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The synthesis, spectral characterization, and crystal structure determination of novel lanthanoid porphyrins, i.e., cerium(IV) bis(octaethylporphyrinate) (Ce(OEP)2) and dicerium(III) tris(octaethylporphyrinate) (Ce2(OEP)3), are described. Synthesis is achieved by prolonged boiling of cerium(III) acetylacetonate (Ce(acac)3) and octaethylporphyrin (H2(OEP)) in

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Persistent spectral holeburning, luminescence line narrowing and selective excitation spectroscopy of the R lines of Cr(III) tris(2,2'bipyridine) in amorphous hosts Chloro-(tetraphenylporphinato)chromium(III) shows relatively normal visible (Q) bands in the region 610-500 nm and a relatively normal Soret (B) band at 447 nm; in addition, there are prominent bands in the near uv region 400--300 nm (2X10 4 < E < 3X10 4 M-1 .cm-1 ) and clear near ir bands in the region 820-610 nm (300 < E < 2100 M -1.cm -l). At 160 0 K there is one main emission band at -815nm (r < 6 ,""sec); at 77"K there are emission bands of comparable intensity at both 811 and 847 nm (r = 44 ,""sec); at 4°K both emission bands appear with intensity ratio 1811/1847 = 0.12. The near ir absorption and emission band at 811 nm is attributed to a "trip-quartet" excited state formed from the (71,71*), S = I porphyrin state coupling to the d 3, S = 3/2 electrons of the Cr(III); the 847 nm emission is attributed to the sextet state that arises from the same electron configuration. The prominent near uv bands are attributed to a 2. (71), a 1.(71) ....... e g(d".) charge transfer transitions. Phenol-phenoxo-(octaethylporphinato)chromium(III) shows similar absorption and emission spectra, but the bands are generally blue shifted.magnetic moment at 25°C (Jleft = 3. 2 Jl B) was determined in CDCls solution by the NMR method. 17 The Cr (m) oxidation state is so stable that the first equivalent of sodium anthracenide reduces t:he porphyrin pi system; whereas with Fe (m), Mn (m), and Mo (V), the first electron goes to the metal. 18 (Redox potentials