Three luminescent alkynylplatinum(II) terpyridyl complexes, [Pt( t Bu3tpy)(C⋮C−C6H4−X-4)](OTf) (X = NH2 1, NCS 2, NHCOCH2I 3), have been synthesized and characterized. Their electrochemical and photophysical properties have been studied, and the molecular structure of 2 has also been determined by X-ray crystallography. Complexes 2 and 3 exhibit strong luminescence in various media, the origin of which has been tentatively assigned as a dπ(Pt) → π*( t Bu3tpy) 3MLCT excited state, with some mixing of a π(C⋮CR) → π*( t Bu3tpy) 3LLCT character. Human serum albumin (HSA) has been labeled by the ready reaction of the isothiocyanate and iodoacetamide functional groups in 2 and 3, to afford the respective bioconjugates, 2-HSA and 3-HSA. Both bioconjugates in 50 mM Tris-Cl buffer (pH 7.4) are highly colored and exhibit luminescence in the visible region upon photoexcitation.

Luminescent square-planar d 8 platinum(II) complexes have attracted much attention because of their intriguing photophysical and spectroscopic properties. [1][2][3][4][5][6][7][8] In particular, platinum(II) derivatives with terpyridyl ligands and their analogues have been widely studied for their luminescence behavior. [3][4][5][6][7] Owing to their planar coordination geometry, which permits easy access to important frontier orbitals of the metal center, d8 -d 8 metal-metal interactions as well as p-p interactions between chromophores of the polypyridyl plat-

Oxygen-sensing elements containing single-layered structures of luminescent indicators of ruthenium(II) bipyridyl complexes on glass surfaces prepared by covalent attachment and LB deposition are described. They are capable of detecting gaseous oxygen concentration by luminescence quenching of the indicator with reproducible and large quenching efficiencies that are comparable to the best quenching efficiencies obtained by other ruthenium(II) polypyridine based complexes immobilized in matrixes. The large quenching efficiencies for both films imply that the probe complexes are effectively quenched by oxygen, which is probably due to the thin single-layered structures with large surface-to-area ratio and short distance between the probe complexes and oxygen.

A novel luminescent hexanuclear platinum(II) complex, [Pt(2)(mu-dppm)(2)(C[triple bond]CC(5)H(4)N)(4)[Pt(trpy)](4)](CF(3)SO(3))(8) (trpy = 2,2':6',2''-terpyridine), was successfully synthesized by using the face-to-face dinuclear platinum(II) ethynylpyridine complex [Pt(2)(mu-dppm)(2)(C[triple bond]CC(5)H(4)N)(4)] as the building block.