Pvt. Ltd., India), 1,3-diaminopropan-2-ol (Aldrich, UK), anhydrous iro- n(III) chloride and all other solvents were purchased from the respective concerns and used as received. Styrene, (E)-stilbene and tert-butyl hydrogen peroxide (TBHP) were purchased from Al- drich and used in the epoxidation experiments without further purification. The solvents were dried according to standard proce- dures and distilled prior to use. 2.2. Physical measurements Elemental analyses (carbon, hydrogen and nitrogen) were per- formed on a Perkin-Elmer 2400 CHNS/O elemental analyzer. IR spectra (KBr discs, 4000 to 300 cm 1 ) were recorded using a 0277-5387/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.poly.2012.12.040 ⇑ Corresponding authors. Tel.: +91 342 2533913x424; fax: +91 342 2530452. E-mail addresses: dasdebasis2001@yahoo.com (D. Das), rajarshi_chem@yahoo. co.in (R. Ghosh). Polyhedron 53 (2013) 264–268 Contents lists available at SciVerse ScienceDirect Polyhedron journal homepage: www.elsevier.com/locate/poly