Optical absorption of Cu-centers in CdCl2 and CdBr2 single crystals

The absorption spectra of CdCl₂ and CdBr₂ single crystals doped with cuprous or cupric halides were measured. Optical bleaching of the absorption bands due to Cu⁺ gives rise to new absorption bands which suggest the conversion of Cu⁺→Cu²⁺. This was confirmed also by detecting the growth in ESR signals characteristic of Cu²⁺ centers.     

Cyano-bridged Mn(III)3M(III) (M(III) = Fe, Cr) complexes: synthesis, structure, and magnetic properties

Two cyano-bridged tetranuclear complexes composed of Mn(III) salen (salen = N,N'-ethylene bis(salicylideneiminate)) and hexacyanometalate(III) (M = Fe, Cr) in a stoichiometry of 3:1 have been selectively synthesized using {NH2(n-C12H25)2}3[M(III)(CN)6] (M(III) = Fe, Cr) starting materials: [{Mn(salen)(EtOH)}3{M(CN)6}] (M = Fe, 1; Cr, 2). Compounds 1 and 2 are isostructural with a T-shaped structure, in which [M(CN)6]3- assumes a meridional-tridentate building block to bind three [Mn(salen)(EtOH)]+ units. The strong frequency dependence and observation of hysteresis on the field dependence of the magnetization indicate that 1 is a single-molecule magnet.     

Apparent horizons of time-symmetric initial value for three black holes

The apparent horizon of three black holes on a time-symmetric space-like hypersurface is examined. The area is computed for various values of separation parameters. Using Hawking's mass formula, we found that the maximum possible efficiency of energy release is no more than 8.44 × 10^-3 when the initial apparent horizon encloses three black holes.