Abstract
Single-molecule magnets are a type of coordination compound that can retain magnetic information at low temperatures. Single-molecule magnets based on lanthanides have accounted for many important advances, including systems with very large energy barriers to reversal of the magnetization, and a di-terbium complex that displays magnetic hysteresis up to 14 K and shows strong coercivity. Ligand design is crucial for the development of new single-molecule magnets: organometallic chemistry presents possibilities for using unconventional ligands, particularly those with soft donor groups. Here we report dysprosium single-molecule magnets with neutral and anionic phosphorus donor ligands, and show that their properties change dramatically when varying the ligand from phosphine to phosphide to phosphinidene. A phosphide-ligated, trimetallic dysprosium single-molecule magnet relaxes via the second-excited Kramers' doublet, and, when doped into a diamagnetic matrix at the single-ion level, produces a large energy barrier of 256 cm−1 and magnetic hysteresis up to 4.4 K.
Highlights
Single-molecule magnets are a type of coordination compound that can retain magnetic information at low temperatures
Some lanthanide single-molecule magnets (Ln-SMMs) have been developed for applications in nanoscale devices by, for example, deposition of TbPc2 onto carbon nanostructures or metallic surfaces[8,9,10,11,12]
The LnPc2 SMMs demonstrated that very large Ueff values can occur in monometallic complexes, and this important observation inspired the development of other monometallic Ln-SMMs with ligands such as polyoxometallates[13] and organometallic ligands such as cyclo-octatetraene[14,15,16]
Summary
Single-molecule magnets are a type of coordination compound that can retain magnetic information at low temperatures. We report dysprosium single-molecule magnets with neutral and anionic phosphorus donor ligands, and show that their properties change dramatically when varying the ligand from phosphine to phosphide to phosphinidene. Since electrostatic interactions strongly influence the electronic structure of lanthanides, the ability to synthesize compounds with similar molecular structures, but where the ligands carry different formal charges, could allow new ways of designing SMMs. Changing the organo-phosphorus ligand should influence the exchange interactions in polymetallic systems, which is important because exchange is known to influence relaxation phenomena[3,4,5]. We show that organo-phosphorus chemistry can be used to influence the dynamic magnetic properties of lanthanide complexes; our observations have general implications for how main group organometallic chemistry can be used to develop new SMMs
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
