Direct use of low pressures of CO2 as a C1 source without concentration from gas mixtures is of great interest from an energy-saving viewpoint. Porous heterogeneous catalysts containing both adsorption and catalytically active sites are promising candidates for such applications. Here, we report a porous coordination polymer (PCP)-based catalyst, PCP-Ru(II) composite, bearing a Ru(II) -CO complex active for CO2 reduction. The PCP-Ru(II) composite showed improved CO2 adsorption behavior at ambient temperature. In the photochemical reduction of CO2 the PCP-Ru(II) composite produced CO, HCOOH, and H2 . Catalytic activity was comparable with the corresponding homogeneous Ru(II) catalyst and ranks among the highest of known PCP-based catalysts. Furthermore, catalytic activity was maintained even under a 5 % CO2 /Ar gas mixture, revealing a synergistic effect between the adsorption and catalytically active sites within the PCP-Ru(II) composite.

The binuclear [FeIII(bpca)(mu-bpca)Dy(NO3)4], having Single Molecule Magnet (SMM) properties, belonging to a series of isostructural FeIIILnIII complexes (Ln = Eu, Gd, Tb, Dy, Ho) and closely related FeIILnIII chain structures, was characterized in concise experimental and theoretical respects. The low temperature magnetization data showed hysteresis and tunneling. The anomalous temperature dependence of Mössbauer spectra is related to the onset of magnetic order, consistent with the magnetization relaxation time scale resulting from AC susceptibility measurements. The advanced ab initio calculations (CASSCF and spin-orbit) revealed the interplay of ligand field, spin-orbit, and exchange effects and probed the effective Ising nature of the lowest states, involved in the SMM and tunneling effects.

The visible absorption, excitation, fluorescence, and phosphorescence spectra have been measured for the monomeric and dimeric forms of rhodamine B and sulforhodamine B (Figure 1). Dimer fluorescence and phosphorescence spectra were assigned through the use of excitation spectroscopy, and polarized excitation spectra were used to determine the polarization of the dimer absorption bands relative to the dimer fluorescencé and phosphorescence emission. The most unexpected finding of these studies is that all major bands associated with the lowest So -Si transition of the dimer have the same polarization. Simple exciton theory in which vibronic interactions are neglected cannot account for the polarization of the dimer absorption spectra, but with the inclusion of vibronic interaction it is possible to account for the polarization of all bands except the origin band. To account for the "anomalous" polarization properties of the origin band it is suggested that the two molecules in the dimer are not equivalent, perhaps due to different orientation of phenyl substituents. The theoretical interpretation of the absorption automatically accounts for the anomalous intensity distribution in the dimer emission and the ~10-fold increase in the fluorescence lifetime produced by dimerization. Less complete results obtained with some eosin, and acridine dyes serve to Confirm the generality of the effects observed with the rhodamine dyes.