From molecular rings to the 3-D solid:: ionization of the neutral [Mo10S10O10(OH)10(H2O)5] molecular ring for the building blocks strategy

The bis chloride complex [Cl2Mo10S10O10(OH)(10)(H2O)(5)](2-) has been crystallized as tetraethylammonium salt (2) in a dimethylformamide solution and has been characterized by single crystal-X ray diffraction (monoclinic, P2(1)2(1)2(1) With 61.5357(3) Angstrom, b = 15.0285(2) Angstrom, c = 23.118(1) Angstrom, beta = 101.053(1)degrees Z= 8). The structure of the discrete anion consists of a neutral decanuclear Mo-10-ring resulting from the cyclic linkage of five {Mo2S2O2} blocks via double hydroxo bridges. The Mole-ring appears bi-capped by two outer chloride ions, which interact with the ring via a H-bonding network to give a supramolecular assembly. The successive ionization steps of the neutral Moro-wheel were evidenced by potentiometry and involve the water molecules lining the cavity of the ring. The crystallization of the (Mo-10}(2-) anion leads to the K-3[ClMo10- S10O10(OH)(12)(H2O)(5)].14H(2)O solid (3). The single crystal-X ray diffraction of 3 (orthorhombic, Pmmn with a = 30.3128(7) A, b = 30.7282(6) Angstrom, c = 13.5159(3) Angstrom, Z= 8) reveals the mono-chloride complex [ClMo10S10O10(OH)(12)(H2O)(3)](3-) which acts as a building wheel for the assembly of a noteworthy 3-D array. The direct connections between the anionic rings and the potassium cations lead to wide open-channels (16.4 x 8 Angstrom) only filled by weakly bound crystallization water. (C) 2001 Elsevier Science Ltd. All rights reserved.