Oxime-Bridged Mn₆ Clusters Inserted in One-Dimensional Coordination Polymer

The reaction of MnCl2·4H2O with salicylaldoxime (H2salox) and the sodium salt of 1,3-bis­(carboxy­propyl)­tetramethyl­disiloxane (H2L) in a 1:1:1 molar ratio led to the self-assembly of {[Mn6O2(salox)6­(H2salox)­(H2O)3(μ-L)]­H2salox·1.2H2O}n, a 1D coordination polymer consisting of hexamanganese­(III) salicylaldoximate cluster as secondary building unit (SBU) and tetramethyl­disiloxane-based dicarboxylate linker, namely, 1,3-bis­(carboxy­propyl)­tetramethyl­disiloxane. The structure of the compound was established by single crystal X-ray diffraction. The Mn­(III) clusters consist of two staggered μ3-oxo-bridged Mn3 triangles held together by the oxygen atoms of the oxime groups. Because of Jahn–Teller distortion, the Mn–O distances reach 2.5 Å for the oxygen atoms located above and below the triangles mean planes. The compound showed a glass transition peak at around 14 °C in the differential scanning calorimetry (DSC) curve. The magnetic susceptibility data were fitted with a set of three intracluster antiferromagnetic exchange interaction coupling constants: J1 = −0.65 cm–1, J2 = −1.5 cm–1, and J3 = −0.9 cm–1. The ac magnetic susceptibility measurements in the 2–5 K temperature range reveal a frequency-dependent behavior indicative of a slow relaxation of magnetization at low temperature. The coexistence of the lypophilic 1,3-bis­(propyl)­tetramethyl­disiloxane moieties and hydrophilic polar SBUs confers to the structure an amphiphilic character. Dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), and transmission (TEM) and scanning (SEM) electron microscopies demonstrate that in dimethyl­formamide (DMF) the coordination polymer organizes as micelles, whereas in chloroform it tends to form inverse micelles and vesicles.