ROFRET: a molecular-scale fluorescent probe displaying viscosity-enhanced intramolecular Förster energy transfer.

The fluorescent probe ROFRET contains a Bodipy molecular rotor connected through a short triazole-based spacer to a fully alkylated Bodipy. Förster resonance energy transfer takes place from the rotor to the other Bodipy, and is enhanced to a limiting value as the viscosity of the solvent increases. Time-resolved spectroscopy and steady-state studies are consistent with both forward and reverse energy transfer, and delayed fluorescence.

Highly luminescent dinuclear platinum(II) complexes incorporating bis-cyclometallating pyrazine-based ligands: a versatile approach to efficient red phosphors.

A series of luminescent dinuclear platinum(II) complexes incorporating diphenylpyrazine-based bridging ligands (L(n)H2) has been prepared. Both 2,5-diphenylpyrazine (L(2)H2) and 2,3-diphenylpyrazine (L(3)H2) are able to undergo cyclometalation of the two phenyl rings, with each metal ion binding to the two nitrogen atoms of the central heterocycle, giving, after treatment with the anion of dipivaloyl methane (dpm), complexes of formula {Pt(dpm)}2L(n). These compounds are isomers of the analogous complex of 4,6-diphenylpyrimidine (L(1)H2).

Exciplex-like emission from a closely-spaced, orthogonally-sited anthracenyl-boron dipyrromethene (Bodipy) molecular dyad.

A molecular dyad, , has been prepared that incorporates a boron dipyrromethene (Bodipy) group functionalized at the meso position with an anthracenyl unit. Emission from the dyad contains contributions from both localized fluorescence from the Bodipy unit and exciplex-like emission associated with an intramolecular charge-transfer state. The peak position, intensity and lifetime of this exciplex emission are solvent dependent and the shift in the emission maximum shows a linear relationship to the solvent polarity function (Deltaf).

Cyclometallated, bis-terdentate iridium complexes as linearly expandable cores for the construction of multimetallic assemblies.

Cyclometallated iridium complexes comprised of two terdentate cyclometallating ligands, of the form [Ir(Ninsertion markCinsertion markN)(Ninsertion markNinsertion markC)](+), have been explored for the preparation of multimetallic systems by palladium-catalysed cross-coupling reactions. An Ninsertion markNinsertion markC-coordinating ligand carrying a boronate ester group has been prepared and complexed to iridium to give a boronic acid appended complex of this type, . This complex has been subjected to cross-coupling with a bromo-substituted bis-terpyridyl iridium complex to give a dinuclear iridium compound , in which one of the two iridium centres is N(6)-coordinated and the other has an N(4)C(2)-coordination sphere.

Light-emitting iridium complexes with tridentate ligands.

Once the Cinderella amongst the Platinum Group Metals at the Photochemistry Ball, iridium has become of intense interest since the beginning of the decade. Complexes of iridium(III) can be prepared that are highly luminescent, with emission wavelengths tuneable over the whole of the visible region. Whilst most studies have focused on tris-bidentate complexes, a rich and varied chemistry is also possible using tridentate ligands.

A new class of iridium complexes suitable for stepwise incorporation into linear assemblies: synthesis, electrochemistry, and luminescence.

A new family of cationic iridium(III) complexes is reported that contain two cyclometalating terdentate ligands. The complex [Ir(N--C--N-dpyx)(N--N--C-phbpy)]+ (1) contains one N--C--N-coordinating ligand, cyclometalating through the central phenyl ring, and one N--N--C-coordinated ligand, cyclometalated at the peripheral phenyl ring [dpyxH = 1,3-di(2-pyridyl)-4,6-dimethylbenzene; phbpyH = 6-phenyl-2,2'-bipyridine]. This binding mode dictates a mutually cis arrangement of the cyclometalated carbon atoms: the complexes are thus bis-terdentate analogues of the well-known [Ir(N--C-ppy)2(N--N-bpy)]+ family of complexes, which similarly contain a cis-C2N4 coordination environment.