Solvent-Dependent Supramolecular Host-Guest Assemblies of Platinum(II) Tweezers and a Guest System: From Discrete Molecules to High-Ordered Oligomers.

A series of platinum(II) calix[4]arene-based molecular tweezers was synthesized. The studies of the host-guest association with a charge-neutral cyclometalated platinum(II) complex showed a drastic color change and the turning on of near-infrared emission resulting from Pt⋅⋅⋅Pt and π-π interactions. Control of the host-guest assembly process by varying the solvent composition can lead to a change from discrete host and guest molecules to high-ordered host-guest oligomers with the formation of sheet-like nanostructures, demonstrating a rare example of three-state supramolecular host-guest system with high solubility in solvents of diverse polarity.

Protamine-Induced Supramolecular Self-Assembly of Red-Emissive Alkynylplatinum(II) 2,6-Bis(benzimidazol-2'-yl)pyridine Complex for Selective Label-Free Sensing of Heparin and Real-Time Monitoring of Trypsin Activity.

A label-free detection assay is developed based on the design and synthesis of a new anionic alkynylplatinum(II) 2,6-bis(benzimidazol-2'-yl)pyridine complex with water-soluble pendants. With the aid of electrostatic interaction and noncovalent metal-metal and π-π stacking interactions, protamine is shown to induce supramolecular self-assembly of platinum(II) complexes with drastic UV-vis absorption and red emission changes. On the basis of the strong binding affinity of protamine and heparin, the ensemble has been further employed to probe heparin by monitoring the spectroscopic changes.

Au ⋅⋅⋅Au Interaction Assisted Host-Guest Interactions and Stimuli-Responsive Self-Assembly in Tetranuclear Alkynylgold(I) Calix[4]arene-Based Isocyanide Complexes.

Multi-stimuli-responsive tetranuclear gold(I) complexes were prepared based on a tetra(alkynyl)calix[4]arene framework, with incorporation of a series of isocyanide ligands of tunable hydrophilicity. This class of complex was found to exhibit high sensitivity towards group IIIA metal ions especially In . Drastic electronic absorption and emission changes were observed, which could be attributed to the formation of Au ⋅⋅⋅Au interactions during the binding event.

Synthesis and Photophysical Studies of Calixarene-Based Alkynylplatinum(II) Terpyridine Complexes with Various Receptor Sites for Colorimetric and Luminescence Sensing of Anions.

A series of mononuclear and dinuclear platinum(II) terpyridine complexes with amide-, sulfonamide-, and urea-containing ligands (1-9) has been successfully designed and synthesized, and their photophysical and anion-binding properties have been studied. The anion-binding properties of the complexes were studied by electronic absorption, emission, and (1)H NMR spectroscopy. Upon the binding with anions, the dinuclear complexes 1-3 exhibit large electronic absorption and emission spectral changes, while for the mononuclear analogues 4-6 much smaller spectral changes were observed.

Synthesis and cation-binding studies of gold(I) complexes bearing oligoether isocyanide ligands with ester and amide as linkers.

A series of dinuclear gold(I) isocyanide complexes of bis(alkynyl)calix[4]arene was designed and synthesized, and their photophysical and cation recognition properties were studied. Complex 1, [{calix[4]arene-(OCH2CONH-C6H4C≡C)2}{Au(CN-C6H4O(CH2CH2O)2CH3)}2], was found to show a high selectivity towards Al(3+) in CH2Cl2-MeCN (1 : 1 v/v). Upon addition of Al(3+), drastic changes in the electronic absorption, emission and (1)H NMR spectra were observed.

Luminescence color switching of supramolecular assemblies of discrete molecular decanuclear gold(I) sulfido complexes.

A series of discrete decanuclear gold(I) μ(3)-sulfido complexes with alkyl chains of various lengths on the aminodiphosphine ligands, [Au(10){Ph(2)PN(C(n)H2(n+1))PPh(2)}(4)(μ(3)-S)(4)](ClO(4))(2), has been synthesized and characterized. These complexes have been shown to form supramolecular nanoaggregate assemblies upon solvent modulation. The photoluminescence (PL) colors of the nanoaggregates can be switched from green to yellow to red by varying the solvent systems from which they are formed.

From {Au(I)···Au(I)}-coupled cages to the cage-built 2-D {Au(I)···Au(I)} arrays: Au(I)···Au(I) bonding interaction driven self-assembly and their Ag(I) sensing and photo-switchable behavior.

Metal-metal bonding interactions have been used to generate a number of unique supramolecular assemblies with fascinating functions. We presented here a new class of gold(I)-containing metallosupramolecular cages and cage-built two-dimensional (2-D) arrays of {Au8L2}n (n = 1 or ∞, L = tetrakis-dithiocarbamato-calix[4]arene, TDCC), 1-3, which are constructed from the self-assembly of deep-cavitand calix[4]arene-based supramolecular cages consisting of octanuclear Au(I) motifs. Synchrotron radiation X-ray diffraction structural analyses of 1-3 revealed their quadruple-stranded helicate dimeric cage structure and the presence of 2-D arrays of cages linked together by inter- and intramolecular Au(I)···Au(I) interactions.

Addition reaction-induced cluster-to-cluster transformation: controlled self-assembly of luminescent polynuclear gold(I) μ₃-sulfido clusters.

Unprecedented addition reaction-induced gold(I) cluster-to-cluster transformation has been observed in the present work. Reaction of the chlorogold(I) precursor, [vdpp(AuCl)2] (vdpp = vinylidenebis(diphenylphosphine)) containing the diphosphine with unsaturated C═C bond, with H2S resulted in a series of polynuclear gold(I) μ3-sulfido clusters bearing Au(I)···Au(I) interactions; the identities of which have been fully characterized by NMR, electrospray-ionization mass spectrometry, elemental analysis, and single crystal X-ray diffraction analysis. Diverse research methods, including UV-vis absorption, (1)H NMR, and (31)P NMR spectroscopy, were employed to detect and monitor the transformation and assembly processes.

Highly selective ion probe for Al3+ based on Au(I)···Au(I) interactions in a bis-alkynyl calix[4]arene Au(I) isocyanide scaffold.

A bis-alkynyl calix[4]arene Au(I) isocyanide complex has been synthesized and demonstrated to be a selective ion probe for Al(3+) based on Au(I)Au(I) interactions.