The ligand dipyrido[3,2-a:2′,3′-c]phenazine (dppz) and its deuterated analogues, d4-dppz, d6-dppz, d10-dppz, and [ReCl(CO)3] complexes with these ligands have been synthesized. Using DFT calculations it is possible to calculate a geometry of the ligand such that it matches the crystallographic data for a variety of dppz complexes. B3LYP/6-31G(d) frequency calculations correspond closely to the experimental IR and Raman data. Analysis of the calculated normal modes of vibration reveals the presence of a number of modes that are localized to the ring sections of the dppz-framework. Modes 79, 78, 77, 50, and 49, which lie at 1602, 1586, 1576, 1071, and 1034 cm-1, respectively, in the experimental spectra of dppz correspond to phenanthroline-based modes. Modes 68 and 67, lying at 1414 and 1402 cm-1 in dppz are phenazine-based vibrations. These provide an insight into the nature of the MLCT transitions for metal complexes with dppz. The preferential enhancement of phenanthroline-based modes in the resonance Raman spectra of these complexes strongly suggests the π* accepting MO is of phenanthroline character. DFT calculations (B3LYP/6-31G(d)) on the radical anion reveal the elongation of bonds about the pyrimidine ring. The frequency calculations also reveal significant changes in the vibrational spectra for dppz•- from the neutral ligand. Experimental resonance Raman data for the electrochemically reduced [ReCl(CO)3(dppz)]- and the deuterated analogues show distinct isotope shifts that may be correlated to results obtained from the calculations. The characteristic bands observed in these spectra are phenanthroline-based. They may be correlated with time-resolved resonance Raman spectra of Ru(II) and Re(I) complexes.

The Automatic Identification System (AIS) is a vessel tracking protocol used by the vast majority of the global maritime community. While AIS is a fantastic tool for preventing vessel collisions, it unfortunately has no built-in security. This project first provides a security vulnerability analysis of the current AIS system. We then propose the outline for a new protocol that addresses these vulnerabilities. This protocol maintains the anti-collision capabilities that AIS was designed to provide, but uses secured communications similar to those proposed in IEEE 1609 combined with a multi-tiered user-level approach to provide greater security. Finally, our proposed protocol is simulated from two perspectives: that of an average user as well as from a network level. In aggregate, the results from these simulations suggest that our protocol keeps the existing usability of AIS while dramatically reducing potential security concerns.

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Ultra‐small‐ and small‐angle neutron scattering techniques were employed to quantify thermally driven changes to the microstructure of the TATB‐based composite high explosive, PBX 9502. Samples of PBX 9502 were studied in‐situ at temperatures ranging from 25 to 220 °C and after re‐equilibration at ambient temperature. Significant changes to the void size and morphology within the PBX 9502 microstructure were observed upon heating and are consistent with the known increase in the shock sensitivity of thermally‐treated PBX 9502. More extensive microstructural changes were found after the thermally treated samples were re‐equilibrated at ambient temperature. Utilizing a model of ramified porosity, the size and the volume and surface dimensions of voids in the PBX 9502 microstructure were quantified as a function of temperature. The temperature dependence of the void radius of gyration is well correlated with the known increase in the shock sensitivity of PBX 9502 with increasing temperature, providing a microstructural origin for the increased shock sensitivity of PBX 9502 at elevated temperatures.

A good-yielding, two-step synthesis of RuH2(CO)(PPh3)3 using conventional or microwave-assisted reflux techniques is described for use in undergraduate teaching 10 laboratories. RuH2(CO)(PPh3)3 is synthesised from RuCl3 . xH2O, PPh3 and KOH in ethanol in two steps under an inert atmosphere or using a one-pot microwave-assisted reflux to reduce the reaction time to approximately 10 minutes. This makes this useful compound readily available within an undergraduate laboratory session via efficient and sustainable syntheses, enabling learning outcomes associated with air sensitive 15 synthesis and application of group theory and spectroscopy to structure determination. GRAPHICAL ABSTRACT