(NME4)[RE3CL10(H2O)2].2H2O - NOT A 5/3-HYDRATE ACCORDING TO [RE3CL9(H2O)3].2H2O

New investigations of the so-called 5/3-hydrate, "[Re3Cl9(H2O)3] - 2H2O", revealed that it is in fact (NMe4)[Re3Cl10(H2O)2] . 2H2O. Low temperature (173 K) single crystal diffractometry confirms the main features of the previously determined crystal structure (hexagonal, P6BAR2c, No. 190; a = 937.3(2), c = 1461.2(3) pm; Z = 2; V(m) = 334.8 cm3/mol; R(w) = 0.030, R(w) = 0.022). There are, however, two important differences. First, the channels in the [00.1] direction contain cations NMe4+. These are disordered in a way that their orientation is "up and down" parallel to [00.1]. Infrared and solid-state C-13-NMR spectra confirm the appearance of the NMe4+ cation. Secondly, the in plane, terminal (i,t) positions at the Re3 triangle are not occupied by H2O ligands alone. Rather, the anion [Re3Cl10(H2O)2]- occurs, with statistical distribution of two water molecules (d(Re-O) = 224(2) pm) and one chloride ion (d(Re-Cl) = 248(1) pm) over the three i,t positions.