Self-assembly of an organo-palladium molecular basket that encapsulates cobalticarborane anion in water

Constructing Supramolecular Frameworks Based Imidazolate-Edge-Bridged Metallacalix[3]arenes via Hierarchical Self-Assemblies

Hierarchical self-assembly of novel supramolecular structures has obtained increasing attention. Herein we design and synthesize the palladium(II)-based molecular basket-like structures, as structural analog of metallacalix[3]arene [M3L3]3+ (M = (dmbpy)Pd, (phen)Pd; dmbpy = 4,4’-dimethyl-bipyridine; phen = 1,10-phenanthroline), by coordination-driven self-assembly from imidazolate-containing ligand [4,5-bis(2,5-dimethylthiophen-3-yl)-1H-imidazole (HL) with palladium(II) nitrate precursors (dmbpy)Pd(NO3)2 and (phen)Pd(NO3)2. The difference of the palladium(II) nitrate precursors with π-surface in complex produces variations of the two-dimensional (2-D) and three-dimensional (3-D) high-ordered supramolecular architectures, constructed by π···π packing and hydrogen bonding interactions, with metallacalixarenes as building blocks. These results provide perceptions of further exploring the hierarchical assembly of supramolecular structures based on π···π packing and multiple hydrogen bonding.

Spheroid Metallacycles and Metallocavitands with Calixarene- and/or Cleft-Shaped Receptors on the Surface

Flexible hexatopic ligands, 1,2,3,4,5,6-hexakis(1H-naphtho[2,3-d]imidazol-1-ylmethyl)benzene (L(2)) and 1,2,3,4,5,6-hexakis(4,5-diphenylimidazol-1-ylmethyl)benzene (L(3)), containing six neutral naphthanoimidazolyl and 4,5-diphenylimidazolyl N donors were synthesized and used to assemble M6L6L'-type [M = Re(CO)3, L = anionic angular rigid NN donors, and L' = flexible hexatopic N donors] spheroid metallacycles. These molecules with a diameter of ∼17 Å were obtained from Re2(CO)10, H-L (imidazole, benzimidazole, and naphthanoimidazole), and L' [1,2,3,4,5,6-hexakis(benzimidazol-1-ylmethyl)benzene (L(1)), L(2), and L(3)] in a one-step process. Ligands L(2) and L(3) were characterized by elemental analysis, electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS), and (1)H NMR spectroscopy. Metallacycles 1-5 were characterized by elemental analysis, ESI-TOF-MS, Fourier transform infrared spectroscopy, and single-crystal X-ray diffraction analysis. Molecules 1, 2, and 4 can be considered as metallocavitands and contain multiple solvent-accessible receptors, i.e., two metallocalix[3]arene units and six/four calix[4]arene-/cleft-shaped receptors, on the surface. Guests such as acetone molecules could be accommodated in the calix[4]arene/cleft-shaped receptor of the metallocavitands.

A chloride capturing system via proton-induced structure transformation between opened- and closed-forms of dodecavanadates

Reactivity of the incorporated chloride was controlled by the reversible structure transformation between two distinct structures of dodecavanadates.