文摘
This work is devoted to the preparation of trans-[Re6S8(CN)4(OH)(H2O)]3鈭?/sup> and trans-[Re6S8(CN)4(H2O)2]2鈭?/sup> cluster complexes starting from trans-[Re6S8(CN)4(OH)2]4鈭?/sup> and a study of their luminescence properties. The controlled separation of each species could be achieved by pH adjustment: pH > 10, 5.5 < pH < 9 and pH < 3.5 for the dihydroxo trans-[Re6S8(CN)4(OH)2]4鈭?/sup>, aquahydroxo trans-[Re6S8(CN)4(OH)(H2O)]3鈭?/sup> and the diaqua trans-[Re6S8(CN)4(H2O)2]2鈭?/sup> complexes, respectively. The stepwise acid dissociation constants of trans-[Re6S8(CN)4(H2O)2]2鈭?/sup> were determined to be pKa1 = 3.3 and pKa2 = 6.6. Five novel compounds built up from the title cluster units were isolated and characterized: (Bu4N)4[Re6S8(CN)4(OH)2]路Bu4NOH (g class="boldFont">1g>), (Ph4P)3[Re6S8(CN)4(OH)(H2O)]路3.5H2O (g class="boldFont">2g>), (Bu4N)3[Re6S8(CN)4(OH)(H2O)]路2H2O (g class="boldFont">3g>), (Bu4N)2K[Re6S8(CN)4(OH)(H2O)]路6H2O (g class="boldFont">4g>) and (Bu4N)2[Re6S8(CN)4(H2O)2] (g class="boldFont">5g>). Compounds g class="boldFont">2g>, g class="boldFont">3g> and g class="boldFont">4g> were characterized by single-crystal X-ray diffraction analysis. For g class="boldFont">2g> and g class="boldFont">3g>, it was found that the availability of the OH鈭?/sup> and H2O ligands in the trans-positions of the complex [Re6S8(CN)4(OH)(H2O)]3鈭?/sup> leads to the formation of intercluster bridging groups through strong hydrogen bonding. The trans disposition of the groups around Re6 enables the formation of polymeric linear chains of cluster complexes.