Carbonate-Templated Self-Assembly of an Alkylthiolate-Bridged Cadmium Macrocycle

In the presence of Cd(ClO4)2 and a base, a new mixed N,S-donor alkylthiolate ligand supported both carbonate formation from atmospheric CO2 and the self-assembly of a novel bicapped puckered (CdS)6 molecular wheel. The remarkable stability of the complex was demonstrated by slow intermolecular ligand exchange on the 2J(HH) and J(111/113Cd1H) time scales at elevated temperature. Both CO2 and the base were required to convert amorphous “CdLClO4” precipitated in the absence of air to the carbonate complex. The complex shares structural features with the ζ-carbonic anhydrase class associating cadmium(II) with the biogeochemical cycling of carbon and is the first structurally characterized carbonate complex of any metal involving an alkylthiolate ligand

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

Characterization of HgCl2 Tridentate Amine Complexes by X-ray Crystallography, NMR and ESI-MS

Two new HgCl2 complexes of tridentate nitrogen ligands were characterized by X-ray crystallography, proton NMR spectroscopy and ESI-MS. The five-coordinate complex [Hg(BMPA)Cl-2] (1) (BMPA = bis(2-pyridylmethyl)amine) crystallized from acetonitrile/m-xylene by slow evaporation in the monoclinic space group P2(1)/n with a = 8.3896(8) , b = 12.8020(13) , c = 13.3526(13) , alpha = 90A degrees, beta A = 90.480(2)A degrees, gamma A = 90A degrees and z = 4. The square pyramidal structure (tau = 0.009) has approximate C (s) symmetry. Despite comparable Hg-N bond lengths in 1, inversion of the central nitrogen was rapid on the chemical shift time scale in dilute solution except at very low temperatures. The related complex [Hg(BEPA)Cl-2] (2) (BEPA = bis(2-{pyrid-2-yl}ethyl)amine) crystallized from acetonitrile/ethyl acetate/hexanes by slow diffusion in the orthorhombic space group Pnma with a = 13.424(3) , b = 14.854(3) , c = 8.118(2) , alpha = 90A degrees, beta A = 90A degrees, gamma A = 90A degrees and z = 4. The mixed geometry structure (tau = 0.56) also has crystallographic mirror symmetry as well as C (s) point group symmetry. In dilute acetonitrile solution, 1 was stable while 2 slowly converted to a more thermodynamically stable complex