Two Gd III Fe III 4 metallacrown complexes are presented and analyzed for their magnetic properties. One of these species is newly identified and exhibits a bent ring geometry as opposed to the more conventional flatter conformation of the other. Both complexes are quite similar magnetically, exhibiting antiferromagnetic exchange coupling values ca . J (Fe III –N–O–Fe III ) = −7 cm −1 and J (Gd III –O–Fe III ) = −0.7 cm −1 . When analyzed for the molecular magnetocaloric effect, maximum −Δ S m values of 7.3 J K −1 kg −1 at 3 K and at 6.1 J K −1 kg −1 at 4 K were exhibited. A detailed structural-magnetic correlation is established and an assessment of several similar magnetic metallacrowns with diverse metal combinations is given with regards to their potential magnetocaloric properties. Strategies for improving the magnetocaloric properties within the Metaln + FeIII4 family of metallacrowns are proposed regarding the ratio between coupling parameters J (Fe III –N–O–Fe III )/ J (Metal n+ –O–Fe III ).
Luminescent Carbazole-Based Eu III and Yb III Complexes with a High Two-Photon Absorption Cross-Section Enable Viscosity Sensing in the Visible and Near IR with One- and Two-Photon Excitation
- Award ID(s):
- 1800392
- Publication Date:
- NSF-PAR ID:
- 10198693
- Journal Name:
- Inorganic Chemistry
- Volume:
- 59
- Issue:
- 5
- Page Range or eLocation-ID:
- 3193 to 3199
- ISSN:
- 0020-1669
- Sponsoring Org:
- National Science Foundation