The [H(+)]-catalyzed dissociation rate constants of several trivalent lanthanide (Ln) complexes of 1,4,7,10-tetraazacyclododecane-1,7-diacetic acid (LnDO2A(+), Ln = La, Pr, Eu, Er and Lu) have been determined in two pH ranges: 3.73-5.11 and 1.75-2.65 at four different temperatures (19-41.0 °C) in aqueous media at a constant ionic strength of 0.1 mol dm(-3) (LiClO(4)). For the study in the highe...

Dissociation kinetic analysis of a complex of Ce(3+) with a polyaminocarboxylic ligand, 8-amino-2-[(2-amino-5-methylphenoxyl)methyl]-6-methoxyquinoline-N,N,N',N',-tetraacetic acid (Quin2), was studied by microchip capillary electrophoretic reactor. Dissociation rate constants, k(d), of Ce(3+)-Quin2 complex in alkaline conditions at pH 8.3 - 9.8 were determined. The linear relationship of k(d) w...

Seven proteins have been isolated from sarcoplasmic reticulum. These proteins have been identified as an ATPase, a series of water soluble, acidic proteins of molecular weights 55,000, 46,500, 38,000, 33,000, and 20,000, and a proteolipid. The interactions of the acidic proteins with Ca2+ have been measured at pH 7.5 in the presence and absence of 0.1 M KCl. The protein of molecular weight 55,0...

A filter binding assay was developed that allows measurement of specific binding of trp repressor to operator DNA. The most important feature of this procedure is the concentration and type of salt present in the binding buffer. Using this assay the dissociation constant of the repressor-operator complex was determined to be 2.6 X 10(-9) M, and 1.34 repressor dimers were found to be bound to ea...

The effect of extracellular and intracellular Na(+) on the single-channel kinetics of Mg(2+) block was studied in recombinant NR1-NR2B NMDA receptor channels. Na(+) prevents Mg(2+) access to its blocking site by occupying two sites in the external portion of the permeation pathway. The occupancy of these sites by intracellular, but not extracellular, Na(+) is voltage-dependent. In the absence o...

Scanning tunneling microscopy study of O2 dissociation on Rh~110! at 170 K shows a low-energy dissociation coordinate for a precursor with the O-O axis aligned in the @001# azimuth, indicating a strong influence of the surface anisotropy on the potential-energy surface. This results in pairs of oxygen atoms oriented along @001#, which aggregate in chains along @11̄0# . The atomic distance in the...

The effect of the large impact parameter near-elastic peak of collisional energy transfer for unimolecular dissociation/bimolecular recombination reactions is studied. To this end, the conventional single exponential model, a biexponential model that fits the literature classical trajectory data better, a model with a singularity at zero energy transfer, and the most realistic model, a model wi...

The dissociation of t-butyl methacrylate-methacrylic acid copolymers in dimethyl sulfoxide was analyzed by a nonaqueous potentiometric titration technique. The negative logarithm of the dissociation constant of the monomer unit of a methacrylic acid (MAA) monotonously increased with the increasing degree of dissociation corresponding to the titrant/MAA amount ratio, and was highly influenced by...

Solar cells based on organometal halide perovskites have seen rapidly increasing efficiencies, now exceeding 15%. Despite this progress, there is still limited knowledge on the fundamental photophysics. Here we use microwave photoconductance and photoluminescence measurements to investigate the temperature dependence of the carrier generation, mobility, and recombination in (CH3NH3)PbI3. At tem...