During the past few decades, the construction of various kinds of platinum-acetylide complexes has attracted considerable attention, because of their wide applications in photovoltaic cells, non-linear optics, and bio-imaging materials. Among these platinum-acetylide complexes, the linear neutral platinum-acetylide complexes, due to their attractive properties, such as well-defined linear geometry, synthetic accessibility, and intriguing photoproperties, have emerged as a rising star in this field. In this personal account, we will discuss how we entered the field of linear neutral platinum-acetylide chemistry and what we found in this field. The preparation of various types of linear neutral platinum-acetylide complexes and their applications in the areas of micro/nanostructure materials, complicated topologies, and dye-sensitized solar cells will be summarized in this account.

Pillarenes (or pillararenes), as a new and rapidly developing class of covalent macrocycles, have stimulated a tremendous upsurge of interest in supramolecular chemistry because of their unique features and potentials in fabricating functional materials. In addition, metallo-supramolecular chemistry has grown steadily over the last few decades. The presence of metal in supramolecular architectures enables the systematic tuning of their properties and endows them with optical, magnetic, and electric etcetera unusual properties. The marriage of these two fields offers new possibilities for the fabrication of novel functional materials and devices. This review article provides an overview of recent advancements on pillararene-based metallic supramolecular assemblies. The fabrication and functionalities of pillararene-decorated metallic macrocycles, metal-organic frameworks (MOFs), and metal nanoparticles are comprehensively summarized and discussed.

The synthesis of discrete multirotaxanes with well-defined structures remains a great challenge. Herein, we present the successful construction of diverse discrete multirotaxanes with well-defined supramolecular metallacycles as cores by a modular approach. Moreover, these novel multirotaxanes featured a stimuli-responsive property that enabled the introduction and removal of the bromide anion by taking advantage of dynamic nature of the supramolecular metallacycle scaffold. Through the combination of rotaxane-containing prefunctionalized building blocks with the corresponding different organoplatinum(II) acceptor building blocks (60, 120, or 180°), diverse discrete multirotaxanes with well-defined metallacycles (rhomboid or hexagon) as cores as well as certain numbers of rotaxane units were successfully obtained quantitatively by means of coordination-driven self-assembly. Furthermore, owing to the existence of a dynamic metallacycle as the supramolecular cores, the resultant multirotaxanes showed anion-induced disassembly and reassembly properties, which allowed for the reversible transformation between multirotaxanes and the corresponding individual rotaxane-containing building blocks. Therefore, this research not only enriches the family of discrete multirotaxanes, but also provides a novel strategy for the construction of “smart” stimuli-responsive multirotaxane systems.

The design and self-assembly of pyrene-modified rhomboidal metallodendrimers R1–R6 via directional metal-ligand bonding approach is described. By employing pyrene-containing 120° di-Pt(II) acceptor and appropriate 60° dendritic dipyridyl donors, a variety of [G-1]–[G-3] pyrene-modified rhomboidal metallodendrimers with well-defined shape and size were prepared under mild conditions in high yields. The supramolecular dendrimers were characterized with multinuclear NMR (¹H and ³¹P) and mass spectrometry (CSI-TOF-MS). Isotopically resolved mass spectrometry data support the existence of the pyrene-modified dendrimers with rhomboidal cavities, and NMR data were consistent with the formation of all ensembles. The shape and size of all rhomboidal dendrimers were investigated with the PM6 semiempirical molecular orbital method. Their primary photochemical properties were studied as well.

A series of new platinum-acetylide complexes containing ethynyl-pyrene moieties as the main skeleton were synthesized and characterized. The investigation of the absorption and emission spectra of these complexes revealed that the extension of the molecular size with the introduction of different numbered platinum-acetylide fragments can efficiently tune the absorption and emission bands from the UV to the longer wavelength region. Moreover, the gelation properties of these complexes were investigated by the “stable-to-inversion-of-a-test-tube” method. Most newly designed platinum-acetylide compounds presented a stable gel-formation property in some of the tested solvents. The morphology of the xerogels was investigated by scanning electron microscopy (SEM). Furthermore, the concentration- and temperature-dependent absorption and emission properties of these complexes were investigated, which support the formation of J-type assemblies during the aggregation process. More importantly, it was found that the complexes 4 a-C6, 4 a, and 4 a-C18 with four platinum-acetylide fragments presented potential applications as luminescent organometallic gels.

A series of new platinum–acetylide complexes 4 a–4 c and 6 a–6 c were synthesized and characterized. The gelation properties of these compounds were investigated by the “stable-to-inversion-of-test-tube” method. Unlike compounds 4 a–4 c, amides 6 b and 6 c can gelate a variety of nonpolar alkyl solvents; this result indicates that the hydrogen bonds between amide groups play an important role in the formation of metallic organogels. Interestingly, compared to the typical morphologies of known organogels or metallic organogels, compounds 6 b and 6 c exhibited highly ordered honeycomb patterns on a large-scale (determined by SEM analysis). To investigate the driving forces for the self-assembly process, concentration-dependent ¹H NMR spectroscopy and a competitive experiment between hydrogen bonds were used to confirm that intermolecular hydrogen bonding play an essential role during the formation of supramolecular aggregates.

The self-organization of multicomponent supramolecular systems involving a variety of two-dimensional (2 D) polygons and three-dimensional (3 D) cages is presented. Nine self-organizing systems, SS₁–SS₉, have been studied. Each involves the simultaneous mixing of organoplatinum acceptors and pyridyl donors of varying geometry and their selective self-assembly into three to four specific 2 D (rectangular, triangular, and rhomboid) and/or 3 D (triangular prism and distorted and nondistorted trigonal bipyramidal) supramolecules. The formation of these discrete structures is characterized using NMR spectroscopy and electrospray ionization mass spectrometry (ESI-MS). In all cases, the self-organization process is directed by: 1)  the geometric information encoded within the molecular subunits and 2) a thermodynamically driven dynamic self-correction process. The result is the selective self-assembly of multiple discrete products from a randomly formed complex. The influence of key experimental variables - temperature and solvent - on the self-correction process and the fidelity of the resulting self-organization systems is also described.