Slow Magnetic Relaxation in Silver(II) Macrocyclic Systems

Abstract

The spin–lattice relaxation time has been studied trough alternating-current susceptometry and ultralow-frequency Raman spectroscopy in a family of silver(II)-derived molecular systems with spin 1/2 and formulas [AgII(m-CTH)(NO3)2] (1) and [AgII(m-CTH)(ClO4)2] (2), where CTH = meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane. The combination of both techniques demonstrates the occurrence of slow spin magnetic relaxation induced by spin–phonon interaction. The magnetic behavior of these silver(II)-derived systems opens the door to a new cation in the scarce family of S = 1/2 systems with slow relaxation of magnetization.

A tetravalent praseodymium complex with field-induced slow magnetic relaxation

“…The past thirty years have witnessed great efforts and significant progress in the research of single-molecule magnets (SMMs or called single-ion magnets (SIMs) for mononuclear complexes), driven primarily by the envisioned applications of such molecule-based materials for high-density storage and quantum processing of information. 1–4 Metal ions with unpaired electrons including those of the transition metals 5–7 and the f-elements 8–15 have been applied as spin centers for SMMs. Of particular note are Dy( iii )-containing SMMs with which large energy barriers over 1800 K 16–20 and high blocking temperatures up to 80 K 18,19 have been achieved.…”