Rare‐Earth Cyclobutadienyl Sandwich Complexes: Synthesis, Structure and Dynamic Magnetic Properties. Issue 63 (30th October 2018)

• Record Type: Journal Article
• Authors: Day, Benjamin M.; Guo, Fu‐Sheng; Giblin, Sean R.; Sekiguchi, Akira; Mansikkamäki, Akseli; Layfield, Richard A.
• Is Part Of: Chemistry. Volume 24:Issue 63(2018)
• Page Start: 16779
• Page End: 16782
• Publication Date: 2018-10-30
• Subjects: cyclobutadienyl ligands -- dysprosium -- organometallics -- rare-earth elements -- single-molecule magnets; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201804776
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: The potassium cyclobutadienyl [K2 {η 4 ‐C4 (SiMe3 )4 }] (1 ) reacts with MCl3 (THF)3.5 (M=Y, Dy) to give the first rare‐earth cyclobutadienyl complexes, that is, the complex anions [M{η 4 ‐C4 (SiMe3 )4 }{η 4 ‐C4 (SiMe3 )3 ‐κ‐(CH2 SiMe2 }] 2−, (2M ), as their dipotassium salts. The tuck‐in alkyl ligand in 2M is thought to form through deprotonation of the "squarocene" complexes [M{η 4 ‐C4 (SiMe3 )4 }2 ] − by 1 . Complex 2Dy is a single‐molecule magnet, but with prominent quantum tunneling. An anisotropy barrier of 323(22) cm −1 was determined for 2Dy in an applied field of 1 kOe, and magnetic hysteresis loops were observed up to 7 K. Abstract : Squarocene complexes : The potassium cyclobutadienyl [K2 {η 4 ‐C4 (SiMe3 )4 }] reacts with MCl3 (THF)3.5 (M=Y, Dy) to give the first rare‐earth cyclobutadienyl complexes, that is, the anions [M{η 4 ‐C4 (SiMe3 )4 }{η 4 ‐C4 (SiMe3 )3 ‐κ‐(CH2 SiMe2 }] 2− (2M ) as their dipotassium salts. The dysprosium complex 2Dy shows single‐molecule magnet behaviour, with an anisotropy barrier of 323 cm −1 and magnetization versus field hysteresis loops up to 7 K.