[ML]-Type Squares Self-Assembled by Dipalladium Corners and Bridging Aromatic Dipyrazole Ligands for Iodine Capture.

Square-like metallamacrocyclic palladium(II) complexes [] () were synthesized by reacting aromatic dipyrazole ligands (HL-HL with pyromellitic arylimide-, 1,4,5,8-naphthalenetetracarboxylic arylimide-, and anthracene-based aromatic groups, respectively) with dipalladium corners ([(bpy)Pd(NO)](NO), [(dmbpy)Pd(NO)](NO), or [(phen)Pd(NO)](NO), where bpy = 2,2'-bipyridine, dmbpy = 4,4'-dimethyl-2,2'-bipyridine, and phen = 1,10-phenanthroline) in aqueous solutions via metal-directed self-assembly. Metallamacrocycles were fully characterized by H and C nuclear magnetic resonance spectroscopy and electrospray ionization mass spectrometry, and the square structure of 8NO was further confirmed via single crystal X-ray diffraction. These square-like metallamacrocycles exhibit effective performance for iodine adsorption.

Self-Assembly and C-H⋅⋅⋅Anion Hydrogen Bonding of Palladium(II)-based Metallacalixarenes Using Pyridyl- or Phenyl-Bridged Di-Naphthoimidazoles.

Metal-directed self-assembly approaches led to the formation of two novel boat-shaped palladium(II)-based metallacalixarenes 1 (1 a, 1 b and 1 c) and 2 (2 a, 2 b and 2 c), by using the two new ligands 2,6-bis(1H-naphtho[2,3]imidazol-1-yl)pyridine (L ) and 1,3-bis(1H-naphtho[2,3]imidazol-1-yl)benzene (L ) with cis-coordinated Pd precursor (tmeda)Pd(ONO ) (tmeda=N, N, N', N'-tetra-methylethylenediamine), repectively. All complexes with different counterions were systematically characterized in solution, and their structures were determined by X-ray single crystallography analyses in the solid state. The crystal architectures were subtly regulated among different anions through two types (inter- and intra-)molecular C-H hydrogen bonding interactions and other weak interactions.

Self-Assembly of Water-Soluble Platinum(II)-Based Metallacalixarenes and Tuning Their Conformational Interconversion via Synergistic Effects between Solvents and Anions.

The aqueous self-assembly of the flexible ligand L bis(1H-benz[d]imidazole-1-yl)methane and cis-coordinated Pt precursors [(en)Pt , (tmeda)Pt , en=ethylenediamine, tmeda=N,N,N',N'-tetramethylethylenediamine)] led to the formation of the metallacalixarenes with full alternative conformations (e.g., two novel water-soluble metallacalixarenes [M L ] and [M L ] with D and D symmetry, respectively).

Self-assembly of metallomacrocycles with dipyrazole ligands and anion sensing of [Pd4Fe2] macrocycle with ferrocene-based dipyrazole ligand.

By employing dipalladium corners [(bpy)(2)Pd(2)(NO(3))(2)](NO(3))(2) or [(phen)(2)Pd(2)(NO(3))(2)](NO(3))(2) (where bpy = 2,2'-bipyridine and phen = 1,10-phenanthroline) to bridge ferrocene-based dipyrazole ligand (L(1)) and m-phenylene-based dipyrazole ligands (L(2-3)) in aqueous solution, a series of positively-charged [M(4)L(2)](4+) metallomacrocycles were obtained. Their structures were characterized by (1)H NMR, electrospray ionization mass spectrometry (ESI-MS), elemental analysis, and single crystal X-ray diffraction analysis for 1·4NO(3) ({[(bpy)Pd](4)L(1)(2)}(NO(3))(4)) and 4·4NO(3) ({[(phen)Pd](4)L(2)(2)}(NO(3))(4)). In their single crystal structures, NO(3)(-) anions are located at the dipalladium corners by C-H.

Development of a Gd(III)-based receptor-induced magnetization enhancement (RIME) contrast agent for β-glucuronidase activity profiling.

β-Glucuronidase is a key lysosomal enzyme and is often overexpressed in necrotic tumor masses. We report here the synthesis of a pro receptor-induced magnetization enhancement (pro-RIME) magnetic resonance imaging (MRI) contrast agent ([Gd(DOTA-FPβGu)]) for molecular imaging of β-glucuronidase activity in tumor tissues. The contrast agent consists of two parts, a gadolinium complex and a β-glucuronidase substrate (β-d-glucopyranuronic acid).

Synthesis and characterization of a new bioactivated paramagnetic gadolinium(III) complex [Gd(DOTA-FPG)(H2O)] for tracing gene expression.

A smart contrast agent for magnetic resonance imaging (MRI) can be used to exploit an enzymatic activity specific to the tissue or disease state signified by converting an MRI-inactivated agent to an activated MRI agent. In this study, a beta-galactopyranose-containing gadolinium(III) complex [Gd(DOTA-FPG)(H 2O)] was designed, synthesized, and characterized as being potentially suitable for a bioactivated MRI contrast agent. The (17)O NMR experiments were conducted to estimate the water exchange rate k e x 298 and rotational correlation time tau R 298 .