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The emission spectrum of a molecular beam of NaI has been measured following excitation by the 248 nm KrF line of an excimer laser. The fluorescence structure, and the lifetime (17±2 ns), indicate the presence of a bound upper state not previously characterized. We identify this state as correlating with Na(3 2P)+I(5 2P3/2) atoms. Through numerical simulation using a Morse function representation for the upper state, we have determined approximate values for the well depth of 530±260 cm−1, well breadth of ∼1.8 Å−1, and equilibrium separation of ∼3.4 Å for this state. As a consequence of the breadth of this weakly bound excited state the bound→bound line spectrum spans a broad spectral range (87% of the ground state well depth) entirely comparable with spectra attributed to free→bound emission.

State-to-state theory of vibrational kinetics and dissociation in three-atomic gases AIP Conf. Proc. 585, 620 (2001); 10.1063/1.1407618State-to-state unimolecular reaction dynamics of HOCl near the dissociation threshold: The role of vibrations, rotations, and IVR probed by time-and eigenstate-resolved spectroscopyThe state-to-state dissociation dynamics of CF 3 NO have been investigated by exciting the parent compound in a supersonic jet expansion with one tunable laser and monitoring the state distribution of the NO fragment by one-or two-photon laser-induced fluorescence using a second tunable laser. At the lowest levels of excitation. CF 3 NO dissociates to give an NO distribution which is consistent with a statistical distribution of energy in the products. As more highly excited vibronic states of S I are selected, the product distribution begins to show signs of nonstatistical behavior, although the deviations are small. The appearance time of the NO decreases nearly monotonically with increasing energy above the S I origin and is equal to the fluorescence lifetime of the CF 3 NO· to within experimental error. It is likely that both the appearance time of the NO and the fluorescence lifetime of the CF 3NO· measure the rate of internal conversion from S I to highly excited vibrational levels of So, which then dissociate in a nearly statistical fashion on the So surface. The barrier to dissociation ofthe CF 3 -NO bond is 39.61 ±0.23 kcaVmol.

A Photofrin dose of 2.5 mg/kg and 120 J/cm2 light are necessary for adequate ablation of atheroma while avoiding extensive medial damage.

Benzoporphyrin derivative monoacid ring A (BPD-MA) is a chlorin-like photosensitizer currently in clinical trials for cancer and psoriasis. It has maximal absorption peaks at both 630 and 690 nm and can be activated at both these wavelengths. In vitro phototoxicity tests using the P815 murine mastocytoma cell lines conducted over wavelengths of light between 678 and 700 nm emitted by an argon-ion pumped dye laser showed that equivalent cell kill could be achieved between 682 and 690 nm. Tests on in vivo phototoxicity of normal skin of DBA/2 mice injected with 2 mg/kg of BPD-MA and exposed to light at 125 J/cm2, between 620 and 700 nm, demonstrated peaks of normal skin damage occurring at 630-640 nm and 680-690 nm. In tests carried out with light between 620 and 700 nm, at 10 nm increments, it was seen that light delivered at 680-690 nm caused slightly more damage to normal skin than light delivered at 630-640 nm. When lower doses of light between 675 and 705 nm were tested using smaller increments, it was determined that equivalent skin damage occurred over a range of 680-695 nm. Antitumor efficacy in tumor-bearing DBA/2 mice was tested between 683 and 695 nm. It was found that equivalent antitumor efficacy, determined by assessing tumor-free status at 20 days posttreatment, occurred at wavelengths between 685 and 693 nm.(ABSTRACT TRUNCATED AT 250 WORDS)