Transformable Nanostructures of Platinum-Containing Organosilane Hybrids: Non-covalent Self-Assembly of Polyhedral Oligomeric Silsesquioxanes Assisted by Pt···Pt and π–π Stacking Interactions of Alkynylplatinum(II) Terpyridine Moieties

Abstract

An alkynylplatinum(II) terpyridine complex functionalized with polyhedral oligomeric silsesquioxanes (POSS) moieties has been demonstrated to exhibit self-association behavior to give various distinguishable nanostructures with interesting morphological transformation from rings to rods in response to solvent conditions through the stabilization of Pt···Pt and π-π stacking interactions as well as hydrophobic-hydrophobic interactions. These changes can be systemically controlled by varying the solvent composition and have been studied by (1)H NMR, electron microscopy, UV-vis absorption, and emission spectroscopies.

Recent Advances in Phosphorescent Pt(II) Complexes Featuring Metallophilic Interactions: Properties and Applications

“…Interestingly also polyhedral oligomeric silsesquioxane (POSS) moieties can be incorporated onto such class of Pt(II) complexes resulting in organosilane hybrids that still exhibit self-association behavior. 50 Importantly, various distinguishable nanostructures, associated with spectroscopic changes due the establishment of Pt£Pt and ππ interactions, can be formed in various solvent media ranging from nanorings to rods, opening up a new strategy for the development of new functional supramolecular materials with defined shape.…”

Control over the Self‐Assembly Modes of PtII Complexes by Alkyl Chain Variation: From Slipped to Parallel π‐Stacks

“…[21][22][23][24][25][26][27][28][29][30] These systems have a strong propensity to aggregate in solution and in the solid state via Pt•••Pt and/or other secondary forces, as recently shown for various classes of complexes in a comprehensive review by Yam and co-workers. 31 Among them, the self-assembly features of hydrophobic Pt(II) complexes with acetylide, [32][33][34][35][36] bidentate, [37][38][39] tridentate N-donor, [40][41][42] and cyclometalating ligands [43][44][45] are relatively well understood. 31 In contrast, their hydrophobic counterparts featuring non-chelating ligands and, in particular, bis(pyridyl) Pt(II) complexes have been limited to liquid crystalline materials [46][47][48] and hydrogen-bonded metallogelators.…”

Self-assembly of alkynylplatinum(II) terpyridine amphiphiles into nanostructures via steric control and metal–metal interactions

“…Oligo(para-phenylene ethynylene)s (OPEs) with solely π−π stacking interactions are well-recognized to self-assemble into supramolecular system of various nanostructures but rarely result in the formation of tubular scaffolds (70)(71)(72)(73). In view of the rich photophysical properties of square-planar d 8 platinum(II) systems and their propensity toward formation of directional Pt···Pt interactions in distinctive morphologies (27)(28)(29)(30)(31)(39)(40)(41)(42)(43)(44)(45), it is anticipated that such directional and noncovalent metal−metal interactions might be capable of directing or dictating molecular ordering and alignment to give desirable nanostructures of helical ribbons or nanotubes in a precise and controllable manner.Herein, we report the design and synthesis of mono-and dinuclear alkynylplatinum(II) terpyridine complexes containing hydrophilic OPEs with two 3,6,9-trioxadec-1-yloxy chains. The mononuclear alkynylplatinum(II) terpyridine complex with Significance Metallosupramolecular π-conjugated amphiphiles have emerged as a building block for supramolecular architectures owing to their interesting luminescence behavior and their propensity to form noncovalent metal-metal interactions.…”

“…Earlier work by our group showed the first example, to our knowledge, of an alkynylplatinum(II) terpyridine system [Pt(tpy)(C ≡ CR)] + that incorporates σ-donating and solubilizing alkynyl ligands together with the formation of Pt···Pt interactions to exhibit notable color changes and luminescence enhancements on solvent composition change (25) and polyelectrolyte addition (26). This approach has provided access to the alkynylplatinum(II) terpyridine and other related cyclometalated platinum(II) complexes, with functionalities that can self-assemble into metallogels (27)(28)(29)(30)(31), liquid crystals (32,33), and other different molecular architectures, such as hairpin conformation (34), helices (35)(36)(37)(38), nanostructures (39)(40)(41)(42)(43)(44)(45), and molecular tweezers (46,47), as well as having a wide range of applications in molecular recognition (48)(49)(50)(51)(52), biomolecular labeling (48)(49)(50)(51)(52), and materials science (53,54). Recently, metalcontaining amphiphiles have also emerged as a building block for supramolecular architectures (42)(43)(44)(55)(56)(57)…”