Two superconductors with a new chiral noncentrosymmetric crystal structure and Hc2 values above the Pauli limit.

We present the crystallographic analysis, superconducting and spectroscopic characterization, and theoretical modeling of CeIr3. Lattice parameters a = 5.2945(1) Å and c = 26.219(1) Å are found for the R-3m symmetry crystal structure, which are close to the literature values. CeIr3 is a moderate type-II superconductor (κGL = 17, λe–p = 0.65) below 2.5 K. Ce ions exhibit a strongly intermediate valence character as evidenced by x-ray photoelectron spectroscopy. The normal state magnetic susceptibility is weakly temperature dependent and follows the inter-configuration fluctuation model with a singlet Ce−4 f 0 ground state. Theoretical calculations support a non-magnetic ground state of the system and reveal that Ir−5d states are dominant at the Fermi level.

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The extent of dimerization in radical trap-assisted atom transfer radical coupling (RTA-ATRC) was studied as a function of solvent composition, with accelerated rates of coupling observed in solvent mixtures consisting of THF and hydrocarbons compared to either pure solvent. Aggregation of the nitroso radical trap was speculated to be responsible for the trend in coupling rates of RTA-ATRC reactions, with less polar solvents such as hydrocarbons favoring the active, monomeric form. The mixed solvent system of THF and cyclohexane was found to be transferrable to the synthesis of macrocyclic PS by intramolecular RTA-ATRC, with 50/50 (v/v) THF:cyclohexane reaction medium giving higher yields of cyclic product compared to reactions performed in the pure solvents.

We show that the full-Heusler compound LiGa 2 Rh is a superconductor with T c = 2.4 K. The new superconductor was found as a result of an intuition-based extension of a database search for superconductors that looked for the presence of peaks in the electronic band structure near the Fermi energy. The measurement of the entropy loss during the transition from the nonsuperconducting to the superconducting state, a straightforward measurement rarely presented in reports of "new" superconducting materials, played a critical role in identifying and isolating the superconducting compound. This study presents a particularly good example of how specific heat measurements are important for the identification and isolation of a new superconductor, since much more frequently reported resistive and magnetic susceptibility characterizations are often not enough to confirm the identification of a new superconducting material.