Synthesis, Characterization, and the Photochromic, Luminescence, Metallogelation and Liquid‐Crystalline Properties of Multifunctional Platinum(II) Bipyridine Complexes

Abstract

A series of multifunctional platinum(II) bipyridine complexes were designed, synthesized, and characterized by (1)H NMR, fast atom bombardment mass spectrometry (FAB-MS), and elemental analysis. Their electrochemical and photophysical properties were investigated. The photochromic properties of the spironaphthoxazine-containing complexes were also studied. Some of these complexes were shown to be capable of forming stable thermoreversible metallogels in organic solvents. In contrast to typical thermotropic organogels and metallogels, one of the complexes could form metallogels in dodecane and is very stable towards external stimuli. The photochromic activation parameters for the bleaching reaction of a representative spironaphthoxazine-containing complex in a dodecane gel were determined through kinetic studies at various temperatures. Lamellar liquid-crystalline behavior was also observed in one of the complexes, and the liquid-crystalline properties were studied by thermogravimetry analysis (TGA), polarized optical microscopy (POM), differential scanning calorimetry (DSC), variable-temperature X-ray diffraction (XRD), and variable-temperature infrared (IR) spectroscopy.

A New Class of Dendritic Metallogels with Multiple Stimuli‐Responsiveness and as Templates for the In Situ Synthesis of Silver Nanoparticles

“…[4] Clearly, the incorporation of metal ions into the supramolecular gels could not only subtly tune the gelation ability by metal-ligand interactions but also endow with the outstanding redox, catalytic, and optical properties associated with the metal centers, which are not accessible to low molecular weight organogels. [2,5] So far, a variety of metallogels formed from various transition-metal complexes, including silver, copper, palladium, gold, platinum, and iron complexes have been reported. [2][3][4][5][6] Some of them were found to be responsive to different external stimuli such as light, redox, chemicals, and mechanical stress.…”

“…[2,5] So far, a variety of metallogels formed from various transition-metal complexes, including silver, copper, palladium, gold, platinum, and iron complexes have been reported. [2][3][4][5][6] Some of them were found to be responsive to different external stimuli such as light, redox, chemicals, and mechanical stress. [4c-e, 5a, 6] In addition, metallogels have recently been utilized for the in situ-synthesis of metal nanoparticles.…”

Structure–Property Relationships and 1O2 Photosensitisation in Sterically Encumbered Diimine PtII Acetylide Complexes

“…[17] Alkynyl Pt II polypyridyl complexes (bipyridyl or terpyridyl) have found application in areas spanning photocatalytic hydrogen production, [18] vapoluminescent materials, [19] chromophores in dye-sensitised solar cells [20] and luminescent labels for bioconjugates, [21] and some exhibit lamellar liquid-crystalline behaviour and thermoreversible metallo-A C H T U N G T R E N N U N G gelation. [22] The high yield of long-lived triplet excited states (e.g., 3 IL) in Pt II and Ir III complexes, a consequence of an efficient intersystem crossing process, has seen them employed as efficient triplet photosensitisers. Alkynyl Pt II polypyridyl complexes have shown application in areas such as photocatalysis [18b, 23] and triplet-triplet energy-transfer (TTET) processes, for example, triplet-triplet annihilation-based upconversion (TTA) and singlet-oxygen sensitisation.…”

Synthesis and Photophysical Properties of Self‐Assembled Metallogels of Platinum(II) Acetylide Complexes with Elaborate Long‐Chain Pyridine‐2,6‐Dicarboxamides

“…[4] Recently, there has been growing interest in the study of metallogels, owing to the rich spectroscopic and luminescence properties exhibited by a variety of transition-metal complexes. [5] In particular, the known metallophilic interactions displayed by Pt II ···Pt II , Au I ···Au I , and Ag I ···Ag I bonds have been masterfully introduced into metallogelating systems as an extra directional intermolecular interaction for subsequent molecular aggregation and gel formation. [5] Moreover, the rich photophysical and photochemical properties associated with the metal centers from these metallogelators are sometimes not accessible from organogelators.…”