Influence of Ligand Backbone and Solvent on Product Distribution of Cu(II) Salts with Imine Based Ligands

The current investigation examines the reactivity of imine based ligands while bound to a copper(II) metal center. The ligands were synthesized by reacting two equivalents of a pyridine aldehyde (R = -H, -Me, -OMe) with ethylenediamine and characterized by 1H NMR and IR spectroscopies. Analogous reactions were carried out in a 1:1 mole ratio of Cu(NO3)2·2.5 H2O or Cu(ClO4)2·5 H2O with each ligand (-Me or -OMe) in methanol. Reactions with the -OMe ligand derivative, PyOMe2(en), and the nitrate salt, resulted in formation of three different products, while only one product is obtained with the perchlorate salt. Compound 1 is found to be a dimeric species with one PyOMe2(en) ligand bridging between two Cu(II) metal centers. The remainder of the coordination sphere around each Cu(II) is composed of the hydrolyzed ligand (PyOMe(enH2)). The Cu(II) center in 2 is found to have a ligand in which both imine groups have reacted with solvent, and the product in 3 has a copper ligated to the partially hydrolyzed ligand. Reaction with the nitrate salt and the -Me analogue (PyMe2(en)) resulted in the formation of complex 4, which contains a ligand frame in which half has hydrolyzed to give bound amine (PyMe(enH2). Reactions with the perchlorate salt and PyMe2(en) resulted in the formation of complex 5, which contains a version of the hydrolyzed ligand where oxygen has replaced the nitrogen of ethylenediamine and methanol has been added. When the perchlorate salt reacted with PyOMe2(en), product 1 was observed. Further investigation is underway to determine the origin of the reactivity within this set

Formal analysis of firewall policies

This dissertation describes a technique for formally analyzing a firewall security policy using a quasi-reduced multiway decision diagram model. The analysis allows a system administrator to detect and repair errors in the configuration of the firewall without a tedious manual inspection of the firewall rules.;We present four major contributions. First, we describe a set of algorithms for representing a firewall rule set as a multi-way decision diagram and for solving logical queries against that model. We demonstrate the application of these techniques in a tool for analyzing iptables firewalls. Second, we present an extension of our work that enables analysis of systems of connected firewalls and firewalls that use network address translation and other packet mangling rules. Third, we demonstrate a technique for decomposing a network into classes of equivalent hosts. These classes can be used to detect errors in a firewall policy without apriori knowledge of potential vulnerabilities. They can also be used with other firewall testing techniques to ensure comprehensive coverage of the test space. Fourth, we discuss a strategy for partially automating repair of the firewall policy through the use of counterexamples and rule history.;Using these techniques, a system administrator can detect and repair common firewall errors, such as typos, out-of-order rules, and shadowed rules. She can also develop a specification of the behaviors of the firewall and validate the firewall policy against that specification