Synthetic catalytic scavengers of reactive oxygen species (ROS) may have broad clinical applicability. In previous papers, two salen-manganese complexes, EUK-8 and EUK-134, had superoxide dismutase (SOD) and catalase activities and prevented ROS-associated tissue injury. This study describes two series of salen-manganese complexes, comparing catalytic ROS scavenging properties and cytoprotectiv...

Salen complexes of the heavy alkaline-earth metals, calcium and strontium, were prepared by the reaction of various salen(t-Bu)H(2) ligands with the metals in ethanol. Six new calcium and strontium compounds, [Ca(salen(t-Bu))(HOEt)(2)(thf)] (1), [Ca(salen(t-Bu))(HOEt)(2)] (2), [Ca(salpen(t-Bu))(HOEt)(3)] (3), [Ca(salophen(t-Bu))(HOEt)(thf)] (4), [Sr(salen(t-Bu))(HOEt)(3)] (5), and [Sr(salophen(...

The ab-initio density matrix renormalization group (DMRG) is a tool that can be applied to a wide variety of interesting problems in quantum chemistry. Here, we examine the density matrix renormalization group from the vantage point of the quantum chemistry user. What kinds of problems is the DMRG well-suited to? What are the largest systems that can be treated at practical cost? What sort of a...

The importance of epoxides as synthetic intermediates in a number of highly added-value chemicals, as well as the search for novel and more sustainable chemical processes have brought considerable attention to the catalytic activity of manganese and iron complexes towards the epoxidation of alkenes using non-toxic terminal oxidants. Particular attention has been given to Mn(salen) and Fe(porphy...

A cobalt salen pentenoate complex [salen=(R,R)-N,N?-bis(3,5-di-tertbutylsalicylidene)-1,2-cyclohexanediamine] is rationally designed as the catalyst for ring-opening copolymerization (ROCOP) of epoxides/anhydrides/CO2. Via migratory insertion carbon monoxide (CO) into Co?O bonds, ROCOP-active species ?-alkene-?-O-CoIII(salen) can be rapidly and quantitatively transformed ?-alkene-?-O2C-CoIII(sa...

The convenient five-coordinate starting materials, Salen((t)Bu)AlCl (Salen((t)Bu) = N,N'-alkylene (or arylene) bis (3,5-di-tert-butyl-2-hydroxybenzylideneamine) (1-4) can be used in a wide range of reactions to form five-coordinate aluminum compounds. Herein, these reagents were used to produce new five-coordinate azides, LAlN(3) (L = Salen((t)Bu) (5), Salpen((t)Bu) (6), and Salomphen((t)Bu) (7...

Meaningful play has served as a useful analytic category for game design researchers. Drawing on Huizinga, who asserted that, "[a]ll play means something," (Huizinga, 1955, p. 1) Salen and Zimmerman set out to construct a productive framework for what they deemed, "meaningful play" (Salen & Zimmerman, 2004, pp. 31-36). In their mobilization of meaningful play, Salen and Zimmerman outline a fram...