Photophysics and photochemistry of water-soluble, sitting-atop bis-thallium(I) 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin.

In aqueous solutions, thallium(I) ions and 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin form a kinetically labile metalloporphyrin of 2 : 1 composition (Tl(2)P(4-)). The formation constant of this sitting-atop (SAT) complex is relatively low (beta2/[H+]2= 3.55 x 10(3) M(-2) at pH = 7), due to the large size and rather small charge of Tl+.

Formation and photoinduced electron ejection of amminedicyanocuprate(I) and cyano-bridged trinuclear copper(I) complexes in aqueous ammonia solution.

UV absorption spectral evidence confirms that a mixed-ligand complex, Cu(CN)(2)(NH(3))(-), is formed in an aqueous solution of KCu(CN)(2) and ammonia. The stepwise stability constant for the reaction, Cu(CN)(2)(-) + NH(3) = Cu(CN)(2)(NH(3))(-), is 2.80 +/- 0.

Nature of Transients in the Laser Flash Photolysis of the Tribromocuprate(I) Complex.

Laser flash excitation of the CTTS band of CuBr(3)(2)(-) at 266 nm results in the formation of a luminescent species which decays through a coupled mechanism consistent with the formation of an emitting triplet tricoordinated exciplex in equilibrium with a nonemitting triplet dicoordinated species. The rate constants for some of the decay processes, as well as the formation constant of the radiative intermediate, are estimated. Hydrated electrons and Cu(II) ions are also efficiently produced in about a 1:1 molar ratio in a competing pathway with the copper(I) exciplex formation.