Excited-state coordination chemistry: excited-state basicity of bis(2,2'-bipyridyl)(2,3-dipyridylpyrazine)ruthenium(II).

The proton dependencies of the absorption and emission spectra of bis(2,2'-bipyridyl)(2,3-bis(2-pyridyl)pyrazine)ruthenium(II), (bpy)(2)Ru(dpp)(2+) indicate that population of the dpp-localized MLCT state increases the basicity of dpp peripheral nitrogens. NMR spectra reveal the protonation of the peripheral dpp pyridine in the ground state, pK(a) of 1.12 +/- 0.

Multiple charge-transfer emissions from different metal-ligand pairs in ruthenium diimines.

Ruthenium diimines are unique in their emissivity. Optical excitation with light of less than 500 nm leads to a strong emission in the 600-700 nm range. All emissive ruthenium complexes appear to undergo intersystem crossing from the absorptive singlet metal-to-ligand charge-transfer (MLCT) state to an emissive triplet MLCT state localized on the lowest-energy metal-ligand pair.

[Fever of intermediate duration].

Fever of intermediate duration (FID) is defined as non-localized fever occurring in the community, lasting from one to four weeks, and having no diagnostic orientation after basic clinical, analytical and radiological evaluations are completed. These may include careful recording of clinical history, physical examination, hemogram, plasma creatinine determination, urinalysis, and chest radiography. The etiology of FID is still not completely defined.