Characterization of Mixed N,S Donor Ligand and Group 12 Metal Complexes with X-Ray Crystallography, ESI-MS, and NMR

Group 12 metal ion complexes of mixed N,S donor ligands N-(2-mercaptoethyl) picolylamine (L) and N-(2-pyridylmethyl)-N-(2-(methylthio)ethyl)-N-(2-thioethyl)-amine (L\u27) were studied. Characterization of the known complex ion [Zn(ZnL2)2]2+ was complemented by X-ray crystallography of a new acetonitrile solvate of the perchlorate salt, ESI-MS and variable temperature NMR studies. In addition, five solvates of the novel alkylthiolate bridged mixed metal complex [Hg(ZnL2)2](ClO4)2 were formed through either indirect and direct methods. Further characterization of the mixed metal complexes was done through variable temperature NMR, ESI-MS and X-ray crystallography. In addition, an unusual bicyclo spiro [5.5] complex with formula [Zn((ZnL\u27)2(m-OH))2](ClO4)4 was prepared and characterized by X-ray crystallography. Characterization of this complex in acetonitrile solution by variable temperature NMR and ESI-MS studies indicated possible formation of a (ZnL¢)4+4 macrocycle as observed for Hg(II) with L\u27, but no evidence for the carbonate complexes formed by Cd(II) with L\u27

Low-Level Placement and Routing Changes to Increase SRAM FPGA Reliability

Mitigation techniques, such as TMR, are used to reduce the negative effects of radiation on FPGAs deployed in space environments. While these techniques increase the robustness of the device, there is still room for improvement in the range of 100 to 1,000x. These improvements can be realized through the low-level implementation of the placement and routing on the device. This work has implemented a wide variety of techniques to realize these gains, achieving an overall improvement of 45,653x through fault-injection testing and an improvement of 368x in radiation testing

Metal Substitution and Solvomorphism in Alkylthiolate-Bridged Zn\u3csub\u3e3\u3c/sub\u3e and HgZn,\u3csub\u3e2\u3c/sub\u3e Metal Clusters

The impact of substituting Hg(II) for Zn(II) in a thiolate-bridged trinuclear cluster with parallels to a metallothionein metal cluster was investigated. A new solvomorph of [Zn(ZnL)2](ClO4)2 (1) (L = N-(2-pyridylmethyl)-N-(2-(ethylthiolato)-amine) and five solvomorphs of a new compound [Hg(ZnL)2](ClO4)2 (2) were characterized by single-crystal X-ray crystallography. The interplay of hydrogen bonding and aromatic-packing interactions in producing lamellar, 2D lamellar, and columnar arrangements of complex cations in the crystalline state is discussed. Both variable temperature proton nuclear magnetic resonance and electrospray ion-mass spectrometry (ESI-MS) suggest that the complex ions of 1 and 2 are the predominant solution species at moderate concentrations. ESI-MS was also used to monitor differences in metal ion redistribution as 1 was titrated with Hg(ClO4)2 and [HgL(ClO4)]. These studies document the facile replacement of Zn(II) by Hg(II) with the preservation of the overall structure in thiolate-rich clusters

Metal Substitution and Solvomorphism in Alkylthiolate-Bridged Zn\u3csub\u3e3\u3c/sub\u3e and HgZn,\u3csub\u3e2\u3c/sub\u3e Metal Clusters

The impact of substituting Hg(II) for Zn(II) in a thiolate-bridged trinuclear cluster with parallels to a metallothionein metal cluster was investigated. A new solvomorph of [Zn(ZnL)2](ClO4)2 (1) (L = N-(2-pyridylmethyl)-N-(2-(ethylthiolato)-amine) and five solvomorphs of a new compound [Hg(ZnL)2](ClO4)2 (2) were characterized by single-crystal X-ray crystallography. The interplay of hydrogen bonding and aromatic-packing interactions in producing lamellar, 2D lamellar, and columnar arrangements of complex cations in the crystalline state is discussed. Both variable temperature proton nuclear magnetic resonance and electrospray ion-mass spectrometry (ESI-MS) suggest that the complex ions of 1 and 2 are the predominant solution species at moderate concentrations. ESI-MS was also used to monitor differences in metal ion redistribution as 1 was titrated with Hg(ClO4)2 and [HgL(ClO4)]. These studies document the facile replacement of Zn(II) by Hg(II) with the preservation of the overall structure in thiolate-rich clusters