Structures and solvatochromic phosphorescence of dicationic terpyridyl-platinum(II) complexes with foldable oligo(ortho-phenyleneethynylene) bridging ligands.
A series of binuclear organoplatinum(II) complexes, [(tBu3tpy)Pt--(C[triple chemical bond]C--1,2-C6H4)n--C[triple chemical bond]C--Pt(tBu3tpy)][ClO4]2 (1-7, n=1, 2, 3, 4, 5, 6, 8; tBu3tpy=4,4',4''-tri-tert-butyl-2,2':6',2''-terpyridine) with foldable oligo(ortho-phenyleneethynylene) linkers were prepared and characterized by spectroscopic methods and/or X-ray crystallographic analyses. In the crystal structures of 32.5 CH3OH, 5CH3CN, and 64 CH3CN, each of the bridging ortho-phenyleneethynylene ligands has a partially folded conformation. In aerated water/acetonitrile mixtures with water percentages larger than 40 %, the emission of complexes 3-7 are red-shifted and enhanced when compared to those recorded in acetonitrile. The red-shift in emission energy and enhanced emission intensity can be attributed to the inter- and/or intramolecular interactions induced by the addition of water to solutions of the platinum(II) complexes in acetonitrile. Data from dynamic light scattering and transmission electron microscopy studies revealed that these binuclear platinum(II) complexes aggregated into nanosized particles in acetonitrile/water mixtures. Hydrophobic folding of the ortho-phenyleneethynylene linkers in acetonitrile/water mixtures is postulated.
Zhu
Ming-Xin
MX
Department of Chemistry and Open Laboratory of Chemical Biology of the Institute of Molecular Technology for Drug Discovery and Synthesis, The University of Hong Kong, Pokfulam Road, Hong Kong (China).
Lu
Wei
W
Zhu
Nianyong
N
Che
Chi-Ming
CM
D000480:Alkynes / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D018360:Crystallography, X-Ray; D004987:Ethers / Q000737:chemistry*; D008024:Ligands; D049408:Luminescent Agents / Q000737:chemistry*; D008163:Luminescent Measurements; D009682:Magnetic Resonance Spectroscopy; D046529:Microscopy, Electron, Transmission; D008958:Models, Molecular; D015394:Molecular Structure; D009944:Organoplatinum Compounds / Q000737:chemistry*; D010777:Photochemistry; D011725:Pyridines / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D013053:Spectrophotometry; D013696:Temperature; D014867:Water / Q000737:chemistry
D000480:Alkynes; D002412:Cations; D004987:Ethers; D008024:Ligands; D049408:Luminescent Agents; D009944:Organoplatinum Compounds; D011725:Pyridines; D012997:Solvents; C436384:phenyleneethynylene; D014867:Water; C023666:pyridine