Polarographic Determination of Stability Constants of Glycolato and Chloroacetato Complexes of Copper, Zinc, Cadmium and Lead

By measuring the half-wave potentials of metal ions in buffer solutions of glycolic and chloroacetic acid the limit concentrations of these acids in the buffer were determined, at which no hydrolysis of metal glycolato and chloroacetato complexes takes place. Furthermore, stability constants of glycofato and chloroacetato complexes of copper, zinc, cadmium and lead were determined under such conditions

Polarographic Investigations of Some Metal Monocarboxylato Complexes . I. Monocarboxylato Complexes of Lead

By the polarographic method of DeFord and Hume the stability constants of plumbous monocarboxylato co mplexes have been determined, in water solutions of a constant ionic s trength 2 and a con stant concentration of 2 M of monocarboxylic acid. The examinations were carried out in the monocarboxyla te concent r a t ion range up to 2 M. The following values of stability const a nts were obtained: formiato complexes /31= 13, /32 = 50, /33 = 30; acetato complexes /31 = 150 , /32 = 900, fJ3 = 3000; propionato complexes fJ 1 = 170, /J2 = 2200, /J3 = 5800 ; butyrato complexes /J 1 = 120 , /32 = 2000 , /3 3 = = 5800. It i s evident that with the increase of b ase strength and the size of the monoc arboxylate ion the complex stability increas es in the m\u27ljority of cases

Leaving the Lecture Hall: Conducting HF/E Outside the Classroom

Georgia Tech HF/E students initiated and managed a multisemester project to experience the nuances of conducting HF/E outside the classroom setting. This article focuses on the lessons learned beyond the classroom: project management, team coordination, communication with non-HF/E team members, application of research methods, and integration of data to prioritize and guide design changes. The goal of this article is to help guide other HF/E students and educators when implementing similar projects by providing the lessons we learned from this experience

On the Polarographic Determination of Stability Constants of Formato, Acetato, Propionato, Butyrato, and Lactato Complexes of Copper, Zinc, Cadmium, and Lead

The half-wave potential of the metal ion is shifted to more positive values when the concentration of the monocarboxylic acid in the monocarboxylate buffer increases. At low monocarboxylic acid concentrations, in which no hydrolysis of complexes occurs, there is a linear relation between the half-wave potential and acid concentration. It makes possible the determination of the limit acid concentration in which no hydrolysis of complexes has yet occurred. At such conditions the stability constants of the formato, acetato, propionato, butyrato, and lactato complexes of copper, zinc, cadmium, and lead were determined

On the Stability of Formato, Acetato, Propionato, Butyrato, Glycolato and Chloroacetato Complexes of Cobalt, Nickel, Copper, Zinc, Cadmium and Lead

Stability constants of formato, acetato, propionato, butyrato, glycolato and chloroacetato complexes of cobalt, nickel, copper, zinc, cadmium and lead have been determined by the potentiometric method. The change of concentration of hydrogen ions in the monocarboxylate buffer has been measured. Stability constants have been obtained by means of a digital computer applying the Gauss Z programme devised by R. S. Tobias. On the basis of these results as well as the results obtained in the former investigations by the polarographic and spectrophotometric method, the stability of the investigated monocarboxylato complexes has been discussed and the corresponding orders of stability were established

Forward Neutron Production at the Fermilab Main Injector

We have measured cross sections for forward neutron production from a variety of targets using proton beams from the Fermilab Main Injector. Measurements were performed for proton beam momenta of 58 GeV/c, 84 GeV/c, and 120 GeV/c. The cross section dependence on the atomic weight (A) of the targets was found to vary as $A^(alpha)$ where $\alpha$ is $0.46\pm0.06$ for a beam momentum of 58 GeV/c and 0.54$\pm$0.05 for 120 GeV/c. The cross sections show reasonable agreement with FLUKA and DPMJET Monte Carlos. Comparisons have also been made with the LAQGSM Monte Carlo.Comment: Accepted for publication in Physical Review D. This version incorporates small changes suggested by referee and small corrections in the neutron production cross sections predicted by FLUK

A synthetic biological quantum optical system

In strong plasmon–exciton coupling, a surface plasmon mode is coupled to an array of localized emitters to yield new hybrid light–matter states (plexcitons), whose properties may in principle be controlled via modification of the arrangement of emitters. We show that plasmon modes are strongly coupled to synthetic light-harvesting maquette proteins, and that the coupling can be controlled via alteration of the protein structure. For maquettes with a single chlorin binding site, the exciton energy (2.06 ± 0.07 eV) is close to the expected energy of the Qy transition. However, for maquettes containing two chlorin binding sites that are collinear in the field direction, an exciton energy of 2.20 ± 0.01 eV is obtained, intermediate between the energies of the Qx and Qy transitions of the chlorin. This observation is attributed to strong coupling of the LSPR to an H-dimer state not observed under weak coupling