Molecular Dumbbell, Sandwich, and Paddle-Wheel Assembled with Methylresorcin[4]arene Cavitands and Organooxotin Clusters

Assemblies of two methylresorcin[4]arene cavitands with Bu2SnO and n-BuSn(O)OH afforded four organooxotin-cluster-based compounds, namely, [(Bu2Sn)(2)(mu(3)-O)(L1)(EtO)](2).2EtOH (1), [(Bu2Sn)(2)(mu(3)-O)(L-2)(EtO)](2).2EtOH (2), [(BuSn)(12)(mu(3)-O)(14)(mu(2)-OH)(6)](L-1)(2).2EtOH (3), and [(BuSn)(mu(3)-O)(L-2)](6).6(toluene) (4) (HL1 = methylresorcin[4]arene cavitand-C1-COOH-in and HL2 = methylresorcin[4]arene cavitand-C1-COOH-out). It is the first time that the methylresorcin[4]arene cavitands were successfully incorporated into the organooxotin clusters. Both 1 and 2 exhibit similar dumbbell-like structures, where the skeletons of methylresorcin[4]arene cavitands stretch in different directions on account of the different configurations of the carboxylate groups of L1 and L2 anions. As a result, the C-H...pi interactions lead to slightly distinct 1D supramolecular architectures of 1 and 2. 3 displays a sandwich-like structure based on one [(BuSn)(12)(mu(3)-O)(14)(mu(2)-OH)(6)](2+) macrocation and two L1 anions, where the macrocation is trapped in the dimeric L1 anions through OH...O hydrogen-bonding interactions. The sandwiches further stack through pi-pi interactions to afford a supramolecular dimer. 4 exhibits an unusual giant paddle-wheel motif composed of a typical Sn(6)O6 drum and six L2 anions. Further, the paddle-wheel motifs are extended by pp interactions to give a supramolecular layer. Moreover, the luminescent properties of 2 and 4 and the preliminary anticancer activity of 4 were also investigated.