ARTICLE DOI: 10.1002/zaac.201100524 A Series of [Mn 6 ] Complexes with Terminal Functional Groups Malgorzata Holyn ´ ska* [a] and Stefanie Dehnen* [a] Keywords: Polynuclear complexes; Manganese; Salicylaldoxime; X-ray diffraction Abstract. A series of [Mn 6 O 2 (R 1 OH) 4 (sao) 6 (R 2 COO) 2 ] complexes with terminal functional groups (1: R 1 = CH 3 , R 2 = HO-C 6 H 4 , 2: R 1 = C 2 H 5 , R 2 =H 2 N-C 6 H 4 , 3: R 1 = CH 3 , R 2 = Cl-C 6 H 4 , 4: R 1 = CH 3 , R 2 = CH 3 S-C 6 H 4 , 5: R 1 = CH 3 , R 2 = I-C 6 H 4 , 6: R 1 = CH 3 , R 2 = pymSCH 2 , 7: R 1 = CH 3 , R 2 = ortho-pyr-SCH 3 , 8: R 1 =C 2 H 5 , R 2 = (CH 3 ) 3 OOCNHCH 2 C 6 H 4 ; sao = doubly deprotonated salicylaldoxime ligand, pym = pyrimidyl, pyr = pyridyl) have been obtained in a reaction of a ligand R 2 C 6 H 4 COOH, salicylaldoxime, manganese(II) perchlorate and Introduction Polynuclear mixed-valent manganese complexes represent an established part of materials science. Since the discovery of the first polynuclear mixed-valence [Mn 12 ] complex [1] exhibit- ing the so-called “single molecule magnet (SMM) behavior” [2] attempts have been made to modify the structure of this com- plex or to create new structural types. An important part of motivation for exploring the chemistry of the ligand part of functionalized SMMs involves the perspective of to attach these molecules to functionalized surfaces via organic reac- tions. [3] New approaches aiming at their assembling into novel frameworks are also worth pursuing, representing part of a “bottom-up“ approach. [4] One possible way into the desired direction would be the functionalization of large metal clusters, which is an uncommon approach in synthetic chemistry, re- cently utilized for chalcogenidometallates. [5] It has been shown, that the synthetic principle of introducing functional groups to larger clusters, is of crucial importance for the design of new materials, in particular bearing applications as labeling and imaging agents for biological systems. [6a] The principle has been especially applied to polyoxoanions of vanadium, molybdenum and tungsten so far. [6] In this paper we communi- cate a series of functionalized complexes with a known [Mn 6 O 2 ] core [7] that was recently published as a complex com- prising a record anisotropy barrier for a SMM: [Mn 6 O 2 (R 1 OH) 4 - (sao) 6 (R 2 COO) 2 ](1: R 1 = CH 3 , R 2 = HO-C 6 H 4 , 2: R 1 =C 2 H 5 , * Prof. Dr. S. Dehnen, Dr. M. Holyn ´ska E-Mail: dehnen@chemie.uni-marburg.de [a] Fachbereich Chemie Wissenschaftliches Zentrum für Materialwissenschaften Philipps-Universität Marburg Hans-Meerwein-Strasse 35043 Marburg, Germany Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/zaac.201100524 or from the author. Z. Anorg. Allg. Chem. 2012, 638, (5), 763–769 © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 763 [NEt 4 ](OH) in methanol or a 1:1 mixture of ethanol and dichlorometh- ane. In this report, structural aspects as well as preliminary studies of magnetic and thermal properties are presented. Compounds 1, 3, 6, 8 exhibit an antiferromagnetic coupling of the Mn 2+ ions, whereas 4 and 7 show ferromagnetic interactions. The title compounds may act as starting materials for further derivatization addressing the functional groups. R 2 =H 2 N-C 6 H 4 , 3: R 1 = CH 3 , R 2 = Cl-C 6 H 4 , 4: R 1 = CH 3 , R 2 = CH 3 S-C 6 H 4 , 5: R 1 = CH 3 , R 2 = I-C 6 H 4 , 6: R 1 = CH 3 , R 2 = pym-SCH 2 , 7: R 1 = CH 3 , R 2 = ortho-pyr-SCH 3 , 8: R 1 =C 2 H 5 , R 2 = (CH 3 ) 3 OOCNHCH 2 C 6 H 4 ; sao = doubly de- protonated salicylaldoxime, pym = pyrimidyl, pyr = pyridyl). Compounds 1–8 contain sterically well available functional groups (Scheme 1). Scheme 1. Formulae of acids that served as ligand sources for the ligands bearing functional groups in 1–8. Results and Discussion Synthesis The formation of the 1–8 took place according to equation (1):